Magnified view of microscopic particle, about 0.01 mm in size, from inside the sample return canister with quartz manipulator used by research team who hope it is first ever material returned from an asteroid. Note shadow of manipulating needle above. .Credit: JAXA

A little while ago we heard about the Hayabusa spacecraft making its way back to Earth after visiting the asteroid Iwotaka.

Part of the mission was to land on the asteroid and collect a sample from the asteroid and return it.  Sadly the sampling mechanism failed to work properly, not firing a projectile into the surface so the dust kicked up could be collected inside a canister.  Could the force of the landing craft kick up enough dust to be sampled?  The scientists and engineers at JAXA were hopeful.

Turns out the canister did indeed contain a few very small particles.  Now the question becomes: are they particles from the asteroid or contamination?  Time will tell.  If these are from Iwotaka they will be the first particles ever returned from an asteroid.  The samples are very small but apparently not so small they are useless and they will be extensively tested.

Hayabusa was the first spacecraft to land and take off from an asteroid.  Hayabusa suffered from some failures of its ion engines and really is a tribute to JAXA and their resolve to get the craft back, even if it did take three years longer.  JAXA is one of those space agencies that will emerge in the forefront of space sciences with what looks like more and more like the imminent demise of NASA.  Oh and don’t count China out, although they might not be as apt to share information believe you me they are up and coming.

It will be interesting to see how the private space industry in the US will stack up with other space launch entities, after all, commercial launches have been doing commercial space launches for quite a few years and are really the leaders in such endeavors at this point.  I kind of expect great things from the US industry, but that still remains to be seen.

Check out the JAXA site for more about what they are doing.

Breaking radio silence here to report on some of the actual work I’ve been able to complete: a new paper with Heywood Tam.

Unitary Evolution and Cosmological Fine-Tuning
Authors: Sean M. Carroll, Heywood Tam
(Submitted on 8 Jul 2010)

Abstract: Inflationary cosmology attempts to provide a natural explanation for the flatness and homogeneity of the observable universe. In the context of reversible (unitary) evolution, this goal is difficult to satisfy, as Liouville’s theorem implies that no dynamical process can evolve a large number of initial states into a small number of final states. We use the invariant measure on solutions to Einstein’s equation to quantify the problems of cosmological fine-tuning. The most natural interpretation of the measure is the flatness problem does not exist; almost all Robertson-Walker cosmologies are spatially flat. The homogeneity of the early universe, however, does represent a substantial fine-tuning; the horizon problem is real. When perturbations are taken into account, inflation only occurs in a negligibly small fraction of cosmological histories, less than 10^{-6.6×10^7}. We argue that while inflation does not affect the number of initial conditions that evolve into a late universe like our own, it nevertheless provides an appealing target for true theories of initial conditions, by allowing for small patches of space with sub-Planckian curvature to grow into reasonable universes.

In English: our universe looks very unusual. You might think we have nothing to compare it to, but that’s not quite right; given the particles that make up the universe (or the quantum degrees of freedom, to be technical about it), we can compare their actual configuration to all the possible configurations they could have been in. The answer is, our observed universe is highly non-generic, and in the past it was even more non-generic, or “finely tuned.” One way of describing this state of affairs is to say that the early universe had a very low entropy. We don’t know why; that’s an important puzzle, worth writing books about.

Part of the motivation of this paper was to put some quantitative meat on some ideas I discussed in my book. The basic argument is an old one, going back to Roger Penrose in the late 1970’s. The advent of inflation in the early 1980’s seemed to change things — it showed how to get a universe just like ours starting from a tiny region of space dominated by “false vacuum energy.” But a more careful analysis shows that inflation doesn’t really change the underlying problem — sure, you can get our universe if you start in the right state, but that state is even more finely-tuned than the conventional Big Bang beginning.

