Spiderwebs, Pakistan

December 14, 2011
Photograph by Russell Watkins

An unexpected side effect of the 2010 flooding in parts of Sindh, Pakistan, was that millions of spiders climbed up into the trees to escape the rising flood waters; because of the scale of the flooding and the fact that the water took so long to recede, many trees became cocooned in spiderwebs. People in the area had never seen this phenomenon before, but they also reported that there were fewer mosquitoes than they would have expected, given the amount of standing water that was left. Not being bitten by mosquitoes was one small blessing for people that had lost everything in the floods.

"God particle" could be found or disproved in 2012, expert predicts.

An illustration of the Higgs-Boson particle.

A typical "candidate event" in the Higgs-hunting CMS experiment. Red lines represent high-energy proton beams while yellow lines show the tracks of particles produced in the collision.
Illustration courtesy CERN

Physicists are hopeful that the long-sought Higgs boson is finally within reach, after two experiments at the proton-smashing Large Hadron Collider (LHC) observed tantalizing hints of the elusive particle.

Speaking today at a public seminar at the European Center for Nuclear Research (CERN) in Geneva, scientists with the LHC's ATLAS and CMS experiments presented data showing that the Higgs boson—if it exists—likely has a mass of around 125 gigaelectron volts (GeV), the unit of mass used by particle physicists.

"We have restricted the most likely mass region for the Higgs boson to 116 to 130 GeV, and over the last few weeks we have started to see an intriguing excess of events in the mass range around 125 GeV," ATLAS spokesperson Fabiola Gianotti said in a statement.

"This excess may be due to a [random] fluctuation, but it could also be something more interesting. We cannot conclude anything at this stage. We need more study and more data."

CERN director general Rolf-Dieter Heuer later cautioned reporters that the results are preliminary.
"We still [need] many more collisions next year to get a definite answer to the Shakespeare question on the Higgs: To be or not to be?" he said.

David Evans is a particle physicist at the University of Birmingham and the leader of the U.K. team that works on the LHC's ALICE experiment, which is not involved in the Higgs hunt.

Evans said the ATLAS and CMS teams have done an "impressive job" of narrowing down the Higgs mass range, and that he expects more exciting results in the near future.

"By the end of next year ... they will have enough data to either discover the Higgs or prove it doesn't exist," he predicted.

Still Counting Higgs "Change"

Higgs bosons are thought to be extremely short-lived subatomic particles, so scientists can detect them only by spotting the particles into which the Higgs decays.

But just as a vending machine might return the same amount of change using different coin combinations, the Higgs can decay into different combinations of other particles. (Explore a Higgs boson interactive.)

What the ATLAS and CMS teams claim to have done is observe excesses of decay particles in the 116 to 130 GeV mass range—hinting that the Higgs could exist in that zone.

The CERN researchers say they have what they call a two-sigma degree of confidence, which translates to about a 95 percent chance that the results are not due to a statistical fluke.

But according to the very stringent standards of particle physics, an experiment must have a sigma level of five—or a 99.99 percent chance—to count as an official discovery.

"We make so many measurements at the LHC that three-sigma effects show up quite often. I've seen three-sigma effects come and go," Evans said.

"So you really do have to have this five-sigma [level of confidence] before the community will accept it as a discovery."

LHC Well Suited to "God Particle" Hunt

Finding the Higgs boson has been a major scientific pursuit, because the particle is crucial to the standard model of physics—the incredibly successful theory that explains how fundamental particles interact with the elementary forces of nature.

Popularly referred to as the God particle, the Higgs boson was proposed in the 1960s by physicist Peter Higgs to explain why some particles, such as electrons and quarks, have mass while others, such as the photon, do not.

Higgs proposed that the universe is bathed in an invisible field similar to a magnetic field. If a particle can move through this field—now known as the Higgs field—with little or no interaction, there will be no drag and that particle will have little or no mass.

On the other hand, if a particle interacts significantly with the Higgs field, it will have a higher mass.

The idea of the Higgs field requires the acceptance of a related particle: the Higgs boson.

"In the standard model, if you have this new type of field, there must be a particle that goes with it," Evans said. "You can't have a field without a field particle." For instance, the particle associated with the electromagnetic field is the photon.

While the standard model predicts the existence of a Higgs boson to go with the Higgs field, it doesn't say anything about its mass, which is one reason why the hunt for the God particle has proven so difficult.

In fact, while most physicists think the Higgs is a single particle, others have proposed a non-standard Higgs model—called the two Higgs doublet model—in which the Higgs is actually made of five distinct particles with similar masses but different electrical charges.

But in the past few years, physicists think they have limited the possible mass of a single, standard-model Higgs to a very narrow range, one which the LHC—the most powerful particle accelerator yet constructed—is quite capable of searching. (See LHC pictures.)

"With the LHC, we know that we will either find the Higgs or prove that it doesn't exist," Evans said.

