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An Extra Special Pretty For You

Posted on November 14, 2010 by Danzig

Take a look at this time-lapse video by Dustin Farrell:

Click here to view the embedded video.

It is a compilation of his own work, mostly taken in and around his home state of Arizona. Each clip was a RAW image sequence (5616 X 3744) which he then rendered out as a 1080P 23.976fps Quick Time movie.

Dustin has some of his stills featured on his website, and they are breathtaking. I especially like this one:

Astrophotography is not an easy skill to master, by any means, and these stand out even in that rarefied atmosphere. If you have a free minute, do browse Dustin’s website.

As always, if you have a question for Dustin, post it to the comments and I’ll forward them to him.

Thanks for sharing, Dustin!

What the Heck Was That?!

Posted on November 14, 2010 by Danzig

Click here to view the embedded video.

What the heck? Apparently a missile launch off the California coast yesterday.

At the moment everybody is saying:

I SEE NOTHING, I HEAR NOTHING, I KNOW NOTHING.

The Moons of Jupiter

Posted on November 14, 2010 by Danzig

Moons of Jupiter. Click for larger. Credit: findtarget.com

It is said that on a January night in the year 1610 Galileo turned his telescope towards Jupiter and he saw “three fixed stars, totally invisible by their smallness”. Thoroughly intrigued subsequent observations on different nights showed the “fixed stars” indeed moved, sometimes even disappearing. He discovered a fourth moon a week after the initial observation.

How could this be? Well of course he came to the conclusion they were orbiting Jupiter. He published his observations in pretty short order, in March 1610 in a paper titled Sidereus Nuncius or Starry Messenger. The observations were confirmed in 1611 at the observatory of Christopher Clavius.

Galileo may have received a hero’s welcome in Rome and had fame in much of Europe the thought of him turning the comfort of Aristotelian Cosmology on it’s ear did nothing for his standing with the church and it wasn’t too many years later his troubles began.

Instead of plowing ahead with his troubles let’s get back to his telescope. The telescope was invented in 1608 by Dutch spectacle makers, supposedly the inventor was Hans Lipperhey but nobody can prove it. In early 1609 you could buy one in Paris and by August of that year they made their way to Italy. Galileo couldn’t get his hands on one but being the resourceful fellow and after he overcame some technical problems, he put his knowledge about lens making to work and he just made his own.

So what does this have to do with anything? What Galileo could see with that 20 power telescope you can see with a pair of binoculars and I would like to suggest you take a look at Jupiter over the coming nights and look at Io, Europa, Ganymede and Callisto and note how they move. Jupiter is super easy to find, just look south (almost due south at 8 pm your local time) it’s the brightest thing out there. Oh sure if you make a sketch you can even figure out which moon is which quite easily on a number of sites, one of my favorites is at Western Washington University – simple and clean.

Also while you are at it, okay, a little later in the night or early morning look for comet Hartley 2, it’s a great time because there is no moon. Basically wait until you can see Orion, then look along a line from Orion’s belt and draw a line from Gemini, the comet will be in that area. Here’s a little chart to help you.

Thoughts on Hind’s Crimson Star

Posted on November 14, 2010 by Danzig

The subject of Saturday’s riddle, Hind’s Crimson Star (R Leporis) is a Mira variable carbon star in the constellation Lepus. Described in 1845 by astronomer J.R. Hind, R Lep is often cited as being one of the most beautiful of the ruby-esque carbon stars.

The constellation Lepus - by Torsten Bronger

With an apparent magnitude variance of +5.5 to +11.7 in an approximate 430 day cycle, R Lep appears the most crimson during the time its magnitude is dimmest. This is probably due to variations in the amount of carbon in the star’s outer atmosphere. The more carbon present, the more blue light is filtered from the visible light spectrum.

R Leporis, image by Adam Block/NOAO/AURA/NSF

Described as a “drop of blood on a black field”, a “glowing red coal”, and a ruby (of course), R Lep is said to eclipse even the ruddy Betelgeuse and Antares. Easily visible with binoculars or a small telescope, this beauty is a sight worth the search. Lepus (the “Hare”) is located south of Orion, and is best seen mid-January. You’ll have the added bonus of viewing T Leporis and M79.

Lepus - R Leporis is in the center, Mu Leporis is in the lower left

Let me know what you think of it when you find it.

A Video Two-fer

Posted on November 14, 2010 by Danzig

First a short video on the EPOXI/Hartley 2 flyby:

Click here to view the embedded video.