We revisit this question, bringing to bear some mathematical heavy machinery developed in the 1980’s by Gary Gibbons, Stephen Hawking, and John Stewart. Previous discussions have invoked general ideas of entropy or reversibility, but we were able to do a relatively down-to-earth calculation using conventional cosmological models. And we tried our best to explicitly list all of the caveats of the argument, which is important in a context like this where we don’t know all the rules.

We find that inflation is very unlikely, in the sense that a negligibly small fraction of possible universes experience a period of inflation. On the other hand, our universe is unlikely, by exactly the same criterion. So the observable universe didn’t “just happen”; it is either picked out by some general principle, perhaps something to do with the wave function of the universe, or it’s generated dynamically by some process within a larger multiverse. And inflation might end up playing a crucial role in the story. We don’t know yet, but it’s important to lay out the options to help us find our way.

This week it’s green for green: On Tuesday, we mentioned that the Department of Energy was giving out loans totaling $2 billion for two big solar panel projects. Now, the DOE has offered $67 million for research on carbon capture, in hopes of propelling nascent carbon capture and storage projects.

Carbon capture, as its name suggests, requires trapping carbon dioxide from fossil fuel-burners like coal power plants before it enters the air. It isn’t easy. For one, you have to figure out what to do with all the CO2 once you capture it. The first power plant to try out carbon sequestration has found that its neighbors aren’t keen on having CO2 pumped deep into the earth below their town.

Also, capturing the greenhouse gas requires energy, adding 80 percent to the cost of electricity for a new pulverized coal plant and around 35 percent for a high-tech coal gasification plant. The goal, the DOE says in the award announcement, is to reduce these costs to less than 30 percent and 10 percent, respectively.

The funded projects look at ways to improve membranes and solvents to capture the gas after the plant burns the coal.

Although current technologies address the problem using separating membranes or chemical solvents at all stages of combustion — including before, during and after the fuel is burned — the money here is aimed at postcombustion projects. The government is providing about $52 million, with an additional $15 million in cost-sharing funds coming from non-federal sources. [New York Times]

Secretary of Energy Steven Chu said that the research is in line with the Obama administration’s goal to have 5 to 10 commercial demonstration carbon capture projects online by 2016.

“Charting a path toward clean coal is essential to achieving our goals of providing clean energy, creating American jobs, and reducing greenhouse gas emissions. It will also help position the United States as a leader in the global clean energy race,” Chu said. [DOE]

Despite this funding, some remain skeptical that carbon capture will ever make coal clean enough, cheaply enough to compete with developing renewable energy sources like wind and solar, which they expect to grow increasingly efficient.

Related content:
80beats: Obama & Chu Push Ahead With Clean Coal Projects Despite the Cost
80beats: World’s First Really Clean Coal Plant Gets a Try-Out in Germany
DISCOVER: Can Clean Coal Actually Work? Time to Find Out.
DISCOVER: Can Coal Come Clean?
DISCOVER: The Key to Safe and Effective Carbon Sequestration

Image: flickr / Rennett Stowe

Teamwork: That’s what it takes to get lucky (if you’re a certain kind of firefly).

Suppose you’re a single male firefly, fluttering about on a muggy night. You flash your bioluminescent signal to try to catch a lady’s attention, but how is she going to pick out your blip from all the other points of light ablaze when various species of firefly zoom around? About 1 percent of firefly species have figured out how to beat the noise: They team up and flash their lights in an unmissable, synchronous signal. And in a study in this week’s Science, researchers unlocked the inner workings of this sexual back-and-forth.

Biologists had long known about the synchronous flashing, but had not tested the idea that each species has its own rhythm—its own signal to complete the optical call-and-response between male and female.

To do this, Andrew Moiseff of the University of Connecticut in Storrs and Jonathan Copeland at the State University of New York at Stony Brook turned to LEDs. They put female synchronous fireflies (Photinus carolinus) in a Petri dish surrounded by green LEDs, and flashed the lights in the same pattern used by male fireflies. The females responded with their signature pattern 82 per cent of the time – but only if the LEDs were synchronised. When the lights did not flash in unison, female response dropped to 10 per cent or less [New Scientist].