According to Evans, the discovery of the standard-model Higgs would be a spectacular validation of the theory—and a find on par with the discovery of the electron by J.J. Thompson in 1897.
"People had been measuring and studying electricity up to that point, and then Thompson discovered the actual particle that was responsible," he said.

Higgs Search Is "No Lose" Situation

The next step for CERN scientists will be to conduct more proton-proton collisions to detect more Higgs signals and bolster their case.

Evans said he expects a conclusive result one way or the other as early as next summer.

Gianotti of ATLAS said that she would prefer that scientists find the standard Higgs, because "we as a community have been looking for for many years, and it would fix many problems in the standard model," such as why certain particles have their associated masses.

For Evans, though, a failure to find the standard-model Higgs would be even more interesting, because it would hint at completely new physics, such as a nonstandard Higgs. (Also see "Strange Particle Created; May Rewrite How Matter's Made.")

"To me," Evans said, "it's a no-lose situation."

The Two Twists that let Hummingbirds fly like Insects

In flight, the hovering hummingbird is more like a insect than a bird. Most most birds only create lift when they flap downwards. But the hummingbird, by flipping its wing before it flaps upwards, can create lift in both directions. Insects do the same thing, but their wings have no bones inside them. How does the hummingbird fly like a fly despite having the bones of a bird?

Tyson Hedrick has found out, by filming hovering hummers with high-speed X-ray cameras. I’ve written about the results in my new piece for Nature News, so go there and read the full story (including details about how hummingbird muscles work at high gear). The meat of it is this:

    By filming ruby-throated hummingbirds (Archilochus colubris) in flight, Hedrick showed that the birds invert their wings by twisting their wrists. “It looks like it’s affecting the whole wing because the bird’s skeleton is very compressed and its wrist isn’t very far from its shoulder,” says Hedrick.

    In most birds, the wrist collapses on the upstroke to draw the wing towards the body as it is raised. Hummingbirds have adapted the same movements to rotate their wings instead. “The usual mechanism makes the upstroke aerodynamically invisible,” says Hedrick. “The hummingbirds’ mechanism makes the upstroke aerodynamically effective.”

    The videos also showed that hummingbirds flap their wings by twisting the humerus (upper arm bone), rather than flapping it up and down from the shoulder like other birds. To understand the difference, Hedrick recommends trying to mimic a bird by flapping your arms. “You’re doing something not too different to what a seagull’s doing,” he says. To mimic a hummingbird, “hold your upper arm close to your body with your elbow on your hip, and flap your forearms back and forth”.

Go try it. You can look as stupid as I did when I was writing about the paper.
Photo by Joe Schneid

All Farewells are Sudden...

http://youtu.be/2X0xYT8Rtiw

Four Hemophiliac Patients Successfully Treated with Gene Therapy

Hemophilia, a disease whose victims can suffer serious internal bleeding and may bleed to death from injuries, has a long and eventful history. Caused by defective blood clotting factors, the disease has been with us since at least the second century, when a rabbi gave mothers whose first two sons had bled to death from circumcision wounds permission to leave the third sons uncircumcised. It also famously  afflicted several members of European royal families. But a study published in the New England Journal of Medicine brings us a bit closer to a new kind of historic event: a cure.

Following up on years of preclinical trials, including the curing of hemophiliac mice earlier this year, scientists gave six patients a  gene therapy treatment, injecting them with a specially built virus carrying a functioning version of the gene for the defective clotting factor. The virus inserted the gene into liver cells, which proceeded to manufacture the clotting factor, and the patients maintained elevated levels of it for over 6 months. Four of the patients were able to stop receiving injections of clotting factor (the current treatment) altogether.

The scientists are monitoring patients for any signs of liver cancer caused by the virus inserting the gene in an inopportune location, a known risk in gene therapy, but thus far, there have been no signs of such complications. The next stage, a trial of 20 patients, will assess what dosage of virus is necessary to get enough liver cells making clotting factor that most (hopefully all) patients can stop receiving injections. There are still plenty of ways that the treatment could fail before reaching the clinic. But here’s hoping that the results continue to be this promising.

Image courtesy of  Andrew Mason / flickr
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December 12th, 2011 4:53 PM

Dr. Sith’s The Grinch Who Stole Christmas Amateur Astronomer Discovers Sungrazing Comet

Back in the day, it used to be that most new comets and asteroids were discovered by astronomers diligently sitting at their eyepieces, spending one cold night after another patiently scanning the skies. The advent of robotic astronomy changed that, and now the vast majority of all celestial newcomers are found automatically.

But Australian "amateur" astronomer Terry Lovejoy changed that last week: not only did he discover a comet — which isn’t that unusual, though still cool — but it turns out to be a sungrazer, a comet that plunges deep down to the center of the solar system, practically skimming the Sun’s surface.

