What Is The Difference Between Posthumanism And Transhumanism?

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A lot of people use the terms posthuman and transhuman interchangeably. To some extent, its reasonably okay to excuse them because these are both fairly new terms.

Posthumanism is traversing the current human condition to eliminate the things that are considered human nature. In other words, a post human state is where humans and genius machines are completely integrated so that its difficult to discern whats human. According to posthuman transcribers, the post human project will change the current perspective of everything considered human, as information patterns that are limiting the potential of humans will all be unlocked. The focus of Posthumanism is therefore on function as opposed to form.

Transhumanism, on the other hand, refers to physically transforming humans with any new technology, including bioengineering, digital technology, genetic engineering and others, to enhance their abilities; for example, making them more intelligent, stronger, immortal, and so on. In a conventional way, transhumanism can be classified as a sub-class of posthumanism. Transumanists are already using certain implants to modify their bodies for enhanced senses or brain power, so the focus is now on using prosthetics and other accessories or modifications as opposed to compensating for human abilities.

The major difference between the two is that Posthumanism puts a lot of emphasis on systems and their components, while transhumanism fully focuses on changing the form and abilities of the present human body. Another difference is that posthumans place importance on information and system theories (cybernetics) and their main relationship is with digital technology, while this is not the same for transhumans.

Posthumanism is a term that has been derived from the term post-human which represents death of a human subject. But what makes human is the qualities in the subjects. So with information these qualities can be modified for a posthuman body. Transhumanism, on the other hand, looks at life from the perspective of using the technology available to produce a super human being, a human of the future, a transhuman.

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What Is The Difference Between Posthumanism And Transhumanism?

Immortality – Tolkien Gateway

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"Who told you, and who sent you?" GandalfThis article or section needs more/new/more-detailed sources to conform to a higher standard and to provide proof for claims made.

The concept of immortality in Arda is very complex, because it differs in nature between the races. Usually, however, it refers to the type of life possessed by the Elves, who do not have the inability to be slain, but rather the inability to age and die of disease (but see below).

The only truly immortal beings (in the sense that death or any loss of their being cannot be brought upon them) in Arda are the Ainur. Because they originally came from beyond E, nothing within its boundaries can hurt them. One reason for this is because their spirits do not need a body to be complete, unlike the Incarnates. The Ainur take visible form at will, and this form was said to be more like clothing than actual incarnation. Forcible removal of this "raiment" (such as that which befell Sauron during the Downfall of Nmenor) was indeed devastating for an Ainu, but could not happen unless either the spirit of the Ainu had already been weakened (see below), or Eru directly intervened.

The most powerful rebellious spirits, Melkor and Sauron, did suffer a loss of their being, but only because they allowed part of it to pass into the materials of Arda. This weakening of their original nature allowed them to be injured by others.

Some among the Ainur did actually incarnate themselves, most notably Morgoth and Gandalf. While in these bodies, they could be forcibly disincarnated or "killed" (though they did not die of old age); but they would suffer no loss of their true being unless previously weakened.

However, upon entering E, the Ainur became bound with it, and thus their fate after its end seems uncertain. This fact brings their ultimate immortality into question.

The Elves did not suffer death from old age or disease, as do Men, but they could be slain by injuries and their own grief. Unlike the Valar, experiencing death (which is the separation of their fa and hra) violates the Elves' nature, since they were made to live as incarnate beings. The Elves were not free from change and aging, either, but they aged in a different sense than Men: the Elves became ever more weary of the world and burdened by its sorrows, and lived more in the past. In Middle-earth, their bodies would slowly be consumed by their spirits until they were little more than wraiths, in the Unseen. Yet, the Elves could escape this fate by traveling west to Aman.

The Elves are also bound to Arda and cannot escape it as long as it lasts, and can thus be reincarnated after their hra is destroyed. When their fa and hra are separated, the fa could travel to the Halls of Mandos. There they can either stay or be reincarnated with a new body identical to the previous hra, after being released by Nmo, and judged by Manwe and Varda to be absolved of any sins or regrets from their previous life. Once they were reincarnated they generally remain in Aman. There are only two Elves known to have left Aman after reincarnation, Glorfindel who was sent back to Middle-earth and Lthien Tinviel who was also sent back to Middle-earth as a mortal.

However, this same fact of their nature means that their fate after Arda's end is unknown; it seems that the Elves must die when Arda ends. They must rely on estel to give them hope that this will not be the case. For this reason, the envy often felt by mortals of the Elves' lifespans comes from ignorance of the nature of these lifespans.

Because the Elves can reincarnate, and because their fate after Arda's end is undiscernable, the life of the Elves is "serial longevity", not "immortality".

The race of Men was made mortal, and no Man (save perhaps Tuor) can truly be called immortal in any sense (but see below). However, mortals can have their lifespans extended by the effects of the Rings of Power and other dark arts. The most infamous example is that of the Nazgl, whose lives were extended by nearly 5,000 years because of their Rings, and the Hobbit Gollum lived 500 years because of his possession of the One Ring. However, because such long life is against the biological and spiritual nature of mortals, it becomes a nearly unendurable torment to them. They also lose their identity and independence; both the Nazgl and Gollum had become utterly enslaved by the power of the Rings.

Andreth told Finrod about a legend that Men were immortal, not different from the Elves.

However, unlike the Valar and Elves, the ultimate future of Men seems much more assured: it is said that they will participate in the Second Music of the Ainur after the end of days.

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About | Intentional Peer Support

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StevenMorgan has worked in peer support services for the past decade. He was originally trained as a Georgia Certified Peer Specialist and worked in traditional service agencies, where he became intimately familiar with the difficulties of practicing peer support within a medical model. This led to an interest in developing alternative supports, so in Vermont he helped create a peer-run respite, was Executive Director for four years of a peer-run agency called Another Way, and finally became project developer for Soteria-Vermont. Steven has provided many trainings in systems change at both a local and national level, and has served on several Boards of Directors for peer support organizations.

In 2013,he joined Intentional Peer Support as Operations Manager with a passion for creating instruments of social change, a love of organizational development, and a belief in the transformative power of community. On full moons, he enjoys writing, playing music, woodworking, and taking long longwalks. You can read more of Stevens story in his writings at http://www.stevenmorganjr.com/read

Eva Dech, Training Manager

Eva has been involved in human rights activism and advocacy for over two decades. As a survivor of childhood trauma and re-traumatization within the mental health and other systems, she is passionate about creating positive systems change to end abuse and neglect in institutions. In particular, she has focused on infusing trauma-informed practices that are recovery-based and person-centered.

After years of developing and working within peer support, she came to believe the path to healing and recovery was through relationships, creating opportunities for empowerment, and building connected, inclusive, and supportive communities.

Eva is an animal lover with three cats. Family is very important to her and she is blessed with a large extended family. Eva attributes her ability to stay healthy and grounded to meditation and personal wellness practices including yoga, gardening, painting, dancing and music.

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About | Intentional Peer Support

Hedonism: Examples and Definition | Philosophy Terms

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I. Definition

Hedonism is the philosophy of pleasure. It means doing whatever brings you the greatest amount of pleasure, regardless of any other effects.

At first glance, hedonism seems pretty simple; just do whatever you like! Eat whatever you want, treat people rudely, lie around in bed all day! But things are not so simple. Philosophers speak of the paradox of hedonism, which refers to the way pleasure seems to go sour after a while.

If youve ever eaten too much candy at one time, you know how this works. You may enjoy the candy at the time, but soon after you get a terrible stomachache, and in the long run, your teeth will rot away.

As it turns out, behaving hedonistically is likely bring you more pain than pleasure, eventually! To get out of the paradox of hedonism, philosophers have suggested all sorts of methods for maximizing happiness in the long term. These methods are sometimes contrasted with pure hedonism, which is pursuing pleasure from moment to moment without regard for the future.

It is a mistaketo suppose that the public wants the environment protected or their lives saved and that they will be grateful to any idealist who will fight for such ends. What the public wants is their own individual comfort. (Isaac Asimov, The Gods Themselves)

The great sci-fi author Isaac Asimov put this line into the mouth of one of his characters. Its not exactly an argument for hedonism; it argues that hedonism is all that motivates most people. Most people, the character says, are motivated by their own pleasure and cant be persuaded to sacrifice that pleasure for any higher goals. This is psychological hedonism (see section 7).

Many of us pursue pleasure with such breathless haste that we hurry past it. (Sren Kierkegaard)

The Christian Danish philosopher Sren Kierkegaard made some remarkable arguments for faith at a time (the late 1800s) when this was a very unfashionable way for a philosopher to think! But Kierkegaards version of Christianity was influenced by many other philosophies and religions, particularly Buddhism (though scholars disagree on how much it influenced him, and how much the similarity is a coincidence). In this quote, he makes a fairly Buddhist statement; that true pleasure does not come from hedonism, but from peace of mind.

Asceticism is sort-of the opposite of hedonism. Where hedonism is all about pursuing pleasure, asceticism is all about doing without pleasure. To an ascetic, indulging in pleasure is a kind of weakness and distraction that would prevent them living up to their spiritual values and attaining their spiritual goalsusually being selfless, without desires, reaching the highest levels of meditation, and serving others purely. They avoid these pitfalls on their spiritual path by denying themselves even the ordinary pleasures of the body, such as fine food, clothing, and sometimes even shelter. Instead, they live on as little and simple food as possible, dress in whatever clothes they happen to own (usually rags), and live simple lives of rugged discipline.

Asceticism is found in nearly all religious traditions, where monks, pilgrims, or sadhus discipline themselves to live without unnecessary physical comforts. It should be said, though, that those who pursue the ascetic path often claim that it eventually brings them a kind of bliss that can never be experienced by those who indulge in physical pleasures. One of the most famous and interesting novels about spirituality, one that most young people enjoy, Siddharta by Herman Hesse tells the story of a Hindu boy, modeled after the Buddha, who spends part of his life as an ascetic, and part as a hedonist, and eventually reaches a kind of enlightenment.

An altruist is someone who puts everyone elses happiness and well-being above their own. Altruism is the ultimate form of generosity and kindness. A woman who gives away her last dollar to a homeless shelter is an example of an extreme altruist. However, you can still call yourself an altruist without hurting yourself; you simply have to do things for other people with no expectation of reward for yourself.

Altruism is often contrasted with hedonism, for obvious reasons. Many people believe that hedonism is the opposite of altruism. However, altruism and hedonism are only different to the extent that my happiness is different from your happiness. Many philosophical and religious traditions have argued that they are not that the greatest joy in life comes from bringing joy to others, and that my well-being ultimately depends on your well-being. If this is true, then the ultimate hedonist would also be the ultimate altruist! This idea is central to many religions, particularly Buddhism.

During the Greek and Roman periods, hedonism was popular but controversial; many Greeks worshipped a god called Dionysus, the god of wine and pleasure. His festivals were crazy hedonistic parties with plenty of drinking, overeating, and reckless behavior. The traditional religious authorities permitted and in some cases encouraged this sort of hedonism. It even played a role in philosophy: one of Platos most famous works is all about a wild drunken party where all the best philosophers gather to discuss the pleasures of love.

Philosophy in the later Roman Empire was dominated by Stoicism, a philosophy with a complex relationship to hedonism. The Stoics are usually thought of as opposite to hedonists. They argued for rigorous discipline and control of the emotions; they were somewhat ascetics. But they also believed in training their minds to get pleasure out of behaving in a healthy and moral way. This strongly resembles Buddhism and many historians believe that Stoicism was influenced by the Greek contact with Buddhists in what is now Pakistan, where Buddhism ruled at that time.

Christianity changed attitudes towards hedonism, since Christians have, historically, been extremely critical of pleasure-seeking. Christians believe that Adam and Eve lived pleasurable lives in Eden, but because of their Original Sin, we all must suffer; and therefore, it is blasphemous to seek pleasure at the expense of our responsibility to God.

Christian asceticism dominated philosophy for much of European history (The Dark Ages), but less and less so following the Enlightenment. Around the early 1800s, several philosophers in Britain invented Utilitarianism, which recommends creating the greatest possible amount of happiness for the largest possible number of people. The important idea here is that happiness, not Gods Will, should determine what people do.

Today, some say more than ever before, there is a lot of conflict between those who believe strongly in one religion or another, or none at all, and hedonism has a lot to do with it. Clearly, our modern lives are more hedonistic in general than ever before; it wasnt even possible for most people in the world to pursue pleasure as most do now, until the past few decades! Those who speak for various religions, including Christianity, Judaism, Islam, Hinduism, and Buddhism argue that our modern lives are much too pleasure-oriented: we shop for expensive clothes, eat pricey food, and spend our time in nightclubs and watching TV, neglecting our spiritual life. Depending on the religion they argue either that hedonism is sinful or simply that its bad for us.

Its very important to keep in mind here that pleasure and happiness are not the same. Buddhists, and others, point out that in spite of all our shopping, eating, and drinking, we are not happy! Suicide rates are rising all over the world, and problems like depression and alcoholism are rampant. They argue that we will be happier if we live simpler, less materialistic, lives.

On Futurama, theres a character called Hedonism-bot. The character is always reclining on a couch, being fed grapes or having warm chocolate drizzled over his solid-gold body. The show also has Bender, an incredibly hedonistic robot who loves cigars, liquor, cruel pranks, and all kinds of unseemly behavior. The shows writers took the familiar image of robots (boring, predictable, selfless automatons) and turned it on its head by portraying robots as hedonists.

In the Sims 2 games, you create characters with aspirations such as wealth, family, or knowledge. One of the options is pleasure; these characters just want to play around, dance, and have fun! Theyre the perfect hedonists. Unfortunately, just like the rest of us, they usually have to go to work in order to make enough money to pay for their pleasurable habits.

Timon and Pumbaa from The Lion King are major hedonists when we first meet them. They roam around the jungle eating, sleeping, singing, and having a good time. During his time hanging out with Timon and Pumbaa, Simba forgets about his home and his responsibilities, and gives himself up entirely to the hedonism.

British philosopher Jeremy Bentham argued that everyone is a hedonist, whether they believe it or not. Bentham argued that all humans basically do whatever they think will give them pleasure.

Example:

When you choose a jelly donut, its because you think it will make you happy. But when you choose a salad instead, thats also because you think it will make you happy.

According to Bentham, the difference isnt about choosing pleasure vs. choosing health, but rather about deciding which of the two things will bring you more pleasure. This is called psychological hedonism. However, critics might argue that this example confuses happiness with pleasure.