And then a little more about the shuttle delay and yet more on the comet flyby:

Click here to view the embedded video.

Hopefully the coming week won’t have me running around like the poor proverbial chicken “com a sua cabeça cortada” .

NCBI ROFL: Sex differences in visual attention to sexually explicit videos: a preliminary study. | Discoblog

Posted on November 14, 2010 by Danzig

3060912706_a9c287ef61 “INTRODUCTION: Although men appear to be more interested in sexual stimuli than women, this difference is not completely understood. Eye-tracking technology has been used to investigate visual attention to still sexual images; however, it has not been applied to moving sexual images. AIM: To investigate whether sex difference exists in visual attention to sexual videos. METHODS: Eleven male and 11 female healthy volunteers were studied by our new methodology. MAIN OUTCOME MEASURES: The subjects viewed two sexual videos (one depicting sexual intercourse and one not) in which several regions were designated for eye-gaze analysis in each frame. Visual attention was measured across each designated region according to gaze duration. Sex differences, the region attracting the most attention, and visually favored sex were evaluated. RESULTS: In the nonintercourse clip, gaze time for the face and body of the actress was significantly shorter among women than among men. Gaze time for the face and body of the actor and nonhuman regions was significantly longer for women than men. The region attracting the most attention was the face of the actress for both men and women. Men viewed the opposite sex for a significantly longer period than did women, and women viewed their own sex for a significantly longer period than did men. However, gaze times for the clip showing intercourse were not significantly different between sexes. CONCLUSIONS: A sex difference existed in visual attention to a sexual video without heterosexual intercourse; men viewed the opposite sex for longer periods than did women, and women viewed the same sex for longer periods than did men. There was no statistically significant sex difference in viewing patterns in a sexual video showing heterosexual intercourse, and we speculate that men and women may have similar visual attention patterns if the sexual stimuli are sufficiently explicit.”

Photo: flickr/dutchlad

WTF is NCBI ROFL? Read our FAQ!

Jurassic Park Watch: Little, Super-Cute, Real Baby Dinosaurs | Science Not Fiction

Posted on November 14, 2010 by Danzig

Sister Discover Blog 80beats reports:

Fossilized dinosaur embryos, found still in their eggshells, have claimed the title of the oldest vertebrate embryos ever seen–they were fossilized in the early Jurassic Period, around 190 million years ago, researchers say. The embryos are from the species Massospondylus, a prosauropod, the family of dinosaurs which gave rise to iconic sauropods like the Brachiosaurus.

Of course, just because we found the well-preserved bones of a dinosaur embryo doesn’t mean we can bring the thing back to life with a snap of the fingers (or even with a crack scientific team “sparing no expense”). But remember that most scientists were very skeptical that any viable tissue could be found in dinosaur bones until Mary Schweitzer did just that—and faced a lot of misguided attacks before her results were confirmed.

dino-embryo Perhaps the most interesting thing about the discovery was the fact that these dinosaur babies are in some important ways baby-like: big heads, no teeth, get around on four legs instead of two (as did Massospondylus adults). The researchers suspect that these little ones therefore probably couldn’t survive on their own, and must have depended on their parents—the oldest ever example of parental care. And if that’s the case, it sort of makes sense that they’d appeal to our weakness for things baby-like, even if they’re not of our species.

So if and when we do bring Massospondylus back from the mass grave of extinction, we better be ready to raise the kids well. Any ideas on how to parent a prosauropod?

Bonus Katz – November 12th, 2010 | Gene Expression

Posted on November 14, 2010 by Danzig

Been a while since I did some bonus kat photos, so here it goes….

blueskykat thedude2 visiting

“Cool It”: Climate Contrarian Bjorn Lomborg Takes His Message to the Movies | 80beats

Posted on November 14, 2010 by Danzig

Climate change is causing areas of the world to heat and cool, and it seems a controversial new climate change film is doing the same to reviewers.

The film is titled Cool It and was based on a book of the same name by Danish writer Bjørn Lomborg, a contrarian who delights in questioning the gravity of our planet’s environmental problems. The movie was directed by Ondi Timoner, an award-winning documentarian.

Lomborg has raised the hackles of environmental activists since he published The Skeptical Environmentalist a decade ago. Since then he has drawn closer to environmentalists on some issues–for example, he now maintains that global warming should be one of the world’s “chief concerns.” But in the new documentary, Lomborg still argues that money spent on trying to limit carbon output would be better spent on investment in green technologies and geoengineering. The film is currently enjoying a limited release across the United States.