The code of flashing lights is not the end of the story, of course. It takes a group of males to flicker in unison, but not all of them will get to mate when the female responds with her “come on over here, fellas” signal.

“Six to a dozen males may be attracted,” said Moiseff. “We don’t know if she’s distinguishing among males when she responds.” When a female firefly — which is really a kind of beetle — ventures to give the signal, she is calling quite a crowd. In the field it’s not at all uncommon to find a solitary female surrounded by a dozen hopeful males, Moiseff said. So there is yet another level of selection that is going on which researchers have yet to discover, he said [Discovery News].

While that second half of sexual selection remains a mystery, the finding presents some enticing hints about the brains of these insects. The males must know how to keep in rhythm with each other, and the females must know how to interpret this flirty Morse code.

The study tells the researchers the following about the firefly brain: it is able to count, measure time differences and pause while awaiting a response. “Our real interest is understanding brain circuitry,” Moiseff says. “The method they’re using to do this is through pattern recognition, something that is important to all animals…. We want to understand how the brain can process these visual signals” [Scientific American].

Related Content:
DISCOVER: 8 Marine Creatures That Light Up the Sea (gallery)
DISCOVER: Femmes Fatales Fireflies
DISCOVER: Firefly Rx (how they contribute to medicine)
The Loom: Fireflies: The Invertebrate Opera

Image: Andrew Moiseff

Rumors are afoot that there will be an Americanized version of Doctor Who. I truly and sincerely hope these are incorrect. Steven Moffat, the current DW showrunner, wrote an amazingly funny show called "Coupling" which ran for four series in the UK. A version created for American audiences was awful, even though it was written by Moffat himself! Somehow, moving it to the west of the Atlantic, um, decoupled it.

Anyway, cartoonist Tim Buckley, of CTL+ALT+DEL heard these rumors, and as an artist came up with a pretty funny drawing for a potential U.S. Who. I don’t want to spoil it (or steal away clicks to his site) so I only show a portion here. Click it to see what he thinks of this idea. NSFW language (which I pretty much totally agree with) in the commentary, too.

Tip o’ the sonic screwdriver to Mark Doyle.

Well, yesterday was quite a day. I'm now ready, I think, to start to go over the facts, and try to set it all straight. (Deep breath.) There are two separate issues to address, so this is just the first post: Sock Puppets. We had sock puppets on the "Intersection," and we weren't aware of it until recently, thanks to the revelations of The Buddha is Not Serious. We had not been in the habit of checking IP addresses or trying to root out these kinds of things. Indeed, at times I would just let our filters run and not even look at what most commenters were saying, especially when threads ran over 100 comments long and I was busy with other things. I see now that there were people abusing the privilege of posting comments on our blog. We've banned the offending IPs that have been discovered and we're also considering further actions to rein in some kinds of comments that don't contribute anything or engage in baseless attacks, etc. To those legitimate commenters who were annoyed by bad behavior---and had reason to be!--I'm sorry we didn't catch on to what was really happening before now. And I want to emphasize: That apology goes out to ANY commenters who may have ...

I’ve mentioned this before, but I thought it would be useful to repeat again. Many of my social science related posts use Berkeley’s web interface with the General Social Survey. Regularly people ask me in the comments details as to the variables, or a more explicit elaboration of the methods. First, this is a weblog, not a venue for me to publish scholarly papers. Most of the GSS related posts are meant to be “quick & dirty,” and stimulate further exploration by readers. Unfortunately follow ups rarely happen. One can speculate why, but that’s how it is. Nevertheless, I thought I would repeat really quickly how to use the GSS in a basic fashion.