The main criticism of psychological hedonism is that its definition of pleasure is too broad. Sure, critics will say, we can define pleasure in such a way that all decisions are made for pleasure. But then the concept of pleasure becomes so broad that its basically meaningless. By pleasure we usually mean something more superficial than happiness, so philosophers should use this definition also. Benthams critics argue that his theory is more based on semantics (the meaning of words) than psychology.

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Hedonism Resorts – Wikipedia

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Hedonism II opened in 1976 as "Negril Beach Village" and was given its current name in 1982; it was built by the Government of Jamaica at a cost of $10 million.[2] and it occupies 22 acres (89,000m2) at the northern end of Negril beach and has 280 rooms in two-story buildings. A 50% interest in the hotel was bought by the SuperClubs in 1989.[3] a unit of the Government of Jamaica, for $12.25 million.[4] In November 2012, the resort was sold to Marshmallow Ltd headed by Harry Lange with a minority stock held by the Issa family[5] and Kevin Levee, a 28-year employee of SuperClubs and its current general manager.[6]

Hedonism III opened in 1999 in Runaway Bay, it was built on 10 acres (40,000m2) and contained 225 rooms in 3-story buildings; on May 12, 2010 the company announced that Hedonism III would close, temporarily, in August 2010 to allow for remodeling work: it reopened on October 14, 2010, as SuperFun Beach Resort and Spa[7] catering to a wider market through additional tour operators, however SuperFun Beach Resort entered receivership in March 2011 and closed in June 2011.[8] While it was an adult-only resort, SuperFun did not allow topless or nude sunbathing but charged premium liquor prices and motorized water sports; the property was leased to SuperClubs by the Development Bank of Jamaica.,[9] the hotel's first-ranked secured lenders are Caribbean Development Bank, PanCaribbean, and Development Bank of Jamaica.[8]

The resort lives up to its reputation mostly during those periods - notably January - when tour companies, catering to swingers, book huge blocks of rooms.

Public nudity is illegal in Jamaica, but the laws are not enforced and may not apply inside the private resort. A nude wedding of eight couples in 2001 at Hedonism III caused protests by the government tourist office and radio talk show hosts, who called the event "improper and offensive." In February 2003, 29 couples were involved in another round of nude weddings at the Hedonism III;[10] Hedonism resorts host nudist and swingers conventions: it has been alleged that open sex is common,[11] including in the hot tubs at night,[12] however SuperClubs owner John Issa said that he was not aware of this.[13]

Issa also declared that he was not running a "whorehouse" and that, to his knowledge, "whores are not working" in his Hedonism hotels;[14] and sued two employees of Unique Vacations in Miami, Florida, over e-mails sent in 2007 and 2008 which - he claimed - contained "defamatory statements" about activities at Hedonism Resorts [15] seeking damages of an unspecified amount, for what he feels are false and malicious statements.

Issa stated that he feels satisfied with Hedonism's image of decadence and debauchery [16] and is satisfied with the idea, expressed on his website, that " When it's good it's oh so good and when it's bad it's even better and yes, everything you ever heard is true ".[17] John Issa was also alleged to have promoted bisexual activities at Hedonism III.[18]

In September 2009, Hedonism Resorts lost a WIPO trial against Relevansanalys[19] related to the registration of the Internet domain name 'hedonismhotels.com'.

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Hedonism Resorts - Wikipedia

Hedonism Specials | Hedonism II

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Departure City

Albany, Ny [ALB]Albuquerque, Nm [ABQ]Allentown, Pa [ABE]Amarillo, Tx [AMA]Anchorage, Ak [ANC]Appleton, Mn [AQP]Arcata, Ca [ACV]Asheville, Nc [AVL]Aspen, Co [ASE]Atlanta, Ga [ATL]Atlantic City, Nj [ACY]Austin, Tx [AUS]Baltimore, Md [BWI]Bangor, Me [BGR]Beaumont, Tx [BPT] Bethel, Ak [BET]Billings, Mt [BIL]Binghamton, Ny [BGM]Birmingham, Al [BHM]Bismarck, Nd [BIS]Bloomington, Il [BMI]Boise, Id [BOI]Boston, Ma [BOS]Brownsville, Tx [BRO]Brunswick, Ga [BQK]Buffalo, Ny [BUF]Burbank, Ca [BUR]Burlington, Vt [BTV]Calgary [YYC]Cedar Rapids, Ia [CID]Charleston, Sc [CHS]Charleston, Wv [CRW]Charlotte, Nc [CLT]Charlottesville, Va [CHO]Chicago (Midway), Il [MDW]Chicago (O'Hare), Il [ORD]Cincinnati, Oh [CVG]Cleveland, Oh [CLE]College Station, Tx [CLL]Colorado Springs, Co [COS]Columbia, Mo [COU]Columbia, Sc [CAE]Columbus, Oh [CMH]Cordova, Ak [CDV]Corpus Christi, Tx [CRP]Dallas Love Field, Tx [DAL]Dallas/Fort Worth, Tx [DFW]Dayton, Oh [DAY]Denver, Co [DEN]Des Moines, Ia [DSM]Detroit, Mi [DTW]Duluth, Mn [DLH]Durango, Co [DRO]Edmonton Intntl [YEG] Eastern Iowa, Ia [CID]El Paso, Tx [ELP]Erie, Pa [ERI]Eugene, Or [EUG]Eureka, Ca [EKA]Fairbanks, Ak [FAI]Fargo, Nd [FAR]Flint, Mi [FNT]Fresno, Ca [FAT]Ft. Lauderdale, Fl [FLL]Ft. Myers, Fl [RSW]Ft. Walton/Okaloosa [VPS]Ft. Wayne, In [FWA]Gainesville, Fl [GNV]Grand Forks, Nd [GFK]Grand Rapids, Mi [GRR]Great Falls, Mt [GTF]Green Bay, Wi [GRB]Greensboro, Nc [GSO]Greenville, Sc [GSP]Gulfport, Ms [GPT]Halifax Intntl [YHZ]Harlingen [HRL]Harrisburg, Pa [MDT]Hartford, Ct [BDL]Helena, Mt [HLN]Hilo, Hi [ITO]Hilton Head, Sc [HHH]Honolulu, Hi [HNL]Houston Hobby, Tx [HOU]Houston Busch, Tx [IAH]Huntington, Wv [HTS]Huntsville Intl, Al [HSV]Idaho Falls, Id [IDA]Indianapolis, In [IND]Islip, Ny [ISP]Ithaca, Ny [ITH]Jackson Hole, Wy [JAC]Jackson Int'L, Ms [JAN] Jacksonville, Fl [JAX]Juneau, Ak [JNU]Kahului, Hi [OGG]Kansas City, Mo [MCI]Kapalua, Hi [JHM]Kauai, Hi [LIH]Key West, Fl [EYW]Knoxville, Tn [TYS]Kona, Hi [KOA]Lanai, Hi [LNY]Lansing, Mi [LAN]Las Vegas, Nv [LAS]Lexington, Ky [LEX]Lincoln, Ne [LNK]Little Rock, Ar [LIT]Long Beach, Ca [LGB]Los Angeles, Ca [LAX]Louisville, Ky [SDF]Lubbock, Tx [LBB]Lynchburg, Va [LYH]Montreal Mirabel [YMX]Montreal Trudeau [YUL]Madison, Wi [MSN]Manchester, Nh [MHT]Maui, Hi [OGG]Mcallen, Tx [MFE]Medford, Or [MFR]Melbourne, Fl [MLB]Memphis, Tn [MEM]Miami, Fl [MIA]Midland/Odessa, Tx [MAF]Milwaukee, Wi [MKE]Minneapolis/St. Paul [MSP]Missoula, Mt [MSO]Mobile Regional, Al [MOB]Molokai, Hi [MKK]Monterey, Ca [MRY]Montgomery, Al [MGM]Myrtle Beach, Sc [MYR] Naples, Fl [APF]Nashville, Tn [BNA]New Braunfels, Tx [BAZ]New Orleans, La [MSY]New York Kennedy, Ny [JFK]New York Laguardia [LGA]Newark, Nj [EWR]Norfolk, Va [ORF]Ottawa Mcdonald [YOW]Oakland, Ca [OAK]Oklahoma City, Ok [OKC]Omaha, Ne [OMA]Ontario, Ca [ONT]Orange County, Ca [SNA]Orlando, Fl [MCO]Palm Springs, Ca [PSP]Panama City, Fl [PFN]Pensacola, Fl [PNS]Peoria, Il [PIA]Philadelphia, Pa [PHL]Phoenix, Az [PHX]Pittsburgh, Pa [PIT]Port Angeles, Wa [CLM]Portland Intl, Or [PDX]Portland, Me [PWM]Providence, Ri [PVD]Quebec Intntl [YQB]Raleigh/Durham, Nc [RDU]Rapid City, Sd [RAP]Redmond, Or [RDM]Reno, Nv [RNO]Richmond, Va [RIC]Roanoke, Va [ROA]Rochester, Ny [ROC]Rockford, Il [RFD]Sacramento, Ca [SMF]Saginaw, Mi [MBS]Salem, Or [SLE]Salt Lake City, Ut [SLC] San Antonio, Tx [SAT]San Diego, Ca [SAN]San Francisco, Ca [SFO]San Jose, Ca [SJC]Santa Barbara, Ca [SBA]Santa Rosa, Ca [STS]Sarasota/Bradenton [SRQ]Savannah, Ga [SAV]Seattle/Tacoma, Wa [SEA]Shreveport, La [SHV]Sioux City, Ia [SUX]Sioux Falls, Sd [FSD]Spokane, Wa [GEG]Springfield, Il [SPI]Springfield, Mo [SGF]St. Louis, Mo [STL]St. Petersburg, Fl [PIE]Syracuse, Ny [SYR]Toronto Pearson [YYZ]Tallahassee, Fl [TLH]Tampa, Fl [TPA]Traverse City, Mi [TVC]Tucson, Az [TUS]Tulsa, Ok [TUL]Vancouver Intntl [YVR]Victoria Intntl [YYJ]Winnipeg Intntl [YWG]Washington Natl, Dc [DCA]Washington/Dulles, Dc [IAD]Wenatchee, Wa [EAT]West Palm Beach, Fl [PBI]White Plains, Ny [HPN]Wichita, Ks [ICT]Wilkes-Barre/Scranton [AVP]

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Whole Food vs. Synthetic Supplements | Melissa Wood, ND

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Ive already discussed the importance of taking natural supplements to support your body and immune system. But which supplements do you take, and how do you know which supplements are the best ones? Americans spend billions of dollars every year on supplements, and its very important to understand that not all supplements are created equal. Sometimes, there are vast differences between products.

So lets talk about the difference between whole food supplements and synthetic supplements a.k.a. isolated or fractionated supplements.

A great example would be just to simply look at almost any multivitamin. When you scan the nutritional content fact and ingredientlabel, youll see quite an assortment of vitamins (Vitamin A, Vitamin C, Vitamin E, etc.).Here is a portion of a label for a common multivitamin:

There are a lot more vitamins listed on this label than I had room for, but I think you get the idea. Look at the items listed under Ingredients.Those are what we call Isolated vitamins and other chemicals.There are no foods or herbal ingredients listed, only partial vitamins and other chemicals.

Nature intended for us to consume food in its WHOLE form because all the vitamins, minerals, antioxidants and enzymes are bound together in one package and work synergistically to deliver the nutrition your body needs.

Synthetic supplements give you isolated or fractionated pieces of the whole. It is simply not the same youre not getting the full benefit nature intended. The other problem is, by taking isolated vitamins, sometimes we are getting massive doses of some vitamins, but not enough of others.This imbalance this can cause health problems too. Arent we trying to get healthier rather than cause more problems?

Whole-Food based supplements are different, as those will, typically, list the foods the supplement was made from. What follows is a partial example of what to look for when searching for a Whole-Food based product.Notice that under the supplemental facts, you still see all the vitamins listed, but theres a huge difference in the ingredients.

What a difference this second product will make in your body vs. the first product!Youll actually be gaining benefits from the WHOLE food and all of the vitamins, minerals, antioxidants and enzymes that occur naturally in the food or plant.

Another way that might make sense is to look at the source.When Vitamin C is listed on a multivitamin label, look for any natural sources, like citrus fruits, papaya or bell peppers.If you see a listing for Ascorbic Acid, that means it is an Isolated product, so you must keep searching for ones that list whole foods.

In summary, be sure you read your labels!It is important to educate yourself about what youll be putting into your body and supplements are no different than anything else.

Its important to read food labels so you know what youre eating. But its just as important, if not moreso, to be sure youre reading all of your supplement labels too!You want to be consuming supplements that have actual whole foods, plants or herbs listed on the label. That way you know it is as close to natural as possible!

And lastly,understand that no supplement alone will help you achieve the level of health you desire. You will have to make lifestyle and behavior changes as well as taking supplements to achieve ultimate health.

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Whole Food vs. Synthetic Supplements | Melissa Wood, ND

Top Nude Beaches : Beaches : Travel Channel | Travel Channel

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While nude beaches remain largely taboo, there are a number of strands, from North and South America to the Caribbean and Europe, that cater to naturists and those who want to feel sun and air on completely bare skin. Here's a list of the best beaches where these sun worshippers can shed their skivvies and work on an all-over tan.

1. Little Beach

2. Haulover Beach

Just north of Miami lies one of the few county-run and government-sanctioned clothing-optional beaches in the United States. For years Haulover Beach has been a haven for naturists from South Florida as well as snowbirds from Canada and Europe. Thanks to the efforts of the South Florida Free Beach Association, this beach has certified lifeguards and organized group activities, such as swimming and volleyball.

3. Red Beach

4. Praia do Pinho

Andrew Herdy, Wikimedia Creative Commons

5. Hedonism II

Johann Vanbeek, Wikimedia Creative Commons

6. Samurai Beach

Raguy, Wikimedia Creative Commons

7. Wreck Beach

Named for a hulking, wrecked vessel that once sat on the sand, Wreck Beach was Canada's first government-sanctioned, clothing-optional beach. The 3-mile-long beach is also a wildlife and nesting area for bald eagles. Still, some sections of the beach assume carnival-like atmosphere thanks to its proximity to the University of British Columbia and its popularity with students. One stretch of sand known as Vendors' Row is a 1-stop shop for souvenirs, refreshments and ever-important sunscreen.