New York Times Dot Earth blogger Andrew Revkin compares Lomborg’s Cool It to Al Gore’s An Inconvenient Truth:

Does the film succeed? “Cool It” is eminently watchable — which is no surprise given Timoner’s involvement. Lomborg, as always, is charming and persuasive, frequently shown riding his bicycle through Copenhagen’s busy streets — in what has to be seen as a dig at Gore, who in his film is often seen racing through airports.

But it suffers from the same simplification syndrome that weakened “An Inconvenient Truth.”… In “Cool It,” Lomborg breezily ticks down a laundry list of high-tech ways to engineer the atmosphere, for example, but punts on the tougher questions related to such planet-scale enterprises — such as the inevitable diplomatic dispute over who sets the planetary thermostat and how blocking the sun does nothing to stem the buildup of carbon dioxide, much of which will stay in the atmosphere for many centuries. [The New York Times]

In the opinion of Wired’s Hugh Hart, Lomborg is a “charismatic tour guide” who ultimately fails to convince.

But when Lomborg — presented much of the time in full lecture mode — takes to the blackboard and scratches out figures numbering in the billions of dollars as estimates for what it would cost to make recommended fixes, one wonders if his largely untested propositions truly carry more weight than the doomsday extrapolations proffered by Gore and company. [Wired]

In contrast, the LA Times’ Betsy Sharkey seems very convinced. She doesn’t question Lomborg’s credibility, and finds the film hopeful and creative:

The range of ideas is eclectic, from the practical simplicity of cooling cities by changing the color of the streets to highly complex systems designed to alter atmospheric conditions. By suggesting there is light at the end of the global warming tunnel, Timoner has made “Cool It” a hopeful film. We just have to know where to look for the switch. [Los Angeles Times]

Michael O’Sullivan with the Washington Post was also swayed by Lomborg’s presentation:

If it’s propaganda, it’s surprisingly effective. With the charismatic, articulate (and, yes, kind of hunky) Lomborg in front of the camera for much of the film — along with a parade of scientists who support his views — “Cool It” makes a convincing case that there are better things we can do than drive a Prius. Not that there’s anything wrong with that, he says; it’s just not going to solve much.

All these critics seem to agree that Cool It is engaging, but none of them really grapple with the ideas presented in the movie. For example, some of the geoengineering schemes that Lomborg advocates could, if adopted on a grand scale, turn down the global thermostat by reducing the amount of sunlight hitting the Earth. But that wouldn’t stop the carbon dioxide in our atmosphere from gradually turning the oceans acidic, a change that could have enormous repercussions.

Watch the trailer below for a better idea of the film’s voice and tone:

Image: IMDB / Cool It

Wild Africa’s Landscapers: Elephants and Rivers | Visual Science

Posted on November 14, 2010 by Danzig

Study: Acne Drugs Aren’t Linked to Suicide—Acne Is | 80beats

Posted on November 14, 2010 by Danzig

Acne Since its emergence in the early 1980s, the drug isotretinoin—used to treat severe acne and sold under a host of different brand names—has been subject to controversy over whether it increases the incidence of suicide attempts in those who take it. But sorting out whether the drug, the acne itself, or some other factor is driving increased suicide risk is quite difficult.

So for a study out in the British Medical Journal, a team of researchers in Sweden looked at a deluge of data for 5,756 people who took the drug. Their conclusion: Severe acne patients who took isotretinoin had an increased risk for suicide attempts both before and after taking it, so they can’t definitively link isotretinoin to suicide.

The drug, perhaps best known as the pharmaceutical company Roche’s Accutane, has been embraced by dermatologists and their suffering patients, but has also been dogged by controversy for its side effects.

While powerful at clearing acne, the drug has been linked to birth defects if taken during pregnancy and has also been suspected of causing mental side effects, although Roche has vigorously defended personal injury claims in this area. [Reuters]

Anders Sundstrom led the current research, which seems to support the theory that the pharmaceutical isn’t a threat to mental health. Said Sundstrom:

“The underlying condition of acne is a more important factor for suicide attempts. We are not certain the drug adds anything.” [BBC News]

Nevertheless, he says, the study does not rule out the drug as contributing to suicide risk, especially considering the highest rates of attempts came in the six months after patients went off isotretinoin.

