How Archimedes Burned Those Roman Ships: Mirror or Steam Cannon? | Discoblog

mirrorHere’s the situation: You spot Roman attack ships headed for your shores. Do you order your troops to ready the cannons? Or–in an ancient MacGyver move–do you use a parabolic mirror, focusing the sun’s rays to set the ships on fire? Though the latter is clearly more suave, recent research has shown that the 212 B.C. legend about Archimedes’ mirror defense is unlikely: He probably pulled out the big guns instead.

Cesar Rossi, a mechanical engineer at the University of Naples in Italy, figured out the numbers. A steam cannon–like the ones Leonardo da Vinci drew in the 1400s–could use less than a tenth of a cup of water to fire a hollow clay ball, at 134 miles per hour, to hit a target 492 feet away. For comparison, an 1854 American Civil War Howitzer cannon could fire a ball about ten times farther–a little less than a mile.

Rossi presented this research at the International World Conference in Syracuse, Italy (the site of the historic Roman attack on the Greek colony) earlier this month. He told LiveScience that after looking at both the historical references to the battle and the feasibility of using the mirrors on moving ships, that the cannons were “much more reasonable than the use of burning mirrors.” The hollow clay cannon balls could have been filled with a mix of incendiary chemicals that would have set the ships afire on impact, Rossi suggests.

In 2005, MIT students recreated the mirror defense and managed to set a wooden “ship” ablaze. On the roof of a Cambridge parking garage, they scorched the ship, but their test required ideal weather conditions and a stationary target. Rossi hopes to team up with other researchers to create his own reenactment using the steam cannons.

Cannons or mirrors, Archimedes couldn’t save Syracuse–and the Romans’ success meant Archimedes’ end.

Related content:
Discoblog: Particle Physics Experiment Will Use Ancient Lead From a Roman Shipwreck
Discoblog: Beijing Installs Giant Deoderant Cannons to Beat Stinky Landfill Stench
Discoblog: How to Date an Ancient Volcanic Eruption: Step 1, Use Fish Sauce
Gene Expression: Brighter than Isaac Newton?

Image: Wikimedia / Giulio Parigi, 1600


Announcement: I’ll be at w00tstock, baby! | Bad Astronomy

I extremely nerded out and pleased and squeeified to announce that I’ll be at w00tstock! At Comic Con. On stage.

I know.

w00tstockw00tstock, for those helplessly normal of you out there, is the premier nerd event in the Orion arm of the Milky Way. Hosted by singers Paul and Storm, Mythbuster and My Close Personal Friend Adam Savage™, and my long-standing and partially-requited nerdcrush Wil Wheaton, w00tstock is billed as "Three hours of geeks and music", which is apt enough. Everyone I know who has gone has raved about it.

And cripes, the talent they get. Bill Corbett, Mike Nelson, and Kevin Murphy from Rifftrax, née Mystery Science Theater 3000. Chris Hardwick, aka The Nerdist. Len Peralta, about whom you’ll be hearing more on this blog pretty shortly. And oh my FSM, I’m really thrilled that my favorite fire-haired songstress Marian Call will be there as well. Apparently I wasn’t the only one who sent a note to TPTB to get her on stage.

One cool thing about w00tstock is that all the stuff done on stage is Creative Commons licensed, so it goes up immediately on Flickr and YouTube. In fact, there are a lot of videos from previous versions online you can check out. If you’re a bona fide nerd you’ll enjoy them.

To say I’m excited and honored is like saying a gamma-ray burst is kinda bright, or a neutron star is somewhat dense, or a Planck length is a tad minuscule.

I’m that excited.

And of course initially panicked over a topic. But then Mrs. BA inspired me, and suddenly, full blown like Minerva from the brow of Jupiter, an idea burst forth from my brain. So now all I have to do is put it together and keep it to ten minutes. Good thing I’m not long-winded.

Anyway, you can get tickets for this, but you’d better hurry because Comic Con is Geek Central and I’m sure they’ll sell out this week.

And as if that’s not enough, I’ll have even more Comic Con news soon. Mwuhahahaha!


Ambush ants capture giant prey using Velcro principles | Not Exactly Rocket Science

In the Brazilian rainforest, a grasshopper lands on a leaf of the Cecropia obtusa tree, and seals its fate. It was after a quick meal but this tree is defended by hidden bodyguards. Underneath its leaves, thousands of Azteca andreae ants lie in ambush, poised at the edges with their jaws outstretched. As soon as the grasshopper lands, the ants rush out from their hiding places, seize it by the legs and pull it spread-eagled. The ambushers hold the victim while their nestmates bite, sting and dismember it. For the grasshopper, the leaf turns from a restaurant into a medieval torture rack.

This hunting strategy is all the more amazing when you consider that the ants weigh just over a milligram each while their prey – including grasshoppers and moths – can weigh up to 10 grams. Ants are famously strong and they obviously hunt in large numbers but even so, holding down a struggling insect that outweighs them by around 10,000 times can’t be easy. It’s the equivalent of a team of humans holding down three struggling blue whales.

The ants manage it because their host plant gives them hitching posts to anchor themselves to. The leaves of C.obtusa have a downy underside made up of tangles of fibres that the ants’ claws hook into. It’s the same principle used by Velcro straps, where a strip of small hooks latches onto a second strip of small loops. The ants and the tree combine forces to create a biological Velcro, and the ants are far stronger on their host plant than on any other.