8. Ocho Rios

Tomash Devenishek, flickr

9. Montalivet Beach

SORTIR, Wikimedia Creative Commons

10. Cap s'Agde

11. Plakias Beach

12. Baker Beach

13. Black's Beach

14. Club Orient

15. Hidden Beach Resort

16. Moshup Beach

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Top Nude Beaches : Beaches : Travel Channel | Travel Channel

Offshore company – Wikipedia

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The term "offshore company" or "offshore corporation" is used in at least two distinct and different ways. An offshore company may be a reference to:

The former use (companies formed in offshore jurisdictions) is probably the more common usage of the term. In isolated instances the term can also be used in reference to companies with offshore oil and gas operations.

In relation to companies and similar entities which are incorporated in offshore jurisdictions, the use of both the words "offshore" and "company" can be varied in application.

The extent to which a jurisdiction is regarded as offshore is often a question of perception and degree.[3] Classic tax haven countries such as Bermuda, British Virgin Islands and the Cayman Islands are quintessentially offshore jurisdictions, and companies incorporated in those jurisdictions are invariably labelled as offshore companies. Thereafter there are certain small intermediate countries or areas such as Hong Kong and Singapore (sometimes referred to as "mid-shore" jurisdictions) which, whilst having oversized financial centres, are not zero tax regimes. Finally, there are classes of industrialised economies which can be used as part of tax mitigation structures, including countries like Ireland, the Netherlands and even the United Kingdom, particularly in commentary relating to corporate inversion. Furthermore, in Federal systems, states which operate like a classic offshore centre can result in corporations formed there being labelled as offshore, even if they form part of the largest economy in the world (for example, Delaware in the United States).

Similarly, the term "company" is used loosely, and at its widest can be taken to refer to any type of artificial entity, including not just corporations and companies, but potentially also LLCs, LPs, LLPs, and sometimes partnerships or even offshore trusts.

Historically, offshore companies were broadly divided into two categories. On the one hand were companies which were statutorily exempt from taxation in their jurisdiction of registration provided that they did not undertake business with persons resident in that jurisdiction. Such companies were usually called International Business Companies, or IBCs. Such companies were largely popularized by the British Virgin Islands, but the model was copied widely. However, in the early 2000s the OECD launched a global initiative to prevent "ring fencing" of taxation in this manner, and many leading jurisdictions (including the British Virgin Islands and Gibraltar) repealed their International Business Companies legislation. But IBCs are still incorporated in a number of jurisdictions today including Anguilla and Panama.

Separately from IBCs, there are countries which operate tax regimes which broadly achieve the same effect: so long as the company's activities are carried on overseas, and none of the profits are repatriated, the company is not subject to taxation in its home jurisdiction. Where the home jurisdiction is regarded as an offshore jurisdiction, such companies are commonly regarded as offshore companies. Examples of this include Hong Kong and Uruguay. However, these tax regimes are not limited to conventional offshore jurisdictions: the United Kingdom operates on broadly similar principles in relation to taxation of companies.

Separately there are offshore jurisdictions which simply do not impose any form of taxation on companies, and so their companies are de facto tax exempt. Historically the best example of these countries were the Cayman Islands and Bermuda,[4] although other countries such as the British Virgin Islands[5] have now moved to this model. These could arguably fit into either of the previous two categories, depending on the fiscal point of view involved.

To the Offshore Company definition, applies five (non-cumulative) limiting conditions:(1) The government in the country of incorporation does not levy an indirect tax on the OAC (however, the OSC must pay an annual fee to the government).(2) Separate laws and regulations apply.(3) The OSC doesnt have its own physical office (address), personnel, means of communication etc. This means that the OAC must have a representative (registered agent) and office address (registered office) in the county of the incorporation.(4) The OSC must be managed and governed by (an employee of) a local trust or law office.(5) There is an instance of elements that benefit anonymity such as bearer shares and no or limited filing obligations.[6]

Although all offshore companies differ to a degree depending upon the corporate law in the relevant jurisdiction, all offshore companies tend to enjoy certain core characteristics:

The absence of taxation or regulation in the home jurisdiction does not, of course, exempt the relevant company from taxation or regulation abroad. For example, Michael Kors Holdings Limited is incorporated in the British Virgin Islands, but is listed on the New York Stock Exchange, where it is subject both the U.S. taxation and to financial regulation by the U.S. Securities and Exchange Commission.

Another common characteristic of offshore companies is the limited amount of information available to the public. This varies from jurisdiction to jurisdiction. At one end of the scale, in the Cayman Islands and Delaware, there is virtually no publicly available information. But at the other end of the scale, in Hong Kong companies file annual returns with particulars of directors, shareholders and annual accounts. However, even in jurisdictions where there is relatively little information available to the public as of right, most jurisdictions have laws which permit law enforcement authorities (either locally or from overseas) to have access to relevant information,[8] and in some cases, private individuals.[9]

In relation to flexible corporate law, most offshore jurisdictions will normally remove corporate fetters such as thin capitalisation rules, financial assistance rules, and limitations on corporate capacity and corporate benefit. A number have also removed or watered down rules relating to maintenance of capital or restrictions on payment of dividends. Beyond the common themes, a number of jurisdictions have also enacted special corporate provisions to try and attract business through offering corporate mechanisms that allow complex business transactions or reorganisations to occur more smoothly.[10]

Offshore companies are used for a variety of commercial and private purposes, some legitimate and economically beneficial, whilst others may be harmful or even criminal. Allegations are frequently made in the press about offshore companies being used for money laundering, tax evasion, fraud, and other forms of white collar crime. Offshore companies are also used in a wide variety of commercial transactions from generic holding companies, to joint ventures and listing vehicles. Offshore companies are also used widely in connection with private wealth for tax mitigation and privacy. The use of offshore companies, particularly in tax planning, has become controversial in recent years, and a number of high-profile companies have ceased using offshore entities in their group structure as a result of public campaigns for such companies to pay their "fair share" of Government taxes.[11]

Detailed information in relation to the use of offshore companies is notoriously difficult to come by because of the opaque nature of much of the business (and because, in many cases, the companies are used specifically to preserve the confidentiality of a transaction or individual). It is a commonly held view that most uses of offshore companies are driven by tax mitigation and/or regulatory arbitrage, although there are some suggestions that the amount of tax structuring may be less than commonly thought.[12] Other commonly cited legitimate uses of offshore companies include uses as joint ventures,[13] financing SPVs, stock market listing vehicles, holding companies and asset holding structures, and trading vehicles.

Intermediate uses of offshore companies (i.e. uses which might be considered legitimate or illegitimate depending upon a particular person's view of legitimacy of globalisation and tax planning) include uses as investment funds and private wealth holding vehicles.

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Offshore company - Wikipedia

Offshore (novel) – Wikipedia

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1979 novel by Penelope Fitzgerald

Offshore is a 1979 novel by Penelope Fitzgerald. The book, her third novel, won the Booker Prize in the same year. The novel explores the emotional restlessness of houseboat dwellers who live neither fully on the water nor fully on the land. It was inspired by the most difficult years of Fitzgerald's own life, years that that she had spent living on an old Thames sailing barge moored at Battersea Reach.

The novel, set in 1961, follows an eccentric community of houseboat owners whose permanently moored craft cluster together along the unsalubrious bank of the Thames at Battersea Reach, London. Nenna, living aboard Grace with her two children Martha and Tilda, is obsessed with thoughts of her estranged husband Edward returning to her, while her children run wild on the muddy foreshore. Maurice, who lives next to her on a barge he has named Maurice, provides a sympathetic ear for her worries. He ekes out a precarious living as a male prostitute, bringing back men each evening from the nearby pub, and allowing his boat to be used for the storage of stolen goods by his shadowy acquaintance, Harry. Willis, an elderly marine painter, lives aboard Dreadnaught which he hopes to sell in spite of its serious leak. Woodie is a retired businessman living aboard Rochester during the summer and with his wife Janet in Purley during the winter. Richard, aboard his converted minesweeper Lord Jim, is looked up to as the unofficial leader of the community, both by temperament and by virtue of his past role with the Royal Naval Volunteer Reserve. His wife Laura hankers to move to a permanent house ashore.

When Dreadnaught unexpectedly sinks, Willis is taken in by Woodie on Rochester. Nenna resists the entreaties of her prosperous and energetic sister who tries to persuade her to move to Canada for the sake of her daughters, and she resolves to confront Edward in his rented room in North London. Failing to persuade him to return, she gets back to Grace late at night feeling desolate, and bumps into Richard who tells her that his wife has just left him. They spend the night together.

Richard discovers Harry acting suspiciously on Maurice. Harry attacks, and Richard ends up in hospital. Laura takes her husband's incapacity as the excuse she needs to sell Lord Jim and to move herself and Richard into a proper house.

Maurice sits out an overnight storm in his cabin, drinking whisky in the dark. He hears blundering footsteps overhead and discovers that Edward has returned, incapably drunk, trying to find Nenna. The storm has blown away the gangplank between Maurice and Grace and, almost delirious with drink, the two men climb down Maurices fixed ladder intending somehow to cross the wild water between the two boats. As they cling to the ladder, Maurices anchor is wrenched from the mud, its mooring ropes part, and the boat puts out on the tide.

The novel's epigraph, "che mena il vento, e che batte la pioggia, e che s'incontran con si aspre lingue" ("whom the wind drives, or whom the rain beats, or those who clash with such bitter tongues") comes from Canto XI of Dante's Inferno.

The book was inspired by the most difficult years of Fitzgerald's own life, years that that she had spent living on an old Thames sailing barge named Grace on Battersea Reach. She later regretted that some translations of the novel's title suggested "far from the shore" when she was in fact writing about boats that were anchored just a few yards from the bank, and the "emotional restlessness of my characters, halfway between the need for security and the doubtful attraction of danger".[2]

In a 2013 introduction Alan Hollinghurst noted that Offshore was the novel in which Fitzgerald found her form her technique and her power. He noted that the group portrait of the boat owners within the novel is constantly developing, change and flux being the essence of the book, with the author moving between the strands of the story with insouciant wit and ease.[2]

The novel was also reviewed in The New York Times Book Review, [3]The Independent[4] and The Guardian.[5]

Offshore won the Booker Prize in 1979.[6] Hilary Spurling, one of the judges, later said that the panel was unable to decide between A Bend in the River and Darkness Visible, settling on Offshore as a compromise.[7] The book's surprise win was greeted with a reaction that Fitzgerald's publisher said was "so unpleasant a demonstration of naked spite".[8]

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Offshore (novel) - Wikipedia

Active Directory, NTP and VMware | www.extropy.com

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Found an interesting issue; I thought we'd be safe allowing VMware tools to update the guest time on our VMs; it turns out that in a domain setting this is a bad idea. If anything happens to the VMware clock, things go badly. This is true even though I configured VMware to pulls its time via NTP from pool.ntp.org. I found that VM clock times were drifting and this was causing havoc with domain and authentication services. When you have problems with those basic services, many other strange unexplained problems will arise. The best way to handle the situation is to configure AD to distribute time as it it designed to and to totally turn off VMware tools time synchronization unless you need it for a specific reason.

Note that part of AD domain services is a basic time service that all member computers get their time from by default without any configuration

Here are the details on how to configure AD properly:

Please note that pool.ntp.org is a free/public and reliable NTP source that is comprised of multiple geographically distributed time servers.

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Active Directory, NTP and VMware | http://www.extropy.com

Cyberpunk 2077’s Release Date Might Be Announced Soon

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It's been a long time coming, but the release date for Cyberpunk 2077 could soon be announced by developer CD Projekt RED. The studio, which is best known for its acclaimed work on The Witcher series, has been working on its new game for some time, andCD Projekt RED has generally been keeping quiet about exactly how thetitle is going to operate as development continues behind the scenes.

That's not to say that the developer has been silent, of course. Already, fans know that CD Projekt RED is planning to make Cyberpunk 2077 into its next blockbuster franchise, for instance, which explains why so many fans of the studio's work have been happy to let CD Projekt RED do its own thing. However, perhaps the most important piece of missing information that has yet to be answered is exactly when Cyberpunk 2077 was going to release.

Related:What The Witchers Geralt Would Look Like in Cyberpunk 2077

Thankfully, the wait for the launch date for Cyberpunk 2077 may soon be over. CD Projekt RED's latest financial report, delivered by its management board, made for some interesting reading for those wanting to know more about the game. Effectively, the report stated that CD Projekt RED will not be paying dividends to stakeholders this year, which is something of an anomaly for the highly profitable company. The reason for this change is that the funds will instead go towards promotion and marketing.

Of course, this means that the marketing campaign for Cyberpunk 2077 is likely to start soon, and this financial impact will be caused by CD Projekt RED's independence this time around, paying out for the promotional budget on its own without ties to another distributor. As such, look out for Cyberpunk 2077 having a presence at E3 2018, and most likely an announcement of its release date either at the expo or soon after.

Although some may feel this tees up the game for a 2018 release, this may be pushing the launch of the game a little too early. After all,Cyberpunk 2077 is going to be much bigger than The Witcher 3, and CD Projekt RED is a developer known for its care and attention. If the marketing budget is only going to be fully utilized starting this year, expect more by way of trailers and other promotion and perhaps a launch date of Spring 2019.

Even if the wait is a little longer than some may want, at the very least it will be good to put a finite point of reference down for when Cyberpunk 2077 can be played. In the meantime, of course, there's always the chance to read up on the title's source material, tabletop game Cyberpunk 2020. That, or CD Projekt RED fans can have a quick look atwhat The Witchers Geralt would look like in Cyberpunk 2077.

More:Cyberpunk 2077: Every Update You Need To Know

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Hellblade: Senua's Sacrifice Switch Port Coming Next Week

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Cyberpunk 2077's Release Date Might Be Announced Soon

Company Seven | Astro-Physics 155mm f7 Telescope, 2.7" Focuser

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155mm f7 STARFIRE EDF APOCHROMATIC REFRACTOR ULTRA-PORTABLE WITH 2.7" FOCUSERthe world-renowned standard of excellence against which all others six inch Apos are measured

Originally introduced with the avid astrophotographer in mind, the 155mm f7 StarFire EDF (6.1 inchaperture) astrograph features the gigantic focuser and included the Field Flattener lens option accommodating up to Pentax 6x7cm camera format with full field illumination. It made an astounding versatile visual telescope too; capable of extraordinarily wide fields of view at lower magnifications, with the capacity to reveal subtle features on the planets at high magnifications that few other 25 lb. telescopes can show. The astronomy community came to appreciate theversatility of this instrument and at the urging of our customers, we now offer the same excellent 155mm f7 lens in a lighter weight tube assembly incorporating the highly regarded Astro-Physics 2.7 inch focuser.