“Some of the patients, possibly vulnerable to isotretinoin, who made their first suicide attempt in close relation to treatment, may have done so as a consequence of exposure to the drug,” they write. “However, patients without a positive effect of treatment might have despaired at the prospect of continuing to live with disfiguring acne.” They also cannot rule out, they say, the possibility that patients who expected their life would be transformed after treatment might be distraught when their social life did not improve. [The Guardian]

Those are just guesses; it will take more studies to further tease out the effects of medication versus underlying condition. In the meantime, Dr. Sarah Bailey says:

“Perhaps their most interesting and novel finding is that the risk of suicide is increased after treatment has stopped and therefore it is essential to continue to monitor patients carefully.” [The Telegraph]

Image: iStockphoto

Friday Fluff – November 12th, 2010 | Gene Expression

Posted on November 14, 2010 by Danzig

FF3

1. First, a post from the past: Extremism in defense of precision is no vice.

2. Weird search query of the week: ‘”it’s a jersey thing” gnxp.’

3. Comment of the week, in response to Tariffs, not trade?:

You’re ignoring intergenerational wealth transfer. Grandparents don’t like to see their grandchildren’s parents out of work, or forced to move out of state to find work. They don’t like to see their former workplaces (whether GM or “Main street” shops) “diminished” by competition from cheap imports.

4) How do you feel about the fact that the raison d’etre of many public libraries is becoming their internet service?

5) And finally, your weekly fluff fix: a little different. Check out how cats lap milk from the recent Science paper.

What Does Your City Smell Like? DARPA Wants to Know | Discoblog

Posted on November 14, 2010 by Danzig

How could the government know about a chemical attack before it wreaks havoc? By smelling it.

But the problem is, to detect an abnormal stench, the government first needs to know the city’s normal aroma, to have an idea of its “chemical profile.” To that effect, DARPA just released a solicitation looking for suggestions on how to best build chemical composition maps of major United States cities. Spencer Ackerman over at Wired’s Danger Room t0ok a look at the solicitation and explained what DARPA is looking for:

The data Darpa wants collected will include “chemical, meteorological and topographical data” from at least 10 “local urban sources,” including “residences, gasoline stations, restaurants and dry cleaning stores that have particular patterns of emissions throughout the day.”

Then, subsequent chemical readings from the area could be compared to the “map” to check for abnormal chemicals in the air. Since many chemicals that can be used in a terrorist attacks are normally found around our cities, it’s difficult to just screen for them without having an idea of their baseline levels, explains Wired:

In theory, chemical attacks can be detected before they happen. Even trace amounts of chemicals give off specific signatures that tools like sorbent tube samplers can register. But in order to figure out if dangerous chemicals are stockpiled somewhere or are floating through the air, the government’s going to have to know the baseline level for those chemicals wafting near your trash receptacle.

DARPA is looking for proposals on how best to collect data while spending less than 30 minutes doing it. They also want to collect information on the two-day fluctuations in chemicals, and take readings at different times of the year, says Wired.

Then they’ll adjust for atmospheric and environmental variables like wind speed, humidity and time of day–when, say, the dry cleaners’ is open to spew perchloroethylene vapor into the air–to account for the impact on chemical potency. They’ll use that data to “predict concentrations down to trace gas concentrations of 10 parts per trillion” across a whole city.

I wonder if they could pick up the maple syrup smell in NYC.

Image: Flickr/Save vs Death

Hit or missile | Bad Astronomy

Posted on November 14, 2010 by Danzig

So I got a bazillion emails and tweets about the so-called "missile launch" off of LA the other day. I was on travel and couldn’t really write about this, and by the time I could it was already being shown to be a plane contrail. And I wouldn’t even write about it now, but I have to link to this clip from The Daily Show where they pretty much nail it:

The Daily Show With Jon Stewart

Mon – Thurs 11p / 10c

Missile: Impossible

http://www.thedailyshow.com

Daily Show Full Episodes

Political Humor

Rally to Restore Sanity

The part about the helicopter pilot is magnifique! That’s a perfect example of skeptical thinking. And Occam’s Razor slices pretty well here; what’s more common in LA, an airplane or a missile launch? It shows the relevance once again of the old skeptical adage: If you hear hoof beats, think horses, not zebras.

Unless you live in the African grassland. Or near a zoo. Whatever.

And I’ll add that a guy appears to have figured out not only that it was a plane, but what flight it was, which I note simply because I know the comments to this post will soon be filled with conspiracy theorists who will claim this is a coverup for a transdimensional porthole like the one over Norway or Australia that were certainly not rocket boosters even though all the evidence points that way because they just know it and use words that sound sciencey but are actually the blog-comment equivalent of an Ogden Nash poem.