The incredible tactics of the Azteca ants were discovered 16 years ago, but the secret behind their prodigious grip has only just been revealed by a team of French and Spanish scientists led by Alain Dejean. They watched the entire hunting sequence by luring large moths to the leaves using ultraviolet light, or by dropping grasshoppers onto them. At the slightest touch, the closest workers attacked the prey and drove it towards others lying in wait, which collectively flipped it underneath the leaf and stretched it out.

To test the workers’ strength, Dejean dangled threads with weights at the end of them in front of their open jaws. He found that each worker can hold onto 8 grams, around 5,700 times her own weight. And as a team, they can manage far more.

The workers also seemed to be particularly strong on the downy underside of the leaves than on the rough upper surface, or on a sheet of smooth plastic. And they were especially mighty on their host plant. When Dejean tested them on a closely related tree with a less downy underside they couldn’t hold onto as much weight.

These ants are one of the many hundreds of ant species that form lasting relationships with plants, defending them from plant-eaters in exchange for shelter and food. But all of them have a problem. Plant nectar is typically poor in proteins and nitrogen, and while some plants pay their bodyguards with special protein-rich food packages, most plant-defending ants must get these nutrients in other ways.

Some rely on thriftiness, by producing workers with very thin shells and venoms that don’t contain any protein. Some rely on bacteria and others farm sap-sucking bugs that they gently nip from time to time. And yet others solve the problem by hunting for fresh meat. Foraging in the forest canopy is difficult so these tree-top predators rely on ambush techniques that make the most of prey that approaches them.

Azteca andreae’s strategy of lying in wait is just one such technique. A related species Azteca bequaerti hides in special hollows produced by their host where it listens for the vibrations of a landing insect and swarms it en masse. Even more elaborately, Allomerus decemarticulatus creates elaborate traps by building layers over tree branches that look like parts of the tree but are actually hiding places for ant ambushers.

The layers are made out of the hairs of its host tree bound together with a fungus that the ants farm. They are pitted with tiny holes that the ants hide in. When a victim lands, the ants launch a grisly surprise attack, rushing out from their holes and grabbing the victim by the legs. As with A.andreae, the victims of A.decemarticulatus are stretched out and eaten. In the rainforest, even a harmless looking leaf or branch can hide a painful death inside or beneath it.

Reference: PLoS ONE http://dx.doi.org/10.1371/journal.pone.0011331

More on ants:

Terminally ill ants choose to die alone

Leafcutter ants rely on bacteria to fertilise their fungus gardens

The rebellion of the ant slaves

Loss of big mammals breaks alliance between ants and trees

Foul-tasting ant parasitises the colonies of other species

Responses to Responses to my WashPo Piece on Science and the Public | The Intersection

Update: Just learned the American Academy paper will be available for download at this link tomorrow. But don't go now, it just gives an error message.... Well, the piece yesterday prompted a lot of commentary on the blogs, on Facebook, on the Post website (214 last time I checked), and through emails directly to me. I want to make some remarks on some of the more interesting--and less interesting--reactions that I received. First, though, a factual point: A lot of folks have asked when the American Academy of Arts and Sciences paper that all of this is based on will be available. The answer is Tuesday, and while this paper is being printed in hard copy--technically an "occasional paper" of the American Academy of Arts and Sciences--an online PDF will also be available. I will link as soon as that occurs. (Tuesday is also day the paper is being rolled out at the other AAAS--American Association for the Advancement of Science--and once again, details on the event are here.) So, on to the responses. First, the ones I don't find all that interesting:
1. I've gotten a lot of emails where there's special pleading being done either about climate change, or about vaccination. ...


More children please: men or women? | Gene Expression

In the post below on Bryan Caplan’s arguments for why one should have more children there was an “interesting” comment:

As if we’re harmless little creatures at one with our environment and put no toll on the balance of nature around us. Funny how we humans act like mindless rabbits and lemmings and put the sole unintelligent directive of our DNA as the mouth of god. Men most interestingly in power or self described intellectuals after sitting around picking belly lint and jerking off in praise of their penises find clever monkey justifications (patriarchal religions mostly) for more more more babies and women must be subservient to male sexual needs and demands of more babies. See a huge male god said so.

Funny how women mostly never jump on the soapbox bandwagon of wanting to pop out tons of kids, just male spermatozoa fed rants formed by the human male organism to insist his natural inclination is the word of gawd. If you can’t use holy massive penised Jehovah to instill this dreck then dream up socio-biological propaganda for the atheist hip guys needing a good shagging with their female cohorts.

Ignoring the weirdness of much the comment, is it true that men are more pro-natalist than women? I have shown that there seems to be a trend within the last 10 years of preference for larger families. What’s the sex breakdown for this?

The correlation between men and women is 0.65 year-to-year in their mean for ideal number of children. About 43% of the variance of the trend over the years can be predicted from one sex to the other. Is there is a systematic difference? Here’s a chart:

fertscreen

The period before 1998 is rather noisy overall. The correlation actually increases after ‘98 because of the concurrent upward trend. That being said, it looks like the pro-natalist bias is more accentuated among women than men. If I constrain the years to the 2000s, and age range to 18-30, the mean ideal number of children for men is 2.88 and for women it is 3.03.

These data indicate that in fact Bryan Caplan marches with the sisterhood on this issue.