First, here’s the URL:
http://sda.berkeley.edu/cgi-bin/hsda?harcsda+gss08

This is the database from 1972 to 2008. You’ll meet a screen like this:

The page is cluttered, but basically the right side is where you enter in your row and column variables which you want to cross or compare together. The left side allows you to explore the variables. Search and selected are pretty straightforward, while you can browse the list of variables in the menu to the bottom left. The easiest thing to do is just look at frequencies of X, Y, and Z against particular categories A, B and C (e.g., educational attainments vs. sex). But you can do more, at the top left if you select “analysis” you have more options:

I’ve been looking at mean values a lot. Sometimes the mean is obvious because the variables are quantitative. But if you’re talking about a dichotomous response it is “recoded” numerically (e.g., 0 vs. 1), so you have to keep in mind that the mean is just a representation of the underlying data. There are correlations and regressions too. You can do a lot with the GSS, but the more complicated or detailed you get in your analysis, the less appropriate for a “quick & dirty” they are. I’ve been shying away from presenting regressions because to do it right you have to be careful, and if you just throw out a bunch of betas people aren’t going to replicate your analysis and might put more stock in the model than they should (and it’s not hard to massage the betas you get with your variables my just manipulating the set of variables).

Here’s a quick example of a query:

WORDSUM will output the % in the sample who score 0, 1, 2, etc. out of 10 on the WORDSUM vocabuary test. I wanted to check it against highest education attained, DEGREE. I decided to combine those without high school diplomas, those with high school diplomas, and some college, into one category, and label it “No College.” Next I combined those with bachelors and graduate degrees into one category. Then I controlled for males and females, so it will output the row and column variables twice for each control. Finally I constrained the data set to non-hispanic whites who were surveyed after 1999 to the present (2008 in this survey).

Here’s the outcome for males:

Meet Mojoceratops, the newly discovered dinosaur with the best head stylings of the Late Cretaceous. A lover–scientists suspect he used his flamboyant frill to attract mates–Mojoceratops lived 75 million years ago, about 10 million years earlier than his more conservatively coiffed cousin, Triceratops.

Mojoceratops owes his name to a few beers. As described in a Yale University press release, Yale post-doc Nicholas Longrich blurted it out one night while throwing a few back with fellow paleontologists:

“It was just a joke, but then everyone stopped and looked at each other and said, ‘Wait–that actually sounds cool’…. I tried to come up with serious names after that, but Mojoceratops just sort of stuck.”

With an article published today in the Journal of Paleontology, the name went down on the books.

Longrich first found Mojoceratops in 2008 while digging through the American Museum of Natural History’s fossil collection. He noted that some skulls, that were believed to belong to a species called Chasmosaurus, looked “wrong.” For one, they had horns that were too long. Investigating at other museums, the distinctive heart-shaped frill also popped up in collections in western Canada. In total, he uncovered eight partial skulls.

Apparently, Mojo couldn’t survive on good looks alone. Longrich suspects that the hippo-sized herbivore roamed Canada’s Alberta and Saskatchewan provinces for only about one million years. Maybe he looked good enough to eat. Squinting at the picture above, does anyone else think chocolate bunny?

Related content:
Discoblog: Squirrel vs Dinosaur: Researchers Find Oldest Known Mammalian Bite Marks
Discoblog: Jurassic Footprints Reveal Dinosaur Dance Party
Discoblog: Will Jurassic Park Ever Really Come True?
80beats: Dinosaurs Ruled the World Because They “Got Lucky,” Say Scientists

Image: Nicholas Longrich / Yale University

In April 2010, I had the pleasure of moderating a panel discussion of astronomers who are searching for planets orbiting other stars, with the hope of eventually finding earth-like planets. The panel, called "Quest for a Living World", was held in Pasadena (sponsored by Discover Magazine, the Thirty Meter Telescope project, and Caltech). We talked about the technology being used to look for planets, how the science is progressing, and even how we look for signs of life.