We continue to be amazed at the compact size of this instrument. At last, a 6.1 inch Apo refractor with an overall length of 40 inches (with dewcap retracted). This is less than half the length of an fl5 and approximately a foot shorter than an f9! In fact, it is about the same length as our 130mm f8, but with an inch more of aperture! You can transport it in a smaller car, store it in less space, invest in a smaller mount and shorter pier/tripod. This instrument is the fulfillment of the astronomer's dream for a truly portable 6.1 inch refractor.

This refractor can, of course, be used photographically with a 35mmcamera at prime focus with only a simple camera adapter or at afast f5.2 with the optional flat- field telecompressor. A single element field flattener is available for the Pentax 6 x 7 medium format camera,however the field is vignetted in the corners due to the restrictions of the 2.7" focuser (full coverage requires the 4"focuser/4" field flattener combination). The 2.7" focuser isinterchangeable with the 4" model should you choose at some timein the future to upgrade to the full EDF 4" package.

"Optical performance of the 155EDT was impressive. It producednary a trace of false color even on Venus. Equally impressive, thisscope provided superb images as soon as it was set outside. Evenin sub-freezing temperatures, image quality, though not perfect atfirst, was surprisingly sharp from the start. In cold weather, after amodest settle-down time of 30 minutes, in-focus star images weretextbook Airy disks with a well-defined first diffraction ring and atrace of a second outer ring. There was no sign of sphericalaberration, lens figure changes, heat plumes, or distorted Airy disksdue to tube turbulence."

We could not have said it better ourselves.

For 2004 Astro-Physics has developed a new specially designed dual-speed pinion fine dual speed geared focuser assembly. Incorporating a 9 to 1 geared reduction knob, this is the Feather Touch Micro Focuser option. It is available as an retrofit kit for existing compatible Astro-Physics focusers. Or you can order it factory installed in your new Traveler telescope.

Right: Feather Touch Focuser option on Astro-Physics 155 mm EDF Apo telescope, optional Astro-Physics 8x 50mm Finder also shown (54,384 bytes).Click on image for higher quality, enlarged view (125,877 bytes).

Left: Color correction of the Astro-Physics 155 mm EDF Apo telescope (69,285 bytes).Click on image for higher quality, enlarged view (178,123 bytes).

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Company Seven | Astro-Physics 155mm f7 Telescope, 2.7" Focuser

NATO | Founders, Members, & History | Britannica.com

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North Atlantic Treaty Organization (NATO), military alliance established by the North Atlantic Treaty (also called the Washington Treaty) of April 4, 1949, which sought to create a counterweight to Soviet armies stationed in central and eastern Europe after World War II. Its original members were Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States. Joining the original signatories were Greece and Turkey (1952); West Germany (1955; from 1990 as Germany); Spain (1982); the Czech Republic, Hungary, and Poland (1999); Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia (2004); Albania and Croatia (2009); and Montenegro (2017). France withdrew from the integrated military command of NATO in 1966 but remained a member of the organization; it resumed its position in NATOs military command in 2009.

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20th-century international relations: The role of NATO

Russian assertiveness complicated Clintons efforts to recast NATO for the post-Cold War world. American neo-isolationists thought that

The heart of NATO is expressed in Article 5 of the North Atlantic Treaty, in which the signatory members agree that

an armed attack against one or more of them in Europe or North America shall be considered an attack against them all; and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defense recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.

NATO invoked Article 5 for the first time in 2001, after terrorist attacks organized by exiled Saudi Arabian millionaire Osama bin Laden destroyed the World Trade Center in New York City and part of the Pentagon outside Washington, D.C., killing some 3,000 people.

Article 6 defines the geographic scope of the treaty as covering an armed attack on the territory of any of the Parties in Europe or North America. Other articles commit the allies to strengthening their democratic institutions, to building their collective military capability, to consulting each other, and to remaining open to inviting other European states to join.

After World War II in 1945, western Europe was economically exhausted and militarily weak (the western Allies had rapidly and drastically reduced their armies at the end of the war), and newly powerful communist parties had arisen in France and Italy. By contrast, the Soviet Union had emerged from the war with its armies dominating all the states of central and eastern Europe, and by 1948 communists under Moscows sponsorship had consolidated their control of the governments of those countries and suppressed all noncommunist political activity. What became known as the Iron Curtain, a term popularized by Winston Churchill, had descended over central and eastern Europe. Further, wartime cooperation between the western Allies and the Soviets had completely broken down. Each side was organizing its own sector of occupied Germany, so that two German states would emerge, a democratic one in the west and a communist one in the east.

In 1948 the United States launched the Marshall Plan, which infused massive amounts of economic aid to the countries of western and southern Europe on the condition that they cooperate with each other and engage in joint planning to hasten their mutual recovery. As for military recovery, under the Brussels Treaty of 1948, the United Kingdom, France, and the Low CountriesBelgium, the Netherlands, and Luxembourgconcluded a collective-defense agreement called the Western European Union. It was soon recognized, however, that a more formidable alliance would be required to provide an adequate military counterweight to the Soviets.

By this time Britain, Canada, and the United States had already engaged in secret exploratory talks on security arrangements that would serve as an alternative to the United Nations (UN), which was becoming paralyzed by the rapidly emerging Cold War. In March 1948, following a virtual communist coup dtat in Czechoslovakia in February, the three governments began discussions on a multilateral collective-defense scheme that would enhance Western security and promote democratic values. These discussions were eventually joined by France, the Low Countries, and Norway and in April 1949 resulted in the North Atlantic Treaty.

Spurred by the North Korean invasion of South Korea in June 1950, the United States took steps to demonstrate that it would resist any Soviet military expansion or pressures in Europe. General Dwight D. Eisenhower, the leader of the Allied forces in western Europe in World War II, was named Supreme Allied Commander Europe (SACEUR) by the North Atlantic Council (NATOs governing body) in December 1950. He was followed as SACEUR by a succession of American generals.

The North Atlantic Council, which was established soon after the treaty came into effect, is composed of ministerial representatives of the member states, who meet at least twice a year. At other times the council, chaired by the NATO secretary-general, remains in permanent session at the ambassadorial level. Just as the position of SACEUR has always been held by an American, the secretary-generalship has always been held by a European.

NATOs military organization encompasses a complete system of commands for possible wartime use. The Military Committee, consisting of representatives of the military chiefs of staff of the member states, subsumes two strategic commands: Allied Command Operations (ACO) and Allied Command Transformation (ACT). ACO is headed by the SACEUR and located at Supreme Headquarters Allied Powers Europe (SHAPE) in Casteau, Belgium. ACT is headquartered in Norfolk, Virginia, U.S. During the alliances first 20 years, more than $3 billion worth of infrastructure for NATO forcesbases, airfields, pipelines, communications networks, depotswas jointly planned, financed, and built, with about one-third of the funding from the United States. NATO funding generally is not used for the procurement of military equipment, which is provided by the member statesthough the NATO Airborne Early Warning Force, a fleet of radar-bearing aircraft designed to protect against a surprise low-flying attack, was funded jointly.

A serious issue confronting NATO in the early and mid-1950s was the negotiation of West Germanys participation in the alliance. The prospect of a rearmed Germany was understandably greeted with widespread unease and hesitancy in western Europe, but the countrys strength had long been recognized as necessary to protect western Europe from a possible Soviet invasion. Accordingly, arrangements for West Germanys safe participation in the alliance were worked out as part of the Paris Agreements of October 1954, which ended the occupation of West German territory by the western Allies and provided for both the limitation of West German armaments and the countrys accession to the Brussels Treaty. In May 1955 West Germany joined NATO, which prompted the Soviet Union to form the Warsaw Pact alliance in central and eastern Europe the same year. The West Germans subsequently contributed many divisions and substantial air forces to the NATO alliance. By the time the Cold War ended, some 900,000 troopsnearly half of them from six countries (United States, United Kingdom, France, Belgium, Canada, and the Netherlands)were stationed in West Germany.

Frances relationship with NATO became strained after 1958, as President Charles de Gaulle increasingly criticized the organizations domination by the United States and the intrusion upon French sovereignty by NATOs many international staffs and activities. He argued that such integration subjected France to automatic war at the decision of foreigners. In July 1966 France formally withdrew from the military command structure of NATO and required NATO forces and headquarters to leave French soil; nevertheless, de Gaulle proclaimed continued French adherence to the North Atlantic Treaty in case of unprovoked aggression. After NATO moved its headquarters from Paris to Brussels, France maintained a liaison relationship with NATOs integrated military staffs, continued to sit in the council, and continued to maintain and deploy ground forces in West Germany, though it did so under new bilateral agreements with the West Germans rather than under NATO jurisdiction. In 2009 France rejoined the military command structure of NATO.

From its founding, NATOs primary purpose was to unify and strengthen the Western Allies military response to a possible invasion of western Europe by the Soviet Union and its Warsaw Pact allies. In the early 1950s NATO relied partly on the threat of massive nuclear retaliation from the United States to counter the Warsaw Pacts much larger ground forces. Beginning in 1957, this policy was supplemented by the deployment of American nuclear weapons in western European bases. NATO later adopted a flexible response strategy, which the United States interpreted to mean that a war in Europe did not have to escalate to an all-out nuclear exchange. Under this strategy, many Allied forces were equipped with American battlefield and theatre nuclear weapons under a dual-control (or dual-key) system, which allowed both the country hosting the weapons and the United States to veto their use. Britain retained control of its strategic nuclear arsenal but brought it within NATOs planning structures; Frances nuclear forces remained completely autonomous.

A conventional and nuclear stalemate between the two sides continued through the construction of the Berlin Wall in the early 1960s, dtente in the 1970s, and the resurgence of Cold War tensions in the 1980s after the Soviet Unions invasion of Afghanistan in 1979 and the election of U.S. President Ronald Reagan in 1980. After 1985, however, far-reaching economic and political reforms introduced by Soviet leader Mikhail Gorbachev fundamentally altered the status quo. In July 1989 Gorbachev announced that Moscow would no longer prop up communist governments in central and eastern Europe and thereby signaled his tacit acceptance of their replacement by freely elected (and noncommunist) administrations. Moscows abandonment of control over central and eastern Europe meant the dissipation of much of the military threat that the Warsaw Pact had formerly posed to western Europe, a fact that led some to question the need to retain NATO as a military organizationespecially after the Warsaw Pacts dissolution in 1991. The reunification of Germany in October 1990 and its retention of NATO membership created both a need and an opportunity for NATO to be transformed into a more political alliance devoted to maintaining international stability in Europe.

After the Cold War, NATO was reconceived as a cooperative-security organization whose mandate was to include two main objectives: to foster dialogue and cooperation with former adversaries in the Warsaw Pact and to manage conflicts in areas on the European periphery, such as the Balkans. In keeping with the first objective, NATO established the North Atlantic Cooperation Council (1991; later replaced by the Euro-Atlantic Partnership Council) to provide a forum for the exchange of views on political and security issues, as well as the Partnership for Peace (PfP) program (1994) to enhance European security and stability through joint military training exercises with NATO and non-NATO states, including the former Soviet republics and allies. Special cooperative links were also set up with two PfP countries: Russia and Ukraine.

The second objective entailed NATOs first use of military force, when it entered the war in Bosnia and Herzegovina in 1995 by staging air strikes against Bosnian Serb positions around the capital city of Sarajevo. The subsequent Dayton Accords, which were initialed by representatives of Bosnia and Herzegovina, the Republic of Croatia, and the Federal Republic of Yugoslavia, committed each state to respecting the others sovereignty and to settling disputes peacefully; it also laid the groundwork for stationing NATO peacekeeping troops in the region. A 60,000-strong Implementation Force (IFOR) was initially deployed, though a smaller contingent remained in Bosnia under a different name, the Stabilization Force (SFOR). In March 1999 NATO launched massive air strikes against Serbia in an attempt to force the Yugoslav government of Slobodan Miloevi to accede to diplomatic provisions designed to protect the predominantly Muslim Albanian population in the province of Kosovo. Under the terms of a negotiated settlement to the fighting, NATO deployed a peacekeeping force called the Kosovo Force (KFOR).

The crisis over Kosovo and the ensuing war gave renewed impetus to efforts by the European Union (EU) to construct a new crisis-intervention force, which would make the EU less dependent on NATO and U.S. military resources for conflict management. These efforts prompted significant debates about whether enhancing the EUs defensive capabilities would strengthen or weaken NATO. Simultaneously there was much discussion of the future of NATO in the post-Cold War era. Some observers argued that the alliance should be dissolved, noting that it was created to confront an enemy that no longer existed; others called for a broad expansion of NATO membership to include Russia. Most suggested alternative roles, including peacekeeping. By the start of the second decade of the 21st century, it appeared likely that the EU would not develop capabilities competitive with those of NATO or even seek to do so; as a result, earlier worries associated with the spectre of rivalry between the two Brussels-based organizations dissipated.

During the presidency of Bill Clinton (19932001), the United States led an initiative to enlarge NATO membership gradually to include some of the former Soviet allies. In the concurrent debate over enlargement, supporters of the initiative argued that NATO membership was the best way to begin the long process of integrating these states into regional political and economic institutions such as the EU. Some also feared future Russian aggression and suggested that NATO membership would guarantee freedom and security for the newly democratic regimes. Opponents pointed to the enormous cost of modernizing the military forces of new members; they also argued that enlargement, which Russia would regard as a provocation, would hinder democracy in that country and enhance the influence of hard-liners. Despite these disagreements, the Czech Republic, Hungary, and Poland joined NATO in 1999; Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia were admitted in 2004; and Albania and Croatia acceded to the alliance in 2009.

Meanwhile, by the beginning of the 21st century, Russia and NATO had formed a strategic relationship. No longer considered NATOs chief enemy, Russia cemented a new cooperative bond with NATO in 2001 to address such common concerns as international terrorism, nuclear nonproliferation, and arms control. This bond was subsequently subject to fraying, however, in large part because of reasons associated with Russian domestic politics.

Events following the September 11 terrorist attacks in 2001 led to the forging of a new dynamic within the alliance, one that increasingly favoured the military engagement of members outside Europe, initially with a mission against Taliban forces in Afghanistan beginning in the summer of 2003 and subsequently with air operations against the regime of Muammar al-Qaddafi in Libya in early 2011. As a result of the increased tempo of military operations undertaken by the alliance, the long-standing issue of burden sharing was revived, with some officials warning that failure to share the costs of NATO operations more equitably would lead to unraveling of the alliance. Most observers regarded that scenario as unlikely, however.