Supersonic Green Machine

Take a look at this:

NASA - Supersonic Green Machine

This came from a NASA news release today, and I thought it looked interesting.  Here’s what NASA has to say about it:

This future aircraft design concept for supersonic flight over land comes from the team led by the Lockheed Martin Corporation.

The team’s simulation shows possibility for achieving overland flight by dramatically lowering the level of sonic booms through the use of an “inverted-V” engine-under wing configuration. Other revolutionary technologies help achieve range, payload and environmental goals.

This supersonic cruise concept is among the designs presented in April 2010 to the NASA Aeronautics Research Mission Directorate for its NASA Research Announcement-funded studies into advanced aircraft that could enter service in the 2030-2035 timeframe.

I wonder what it’s fuel consumption would be, and if something like this would be available for civilian traffic.

What do you think about the Supersonic Green Machine?

NCBI ROFL: A foot needs a nipple like a fish needs a bicycle. | Discoblog

footcensored[Uncensored photo below]

Case report: Ectopic nipple on the sole of the foot, an unexplained anomaly.

“Supernumerary nipples are common congenital anomalies, most often occurring along the embryonic milk lines. We present a patient with an ectopic nipple on the foot. We are unable to explain the aetiology of this anomaly; however, several theories have been proposed.”

foot_nipples

Bonus figures:

nipple_foot_images“The patient considered the lesion to be a cosmetic blemish and refused to have it excised. He was advised follow-up every 6-months or to seek consultation if any features of the nipple changed.”

Related content:
Discoblog: NCBI ROFL: No bra + Wringer washing machine = squished boob.
Discoblog: NCBI ROFL: Eye Tracking of Men’s Preferences for Female Breast Size and Areola Pigmentation.
Discoblog: NCBI ROFL: Bad news: you have a tumor. Good news: it’s really cute!

WTF is NCBI ROFL? Read our FAQ!


If Only Oil Spills Would Evaporate Like Climategate | Cosmic Variance

Even if I’m on hiatus, there’s no reason not to post links to interesting things that I would be tweeting anyway. Blogs are still much better places to have conversations, whatever the Twitter triumphalists might think.

With that in mind: check out this story by Sharon Begley from Newsweek, on how media are slowly backing away from the Climategate hysteria. (Via PZ.) She very rightly highlights the real damage: the backing-away won’t undo all the misimpressions of scientific malfeasance that people absorbed when the story was at its height.


New Report Says a Fetus Can’t Feel Pain Before 24 Weeks | 80beats

24weeksIn a development that’s certain to stir passions in the abortion debate, the Royal College of Obstetricians and Gynaecologists in the UK published a report today on “fetal awareness.” The group states, citing a review of current research, that human fetuses cannot feel pain before 24 weeks.

The group’s reasoning, as described in a press release, is based on these points:

-The fetus cannot feel pain before 24 weeks because the connections in the fetal brain are not fully formed
-The fetus, while in the chemical environment of the womb, is in a state of induced sleep and is unconscious
-Because the 24 week-old fetus has no awareness nor can it feel pain, the use of analgesia is of no benefit
-More research is needed into the short and long-term effects of the use of fetal analgesia post-24 weeks [Royal College of Obstetricians and Gynaecologists]

This is certainly not the first debate over whether a fetus can feel pain. Fetal surgeries have led doctors to ask this question, as they determined whether anesthesia was appropriate and at what stage in development. As summarized in a 2008 New York Times Magazine article, researchers have looked at fetal flinch responses, heart rate, and levels of stress hormones. But any metric has remained controversial. Take stress hormones, for example. Do you say that any fetus that can release these hormones feels pain? Or do you wait until it develops the nervous system to register those hormones? Or do you say that an undeveloped nervous system makes the fetus more susceptible to pain, since it hasn’t developed the system to suppress it?

In April, Kanwaljeet Anand, director of the Pain Neurobiology Laboratory at the University of Tennessee Health Science Center in Memphis and an often-quoted researcher in the debate, described some of the issues:

When a fetus of that age [18 to 20 weeks] gets a blood transfusion, for example, changes in heart rate and blood pressure accompany shifts in circulation and spikes in stress hormones. A morphine-like drug calms all of those responses down. “The die-hards will say these are all reflexes,” Anand said. But new evidence, he argued, suggests that the very young brain is developed enough in the right places to take in those sensations and translate them into pain. [Discovery News]

The Royal College of Obstetricians and Gynaecologists’ report differs from Anand’s assessment, and argues that fetuses younger than 24 weeks don’t have the brain connections to register pain, and if they could register the chemical signals, they couldn’t make out what they mean.

The report on pain perception says: “It was apparent that connections from the periphery to the cortex are not intact before 24 weeks of gestation and, as most neuroscientists believe that the cortex is necessary for pain perception, it can be concluded that the foetus cannot experience pain in any sense prior to this gestation.” Even after 24 weeks, “it is difficult to say that the foetus experiences pain because this, like all other experiences, develops post-natally along with memory and other learned behaviours”. [The Gaurdian]

Understanding when a fetus can feel pain has implications for abortion laws, and groups on both side of the debate have weighed in on today’s reports.