The video from the panel is now available:

Watching it again I was struck by how young these scientists are. They have not only their whole careers ahead of them, but also an entirely new field of science they’re exploring: exoplanetary science. Think of it! For thousands of years we wondered if there were other worlds out there like ours, or even unlike ours. Now we not only have answers to that question, but we’re actually learning about the physics of these worlds, their chemistry… and who knows? In a few years, we may even be investigating their biospheres.

I love the splashy full-color pictures of Saturn, but sometimes grayscale (or what is commonly, and incorrectly, called black-and-white) is what’s needed to capture a mood. Take a look at Cassini’s latest view of the ringed planet:

Sigh. Oh my. Click to enjovianate.

If Saturn looks a little different here it’s because this image isn’t made with visible light. The light we can see with our eyes is easily absorbed by Saturn’s atmosphere, so when we look at Saturn we only see the very tops of the clouds. But this picture was made with infrared light, which can come from deeper in Saturn’s thick atmosphere and pass through the upper layers unimpeded. This allows us to see the delicate patterns of the planet’s banding, making it look more like its big brother Jupiter. Note the incredibly beautiful swirl in the lower part, curling up into what looks almost like Jupiter’s Red Spot! But don’t let its grace and beauty fool you: all those curves and whorls are storms with winds moving at hundreds of kilometers per hour, dwarfing any mere terrestrial hurricane.

Pictures like this remind us that Saturn is a dynamic world in and of itself, more than just a host for rings.

But still, the rings really are cool. This picture was taken when Cassini was almost perfectly in the plane of the extremely thin rings, so they look like a bright line across the planet. The dark stripes below are actually the shadows of the rings! You can even easily see the gaps in the rings, where the ice particles have been swept clear by the gravity of Saturn’s fleet of moons.

I’m not an expert in planetary atmospheres or ring systems, and I’ve learned a lot over the years by looking at these images, reading the papers, and talking with the Cassini imaging team leader Carolyn Porco. I’ll never understand the planet as well as she does, or the dozens, hundreds of scientists who make up the team responsible for analyzing Cassini’s data. But that’s OK: I know they’ll be kept busy for decades poring over images like these, and it’s a good thing when scientists are busy.

And, of course, those of us looking in from the outside get to see breathtaking pictures of the solar system’s loveliest planet. All in all, it’s a pretty good deal for everyone.

Tip o’ the F Ring to Carolyn Porco. Image credit: NASA/JPL/Space Science Institute

We can predict your chances of living exceptionally long, with 77 percent accuracy, by looking at 150 tiny genetic variants. That’s what researchers claimed in a Science paper that we described last week. Those predictive powers have left some feeling a little uneasy–and not just about what futures are buried in their genomes. Where the paper’s authors saw correlations, some experts are now seeing errors from DNA testing chips.

No DNA chip is perfect; it can get things wrong as it sorts through hundreds of thousands of genetic variants. In fact, certain chips might even make the same error repeatedly. That could cause problems, because what looks like a genetic variant common to a group of people could instead just be an echoed flaw in one chip’s testing capabilities.

Newsweek, which broke this story, reports that the Boston University researchers who led the study did, in fact, use different chips, but not enough different chips to rule out this potential error. They used two different types of DNA chips to test the centenarian group (about 1,000 people whose ages ranged from 95 to 119): a 370 chip that examines 370,000 genetic variants and a 610-Quad that examines 610,000 variants. The control group (of about 1,200 younger people) was tested with those two chips and a few others, thus possibly hiding any shared errors.

David Goldstein, the Duke University geneticist who first questioned this method at Newsweek last week, says that using similar chips (both made by Illumina) for the centenarian group and a collection of different ones for the control group could have left the researchers wide open for errors.