Say.

Tip o’ the tin foil beanie to reddit for that last bit about the plane spotter.

World’s Oldest Embryo Fossils Shed Light on Dinosaur Parenting | 80beats

Posted on November 14, 2010 by Danzig

Fossilized dinosaur embryos, found still in their eggshells, have claimed the title of the oldest vertebrate embryos ever seen–they were fossilized in the early Jurassic Period, around 190 million years ago, researchers say. The embryos are from the species Massospondylus, a prosauropod, the family of dinosaurs which gave rise to iconic sauropods like the Brachiosaurus.

Robert Reisz and his team found the embryos when analyzing a clutch of fossilized eggs collected in South America in 1976. The find was just published in the Journal of Vertebrate Paleontology.

“This project opens an exciting window into the early history and evolution of dinosaurs,” said Professor Reisz. “Prosauropods are the first dinosaurs to diversify extensively, and they quickly became the most widely spread group, so their biology is particularly interesting as they represent in many ways the dawn of the age of dinosaurs.” [BBC News]

dino-embryo The well-preserved embryos are about 8 inches long and are detailed enough to give researchers a good look at what the juvenile Massospondylus looked like. What they found wasn’t exactly elegant. The juveniles looked similar to adult sauropods like Brachiosaurus, with an oversized head and four-legged strut (unlike the adult Massospondylus, which walked on two legs).

To some extent, these dinosaurs then developed as humans do today. The infancy is “awkward,” as the researchers put it, and a more erect stance and evenly-proportioned body only comes later. Additionally, the embryos lack teeth. With the awkward body proportions, it’s then likely that the hatchlings would have required parental care. If that’s the case, these fossils also document the oldest record of parental care, according to the paleontologists. [Discovery]

Images: Heidi Richter, Diane Scott

Nutritionists to America: For the Love of God, Don’t Try the Twinkie Diet | Discoblog

Posted on November 14, 2010 by Danzig

It’s been making headlines all week (”Twinkie diet helps man lose weight” and “Trying To Lose Weight… Try The Junk Food Diet” might be some of the worst health-related headlines I’ve seen in awhile) as the Ding-Dong Diet or the Twinkie Diet, but let’s just call it the worst diet ever for short.

The newsplosion came from an experiment by Mark Haub, an associate professor in the department of human nutrition at Kansas State University. In an effort to prove to his class the importance of calories in weight gain and loss, he decided to drastically change his eating habits.

He embarked from the shores of a balanced diet of fruits, vegetables, grains, and meat (totaling about 2,600 calories per day) to a junk food diet consisting of Twinkies, Hostess and Little Debbie snack cakes, and Doritos–with sides of vitamin pills, protein shakes, and small portions of vegetables. He lost 27 pounds in 10 weeks. Why? Because he restricted his new diet to a total of 1,800 calories per day.

He expected to lose weight, but was unsure about the other health outcomes of the diet. Ten weeks later his blood tests showed that both his lipid levels and glucose had lowered, a fact that would put him in a healthier heart state, according to the American Heart Association’s guidelines. According to ABC News, Haub even felt better:

The thing is, he began to feel healthier. He had more energy, stopped snoring, and not only did he lose enough weight to drive down his overall cholesterol and body mass index (BMI), his good HDL cholesterol crept up two points and his blood glucose — despite all that cream filling — dropped 17 percent.

Discoblog was skeptical about the hype over Haub’s junk food binge, so we asked some nutritionists and doctors what they thought of it. We came back with several different takes, but one general message. In a loud and clear voice, these nutritionists are telling America that this diet is a bad idea, and pleading with people not to try it.

The experts did agree that the diet had one important lesson: It really showed just how much weight loss can improve your health. It also demonstrated that just cutting the number of calories you take in is enough to make you lose weight. But James Hill, the director of human nutrition at the University of Colorado, Denver told Discoblog that health-conscious people shouldn’t emulate Haub:

“This is not the diet you should be eating. The goal is to find a way you can eat forever and this isn’t a way to eat forever. This is a stunt, the stunt illustrates it doesn’t matter what you eat, if you take in less than you expend you will lose weight, but nobody should be promoting this as a way of eating.“

Our nutritionists all agreed: This kind of diet isn’t sustainable in the long run. “Health is not measured in your habits of days and weeks,” said Miriam Pappo, director of clinical nutrition at Montefiore Medical Center.