As the BBC reports, those in the United Kingdom question the reports’ implications for the 1967 Abortion Act, which covers all parts of the UK apart from Northern Ireland, and caps legal abortion at 24 weeks (with some exceptions, regarding dangers to the life of the pregnant woman or evidence of serious fetal abnormality). Some activists had campaigned to reduce that timeframe, but UK government representatives have said that there are currently no plans to change the act.

A Downing Street spokeswoman said: “The Prime Minister’s view is that he will be led by the science.” She added: “At the moment there are no plans to change the policy.” [BBC]

Related content:

DISCOVER: When Does a Fetus Feel Pain?
80beats: Sex-Selective Abortions in China Have Produced 32 Million Extra Boys
80beats: Obama to Rescind “Conscience” Rule on Abortion and Birth Control
80beats: Federal Rule Lets Doctors Deny Medical Care Based on Religious Concerns
80beats: Leftover Embryos at Fertility Clinics Pose Troubling Questions for Patients

Image: flickr / Chris Denbow


First they came for Dave Weigel | Gene Expression

Dave Weigel of The Washington Post has resigned over his juvenile postings on an e-list. Basically the postings allowed for Weigel’s mask to slip, and showed him to be a vulgar and immature young man in some contexts. That’s no different from many of us in the proper context. The e-list is now defunct because of this information break.

Someone like Dave Weigel, a reporter who has to make a public pretense toward objectivity, and a somewhat public person, is atypical. But I think it’s the tip of the iceberg. People who know me in “real life” know that nothing they say to me will ever show up on this blog; it’s private, and my day to day interactions almost never intersect with the topicality here. If I want to introduce an idea or concept that someone else familiarized me with I will ask if I can do so, and credit them if they request. But that’s the nature of this blog, which draws more upon the scientific literature or reader feedback. Other outlets blur the line between private & public more explicitly, and if you meet someone with such an outlet, watch what you say, watch what you do. I’ve been on private e-lists where people say things that in public that could really compromise them. I’ve even gotten into disputes with people who were taking one stand in public which I knew could be easily undercut if I “exposed” what they’d said in private.

In the short term by breaking down barriers to information flow the internet is going to result in people retrenching to the narrowest and most trusted circles to “let their hair down.” In the long term I think we might have to reconceptualize what we think of as private or public. Soon enough a whole host of data on anyone you meet will be available on demand. And your data will also be available to them.

Buzz Aldrin Explains: How to Take a Whiz on the Moon | Discoblog

144832main_aldrin_bootprintCharged with writing to an astronaut, a five-year-old boy asked a burning question: How do you pee and poop in your astronaut suit?

In an interview with Buzz Aldrin just published in Vanity Fair, contributing reporter Eric Spitznagel finally got this answer:

“We were well skilled in the art of disposal waste. There was such a thing called a ‘blue bag,’ which was kind of messy. There was a stickum on it, and you could stick it around your posterior. For urinating we had an ego-buster, which was like a condom catheter. We were cautioned not to overestimate our size. (Laughs.) Because if the condom was too big, there might be a little leakage.”

The story continues: Aldrin describes in full detail what happens if you *do* have a little “leakage” (wiggle it out into a larger bag) and where astronauts flush those blue baggies. Aldrin tells Spitznagel about a newbie mistake of tossing the bags (during extra-vehicular activity) in a trajectory that brought them straight back at their capsule.

“We looked out the window and there were three bags in a row, heading straight for us.”

In case, Spitznagel isn’t the only one wondering about space crap, you should know that taking care of business has come a long way since blue bags. Astronauts potty train using simulators before their travels. The Space Shuttles and International Space Station both have air-flushing toilets, and the International Space Station recycles pee.

Related content:
Discoblog: California Lays Claim to Astronaut Garbage Left Behind on the Moon
Discoblog: Scientists Examine Underwear Astronaut Wore for a Month
Discoblog: Astronauts in Space Finally Enter the Intertubes
Discoblog: Yum! Silkworms Could Be the Next Astronaut Food
80beats: Strife on the Space Station: Russians Can’t Use the American Toilet

Image: NASA


The Human Genome at 10: What It Did—and Didn’t—Deliver | 80beats

DNAHappy Birthday, human genome. On June 26, 2000 a group of scientists at the White House announced that they had a working draft of our genetic blueprints. They hadn’t sequenced all our genes; the Human Genome Project and its private-sector competitor Celera Genomics still had some gaps to fill in. Still, scientists believed this data might hold clues to the causes of certain diseases and could lead to new treatments.

Even before the project’s start, some scientists were skeptical: Was mapping our genome a waste of money and time? Even among public hoopla and presidential speeches, scientists cautioned that applying the results would take time. Now, ten years later, many are asking: What have we learned? Here we round up some opinions about the impact of the project.

The Bad?

Some see fewer medical treatments than advertised. Instead of simple relationships between common variants and specific diseases, sequencing uncovered sheer complexity. Researchers now think that intricate relationships between rare variants may cause many diseases.

The difficulties were made clear in articles by Nicholas Wade and Andrew Pollack in The Times this month. One recent study found that some 100 genetic variants that had been statistically linked to heart disease had no value in predicting who would get the disease among 19,000 women who had been followed for 12 years. The old-fashioned method of taking a family history was a better guide. Meanwhile, the drug industry has yet to find the cornucopia of new drugs once predicted and is bogged down in a surfeit of information about potential targets for their medicines. [The New York Times]

As genetic sequencing goes, what once took years and millions of dollars can now take months and thousands. Still, some worry that the drive to sequence more, faster has led to techniques that make reading results increasingly hard.