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NATO | Founders, Members, & History | Britannica.com

NATO: Definition, Purpose, History, Members – The Balance

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NATO is an alliance of 28 countries bordering the North Atlantic Ocean. It includesthe United States, most European Union members, Canada, and Turkey. NATO is an acronym for the North Atlantic Treaty Organization.

At the July 11, 2018, NATO summit, President Trump requested that NATO nations increase their defense spending to 4 percent of GDP. In 2017, the United States spent 4.5 percent. That's $886 billion in military spending divided by $20 trillion in U.S. GDP.

Trump also criticized Germany for asking the United States to protect it from Russia while importing billions in natural gas from it.

Trump has accused NATO of being obsolete. He argued that the organization focuses on defending Europe against Russia instead of combating terrorism.Member countries worry that Trump's criticism of NATO and praise of Russia's leader, Vladimir Putin, mean they can no longer rely on the United States as an ally in case of attack.

NATO's mission is to protect the freedom of its members. Its targets includeweapons of mass destruction, terrorism, and cyber attacks.

At its July 11, 2018, meeting, NATO approvednew steps to contain Russia. These include two new military commands and expanded efforts against cyberwarfare and counterterrorism. It also contains a new plan to deter Russian aggression against Poland and the Baltic States. Trump agreed to these measures.

On November 16, 2015, NATO responded to theterrorist attacks in Paris. It called for a unified approach with the European Union, France, and NATO. France did notinvoke NATO'sArticle 5. That would be a formal declaration of war uponthe Islamic state group. France preferred to launch air strikes on its own. Article 5 states, "an armed attack upon one... shall be considered an attack upon them all."

NATO's protection does not extend to members' civil wars or internal coups. On July 15, 2016, the Turkish military announced it had seized control of the government in a coup. But Turkish President Recep Erdogan announced early on July 16 that the coup had failed. As a NATO member, Turkey would receive its allies' support in the case of an attack. But in case of a coup, the country will not get allied help.

NATO's secondary purpose is to protect the stability of the region.

If the stability is threatened, NATO would defend non-members. On August 28,2014, NATO announcedit had photos proving that Russiainvaded Ukraine. Although Ukraine is not a member, it had worked with NATO over the years. Russia's invasion of Ukraine threatenednearby NATO members. They worried other former USSR satellite countries would be next.

As a result, NATO'sSeptember 2014 summitfocused on Russia' aggression. President Putin vowed to create a "NewRussia" out of Ukraine's eastern region.President Obamapledged to defend countries such as Latvia, Lithuania, and Estonia.

NATO itself admits that "Peacekeeping has become at least as difficult as peacemaking." As a result, NATO is strengthening alliances throughout the world. In the age of globalization, transatlantic peace has become a worldwide effort. Itextends beyond military might alone.

NATO's 28 members are: Albania, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary,Iceland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom, and the United States.

Each member designates an ambassador to NATO. They supply officials to serve on NATO committees. They send the appropriate official to discuss NATO business. That includes a countrys president, prime minister, foreign affairs minister or head of the department of defense.

On December 1, 2015, NATO announced its first expansion since 2009. It offered membership to Montenegro. Russia responded by calling the move a strategic threat to its national security. Its worried by the number of Balkan countries along its border that have joined NATO.

NATO participates in three alliances. They expands its influence beyond its 28 member countries. The Euro-Atlantic Partnership Council helps partners become NATO members.Itincludes 23 non-NATO countries that support NATO's purpose. It beganin 1991.

The Mediterranean Dialogue seeks to stabilize the Middle East. Its non-NATO members include Algeria, Egypt, Israel, Jordan, Mauritania, Morocco, and Tunisia. It began in1994.

The Istanbul Cooperation Initiativeworks forpeace throughout the larger Middle East region.It includes four members of theGulf Cooperation Council. They are Bahrain, Kuwait, Qatar, and the United Arab Emirates. It began in 2004.

NATO cooperates with eight other countries in joint security issues. There are five in Asia. They are Australia,Japan, Republic of Korea, Mongolia, and New Zealand. There are two in the Middle East: Afghanistan and Pakistan.

NATO'sprimary purpose was to defend member nations from threats by communist countries. The United States also wanted to maintain a presence in Europe. It soughtto prevent a resurgence of aggressive nationalism and foster political union. In this way, NATO made the formation of the European Union possible.U.S. military protection gave European nations the safety needed to rebuild after World War II's devastation.

During the Cold War, NATO's mission expanded to prevent nuclear war.

After West Germany joined NATO, thecommunistcountriesformed theWarsaw Pact alliance. That included the USSR, Bulgaria, Hungary, Romania, Poland, Czechoslovakia, and EastGermany. In response, NATO adopted the "Massive Retaliation" policy. It promised to usenuclear weaponsif the Pact attacked. NATO'sdeterrence policy allowed Europe to focus oneconomic development. It didn't have to build large conventional armies.

The Soviet Union continued to build its military presence. By the end of theCold War, it was spending three times what the United Stateswas with only one-third the economic power. When theBerlin Wallfell in 1989, it was due to economic as well as ideological reasons.

After the USSR dissolved in the late 1980s, NATO's relationship with Russia thawed. In 1997, they signed the NATO-Russia Founding Act to build bilateral cooperation. In 2002, they formed the NATO-Russia Council to partner on shared security issues.

The collapse of the USSR led to unrest in its former satellite states. NATO got involved when Yugoslavia's civil war becamegenocide. NATO's initial support of aUnited Nationsnaval embargo led to the enforcement of ano-fly zone. Violations then led to a few airstrikes until September 1999. That's when NATO conducted a nine-day air campaign that ended the war. By December of that year, NATO deployed a peace-keeping force of 60,000 soldiers. That ended in 2004 when NATO transferred this function to theEuropean Union.

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NATO: Definition, Purpose, History, Members - The Balance

comet | Definition, Composition, & Facts | Britannica.com

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HistoryAncient Greece to the 19th century

The Greek philosopher Aristotle thought that comets were dry exhalations of Earth that caught fire high in the atmosphere or similar exhalations of the planets and stars. However, the Roman philosopher Seneca thought that comets were like the planets, though in much larger orbits. He wrote:

The man will come one day who will explain in what regions the comets move, why they diverge so much from the other stars, what is their size and their nature.

Aristotles view won out and persisted until 1577, when Danish astronomer Tycho Brahe attempted to use parallax to triangulate the distance to a bright comet. Because he could not measure any parallax, Brahe concluded that the comet was very far away, at least four times farther than the Moon.

Brahes student, German astronomer Johannes Kepler, devised his three laws of planetary motion using Brahes meticulous observations of Mars but was unable to fit his theory to the very eccentric orbits of comets. Kepler believed that comets traveled in straight lines through the solar system. The solution came from English scientist Isaac Newton, who used his new law of gravity to calculate a parabolic orbit for the comet of 1680. A parabolic orbit is open, with an eccentricity of exactly 1, meaning the comet would never return. (A circular orbit has an eccentricity of 0.) Any less-eccentric orbits are closed ellipses, which means a comet would return.

Newton was friends with English astronomer Edmond Halley, who used Newtons methods to determine the orbits for 24 observed comets, which he published in 1705. All the orbits were fit with parabolas because the quality of the observations at that time was not good enough to determine elliptical or hyperbolic orbits (eccentricities greater than 1). But Halley noted that the comets of 1531, 1607, and 1682 had remarkably similar orbits and had appeared at approximately 76-year intervals. He suggested that it was really one comet in an approximately 76-year orbit that returned at regular intervals. Halley predicted that the comet would return again in 1758. He did not live to see his prediction come true, but the comet was recovered on Christmas Day, 1758, and passed closest to the Sun on March 13, 1759. The comet was the first recognized periodic comet and was named in Halleys honour, Comet Halley.

Halley also speculated whether comets were members of the solar system or not. Although he could only calculate parabolic orbits, he suggested that the orbits were actually eccentric and closed, writing:

For so their Number will be determinate and, perhaps, not so very great. Besides, the Space between the Sun and the fixd Stars is so immense that there is Room enough for a Comet to revolve tho the period of its Revolution be vastly long.

The German astronomer Johann Encke was the second person to recognize a periodic comet. He determined that a comet discovered by French astronomer Jean-Louis Pons in 1818 did not seem to follow a parabolic orbit. He found that the orbit was indeed a closed ellipse. Moreover, he showed that the orbital period of the comet around the Sun was only 3.3 years, still the shortest orbital period of any comet on record. Encke also showed that the same comet had been observed by French astronomer Pierre Mchain in 1786, by British astronomer Caroline Herschel in 1795, and by Pons in 1805. The comet was named in Enckes honour, as Comet Halley was named for the astronomer who described its orbit.

Enckes Comet soon presented a new problem for astronomers. Because it returned so often, its orbit could be predicted precisely based on Newtons law of gravity, with effects from gravitational perturbations by the planets taken into account. But Enckes Comet repeatedly arrived about 2.5 hours too soon. Its orbit was slowly shrinking. The problem became even more complex when it was discovered that other periodic comets arrived too late. Those include the comets 6P/DArrest, 14P/Wolf 1, and even 1P/Halley, which typically returns about four days later than a purely gravitational orbit would predict.

Several explanations were suggested for this phenomenon, such as a resisting interplanetary medium that caused the comet to slowly lose orbital energy. However, that idea could not explain comets whose orbits were growing, not shrinking. German mathematician and astronomer Friedrich Bessel suggested that expulsion of material from a comet near perihelion was acting like a rocket motor and propelling the comet into a slightly shorter- (or longer-) period orbit each time it passed close to the Sun. History would prove Bessel right.

As the quality of the observations and mathematical techniques to calculate orbits improved, it became obvious that most comets were on elliptical orbits and thus were members of the solar system. Many were recognized to be periodic. But some orbit solutions for long-period comets suggested that they were slightly hyperbolic, suggesting that they came from interstellar space. That problem would not be solved until the 20th century.

Another interesting problem for astronomers was a comet discovered in 1826 by the Austrian military officer and astronomer Wilhelm, Freiherr (baron) von Biela. Calculation of its orbit showed that it, like Enckes Comet, was a short-period comet; it had a period of about 6.75 years. It was only the third periodic comet to be confirmed. It was identified with a comet observed by French astronomers Jacques Lebaix Montaigne and Charles Messier in 1772 and by Pons in 1805, and it returned, as predicted, in 1832. In 1839 the comet was too close in the sky to the Sun and could not be observed, but it was seen again on schedule in November 1845. On January 13, 1846, American astronomer Matthew Maury found that there was no longer a single comet: there were two, following each other closely around the Sun. The comets returned as a pair in 1852 but were never seen again. Searches for the comets in 1865 and 1872 were unsuccessful, but a brilliant meteor shower appeared in 1872 coming from the same direction from which the comets should have appeared. Astronomers concluded that the meteor shower was the debris of the disrupted comets. However, they were still left with the question as to why the comet broke up. That recurring meteor shower is now known as the Andromedids, named for the constellation in the sky where it appears to radiate from, but is also sometimes referred to as the Bielids.

The study of meteor showers received a huge boost on November 12 and 13, 1833, when observers saw an incredible meteor shower, with rates of hundreds and perhaps thousands of meteors per hour. That shower was the Leonids, so named because its radiant (or origin) is in the constellation Leo. It was suggested that Earth was encountering interplanetary debris spread along the Earth-crossing orbits of yet unknown bodies in the solar system. Further analysis showed that the orbits of the debris were highly eccentric.

American mathematician Hubert Newton published a series of papers in the 1860s in which he examined historical records of major Leonid meteor showers and found that they occurred about every 33 years. That showed that the Leonid particles were not uniformly spread around the orbit. He predicted another major shower for November 1866. As predicted, a large Leonid meteor storm occurred on November 13, 1866. In the same year, Italian astronomer Giovanni Schiaparelli computed the orbit of the Perseid meteor shower, usually observed on August 1012 each year, and noted its strong similarity to the orbit of Comet Swift-Tuttle (109P/1862 O1) discovered in 1862. Soon after, the Leonids were shown to have an orbit very similar to Comet Tempel-Tuttle (55P/1865 Y1), discovered in 1865. Since then the parent comets of many meteoroid streams have been identified, though the parent comets of some streams remains a mystery.

Meanwhile, the study of comets benefitted greatly from the improvement in the quality and size of telescopes and the technology for observing comets. In 1858 English portrait artist William Usherwood took the first photograph of a comet, Comet Donati (C/1858 L1), followed by American astronomer George Bond the next night. The first photographic discovery of a comet was made by American astronomer Edward Barnard in 1892, while he was photographing the Milky Way. The comet, which was in a short-period orbit, was known as D/Barnard 3 because it was soon lost, but it was recovered by Italian astronomer Andrea Boattini in 2008 and is now known as Comet Barnard/Boattini (206P/2008 T3). In 1864 Italian astronomer Giovanni Donati was the first to look at a comet through a spectroscope, and he discovered three broad emission bands that are now known to be caused by long-chain carbon molecules in the coma. The first spectrogram (a spectrum recorded on film) was of Comet Tebbutt (C/1881 K1), taken by English astronomer William Huggins on June 24, 1881. Later the same night, an American doctor and amateur astronomer, Henry Draper, took spectra of the same comet. Both men later became professional astronomers.

Some years before the appearance of Comet Halley in 1910, the molecule cyanogen was identified as one of the molecules in the spectra of cometary comae. Cyanogen is a poisonous gas derived from hydrogen cyanide (HCN), a well-known deadly poison. It was also detected in Halleys coma as that comet approached the Sun in 1910. That led to great consternation as Earth was predicted to pass through the tail of the comet. People panicked, bought comet pills, and threw end-of-the-world parties. But when the comet passed by only 0.15 AU away on the night of May 1819, 1910, there were no detectable effects.

The 20th century saw continued progress in cometary science. Spectroscopy revealed many of the molecules, radicals, and ions in the comae and tails of comets. An understanding began to develop about the nature of cometary tails, with the ion (Type I) tails resulting from the interaction of ionized molecules with some form of corpuscular radiation, possibly electrons and protons, from the Sun, and the dust (Type II) tails coming from solar radiation pressure on the fine dust particles emitted from the comet.