“Unfortunately, different chips have their own little problems for specific [genetic variants],” he says. The key to keeping false positives at bay is to ensure that cases and control groups are analyzed using exactly the same techniques. If you use one type of chip to analyze your cases and a different type to analyze your control group, “you can see any [variants] that are genotyped differently on the different chips ‘lighting up’ as apparently associated with the trait,” says Goldstein, when in fact that pattern is just an experimental artifact. [Newsweek]

DISCOVER’s Razib Khan has also posted in Gene Expression on various hints that this study might not be all that it’s cracked up to be. Khan takes note of skeptical claims from other experts and the commercial testing company 23andMe, which, after the study’s fanfare, tried to see the relationship between these tiny variants (called SNPs) highlighted by the study and their older clients’ genomes.

We took a preliminary look in our customer data to see if the proposed SNP-based model described in Sebastiani et al. is predictive of exceptional longevity. . . . [B]ased on our data, performance of this model is not significantly better than random. [23andMe]

The study’s authors led by Paola Sebastiani and Thomas Perls released a statement yesterday apparently in response to the Newsweek article and comments from Kari Stefansson, the leader of a similar study quoted in the New York Times. The Boston University researchers are checking their results.

“We have been made aware that there is a technical error in the lab test used on approximately 10% of the centenarian sample that involved the two of the 150 variants. Our preliminary analysis of this issue suggests that the apparent error would not effect the overall accuracy of the model. Because the issue has been raised since the publication of the paper, we are now closely re-examining the analysis. Another question that was raised concerns the criteria used to determine if an association between a genetic variant and exceptional longevity was statistically significant. We used standard criteria for the analysis, and we are confident that the appropriate threshold was used.” [Newsweek]

Related content:
Gene Expression: The short life expectancy of longevity genes (?)
80beats: What Can Centenarians’ Genes Tell Us About Getting Old?
Not Exactly Rocket Science: Genetic signatures for extreme old age accurately predict odds of living past 100
80beats: A Life-Extending Coup: Flies That Can’t Smell Food Live 30 Percent Longer
80beats: Low-Calorie Diet Staves off Aging & Death in Monkeys
80beats: Immunosuppressant Drug Extends Lifespan of Elderly Mice

Image: Wikimedia / Schutz

Some birds can sense the Earth’s magnetic field and orientate themselves with the ease of a compass needle. This ability is a massive boon for migrating birds, keeping frequent flyers on the straight and narrow. But this incredible sense is closely tied to a more mundane one – vision. Thanks to special molecules in their retinas, birds like the European robins can literally see magnetic fields. The fields appear as patterns of light and shade, or even colour, superimposed onto what they normally see.

Katrin Stapput from Goethe University has shown that this ‘magnetoreception’ ability depends on a clear image from the right eye. If the eye is covered by a translucent frosted goggle, the birds become disorientated; if the left eye is covered, they can navigate just fine. So the robin’s vision acts as a gate for its magnetic sense. Darkness (or even murkiness) keeps the gate shut, but light opens it, allowing the internal compass to work.

The magnetic sense of birds was first discovered in robins in 1968, and its details have been teased out ever since. Years of careful research have told us that the ability depends on light and particularly on the right eye and the left half of the brain. The details still aren’t quite clear but, for now, the most likely explanation involves a molecule called cryptochrome. Cryptochrome is found in the light-sensitive cells of a bird’s retina and scientists think that it affects just how sensitive those cells are.

When cryptochrome is struck by blue light, it shifts into an active state where it has an unpaired electron – these particles normally waltz in pairs but here, they dance solo. The same thing happens in a companion molecule called FAD. Together, cryptochrome and FAD, both with unpaired electrons, are known as a “radical pair”. Magnetic fields act upon the unpaired electrons and govern how long it takes for the radical pair to revert back to their normal, inactive state. And because cryptochrome affects the sensitivity of a bird’s retina, so do magnetic fields.

The upshot is that magnetic fields put up a filter of light or dark patches over what a bird normally sees. These patches change as the bird turns and tilts its head, providing it with a visual compass made out of contrasting shades.