The advances in speed … have come at a cost. Only short stretches of DNA can be sequenced at a time, so the pieces have to be joined together by looking for overlaps between them. While early instruments sequenced pieces up to 900 base pairs long, most high-speed machines produce “reads” of less than 100 base pairs. That means the overlaps are much shorter, making it far harder to join the pieces together, so assemblers use existing genomes as a guide — which can lead to mistakes. [New Scientist]

The Good?

Though the Human Genome Project may have thus far yielded fewer advanced medical treatments than hoped for, the findings for biologists seem greater than expected. The complexity that frustrated those looking for practical, clinical applications has led to rich veins of research.

Nature News surveyed more than 1,000 life scientists, many who said that the sequenced genome had greatly benefited their work:

Almost all biologists surveyed have been influenced in some way by the availability of the human genome sequence. A whopping 69% of those who responded to Nature ’s poll say that the human genome projects inspired them either to become a scientist or to change the direction of their research. Some 90% say that their own research has benefited from the sequencing of human genomes — with 46% saying that it has done so “significantly”. And almost one-third use the sequence “almost daily” in their research. “For young researchers like me it’s hard to imagine how biologists managed without it,” wrote one scientist. [Nature News]

Some also praise the accessibility of genomic data from this research as a means to advance further research–among them, Francis Collins, current NIH director and former head of the Human Genome Project.

“For example, the search for the cystic fibrosis gene finally succeeded in 1989 after years of effort by my lab and several others, at an estimated cost of U.S. $50 million,” Collins writes in an opinion piece published in this week’s issue of the journal Nature. “Such a project could now be accomplished in a few days by a good graduate student. … ,” he writes. All the budding geneticist needs, Collins says, is the Internet, some inexpensive chemicals, a thermal cycling machine to amplify specific DNA segments, and access to a DNA sequencer, which “reads” DNA via light signals. [National Geographic]

Nature Newspoll also hints that scientists believe that a better understanding of the underpinnings of human genetics, better systems to analyze the sequenced data, and more information from other research like the Human Epigenome Project will help turn this biological knowledge into clinical applications–some argue within the next 10 to 15 years.

Others say we can only wait and see. That’s what Eric S. Lander, director of the Broad Institute, told The New York Times regarding a direct connection between sequencing and treatments.

“The only intellectually honest answer is that there’s no way to know,” Dr. Lander said. “One can prefer to be an optimist or a pessimist, but the best approach is to be an empiricist.” [The New York Times]

Related content:
80beats: Court Strikes Down Patents on Two Human Genes; Biotech Industry Trembles
80beats: IBM’s “DNA Transistor” Could Sequence Genomes on the Cheap
80beats: New Lawsuit Challenges the Patenting of Human Genes
80beats: Big Autism Study Reveals New Genetic Clues, but Also Baffling Complexity

Image: flickr / net efekt


How to Build a Working Rat Lung in a Lab | 80beats

rat-lungStep 1: Take a rat lung. Step 2: Strip away all of its living cells, leaving only a fibrous “scaffold” of connective tissue. Step 3: Bathe the scaffold in lung cells taken from newborn rats, and put the whole thing in a bioreactor to let the cells multiply and spread. Step 4: A few days later, when the reconstructed lung is again filled with blood vessels and alveoli, transplant the organ into a living rat. Step 5: Watch in awe as the lung begins to function.

That’s the short version of the experiment Yale University researchers just published in Science. The study was a result of a change in direction for lead researcher Laura Niklason:

Niklason spent several years trying to create a synthetic lung scaffold, but in the end concluded it was too difficult. “I decided I couldn’t do it, and probably nobody else could either,” she said. [National Geographic]

The proof-of-concept study showed that a lung reconstructed on a natural scaffold could serve its intended purpose in vivo at least temporarily, but the medical applications of this technology are far off. Theoretically, a fibrous collegen scaffold could be taken from a dead donor and put into a living patient without triggering an immune response, but living cells are another matter. To prevent the patient from rejecting the new lung, researchers will have to find a better source for the cells that would coat the scaffold.

Scientists could perhaps take healthy cells from a patient’s lungs, or they could take other cells from the patient and coax them back into a stem cell-like state, allowing them to grow into all the necessary forms of lung tissue.

“I clearly don’t think we’ve solved the whole problem, but I sort of feel like we’re laying train tracks into the mountains,” Niklason said. “We haven’t gotten to the other side of the mountain range yet, but when we do, I hope there’s a big bus of stem cells waiting for us.” [Los Angeles Times]

For a more thorough explanation of this work and its potential implications for human medicine, check out Ed Yong’s post at Not Exactly Rocket Science.

Related Content:
Not Exactly Rocket Science: Lungs Rebuilt in Lab and Transplanted Into Rats
80beats: Can Sight Be Restored With Stem Cells Grown on Contact Lenses?
80beats: Brain Reconstruction: Stem-Cell Scaffolding Can Repair Stroke Damage
80beats: Doctors Use a Patient’s Own Stem Cells to Build Her a New Windpipe
80beats: Researchers Could Grow Replacement Tissue to Patch Broken Hearts

Image: Science / Thomas Petersen, et al.


Two teachers doing good work to promote science education | Bad Astronomy

I have two tales of teachers trying to teach, um, science (nuts, ran out of t words).