Astronomers continued to ask, Where do the comets come from? There were three schools of thought: (1) that comets were captured from interstellar space, (2) that comets were erupted out of the giant planets, or (3) that comets were primeval matter that had not been incorporated into the planets. The first idea had been suggested by French mathematician and astronomer Pierre Laplace in 1813, while the second came from another French mathematician-astronomer, Joseph Lagrange. The third came from English astronomer George Chambers in 1910.

The idea of an interstellar origin for comets ran into some serious problems. First, astronomers showed that capture of an interstellar comet by Jupiter, the most massive planet, was a highly unlikely event and probably could not account for the number of short-period comets then known. Also, no comets had ever been observed on truly hyperbolic orbits. Some long-period comets did have orbit solutions that were slightly hyperbolic, barely above an eccentricity of 1.0. But a truly hyperbolic comet approaching the solar system with the Suns velocity relative to the nearby stars of about 20 km (12 miles) per second would have an eccentricity of 2.0.

In 1914 Swedish-born Danish astronomer Elis Strmgren published a special list of cometary orbits. Strmgren took the well-determined orbits of long-period comets and projected them backward in time to before the comets had entered the planetary region. He then referenced the orbits to the barycentre (the centre of mass) of the entire solar system. He found that most of the apparently hyperbolic orbits became elliptical. That proved that the comets were members of the solar system. Orbits of that type are referred to as original orbits, whereas the orbit of a comet as it passes through the planetary region is called the osculating (or instantaneous) orbit, and the orbit after the comet has left the planetary region is called the future orbit.

The idea of comets erupting from giant planets was favoured by the Soviet astronomer Sergey Vsekhsvyatsky based on similar molecules having been discovered in both the atmospheres of the giant planets and in cometary comae. The idea helped to explain the many short-period comets that regularly encountered Jupiter. But the giant planets have very large escape velocities, about 60 km (37 miles) per second in the case of Jupiter, and it was difficult to understand what physical process could achieve those velocities. So Vsekhsvyatsky moved the origin sites to the satellites of the giant planets, which had far lower escape velocities. However, most scientists still did not believe in the eruption model. The discovery of volcanos on Jupiters large satellite Io by the Voyager 1 spacecraft in 1979 briefly resurrected the idea, but Ios composition proved to be a very poor match to the composition of comets.

Another idea about cometary origins was promoted by the English astronomer Raymond Lyttleton in a research paper in 1951 and a book, The Comets and Their Origin, in 1953. Because it was known that some comets were associated with meteor showers observed on Earth, the sandbank model suggested that a comet was simply a cloud of meteoritic particles held together by its own gravity. Interplanetary gases were adsorbed on the surfaces of the dust grains and escaped when the comet came close to the Sun and the particles were heated. Lyttleton went on to explain that comets were formed when the Sun and solar system passed through an interstellar dust cloud. The Suns gravity focused the passing dust in its wake, and these subclouds then collapsed under their own gravity to form the cometary sandbanks.

One problem with that theory was that Lyttleton estimated that the gravitational focusing by the Sun would bring the particles together only about 150 AU behind the Sun and solar system. But that did not agree well with the known orbits of long-period comets, which showed no concentration of comets that would have formed at that distance or in that direction. In addition, the total amount of gases that could be adsorbed on a sandbank cloud was not sufficient to explain the measured gas production rates of many observed comets.

In 1948 Dutch astronomer Adrianus van Woerkom, as part of his Ph.D. thesis work at the University of Leiden, examined the role of Jupiters gravity in changing the orbits of comets as they passed through the planetary system. He showed that Jupiter could scatter the orbits in energy, leading to either longer or shorter orbital periods and correspondingly to larger or smaller orbits. In some cases the gravitational perturbations from Jupiter were sufficient to change the previously elliptical orbits of the comets to hyperbolic, ejecting them from the solar system and sending them into interstellar space. Van Woerkom also showed that because of Jupiter, repeated passages of comets through the solar system would lead to a uniform distribution in orbital energy for the long-period comets, with as many long-period comets ending in very long-period orbits as in very short-period orbits. Finally, van Woerkom showed that Jupiter would eventually eject all the long-period comets to interstellar space over a time span of about one million years. Thus, the comets needed to be resupplied somehow.

Van Woerkoms thesis adviser was the Dutch astronomer Jan Oort, who had become famous in the 1920s for his work on the structure and rotation of the Milky Way Galaxy. Oort became interested in the problem of where the long-period comets came from. Building on van Woerkoms work, Oort closely examined the energy distribution of long-period comet original orbits as determined by Strmgren. He found that, as van Woerkom had predicted, there was a uniform distribution of orbital energies for most energy values. But, surprisingly, there was also a large excess of comets with orbital semimajor axes (half of the long axis of the comets elliptical orbit) larger than 20,000 AU.

Oort suggested that the excess of orbits at very large distances could only be explained if the long-period comets came from there. He proposed that the solar system was surrounded by a vast cloud of comets that stretched halfway to the nearest stars. He showed that gravitational perturbations by random passing stars would perturb the orbits in the comet cloud, occasionally sending a comet into the planetary region where it could be observed. Oort referred to those comets making their first passage through the planetary region as new comets. As the new comets pass through the planetary region, Jupiters gravity takes control of their orbits, spreading them in orbital energy, and either capturing them to shorter periods or ejecting them to interstellar space.

Based on the number of comets seen each year, Oort estimated that the cloud contained 190 billion comets; today that number is thought to be closer to one trillion comets. Oorts hypothesis was all the more impressive because it was based on accurate original orbits for only 19 comets. In his honour, the cloud of comets surrounding the solar system is called the Oort cloud.

Oort noticed that the number of long-period comets returning to the planetary system was far less than what his model predicted. To account for that, he suggested that the comets were physically lost by disruption (as had happened to Bielas Comet). Oort proposed two values for the disruption rate of comets on each perihelion passage, 0.3 and 1.9 percent, which both gave reasonably good results when comparing his predictions with the actual energy distribution, except for an excess of new comets at near-zero energy.

In 1979 American astronomer Paul Weissman (the author of this article) published computer simulations of the Oort cloud energy distribution using planetary perturbations by Jupiter and Saturn and physical models of loss mechanisms such as random disruption and formation of a nonvolatile crust, based on actual observations of comets. He showed that a very good agreement with the observed energy distribution could be obtained if new comets were disrupted about 10 percent of the time on the first perihelion passage from the Oort cloud and about 4 percent of the time on subsequent passages. Also, comet nuclei developed nonvolatile crusts, cutting off all coma activity, after about 10100 returns, on average.

In 1981 American astronomer Jack Hills suggested that in addition to the Oort cloud there was also an inner cloud extending inward toward the planetary region to about 1,000 AU from the Sun. Comets are not seen coming from this region because their orbits are too tightly bound to the Sun; stellar perturbations are typically not strong enough to change their orbits significantly. Hills hypothesized that only if a star came very close, even penetrating through the Oort cloud, could it excite the orbits of the comets in the inner cloud, sending a shower of comets into the planetary system.

But where did the Oort cloud come from? At large distances on the order of 104105 AU from the Sun, the solar nebula would have been too thin to form large bodies like comets that are several kilometres in diameter. The comets had to have formed much closer to the planetary region. Oort suggested that the comets were thrown out of the asteroid belt by close encounters with Jupiter. At that time it was not known that most asteroids are rocky, carbonaceous, or iron bodies and that only a fraction contain any water.

Oorts work was preceded in part by that of the Estonian astronomer Ernst pik. In 1932 pik published a paper examining what happened to meteors or comets scattered to very large distances from the Sun, where they could be perturbed by random passing stars. He showed that the gravitational tugs from the stars would raise the perihelion distances of most objects to beyond the most distant planet. Thus, he predicted that there would be a cloud of comets surrounding the solar system. However, pik said little about the comets returning to the planetary region, other than that some comets could be thrown into the Sun by the stars during their evolution outward to the cloud. Indeed, pik concluded:

comets of an aphelion distance exceeding 10,000 a.u., are not very likely to occur among the observable objects, because of the rapid increase of the average perihelion distance due to stellar perturbations.

pik also failed to make any comparison between his results and the known original orbits of the long-period comets.

Oorts paper, published in 1950, revolutionized the field of cometary dynamics. Two months later a paper on the nature of the cometary nucleus by Fred Whipple would do the same for cometary physics. Whipple combined many of the ideas of the day and suggested that the cometary nucleus was a solid body made up of volatile ices and meteoritic material. That was called the icy conglomerate model but also became more popularly known as the dirty snowball.

Whipple provided proof for his model in the form of the shrinking orbit of Enckes Comet. Whipple believed that, as Bessel had suggested, rocket forces from sublimating ices on the sunlit side of the nucleus would alter the comets orbit. For a nonrotating solid nucleus, the force would push the nucleus away from the Sun, appearing to lessen the effect of gravity. But if the comet nucleus was rotating (as most solar system bodies do) and if the rotation pole was not perpendicular to the plane of the comets orbit, both tangential forces (forward or backward along the comets direction of motion) and out-of-plane forces (up or down) could result. The effect was helped by the thermal lag caused by the Sun continuing to heat the nucleus surface after local noontime, just as temperatures on Earth are usually at their maximum a few hours after local noon.

Thus, Whipple explained the slow shrinking of Enckes orbit as the result of tangential forces that were pointed opposite to the comets direction of motion, causing the comet nucleus to slow down, slowly shrinking the orbit. That model also explained periodic comets whose orbits were growing, such as DArrest and Wolf 1, depending on the direction of the nucleis rotation poles and the direction in which the nuclei were rotating. Because the rocket force results from the high activity of the comet nucleus near perihelion, the force does not change the perihelion distance but rather the aphelion distance, either raising or lowering it.

Whipple also pointed out that the loss of cometary ices would leave a layer of nonvolatile material on the surface of the nucleus, making sublimation more difficult, as the heat from the Sun needed to filter down through multiple layers to where there were fresh ices. Furthermore, Whipple suggested that the solar systems zodiacal dust cloud came from dust released by comets as they passed through the planetary system.

Whipples ideas set off an intense debate over whether the nucleus was a solid body or not. Many scientists still advocated Lyttletons idea of a sandbank nucleus, simply a cloud of meteoritic material with adsorbed gases. The question would not be put definitively to rest until the first spacecraft encounters with Halleys Comet in 1986.

Solid proof for Whipples nongravitational force model came from English astronomer Brian Marsden, a colleague of Whipples at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts. Marsden was an expert on comet and asteroid orbits and tested Whipples icy conglomerate model against the orbits of many known comets. Using a computer program that determined the orbits of comets and asteroids from observations, Marsden added a term for the expected rocket effect when the comet was active. In this he was aided by Belgian astronomer Armand Delsemme, who carefully calculated the rate of water ice sublimation as a function of a comets distance from the Sun.

When one calculates an orbit for an object, the calculation usually does not fit all the observed positions of the object perfectly. Small errors creep into the observed positions for many reasons, such as not knowing the exact time of the observations or finding the positions using an out-of-date star catalog. So every orbit fit has a mean residual, which is the average difference between the observations and the comets predicted position based on the newly determined orbit. Mean residuals of less than about 1.5 arc seconds are considered a good fit.

When Marsden calculated the comet orbits, he found that he could obtain smaller mean residuals if he included the rocket force in his calculations. Marsden found that for a short-period comet, the magnitude of the rocket force was typically only a few hundred-thousandths of the solar gravitational attraction, but that was enough to change the time when the comet would return. Later, Marsden and colleagues computed the rocket forces for long-period comets and found that there too the mean residuals were reduced. For the long-period comets, the rocket force was typically a few ten-thousandths of the solar gravitational attraction. Long-period comets tend to be far more active than short-period comets, and thus for them the force is larger.

A further interesting result of Marsdens work was that when he performed his calculations on apparently hyperbolic comet orbits, the resulting eccentricities often changed from hyperbolic to elliptical. Very few comets were left with hyperbolic original orbits, and all of those were only slightly hyperbolic. Marsden had provided further proof that all long-period comets were members of the solar system.

In 1951 the Dutch American astronomer Gerard Kuiper published an important paper on where the comets had formed. Kuiper was studying the origin of the solar system and suggested that the volatile molecules, radicals, and ions observed in cometary comae and tails (e.g., CH, NH, OH, CN, CO+, CO2+, N2+) must come from ices frozen in the solid nucleus (e.g., CH4, NH3, H2O, HCN, CO, CO2, and N2). But those ices could only condense in the solar nebula where it was very cold. So he suggested that comets had formed at 3850 AU from the Sun, where mean temperatures were only about 3045 K (243 to 228 C, or 406 to 379 F).

Kuiper suggested that the solar nebula did not end at the orbit of what was then considered the most distant planet, Pluto, at about 39 AU, but that it continued on to about 50 AU. He believed that at those large distances from the Sun neither the density of solar nebula material nor the time was enough to form another planet. Rather, he suggested that there would be a belt of smaller bodiesi.e., cometsbetween 38 and 50 AU. He also suggested that Pluto would dynamically eject comets from that region to distant orbits, forming the Oort cloud.

Astronomers have since discovered that Pluto is too small to have done that job (or even to be considered a planet), and it is really Neptune at 30 AU that defines the outer boundary of the planetary system. Neptune is large enough to slowly scatter comets both inward to short-period orbits and outward to the Oort cloud, along with some help from the other giant planets.

Kuipers 1951 paper did not achieve the same fame as those by Oort and Whipple in 1950, but astronomers occasionally followed up his ideas. In 1968 Egyptian astronomer Salah Hamid worked with Whipple and Marsden to study the orbits of seven comets that passed near the region of Kuipers hypothetical comet belt beyond Neptune. They found no evidence of gravitational perturbations from the belt and set upper limits on the mass of the belt of 0.5 Earth masses out to 40 AU and 1.3 Earth masses out to 50 AU.

The situation changed in 1980 when Uruguayan astronomer Julio Fernndez suggested that a comet belt beyond Neptune would be a good source for the short-period comets. Up until that time it was thought that short-period comets were long-period comets from the Oort cloud that had dynamically evolved to short-period orbits because of planetary perturbations, primarily by Jupiter. But astronomers who tried to simulate that process on computers found that it was very inefficient and likely could not supply new short-period comets fast enough to replace the existing ones that either were disrupted, faded away, or were perturbed out of the planetary region.