After the weight loss benefits from the caloric restriction kick in, the dangerous combination of fat and sugar in these processed foods will start to take their toll. Also, Haub’s diet is lacking in a variety of basic nutrients that will risk his health in the long run, according to Pappo:

“The effects of what he did showed the importance of weight loss and how immediately weight loss can effect our well being and our lab results. However, long term, his diet was one that was void of antioxidants, phytonutrients, and fiber, all of which have been associated with longevity, with cancer prevention, diabetes control, and mental acuity, among other things. So, he would probably not fare well in the long term.”

And while the weight loss benefits are showing in Haub’s blood tests now, it’s not certain that once he reaches his goal weight these benefits will be sustainable on a diet with such a high fat and sugar content. Hill doesn’t believe the he will be able to keep the weight off in the long run:

“Weight loss isn’t any long term benefit unless you keep it off. If you lose weight and regain it, you are right back where you started. And most diets, that’s what happens. And I’m sure it’s going to happen to this guy.”

“Man has the unique ability to take a very healthy food substance and to chemically alter it into something that is not healthy, ” said Pappo, who also made the point that even some foods labeled low-fat or low-sugar can have negative health consequences. Walter Willet, from the department of nutrition at Harvard University, agrees:

“Much confusion exists about the definition of junk vs healthy food. Many people still believe that a bagel with jelly is a healthy food because it is low in fat, but in reality almost nothing could be worse than this large dose of refined starch and sugar. In contrast, Doritos and most other chip are now trans fat free and made with unsaturated fats that reduce blood cholesterol and risk of heart disease. Thus, they will be healthier than most of the foods consumed by Americans, which is not to say that a Dorito diet is recommended.”

My takeaway from this this little nutrition experiment is strikingly similar to author Michael Pollan’s thesis in much of his writing on nutrition:

Eat food. Not too much. Mostly plants.

That, more or less, is the short answer to the supposedly incredibly complicated and confusing question of what we humans should eat in order to be maximally healthy.

Image: Flickr/franckdetheir and Prof Haub’s Diet Experiment Facebook Page

Rising Mountains & Spiking Temperatures Spurred Amazon’s Biodiversity | 80beats

Posted on November 14, 2010 by Danzig

AmazonRforest What does it take to make a wellspring of biodiversity like the Amazon rainforest? A huge mountain range, a blast of heat, and a little time.

A pair of studies in this week’s edition of Science attempt to sort through tropical natural history and reach the root causes of Amazonia’s embarrassment of biological riches. The first, led by palaeoecologist Carina Hoorn, points to the influence of the Andes Mountains, the spine of South America that runs up its western coast. Sometime between about 35 and 65 million years ago, colliding tectonic plates sent the Andes bulging up. According to the researchers, the birth of a mountain range set of an ecological chain reaction.

The rising mountains that resulted from the uplift blocked humid air from the Atlantic, eventually increasing rainfall along the eastern flank of what became the Andes that eroded nutrient-loaded soils off the mountains. The Andes also kept water from draining into the Pacific, helping form vast wetlands about 23 million years ago that were home to a wide range of mollusks and reptiles. [LiveScience]

About 7 million years ago those wetlands dried up. But they left behind a swath of fertile soil, the scientists say, perfect for a rainforest to colonize. A little later, about 3.5 million years ago, the Panama isthmus emerged, and that sliver of land provided a bridge for even more species to reach the Amazon.

And then there’s the heat. A little than 56 million years ago—during the window when the Andes commenced their ascent—a blast of sudden warming struck the Earth. The event is called the Palaeocene-Eocene Thermal Maximum (PETM), during which the temperature shot up by as much as 5 degrees Celsius (9 degrees Fahrenheit) and the global thermostat stayed there for about 200,000 years. One might think that a temperature shock would suppress biodiversity, but that is not what the scientists found in the fossil record when they surveyed in Colombia and Venezuela.

“We were expecting to find rapid extinction, a total change in the forest,” says study leader Carlos Jaramillo, a biologist at the Smithsonian Tropical Research Institute in Balboa, Panama. “What we found was just the opposite — a very fast addition of many new species, and a huge spike in the diversity of tropical plants.” [Science News]

Indeed, this warm period invited some of the Amazon’s signature species, Jaramillo says.