The first is about Joanne Manaster — you may remember her review of my book. She has set up a contest for kids to read science books and then create a short video based on the book. There are two levels: Kids Read Science aimed at ages 8-12, and Teens Read Science for ages 13-18.

This is a terrific idea! It’s a great way to get kids to read about science (and scientists!). She made a short video describing the project:

The deadline is 11 p.m. central time on September 22, 2010, so if you have a kid that age or know one, encourage them to participate — one of the prizes is a copy of my book!


The second tale is about Alan Leipzig, a middle school teacher in Florida. He contacted me a little while back to let me know he was trying to raise money to buy a class set of my book, Death from the Skies! Before I could even reply, he actually got all the money he needed, which is terrific! So now he’s looking to buy a second set so the students can bring the book home. If you’re interested in donating to him, he’s set up a link on Donor’s Choose, a terrific site that lets educators create donation pages for their individual projects. Remember: this is your chance to help kids read, learn about astronomy, and get the crap scared out of them. So give!


Is Louisiana’s Oil-Blocking Sand Berm Project Doomed? | 80beats

ChandeleurBuild a wall of sand: That was Louisiana Governor Bobby Jindal’s answer to protecting the state’s delicate marshlands when it became clear that BP wasn’t going to stop its gushing oil leak anytime soon. But now the federal government has put the kibosh on Louisiana’s construction, saying that the project to save one ecologically sensitive area will ruin another.

Scientists raised several objections to the state’s first proposal last month to build a long line of sand berms on 10 May. One key concern was that taking sand from in front of the Chandeleur Islands would make them more vulnerable to erosion. The state agreed to change its approach by taking sand from a site further away and then pumping it through pipes to build the berms [ScienceNOW].

However, that didn’t happen. Louisiana officials said they couldn’t get the pipes built in time, and asked the feds to let them dredge near Chandeleur at least until the other site was ready. OK, the Interior Department said—you’ve got a week. That week has lapsed, but Louisiana is still requesting more time to dredge near Chandeleur, promising to return the sand once the berm project has done its job.

That didn’t impress Tom Strickland, the Assistant Interior Secretary for Fish, Wildlife and Parks. He says dredging more material puts the already-eroding Chandeleurs at too much risk.

The Chandeleurs, in the Breton National Wildlife Refuge east of the Mississippi, are nesting grounds for species such as the brown pelican, and they are part of a diminishing natural hurricane barrier for Louisiana. Federal and state officials hope to someday fully restore the islands, which have been eroding for decades. Strickland said the berms are expected to last only about 90 days, maybe not even that long in an active hurricane season [BusinessWeek].

Even if you put the sand back there once you’re done with it, he says, it won’t be packed in or bonded like it was before, and might be washed away more easily.

The feds’ sudden outburst of concern failed to impress the already frustrated Gov. Jindal.

“We’ve been losing 300 feet every year off these islands — where has the federal government been?” he told reporters after touring the dredging site Wednesday. “All of a sudden when we’re building new land to protect our coast, they’re worried about a hypothetical” [CNN].

Previous posts on the BP oil spill:
80beats: Will Methane Gas in Gulf Waters Create a Massive Dead Zone?
80beats: From Marsh Grass to Manatees: The Next Wave of Life Endangered by BP’s Oil
80beats: Obama’s Speech on the Oil Spill: What Do You Think of His “Battle Plan”?
80beats: BP to Kevin Costner: We’ll Take 32 of Your Oil Clean-up Machines

Image: NASA Earth Observatory


The Large Cryogenic Gravitational-wave Telescope | Cosmic Variance

LCGT posterI am presently in Japan, participating in the Gravity and Cosmology workshop at the Yukawa Institute for Theoretical Physics on the Kyoto University campus. The big news here is that the Large Cryogenic Gravitational-wave Telescope (LCGT) was just approved for funding! I believe that this is the press release, as witnessed by the exclamation mark at the end of the title (a Japanese speaker will no doubt correct me if I’m wrong). Apparently they have been granted roughly half of their estimated price tag (of >$200 million). This is a critical step, and I am told that once the Japanese government commits funds, it is highly unlikely to change its mind down the road. So LCGT is a huge step closer to becoming a reality.

We have waxed poetic about gravitational-wave detectors before (here, here, and here). These instruments are truly amazing feats of engineering, with the power to unlock a whole new window on our Universe. LCGT would be even more impressive than the current instruments (LIGO and Virgo): it takes its 3-kilometer long power-recycled Fabry–Perot–Michelson interferometer arms, and places them one kilometer underground (to reduce seismic noise, which sets the low-frequency [<10 Hz] noise floor). As if that’s not enough, it also cools its mirrors to ~20 degrees above absolute zero (which reduces thermal noise, which sets the intermediate-frequency [10--100 Hz] noise floor).

As it happens, I am in the midst of finishing a project with Samaya Nissanke (at JPL) and Scott Hughes (at MIT), trying to determine how well various gravitational-wave networks detect gravitational-wave standard sirens (stellar mass black hole and/or neutron star binary inspirals; more on why these are interesting in a future post). In particular, we are finding that adding LCGT to the expected Advanced LIGO-Virgo network increases the number of detected binaries by 50%, and generates more uniform sky coverage. LCGT will substantially enhance our view of the gravitational-wave sky, and will improve the science coming out of all the upcoming gravitational-wave detectors. Congratulations to the Japanese for pushing this observatory forward!