Fernndez recognized that a key element in understanding the short-period comets was their relatively low-inclination orbits. Typical short-period comets have orbital inclinations up to about 35, whereas long-period comets have completely random orbital inclinations from 0 to 180. Fernndez suggested that the easiest way to produce a low-inclination short-period comet population was to start with a source that had a relatively low inclination. Kuipers hypothesized comet belt beyond Neptune fit this requirement. Fernndez used dynamical simulations to show how comets could be perturbed by larger bodies in the comet belt, on the order of the size of Ceres, the largest asteroid (diameter of about 940 km [580 miles]), and be sent into orbits that could encounter Neptune. Neptune then could pass about half of the comets inward to Uranus, with the other half being sent outward to the Oort cloud. In that manner, comets could be handed down to each giant planet and finally to Jupiter, which placed the comets in short-period orbits.

Fernndezs paper renewed interest in a possible comet belt beyond Neptune. In 1988 American astronomer Martin Duncan and Canadian astronomers Thomas Quinn and Scott Tremaine built a more complex computer simulation of the trans-Neptunian comet belt and again showed that it was the likely source of the short-period comets. They also proposed that the belt be named in honour of Gerard Kuiper, based on the predictions of his 1951 paper. As fate would have it, the distant comet belt had also been predicted in two lesser-known papers in 1943 and 1949 by a retired Irish army officer and astronomer, Kenneth Edgeworth. Therefore, some scientists refer to the comet belt as the Kuiper belt, while others call it the Edgeworth-Kuiper belt.

Astronomers at observatories began to search for the distant objects. In 1992 they were finally rewarded when British astronomer David Jewitt and Vietnamese American astronomer Jane Luu found an object well beyond Neptune in an orbit with a semimajor axis of 43.9 AU, an eccentricity of only 0.0678, and an inclination of only 2.19. The object, officially designated (15760) 1992 QB1, has a diameter of about 200 km (120 miles). Since 1992 more than 1,500 objects have been found in the Kuiper belt, some almost as large as Pluto. In fact, it was the discovery of that swarm of bodies beyond Neptune that led to Pluto being recognized in 2006 as simply one of the largest bodies in the swarm and no longer a planet. (The same thing happened to the largest asteroid Ceres in the mid-19th century when it was recognized as simply the largest body in the asteroid belt and not a true planet.)

In 1977 American astronomer Charles Kowal discovered an unusual object orbiting the Sun among the giant planets. Named 2060 Chiron, it is about 200 km (120 miles) in diameter and has a low-inclination orbit that stretches from 8.3 AU (inside the orbit of Saturn) to 18.85 AU (just inside the orbit of Uranus). Because it can make close approaches to those two giant planets, the orbit is unstable on a time span of several million years. Thus, Chiron likely came from somewhere else. Even more interesting, several years later Chiron began to display a cometary coma even though it was still very far from the Sun. Chiron is one of a few objects that appear in both asteroid and comet catalogs; in the latter it is designated 95 P/Chiron.

Chiron was the first of a new class of objects in giant-planet-crossing orbits to be discovered. The searches for Kuiper belt objects have also led to the discovery of many similar objects orbiting the Sun among the giant planets. Collectively they are now known as the Centaur objects. About 300 such objects have now been found, and more than a few also show sporadic cometary activity.

The Centaurs appear to be objects that are slowly diffusing into the planetary region from the Kuiper belt. Some will eventually be seen as short-period comets, while most others will be thrown into long-period orbits or even ejected to interstellar space.

In 1996 European astronomers Eric Elst and Guido Pizarro found a new comet, which was designated 133P/Elst-Pizarro. But when the orbit of the comet was determined, it was found to lie in the outer asteroid belt with a semimajor axis of 3.16 AU, an eccentricity of 0.162, and an inclination of only 1.39. A search of older records showed that 133P had been observed previously in 1979 as an inactive asteroid. So it is another object that was catalogued as both a comet and an asteroid.

The explanation for 133P was that, given its position in the asteroid belt, where maximum solar surface temperatures are only about 48 C (54 F), it likely acquired some water in the form of ice from the solar nebula. Like in comets, the ices near the surface of 133P sublimated early in its history, leaving an insulating layer of nonvolatile material covering the ice at depth. Then a random impact from a piece of asteroidal debris punched through the insulating layer and exposed the buried ice. Comet 133P has shown regular activity at the same location in its orbit for at least three orbits since it was discovered.

Twelve additional objects in asteroidal orbits have been discovered since that time, most of them also in the outer main belt. They are sometimes referred to as main belt comets, though the more recently accepted term is active asteroids.

The latter half of the 20th century saw a massive leap forward in the understanding of the solar system as a result of spacecraft visits to the planets and their satellites. Those spacecraft collected a wealth of scientific data close up and in situ. The anticipated return of Halleys Comet in 1986 provided substantial motivation to begin using spacecraft to study comets.

The first comet mission (of a sort) was the International Cometary Explorer (ICE) spacecrafts encounter with Comet 21P/Giacobini-Zinner on September 11, 1985. The mission had originally been launched as part of a joint project by the U.S. National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) known as the International Sun-Earth Explorer (ISEE). The mission consisted of three spacecraft, two of them, ISEE-1 and -2, in Earth orbit and the third, ISEE-3, positioned in a heliocentric orbit between Earth and the Sun, studying the solar wind in Earths vicinity.

In 1982 and 1983 engineers maneuvered ISEE-3 to accomplish several gravity-assist encounters with the Moon, which put it on a trajectory to encounter 21P/Giacobini-Zinner. The spacecraft was targeted to pass through the ion tail of the comet, about 7,800 km (4,800 miles) behind the nucleus at a relative velocity of 21 km (13 miles) per second, and returned the first in situ measurements of the magnetic field, plasma, and energetic particle environment inside a comets tail. Those measurements confirmed the model of the comets ion tail first put forward in 1957 by the Swedish physicist (and later Nobel Prize winner) Hannes Alfvn. It also showed that H2O+ was the most common ion in the plasma tail, consistent with the Whipple model of an icy conglomerate nucleus. However, ICE carried no instruments to study the nucleus or coma of the comet.

In 1986 five spacecraft were sent to encounter Halleys Comet. They were informally known as the Halley Armada and consisted of two Japanese spacecraft, Suisei and Sakigake (Japanese for comet and pioneer, respectively); two Soviet spacecraft, Vega 1 and 2 (a contraction of Venus-Halley using Cyrillic spelling); and an ESA spacecraft, Giotto (named after the Italian painter who depicted the Star of Bethlehem as a comet in a fresco painted in 130506).

Suisei flew by Halley on March 8, 1986, at a distance of 151,000 km (94,000 miles) on the sunward side and produced ultraviolet images of the comets hydrogen corona, an extension of the visible coma seen only in ultraviolet light. It also measured the energetic particle environment in the solar wind ahead of the comet. Sakigakes closest approach to the comet was on March 11, 1986, at a distance of 6.99 million km (4.34 million miles), and it made additional measurements of the solar wind.

Before flying past Halleys Comet, the two Soviet spacecraft had flown by Venus and had each dropped off landers and balloons to study that planet. Vega 1 flew through the Halley coma on March 6, 1986, to within 8,889 km (5,523 miles) of the nucleus and made numerous measurements of the coma gas and dust composition, plasma and energetic particles, and magnetic field environment. It also returned the first picture ever of a solid cometary nucleus. Unfortunately, the camera was slightly out of focus and had other technical problems that required considerable image processing to see the nucleus. Vega 2 fared much better when it flew through the Halley coma on March 9 to within 8,030 km (4,990 miles) of the nucleus, and its images clearly showed a peanut-shaped nucleus about 16 by 8 km (10 by 5 miles) in diameter. The nucleus was also very dark, reflecting only about 4 percent of the incident sunlight, which had already been established from Earth-based observations.

Both Vega spacecraft carried infrared spectrometers designed to measure the temperature of the Halley nucleus. They found quite warm temperatures between 320 and 400 K (47 and 127 C [116 and 260 F]). That surprised many scientists who had predicted that the effect of water ice sublimation would be to cool the nucleuss surface; water ice requires a great deal of heat to sublimate. The high temperatures suggested that much of the nucleuss surface was not sublimating, but why?

Whipples classic paper in 1950 had suggested that as comets lost material from the surface, some particles were too heavy to escape the weak gravity of the nucleus and fell back onto the surface, forming a lag deposit. That idea was later studied by American astronomer and author David Brin in his thesis work with his adviser, Sri Lankan physicist Asoka Mendis, in 1979. As the lag deposit built up, it would effectively insulate the icy materials below it from sunlight. Calculations showed that a layer only 10100 cm (439 inches) in thickness could completely turn off sublimation from the surface. Brin and Mendis predicted that Halley would be so active that it would blow away any lag deposit, but that was not the case. Only about 30 percent of Halleys sunlit hemisphere was active. Bright dust jets could be seen coming from specific areas on the nucleus surface, but much of the surface showed no visible activity.

Giotto flew through Halleys coma on March 14, 1986, and passed only 596 km (370 miles) from the nucleus. It returned the highest-resolution images of the nucleus and showed a very rugged terrain with mountain peaks jutting up hundreds of metres from the surface. It also showed the same peanut shape that Vega 2 saw but from a different viewing angle and with much greater visible detail. Discrete dust jets were coming off the nucleus surface, but the resolution was not good enough to reveal the source of the jets.

Giotto and both Vega spacecraft obtained numerous measurements of the dust and gas in the coma. Dust particles came in two types: silicate and organic. The silicate grains were typical of rocks found on Earth such as forsterite (Mg2SiO4), a high-temperature mineralthat is, one which would be among the first to condense out of the hot solar nebula. Analyses of other grains showed that the comet was far richer in magnesium relative to iron. The organic grains were composed solely of the elements carbon, hydrogen, oxygen, and nitrogen and were called CHON grains based on the chemical symbol for each of those elements. Larger grains were also detected that were combinations of silicate and CHON grains, supporting the view that comet nuclei had accreted from the slow aggregation of tiny particles in the solar nebula.

The three spacecraft also measured gases in the coma, water being the dominant molecule but also carbon monoxide accounting for about 7 percent of the gas relative to water. Formaldehyde, carbon dioxide, and hydrogen cyanide were also detected at a few percent relative to water.

The Halley Armada was a rousing success and resulted from international cooperation by many nations. Its success is even more impressive when one considers that the spacecraft all flew by the Halley nucleus at velocities ranging from 68 to 79 km per second (152,000 to 177,000 miles per hour). (The velocities were so high because Halleys retrograde orbit had it going around the Sun in the opposite direction from the spacecraft.)

Giotto was later retargeted using assists from Earths gravity to pass within about 200 km (120 miles) of the nucleus of the comet 26P/Grigg-Skjellrup. The flyby was successful, but some of the scientific instruments, including the camera, were no longer working after being sandblasted at Halley.

The next comet mission was not until 1998, when NASA launched Deep Space 1, a spacecraft designed to test a variety of new technologies. After flying past the asteroid 9969 Braille in 1999, Deep Space 1 was retargeted to fly past the comet 19P/Borrelly on September 22, 2001. Images of the Borrelly nucleus showed it to be shaped like a bowling pin, with very rugged terrain on parts of its surface and mesa-like formations over a large area of it. Individual dust and gas jets were seen emanating from the surface, but the activity was far less than that of Halleys Comet.

The NASA Stardust mission was launched in 1999 with the goal of collecting samples of dust from the coma of Comet 81P/Wild 2. At a flyby speed of 6.1 km per second (13,600 miles per hour), the dust samples would be completely destroyed by impact with a hard collector. Therefore, Stardust used a material made of silica (sand) called aerogel that had a very low density, approaching that of air. The idea was that the aerogel would slow the dust particles without destroying them, much as a detective might shoot a bullet into a box full of cotton in order to collect the undamaged bullet. It worked, and thousands of fine dust particles were returned to Earth in 2006. Perhaps the biggest surprise was that the sample contained high-temperature materials that must have formed much closer to the Sun than where the comets formed in the outer solar system. That unexpected result meant that material in the solar nebula had been mixed, at least from the inside outward, during the formation of the planets.

Stardusts images of the nucleus of Wild 2 showed a surface that was radically different from either Halley or Borrelly. The surface appeared to be covered with large flat-floored depressions. Those were likely not impact craters, as they did not have the correct morphology and there were far too many large ones. There was some suggestion that it was a very new cometary surface on a nucleus that had not been close to the Sun before. Support for that was the fact that Wild 2 had been placed into its current orbit by a close Jupiter approach in 1974, reducing the perihelion distance to about 1.5 AU (224 million km, or 139 million miles). Before the Jupiter encounter, its perihelion was 4.9 AU (733 million km, or 455 million miles), beyond the region where water ice sublimation is significant.

In 2002 NASA launched a mission called Contour (Comet Nucleus Tour) that was to fly by Enckes Comet and 73P/Schwassman-Wachmann 3 and possibly continue on to 6P/DArrest. Unfortunately, the spacecraft structure failed when leaving Earth orbit.

In 2005 NASA launched yet another comet mission, called Deep Impact. It consisted of two spacecraft, a mother spacecraft that would fly by Comet 9P/Tempel 1 and a daughter spacecraft that would be deliberately crashed into the comet nucleus. The mother spacecraft would take images of the impact. The daughter spacecraft contained its own camera system to image the nucleus surface up to the moment of impact. To maximize the effect of the impact, the daughter spacecraft contained 360 kg (794 pounds) of solid copper. The predicted impact energy was equivalent to 4.8 tonnes of TNT.

The two spacecraft encountered Tempel 1 on July 4, 2005. The impactor produced the highest-resolution pictures of a nucleus surface ever, imaging details less than 10 metres (33 feet) in size. The mother spacecraft watched the explosion and saw a huge cloud of dust and gas emitted from the nucleus. One of the mission goals was to image the crater made by the explosion, but the dust cloud was so thick that the nucleus surface could not be seen through it. Because the mission was a flyby, the mother spacecraft could not wait around for the dust to clear.

Images of the Tempel 1 nucleus were very different from what had been seen before. The surface appeared to be old, with examples of geologic processes having occurred. There was evidence of dust flows across the nucleus surface and what appeared to be two modest-sized impact craters. There was evidence of material having been eroded away. For the first time, icy patches were discovered in some small areas of the nucleus surface.