To test the bounds of this ability, Stapput wanted to see what would happen if she blurred a robin’s vision. She outfitted her robins with somewhat unflattering goggles, with clear foil on one side and frosted foil on the other. Both allowed 70% of light to get through, but the frosted foil disrupted the clarity of the image.

The robins were kept in cages until they were ready to migrate and let loose in funnel-shaped cages lined with correction fluid. As they orientated themselves and changed course, they created scratches on the cage walls which told Stapput which direction they were heading in. These scratches revealed that with both eyes open, the robins flew straight north as they would normally do in the wild. If their left field of vision was frosted, they went the same way. But if their right eye was covered, they became disorientated, heading in completely random directions.

This experiment shows that the internal compass doesn’t just depend on light – birds also need to see a clear image with their right eye in order to find they way. After all, their magnetic sense only provides them with information that lies on top of the images they normally see. If that image is blurry, the magnetic sense is useless. To put it another way, driving with an excellent Satnav won’t do you much good if your windscreen is covered in frost.

But Stapput thinks that birds also need a sharp, focused image to separate the information from their visual and magnetic senses. Since both lie on top of each other, and both involve differences in light and shade, the potential for confusion is high. But thanks to lines and edges, the images that birds see tend to have sharp transitions between light and shade; by contrast, changes in magnetic fields are smooth and more gradual. So sharp changes in contrast are probably due to the boundaries of objects, but smoother changes are probably due to magnetic effects.

Stapput’s study certainly provides good support for the “radical pair” explanation, but it doesn’t rule out an alternative hypothesis. Some birds, such as pigeons, have small crystals of magnetite in their beaks. This iron-rich magnetic mineral could provide further clues about the surrounding magnetic fields, especially in darkness.

Reference: Current Biology http://dx.doi.org/10.1016/j.cub.2010.05.070

Image from Ernst Vikne and Theoretical and Computational Physics Group

More on magnetic senses:

• Google Earth shows that cow and deer herds align like compass needles
• Bats: compasses, tongues and memories
• Power lines disrupt the magnetic alignment of cows and deer

A quick update to my post from yesterday about Scienceblogs. The dreaded Pepsi blog is gone. Details from PZ Myers and Paul Raeburn.

It wasn’t supposed to be like this. The Higgs boson, dark matter, neutrinos—weird or poorly understood phenomena like these seemed the likely candidates to provide a surprise that changes particle physics. Not an old standby like the proton.

But the big story this week in Nature is that we might have been wrong all along in estimating something very basic about the humble proton: its size. A team from the Paul-Scherrer Institute in Switzerland that’s been tackling this for a decade says its arduous measurements of the proton show it is 4 percent smaller than the previous best estimate. For something as simple as the size of a proton, one of the basic measurements upon with the standard model of particle physics is built, 4 percent is a vast expanse that could shake up quantum electrodynamics if it’s true.

If the [standard model] turns out to be wrong, “it would be quite revolutionary. It would mean that we know a lot less than we thought we knew,” said physicist Peter J. Mohr of the National Institute of Standards and Technology in Gaithersburg, Md., who was not involved in the research. “If it is a fundamental problem, we don’t know what the consequences are yet” [Los Angeles Times].

Simply, the long-standing value used for a proton’s radius is 0.8768 femtometers, (a femtometer equals one quadrillionth of a meter). But the study team found it to be 0.84184 femtometers. How’d they make their measurement? First, think of the standard picture of electrons orbiting around a proton:

According to quantum mechanics, an electron can orbit only at certain specific distances, called energy levels, from its proton. The electron can jump up to a higher energy level if a particle of light hits it, or drop down to a lower one if it lets some light go. Physicists measure the energy of the absorbed or released light to determine how far one energy level is from another, and use calculations based on quantum electrodynamics to transform that energy difference into a number for the size of the proton [Wired.com].