What has Rome to do with Nairobi? | Gene Expression

rule-empires-those-who-built-them-timothy-parsons-hardcover-cover-artThere are very few books which would attempt to connect the experiences of the 1st century British who lived through Roman conquest with the French under the Vichy regime in World War II. The The Rule of Empires: Those Who Built Them, Those Who Endured Them, and Why They Always Fall by Timothy Parsons attempts to do just that. As John Emerson observed the subtitle is obnoxious; all states fall, not just empires. But in the author’s defense usually they are not the ones who decide upon the title, rather the publishers look for sentences which are catchy and can move some units. A grand explanation of why empires fall may appeal to the average reader. A disparate collection of descriptions of the imperial experience, filtered through a prism strongly shaped by 20th century perceptions and models of colonialism, perhaps not. The latter is what the The Rule of Empires is. The author is a professor of 20th century African social history, and the specter of the European colonialism of the Dark Continent haunts even the chapters on Roman Britain or Umayyad Spain. Though Parsons’ sympathy with the subjugated is obvious he restrains himself enough so that tiresome polemic does not interfere excessively with the collation of fact or the attempt to engage in objective analysis. Unfortunately the project of a grand theory of the rise and fall of empires, or more accurately the colonized experience, falls short of its goals. I was totally unpersuaded that the fall of Napoleonic Italy, Roman Britain, or British Kenya, were united in any deep way by inevitable social or institutional forces of history which thread together all empires. Though there are many interesting facts on display, it does seem to me that the author falls into a tendency to transform all imperialists into 20th century British, and all subjects into 20th century Kikuyu. The most recent imperial adventures serve as the models, or the skeleton, around which the grand theory is built, and that only distracts from the specific chapters which are rich with specific detail.


Consider the stab at describing and decomposing the British Celtic experience of Roman conquest and colonization. The reality is that we don’t know much about this experience, a reality which the author admits. Even the most gripping narrative nugget, the rebellion of Boudica and the Iceni against the depredations of the Romans, is historically fraught. To add firmness to this section Timothy Parsons engages in supposition and extrapolation. Some of it is rather stretched to the extreme. Like most social historians he cautions against back-projecting modern notions of nationhood to antiquity, but he can’t help but slipping this framework into his dyads of conqueror and conquered. For narrative purposes setting the Romans against the vague and incomprehensible welter of diffuse Celtic tribes and local affinities would be absolutely unreadable, and analytically intractable. And yet there was no singular British nation which was oppressed by a singular Roman nation. Ancient identity was somewhat different than modern identity. Parsons acknowledges this, and then periodically ignores it nonetheless.

More problematically the author makes some elementary errors in classical history which trouble me. He asserts as a theoretical truth that the distinction between conquered and conqueror must be maintained for proper order of empire through the text. One particular passage in the Roman chapter really jumped out at me:

…Caracalla bestowed blanket citizenship on all residents of the empire in A.D. 212. Those who prefer to imagine the Roman Empire as a civilizing force cite this mass enfranchisement as evidence of its benevolence, but it is more likely that Caracalla’s concession was a pragmatic acknowledgement that the boundaries of true subjecthood had blurred to the point where the Roman Empire was actually no longer an imperial institution by strict definition.

…the respectable and military classes of the empire had become so romanized that the distinction between citizen and subject no longer mattered at the elite level. This universal enfranchisement must have tempered the extractive power of the state and may have contributed to the financial crisis that best the later Roman Empire.

First, the evidence for the economic state of the later Empire is confused. Some scholars assert that after the 3rd century chaos the 4th century empire was nearly as robust as that of the 1st and 2nd centuries. In other words, there is no consensus that revenue extraction decline monotonically; the chaos of the 3rd century may have been an interregnum. It seems rather bizarre to assume a priori that blurred boundaries necessarily entailed lower taxation rates. In fact one of the rationales given for the ease of Arab conquest of the Byzantine Near East was that the Arabs imposed lower taxes than the Byzantines. Whether this is correct, the rate of taxation is subject to may variables and I am not convinced that the theoretical presupposition which Parsons holds to is strong enough to take it as a given.

But the bigger issue is that the description of the consequence of Caracalla’s granting of universal citizenship to free men in the Roman Empire totally ignores the conventional starting point: that it was an attempt to increase the Empire’s tax base! Or at least that is the reason given by Cassius Dio in his description of the edict. Whether this was correct or not, any discussion of this act’s impact on revenue should at least make note of this orthodoxy. I have to wonder then if the author was simply not aware of this basic fact.

Obviously to many this discussion may seem a bit pedantic, but The Rule of Empires is a book rich in fact and dense with data, and in many of the other chapters my own base of data was thinner so I would naturally rely on the author. But if such glaring problems of analysis are present in the section on Rome, a period with which I am familiar, I must admit to some caution at accepting the rest of the data at face value.