For the first time, a mission was also able to measure the mass and density of a cometary nucleus. Typically, the nuclei are too small and their gravity too weak to affect the trajectory of the flyby spacecraft. The same was true for Tempel 1, but observations of the expanding dust cloud from the impact could be modeled so as to solve for the nucleus gravity. When combined with the volume of the nucleus as obtained from the camera images, it was shown that the Tempel 1 nucleus had a bulk density between 0.2 and 1.0 gram per cubic centimetre with a preferred value of 0.4 gram per cubic centimetre, less than half that of water ice. The measurement clearly confirmed ideas from telescopic research that comets were not very dense.

After the great success of Stardust and Deep Impact, NASA had additional plans for the spacecraft. Stardust was retargeted to go to Tempel 1 and image the crater from the Deep Impact explosion as well as more of the nucleus surface not seen on the first flyby. Deep Impact was retargeted to fly past 103P/Hartley 2, a small but very active comet.

Deep Impact, in its postimpact EPOXI mission, flew past Comet Hartley 2 on November 4, 2010. It imaged a small nucleus about 2.3 km (1.4 miles) in length and 0.9 km (0.6 mile) wide. As with Halley and Borrelly, the nucleus appeared to be two bodies stuck together, each having rough terrain but covered with very fine, smooth material at the neck where they came together. The most amazing result was that the smaller of the two bodies making up the nucleus was far more active than the larger one. The activity on the smaller body appeared to be driven by CO2 sublimationan unexpected result, given that short-period comets are expected to lose their near-surface CO2 early during their many passages close to the Sun. The other half of the nucleus was far less active and only showed evidence of water ice sublimation. The active half of the comet also appeared to be flinging baseball- to basketball-sized chunks of water ice into the coma, further enhancing the gas production from the comet as they sublimated away.

The EPOXI images also showed that the nucleus was not rotating smoothly but was in complex rotationa state where the comet nucleus rotates but the direction of the rotation pole precesses rapidly, drawing a large circle on the sky. Hartley 2 was the first encountered comet to exhibit complex rotation. It was likely driven by the very high activity from the smaller half of the nucleus, putting large torques on the nucleus rotation.

Stardust/NExT (New Exploration of Tempel 1) flew past Tempel 1 on February 14, 2011, and it imaged the spot where the Deep Impact daughter spacecraft had struck the nucleus. Some scientists believed that they saw evidence of a crater about 150 metres (500 feet) in diameter, but other scientists looked at the same images and saw no clear evidence of a crater. Some of the ambiguity was due to the fact that the Stardust camera was not as sharp as the Deep Impact cameras, and some of it was also due to the fact that sunlight was illuminating the nucleus from a different direction. The debate over whether there was a recognizable crater lingers on.

Among the new areas observed by Stardust-NeXT there was further evidence of geologic processes, including layered terrains. Using stereographic imaging, the scientists traced dust jets observed in the coma back to the nucleus surface, and they appeared to originate from some of the layered terrain. Again, the resolution of the images was not good enough to understand why the jets were coming from that area.

In 2004 ESA launched Rosetta (named after the Rosetta Stone, which had unlocked the secret of Egyptian hieroglyphics) on a trajectory to Comet 67P/Churyumov-Gerasimenko (67P). Rendezvous with 67P took place on August 6, 2014. Along the way, Rosetta successfully flew by the asteroids 2849 Steins and 21 Lutetia and obtained considerable scientific data. Rosetta uses 11 scientific instruments to study the nucleus, coma, and solar wind interaction. Unlike previous comet missions, Rosetta will orbit the nucleus until December 2015, providing a complete view of the comet as activity begins, reaches a maximum at perihelion, and then wanes. Rosetta carried a spacecraft called Philae that landed on the nucleus surface on November 12, 2014. Philae drilled into the nucleus surface to collect samples of the nucleus and analyze them in situ. As the first mission to orbit and land on a cometary nucleus, Rosetta is expected to answer many questions about the sources of cometary activity.

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comet | Definition, Composition, & Facts | Britannica.com

In Depth | Comets Solar System Exploration: NASA Science

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OverviewIn the distant past, people were both awed and alarmed by comets, perceiving them as long-haired stars that appeared in the sky unannounced and unpredictably. Chinese astronomers kept extensive records for centuries, including illustrations of characteristic types of comet tails, times of cometary appearances and disappearances, and celestial positions. These historic comet annals have proven to be a valuable resource for later astronomers.

We now know that comets are leftovers from the dawn of our solar system around 4.6 billion years ago, and consist mostly of ice coated with dark organic material. They have been referred to as "dirty snowballs." They may yield important clues about the formation of our solar system. Comets may have brought water and organic compounds, the building blocks of life, to the early Earth and other parts of the solar system.

Where Do Comets Come From?

As theorized by astronomer Gerard Kuiper in 1951, a disc-like belt of icy bodies exists beyond Neptune, where a population of dark comets orbits the Sun in the realm of Pluto. These icy objects, occasionally pushed by gravity into orbits bringing them closer to the Sun, become the so-called short-period comets. Taking less than 200 years to orbit the Sun, in many cases their appearance is predictable because they have passed by before. Less predictable are long-period comets, many of which arrive from a region called the Oort Cloud about 100,000 astronomical units (that is, about 100,000 times the distance between Earth and the Sun) from the Sun. These Oort Cloud comets can take as long as 30 million years to complete one trip around the Sun.

Each comet has a tiny frozen part, called a nucleus, often no larger than a few kilometers across. The nucleus contains icy chunks, frozen gases with bits of embedded dust. A comet warms up as it nears the Sun and develops an atmosphere, or coma. The Sun's heat causes the comet's ices to change to gases so the coma gets larger. The coma may extend hundreds of thousands of kilometers. The pressure of sunlight and high-speed solar particles (solar wind) can blow the coma dust and gas away from the Sun, sometimes forming a long, bright tail. Comets actually have two tailsa dust tail and an ion (gas) tail.

Most comets travel a safe distance from the Suncomet Halley comes no closer than 89 million kilometers (55 million miles). However, some comets, called sungrazers, crash straight into the Sun or get so close that they break up and evaporate.

Exploration of Comets

Scientists have long wanted to study comets in some detail, tantalized by the few 1986 images of comet Halley's nucleus. NASA's Deep Space 1 spacecraft flew by comet Borrelly in 2001 and photographed its nucleus, which is about 8 kilometers (5 miles) long.

NASA's Stardust mission successfully flew within 236 kilometers (147 miles) of the nucleus of Comet Wild 2 in January 2004, collecting cometary particles and interstellar dust for a sample return to Earth in 2006. The photographs taken during this close flyby of a comet nucleus show jets of dust and a rugged, textured surface. Analysis of the Stardust samples suggests that comets may be more complex than originally thought. Minerals formed near the Sun or other stars were found in the samples, suggesting that materials from the inner regions of the solar system traveled to the outer regions where comets formed.

Another NASA mission, Deep Impact, consisted of a flyby spacecraft and an impactor. In July 2005, the impactor was released into the path of the nucleus of comet Tempel 1 in a planned collision, which vaporized the impactor and ejected massive amounts of fine, powdery material from beneath the comet's surface. En route to impact, the impactor camera imaged the comet in increasing detail. Two cameras and a spectrometer on the flyby spacecraft recorded the dramatic excavation that helped determine the interior composition and structure of the nucleus.

After their successful primary missions, the Deep Impact spacecraft and the Stardust spacecraft were still healthy and were retargeted for additional cometary flybys. Deep Impact's mission, EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation), comprised two projects: the Deep Impact Extended Investigation (DIXI), which encountered comet Hartley 2 in November 2010, and the Extrasolar Planet Observation and Characterization (EPOCh) investigation, which searched for Earth-size planets around other stars on route to Hartley 2. NASA returned to comet Tempel 1 in 2011, when the Stardust New Exploration of Tempel 1 (NExT) mission observed changes in the nucleus since Deep Impact's 2005 encounter.

How Comets Get Their Names

Comet naming can be complicated. Comets are generally named for their discoverereither a person or a spacecraft. This International Astronomical Union guideline was developed only in the last century. For example, comet Shoemaker-Levy 9 was so named because it was the ninth short-periodic comet discovered by Eugene and Carolyn Shoemaker and David Levy. Since spacecraft are very effective at spotting comets many comets have LINEAR, SOHO or WISE in their names.

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In Depth | Comets Solar System Exploration: NASA Science

What is Jitsi? – open source video conferencing API’s …

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Jitsi is a set of open-source projects that allows you to easily build and deploy secure videoconferencing solutions. At the heart of Jitsi are Jitsi Videobridge and Jitsi Meet, which let you have conferences on the internet, while other projects in the community enable other features such as audio, dial-in, recording, and simulcasting.

Jitsi started life as a way to talk to people over the internet using audio and video. Over the course of a decade, though, its become so much more. Today, Jitsi is:

A vibrant developer community.

First and foremost, Jitsi is a community of developers that are pushing the envelope of video conferencing quality on the web. Come join us!

The foundation of some really amazing products.

Our community members have developed countless projects and products that started with Jitsi code. Check em out!

A crazy-good, completely free video conferencing solution that anyone can use.

Jitsi is a favorite videoconferencing solution for anyone with privacy concerns, journalists, for example. Theres a reason so many people use Jitsi Meet as a Skype alternative for video conferencing. Try it out and download it for free.

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Oceania – Simple English Wikipedia, the free encyclopedia

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Oceania is a name used in geography for the region made up of Australia, New Zealand, New Guinea, and several other island nations in the surrounding area. Some people call this part of the world Australasia instead.

The term "Oceania" does not have one single agreed definition. In politics (United Nations etc.), it includes Australia and the nations of the Pacific from Papua New Guinea east, but not the Malay Archipelago or Indonesian New Guinea.

The widest definition of Oceania includes the entire region between continental Asia and the Americas, including islands in the Pacific Rim such as the Japanese archipelago, Taiwan, and the Aleutian islands. On the other hand, the Oceania ecozone includes all of Micronesia, Fiji, and all of Polynesia except New Zealand.

Sometimes, people use the term 'Oceania' to include only the Polynesian and Melanesian islands in the Pacific Ocean, as separate from Australasia.

For these reasons, it is not correct to say that Australasia is part of Oceania, because what is meant by 'Oceania' is not clear. Australasia has an exact definition in biogeography and geology. Australasia includes New Zealand, Australia (including Tasmania), and Melanesia, New Guinea, and the islands just north and east of Australia. All these are south-east of the BaliLombok line. This is known as the Wallace Line, after Alfred Russel Wallace.

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U.S. Decision To Cut Central America Aid Could Worsen …

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President Trump says he will close the United States' Southern border, or large sections of it, next week if Mexico does not immediately stop illegal immigration. Here Trump speaks to reporters during a visit to Lake Okeechobee and Herbert Hoover Dike at Canal Point, Fla., on Friday. Manuel Balce Ceneta/AP hide caption

President Trump says he will close the United States' Southern border, or large sections of it, next week if Mexico does not immediately stop illegal immigration. Here Trump speaks to reporters during a visit to Lake Okeechobee and Herbert Hoover Dike at Canal Point, Fla., on Friday.

Updated at 5:13 p.m. ET

President Trump's call to cut aid to El Salvador, Guatemala and Honduras is raising concerns among lawmakers and national security and development experts, who say cutting aid will exacerbate the migrant crisis that is already crippling U.S. resources at the Southern border.

A spokesperson for the U.S. Agency for International Development told NPR on Tuesday that the agency is carrying out the president's order to end foreign assistance programs for the Northern Triangle, the area that comprises those three Central American nations. The spokesperson said the agency is still finalizing the allocation of funds for 2019.

Trump has blamed the Central American countries for sending migrant caravans through Mexico to the U.S. border, an idea Trump has repeatedly promoted to raise the alarm about illegal immigration. In tweets on Saturday, Trump also returned to his previous threat to completely seal off the Southern border, blaming Democrats and Mexico for the turmoil at the border.

In an interview on CNN on Sunday, acting White House Chief of Staff Mick Mulvaney defended the administration's decision to stop aid, claiming U.S. funding to Central America isn't doing enough to stifle the recent spike in migrants coming from the region.

"The people say it's working, but the proof is in the numbers. It's not working well enough to help us solve our border crisis, and that's what the president is focused on," Mulvaney said. "And if we're going to give these countries hundreds of millions of dollars, we would like them to do more."

The U.S. has allocated $2.1 billion in aid to Central America since 2016, according to a report this year by the Congressional Research Service. Aid to Central America greatly increased under the Obama administration to promote economic prosperity and reduce violence in the region, with the idea being that achieving those two goals would mean fewer people would need to flee to the United States.

Former Secretary of Homeland Security Jeh Johnson says that this investment is "beginning to show positive signs."

"Suspending aid to Central America, as President Trump has threatened to do, in my judgment, is the exact wrong thing to do," he told Morning Edition.

Much of the appropriated funding isn't sent directly to governments. Instead, it is sent to nonprofits and nongovernmental organizations that are working to deal with the root causes of migration, according to NPR international correspondent Carrie Kahn, who's based in Mexico City. The funds have supported efforts such as strengthening police forces, border security and judicial systems, as well as gang prevention and food security programs.

Aid groups worry that suddenly slashing funds will have big repercussions, according to Ken Baker, CEO of Glasswing, a nonprofit group working in Central America.

"One of the things that has been talked about is how, you know, that [these countries] aren't doing enough. But they really do work with us," Baker says. "They do work with the U.S. government. It is in their interests."

Many experts say it's too soon to determine whether those programs are working, but in El Salvador, officials have praised the country's cooperation with the U.S. for dramatically reducing migration. The number of Salvadorans detained at the U.S. border dropped by more than half, down from nearly 72,000 in 2016 to more than 31,000 in 2018, according to U.S. Border Patrol data.

"The decision to cut funding contradicts the results of what we have accomplished together," Ral Lpez, El Salvador's vice minister of justice, said Monday. "The fact is that migration from El Salvador is declining, thanks to our work."

The U.S. Global Leadership Coalition, a nonprofit that supports diplomacy in the U.S., found that in areas where the U.S. Agency for International Development worked in El Salvador, the homicide rate dropped by 45 percent on average from 2015 to 2017.

When homicides spike, so does migration. For every 10 murders in El Salvador, Guatemala and Honduras, six children leave for the United States.

Liz Schrayer, president of the U.S. Global Leadership Coalition, told Here & Now's Robin Young that more work needs to be done in the region to hold these countries accountable and to support active diplomacy. But she warns that without aid programs, the migrant crisis will worsen.

"One thing we should not be doing is pulling out our aid programs. If we do that, it's only going to exacerbate the unrest," she says. "People will leave if the violence continues, if they don't have economic opportunities and if they can't put food on their table."

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