That was how physicists derived their previous estimate, using simple hydrogen atoms. But this team relied on muons instead of electrons. Muons are 200 times heavier than electrons; they orbit closer to protons and are more sensitive to the proton’s size. However, they don’t last long and there aren’t many of them, so the team had to be quick:

The team knew that firing a laser at the atom before the muon decays should excite the muon, causing it to move to a higher energy level—a higher orbit around the proton. The muon should then release the extra energy as x-rays and move to a lower energy level. The distance between these energy levels is determined by the size of the proton, which in turn dictates the frequency of the emitted x-rays [National Geographic].

Thus, they should have seen the specific frequency related to the accepted size of a proton. Just one problem: The scientists didn’t see that frequency. Instead, their x-ray readings corresponded to the 4-percent-smaller size.

Now the task at hand is to check whether this study is somehow flawed, or is in fact a finding that will shake up physics.

In an editorial accompanying the report in the journal Nature, physicist Jeff Flowers of the National Physical Laboratory in Teddington, England, said there were three possibilities: Either the experimenters have made a mistake, the calculations used in determining the size of the proton are wrong or, potentially most exciting and disturbing, the standard model has some kind of problem [Los Angeles Times].

Related Content:
DISCOVER: Is the Search for Immutable Laws of Nature a Wild Goose Chase?
DISCOVER: Ice Fishing for Neutrinos from the Middle of the Galaxy
DISCOVER: The Mystery of the Rocketing Particles That Shouldn’t Exist
80beats: A Sweet Smashup: The LHC Shatters the Collision Energy Record

Image: F. REISER & A. ANTOGNINI, PAUL-SCHERRER-INST (the laser used in the research)

Lightsabers have come a long way since the telescoping plastic toys of yesteryear. We’re not talking about realistic sound effects or iPhone apps. We’re talking flesh-burning, eye-blinding lasers.

Although this gadget is dangerous enough to require customers to fill out a “Class 4 Laser Hazard Acknowledgment Form,” the Spyder III Pro Arctic Laser looks like it might be found in a Toys-R-Us, next to rows of action figures and Yoda dolls.

At least George Lucas thinks so; Lucasfilm is now threatening to sue the manufacturer. As reported in DailyTech, where we first saw this story, Lucasfilm feels a great disturbance with the similarities.

“It is apparent from the design of the Pro Arctic Laser that it was intended to resemble the hilts of our lightsaber swords, which are protected by copyright…”

These are no toys, counters the seriously-named manufacturer, WickedLasers. They have added several security measures, including “training lenses,” but don’t appear to be willing to change their Jedi-like hilts anytime soon. Cue Duel of the Fates.

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Success for Solar Impulse: This morning the solar-powered plane touched down in Switzerland after more than 26 hours in the sky—including flying overnight on battery power.

As we noted yesterday, this was by far the most ambitious test of adventurer Bertrand Piccard’s experimental aircraft, which is covered by 12,000 solar cells. Swiss pilot André Borschberg had to decide last night whether those cells had absorbed enough battery power during the day to coast through the night, and he managed to do it.

“I’ve been a pilot for 40 years now, but this flight has been the most incredible one of my flying career,” Mr. Borschberg said as he landed, according to a statement from the organizers of the project. “Just sitting there and watching the battery charge level rise and rise thanks to the sun. I have just flown more than 26 hours without using a drop of fuel and without causing any pollution” [The New York Times].

Sun power won’t replace jet fuel anytime soon, of course. Staying aloft on battery power meant scrimping on luxuries, so Borschberg spent the night flying in a cramped cockpit at below-zero temperatures that made his iPod freeze up—so no listening to sweeping arias while coasting over the majestic Swiss landscape for Mr. Borschberg.

Spartan quarters aside, the next challenge calls to Piccard and Solar Impulse: flying around the world. Now that the plane has flown a day, he wants to show that it can fly without end.

The team says it has now demonstrated that the single-seat plane can theoretically stay in the air indefinitely, recharging its depleted batteries using 12,000 solar cells and nothing but the rays of the sun during the day [AP].

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Image: Solar Impulse