The pollen fossil record shows that some important plant families, such as Myrtaceae, which includes eucalyptus, and Passifloraceae–the passion flowers–made their first appearance during the thermal maximum. The tropics have remained the most species-diverse area of the world ever since. [Scientific American]

On the surface, this burst of biodiversity during a warm spike might suggest plants actually could thrive if the planet suddenly heats up. But Jaramillo—admittedly wary that his study of the Earth 56 million years ago will be used as ammunition to argue that modern climate change doesn’t matter—warns that this connection is far from clear. First, 200,000 years is hasty on the geological time scale, but global warming is happening at a much faster pace. Furthermore, he says, Earth was wetter during the PETM that it’s likely to be in the near future, and deforestation has rendered the rainforest thinner today that it probably was then.

Image: Wikimedia Commons

The Science of Kissing In Redbook | The Intersection

Posted on November 14, 2010 by Danzig

With a month and a half before The Science of Kissing’s debut, Ayana Byrd at Redbook interviewed me for a fun article in their December issue called The Kissing Project. The piece explores why we kiss and I’m quoted:

“Research suggests that men may have an unconscious tendency to swap lots of spit because they transfer testosterone (which raises libido over time) to their mate through saliva.”
“Whether a couple has been together for four months or 40 years, kissing promotes feelings of intimacy and security.”

Of course, that’s just a hint of what’s in the actual book: I spend a chapter exploring gender differences and several more on the hormones and neurotransmitters involved. While I don’t want to give too much away yet, it’s neat to see a nod to The Science of Kissing in print!

More will be revealed over the coming weeks…

WISE finds the coolest stars. Literally. | Bad Astronomy

Posted on November 14, 2010 by Danzig

I have a few pet objects in astronomy that fascinate me endlessly. One of these is brown dwarfs, objects that are bigger than planets, but too small to be bona fide stars. They are much cooler and fainter even than dinky red dwarfs, making them very difficult to find… unless you are WISE:

[Click to embiggen.]

See that pale green dot in the middle? That’s a brown dwarf! I know, it’s not brown, it’s green, but that’s kosher since brown dwarfs are really magenta.

OK, hang on a sec. I’ll explain that in a minute.

The important thing is that this image shows a very nearby brown dwarf, maybe 18 – 30 light years away (the distance is hard to determine, but observations taken over the next year or so should pin it down). That’s really close! The nearest known star, Proxima Centauri (a faint red dwarf) is 4.2 light years away, and only a few hundred stars are within 30 light years. That makes this brown dwarf, named WISEPC J045853.90+643451.9 (after its location in the sky), one of the closest stars known.

You’d think think we’d have a pretty good idea of all the stars near us, since they’d be among the brightest in the sky. But in fact brown dwarfs are so faint that to optical telescopes they can escape detection even if they’re our cosmic neighbors. WISE, however, looks in the infrared, where brown dwarfs glow considerably brighter.

And that brings me to the weird colorful adjectives we use for these objects.

The color of a star depends mostly on its temperature (and the way our eyes see the mixed colors from stars, which is complicated, and I will ignore here). Very hot stars are blue, middlin’ hot are white (like the Sun), cooler ones are orange, and very cool ones are red. Brown dwarfs are even milder than red dwarfs, and their spectrum actually peaks in the infrared.

But it’s a bit more complicated than that. Brown dwarfs are so cool that actual molecules can exist in their atmosphere, like water (well, steam), titanium oxide, ammonia, even hydrogen sulfide (which makes eggs smell rotten). These molecules absorb light at certain colors, and that absorption can really mess with a brown dwarf’s color. Sometimes, a cooler brown dwarf can actually be more blue than a warmer one, because those molecules absorb the redder light the object emits. It’s weird. So a lot of these brown dwarfs actually would appear to be magenta to the eye.

So why are they called brown dwarfs? Blame SETI’s Jill Tarter. She just wanted a name for the critters, and compromised on a color between red and black. Stars can’t be brown, really, but the name stuck.

Anyway, if they’re magenta and not brown, why does that one look green in the WISE picture? It’s because WISE look in the infrared, which our eyes can’t perceive. So when they make pictures form the data, astronomers use false colors; they let blue represent the shortest IR wavelength WISE sees, green the intermediate, and red the longest wavelength — this corresponds to visible light, with wavelength getting longer from blue to green to red. It’s a shorthand that astronomers use that makes images like this easier to interpret.

As it happens, brown dwarfs at a certain temperature emit very strongly in the infrared wavelength astronomers code as green in the WISE images. So finding brown dwarfs is actually not too hard: just look for green stars! Those are really the magenta brown dwarfs.