More abstractly it seems that the biggest failure of Timothy Parson’s framework is its economic ahistoricism. Prior to the industrial revolution the vast majority of humanity experienced life on the Malthusian margin, and the game of empire was a matter of elites stealing from each other’s human cattle. Additionally, if political orders are broken up into smaller units that would introduce multiplicity of function and possibly greater costs to the peasant producer. More plainly Roman conquest may have introduced economies of scale as well as greater peace in the life of the British peasant, who admittedly had little national identity as it was. This is not the story in The Rule of Empires, even though the author admits that there’s very little empirically to go on. With a unified theoretical framework from the 2nd to the 20th century one might presume that the Romans as rapacious alien conquerors with little sympathy for British peasants would increase taxation, but the 2nd century was a world where all elites were rapacious and had little sympathy for peasants, and the economic pie was notably stagnant in its extent.

In contrast Parsons correctly observes that the the European colonization of Africa was a negative sum affair. In an age of real economic productivity growth and demographic transitions, the gains to colonialism were of symbolism, as well as to a small minority of sub-elites whose primary aim was to exploit the natives for profit. A classic instance of socializing the losses of failed expeditions, and privatizing their gains. The density of the later chapters, and their analytical heft, is a sharp contrast with the often platitudinous regurgitations of secondary literature which seem to dominate the sections on antiquity and the medieval period. Timothy Parsons would have benefited from being less ambitious, and simply admitting that his definition of empire makes no sense before 1800.

Nairobi truly does have little to do with Rome.

Everybody Panic! Reusable Shopping Bags Harbor Bacteria | Discoblog

reusable-bagSo at some point you decided to do the right thing for the environment, and plonked down a couple of dollars for a reusable grocery bag. Bet you felt pretty good about yourself, huh? Well, some researchers have now come along to rain on your virtue parade. According to a new report (pdf), that bag is probably crawling with bacteria.

The researchers tested 84 bags, and found that all but one harbored bacterial colonies, and half contained coliform bacteria that suggest raw meat or uncooked food contamination. They also surveyed consumers about their use of these bags, and found that most people don’t keep separate bags for meat, and that they’re likely to tote clothes and all sorts of other things in these bags when they’re not grocery store-bound. Both these practices could allow for bacterial colonization.

But before you burn your reusable bags in a cleansing fire, consider this: The researchers also determined that either chucking a bag in the washing machine or rinsing it by hand reduced the bacterial counts to almost zero.

And The Washington Post dispassionately chimes in on another very relevant note:

The study was funded by the American Chemistry Council amid debate over a California bill that would ban single-use plastic bags. The council is opposed to that measure.

Related Content:
Discoblog: It’s In the Bag! Teenager Wins Science Fair, Solves Massive Environmental Problem
Discoblog: Got Too Many Plastic Bags? Recycle Them Into Nanotubes
80beats: Will California Be the First State to Ban the Plastic Shopping Bag?
80beats: Did Your Morning Shower Spray You With Bacteria?

Image: flickr/ foldablebags.com


Want Someone to Take a Decision Seriously? Hand Them Something Heavy | 80beats

fingerprintTouch comes first. It’s the first way that people interact with the world, MIT’s Josh Ackerman says, and touch can change the way you feel about the world or engage with it.

Ackerman and colleagues published a study in Science this week further uncovering the ways that what we touch influences what we think. In a series of experiments, his team demonstrated numerous examples of the tactile altering the mental, like people negotiating more stubbornly when sitting in hard, uncomfortable chairs, or taking decisions more seriously when holding a weighty object like a clipboard.

The idea, then, is that due to the strong connection between our senses and our thoughts, touching a surface can trigger feelings related to the metaphorical value we assign to it. Or, more simply, the feeling of weight makes us feel like a decision is more “weighty,” a harsh surface like sandpaper leads to harsh feelings toward other people, and the touch of smoothness makes us feel like things are going to smooth over.

“The tactile sensation is extremely important early in development. The idea that other associations would be built on that makes intuitive sense,” said Franklin & Marshall College psychologist Michael Anderson, who was not involved in the study. “Brain regions that may initially have been dedicated to one particular task, turn out to contribute to multiple tasks” [Wired.com].

For more on this, check out Ed Yong’s in-depth post at Not Exactly Rocket Science.

Related Content:
Not Exactly Rocket Science: Heavy, Rough, and Hard: How Things We Touch Affect Our Judgment And Decisions
80beats: In a Sensory Hack, What You Touch Affects What You See
80beats: Fingerprints Are Tuned to Amplify Vibrations and Send Info to the Brain
80beats: Warm Hands Give People a Friendly, Generous Outlook
80beats: Hand Washing After a Decision Scrubs Away Those Lingering Doubts

Image: Science/AAAS


Western US lunar eclipse June 26 | Bad Astronomy

There will be a partial lunar eclipse on Saturday, June 26, for folks in the central and western part of the United States. It’s in the morning, so you’ll have to get up early to see it. Here’s what it’ll look like, more or less, from the Mountain Time Zone (so mid-eclipse is at 06:38 central time or 04:38 Pacific):

lunareclipsejune262010

The folks at Stardate.org have more info.

A lunar eclipse is when the Moon passes into the shadow cast by the Earth. It can be seen by anyone as long as the Moon is up and visible when it’s in the shadow. In this case, the farther west you are the better; the Moon will set before the action really gets going for people on the east coast, and sets mid-eclipse for Central and Mountain timers. If you’re in Hawaii, you can see the whole thing.

Lunar eclipses are pretty, and they last for a long time, so you can get a decent chance of seeing it. They’re also pretty easy to photograph, so if you get some images online link to ‘em in the comments and let us ooooh and ahhh over them!