See?

Anyway, I for one welcome WISEPC J045853.90+643451.9 to our little clan of nearby stars, and hope we find more. For quite a long time I’ve wondered if Proxima Cen really is the closest object to the Sun, or if there might be a faint brown dwarf even closer. Since brown dwarfs aren’t considered stars, Proxima may yet hold on to the title of "nearest star". But if we ever do find something even closer, it would literally be very cool.

Related posts:
- Two nearby galaxies peek out through the dust
- A WISE flower blooms in space
- The seven WISE sisters
- Three views to a comet

Was the Pocahontas exception necessary? | Gene Expression

Posted on November 14, 2010 by Danzig

Harry_F._Byrd In Jonathan Spiro’s Defending the Master Race it is recounted that as American states were passing more robust anti-miscegenation laws and legally enshrining the concept of the one-drop-rule an exception was made in Virginia for those with 1/16^th or less Native American ancestry. The reason for this was practical: many of the aristocratic “First Families of Virginia” claimed descent from Pocahontas. Included within this set was Senator Harry F. Byrd Sr. of Virginia, who was 1/16th Native American, being a great-great-grandson of Pocahontas. This sort of background was probably not exceptional among the “Founding Stock” of Anglo-Americans whose ancestors were resident within the boundaries of the American republic at independence. Only around 1700 did the white population of the American British colonies exceed the indigenous, so no doubt some amalgamation did occur.

But from what I’ve seen the extent of admixture with the indigenous substrate was very marginal, especially in comparison to white populations in Argentina or Brazil. Or so I thought. In conversation a friend recently claimed that over 50% of American whites were 5% or more non-European in ancestry. I expressed skepticism, and he dug up the citation. Genetic ancestry: A new look at racial disparities in head and neck cancer:

The study included 358 patients; 37 percent were African American.
The researchers examined diagnosis (late versus early stage) and overall survival for African Americans with HNSCC based on self-reported race and genetic West African ancestry.
During the past decade, many groups have developed and characterized sets of single nucleotide polymorphism markers that can distinguish genetic ancestry among major ethnic groups such as Asian and West African, called ancestry information makers (AIMs).
For the study, genetic ancestry was based on a panel of 100 AIMs to estimate genetic background.
“Using these genetic markers gives you additional statistical power. It’s no longer two just categories – Black or White; it becomes a continuous variable. Race is not equal to genetics. Genetic markers don’t define specific races,” says Dr. Worsham.
Ultimately, the study found no correlation between West African genetic ancestry and HNSCC outcomes. Only self-reported race was associated with head and neck cancer stage.
Only 5 percent of self-reported African Americans had more than 95 percent West African ancestry, with 27 percent having less than 60 percent West African ancestry. By comparison, 48 percent who self-reported as Caucasian had more than 95 percent European American ancestry.

I’m not too worried about the number of markers. 100 should be sufficient on the scale of continents if well selected. But I’m curious about the representativeness of the sample. The African American one seems more European than others I’ve seen previously. And I really haven’t seen that much admixture with non-Europeans in the CEPH Utah white sample in the HapMap. But perhaps the Utah whites aren’t representative? Dienekes ran ADMIXTURE on the HapMap3 populations a few weeks ago, and I don’t see any elevated component of non-European ancestry in the Utah whites when compared to the Tuscans from Italy.

admixhapmap3

A factoid such as that less than 50% of white Americans are 95% or more European in ancestry can get traction quickly. But I think we should wait a bit and just get more samples. The results are from a presentation at a conference, not even a paper. Of course there’s a possibility that many people have more interesting backgrounds than multi-generational families which settled in Utah rather early. Time will tell.

Addendum: I believe that Native American admixture is going to be more common among the white Americans of the South than Yankees from New England. The reason I would give is that powerful and populous tribes and confederacies such as the Creek and Cherokee persisted in the Southern highlands far longer than in New England. The CEPH sample is going to be biased toward Yankees, as well as European converts from the British Isles and Scandinavia, so perhaps giving a somewhat lower result for non-European ancestry in American whites.

Addendum II: I thought about it more. Something went wrong in their analysis, or they had a very unrepresentative sample. Perhaps they had many Latinos and only coded their self-identified race and not ethnicity (50% of American Latinos identify as white). Maybe the AIMs aren’t good. I don’t know. But I do know that American genealogy buffs who assume Native American ancestry are often very disappointed. They seem to far outnumber those who find surprising non-white ancestry.

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