Here is Lovejoy’s discovery image:

This is a combination of three images; the comet moves between exposures a bit so he re-centered the comet in each shot and added them together. It’s the fuzzy blob in the middle of the frame. The comet’s official name is C/2011 W3 (Lovejoy), and on December 16th it will pass just about 880,000 km (500,000 miles) from the Sun’s surface — only a little bit more than than the radius of the Sun itself! 180,000 km (110,000 miles) — less than half the distance from the Earth to the Moon!* This may be a death dive, since many such comets don’t survive the intense heat of the Sun from that distance. Comets are composed of lots of rock held together by ice, so when the ice vaporizes, the comets disintegrates.

Michael Mattiazzo took the shot shown here of the comet on the evening of December 2. It’s a combination of ten short exposures lasting only minutes in total, but the comet moves enough during that time to trail in the final image. As you can see, it’s faint but moving rapidly as it heads down to its rendezvous with the Sun. You can also see more images of it at Astro Bob’s website.

Sometimes these sungrazer comets — technically called Kreutz family comets, after the man who figured out they all came from the same parent comet — survive their passage and sometimes they don’t. Sometimes they also get bright enough to be seen with the naked eye, though 2011 W3 is pretty faint right now and probably won’t brighten. But comets are difficult to predict; each is different and can surprise us. If this one flares up I’ll be sure to let you know.

This is a pretty good find by Mr. Lovejoy: most sungrazer comets are first seen when they appear in data from the SOHO solar observing satellite, already very near the Sun. It’s hard to find them when they’re far from the Sun since they’re usually so faint, and in fact this is the first such sungrazing comet found from the ground in over 40 years! So it’s quite a nice discovery. Congrats to Mr. Lovejoy, and we’ll have to see what happens to his comet over the next couple of weeks!

Image credits: Terry Lovejoy, courtesy José Luis Galache; Michael Mattiazzo. Both used by permission.

* I originally found a set of numbers that gave the closest approach distance to the Sun of 880,000 km, but turns out that was the distance to the Sun’s center. Subtracting the Sun’s radius of 695,000 km yields the surface-skimming distance of roughly 180,000 km. My apologies for the error.

One True God-Not as Popular as You Might Think

The above results are from an Ipsos MORI from last summer. Please note, the opinions above are restricted only to those who asserted a religious affiliation. Obviously in Saudi Arabia this is irrelevant, as nearly the whole population has a religious affiliation. But it is important in Japan, because there nearly 2 out of 3 individuals in the survey reported no religion, so these are results from the minority who reported having an affiliation (mostly Buddhist). As they say, read the whole thing. Here are some conclusions I drew from these data:

- Even in Saudi Arabia 25 percent of the population would not sign on to a very exclusive reading of their religion. This is not surprising to me. Very exclusive adherence to the proposition that all non-believers are damned is often hard to adhere to in any marginally cosmopolitan circumstance. Obviously there are people who will agree that Gandhi is in hell (this is a litmus test used to smoke out heterodox deviation in some fundamentalist Protestant churches in the USA), or that their close friend is going to hell, but when push comes to shove most people flinch. There seems to be a wide range in responses to this question about religious exclusivism, and I think that’s probably due to differences in priming.

- I have gotten into arguments with Hindus and New Atheists about the exclusive nature of Christianity online. My argument is that they tend to confuse fundamentalist Protestantism with Christianity qua Christianity. If I we believed that Christianity had a basis in truth this sort of attitude might make sense, but as that is not the case I don’t see the line of reasoning where non-Christians can assess who is, or isn’t, exhibiting more fidelity to Christianity. Granted, you can think of religion as a mathematical system where you can test propositions by inference from axioms. But I don’t think that’s too useful, though I see its logical coherency (and even in that case, it is trivially obvious to show that “fundamentalists” are themselves often revisionists who play fast & loose with what might “plainly” be inferred from the source text of a religion). The reality is that in most developed nations the vast majority of Christians no longer adhere to a position exclusivism which has come to make the Abrahamic religions particular distinctive. In fact, if you look at the survey in the results it indicates that Hindus in India are as exclusive in their understanding of their religion as Christians in the United States!

- Speaking of Hindus (and Buddhists to a lesser extent), these data speak to a difference between Abrahamic and non-Abrahamic religions. Though Hindus are not quite as universalist as Swedish Christians, matching social development they are quite tolerant. The Hindu model in India in a religious sense mixes a moderately high level of commitment with an acceptance of pluralism. This is pretty much the stereotype of Hindus in relation to Abrahamic faiths. In contrast, you have the Muslim model, which combines high levels of commitment with low levels of pluralism. Finally, you have the developed nations model, excepting the USA, which combines low commitment and high pluralism. India and the USA seem to occupy similar space in many ways in these data.

- Finally, in these results Turkey and Saudi Arabia seem to be positioned at the two poles of Islamic piety. I think that that is actually a good choice, as all other data indicates that Tunisia and Egypt would fall in the middle of these extremes (Tunisia closer to Turkey, Egypt to Saudi Arabia). What does that tell us? If you look at the results you’ll see that Turks as a nation seem to express attitudes and sentiments not too far from those of the USA. As I’ve long said, this is an important insight about the Islamic world: one of the most organically secular Muslim nations is in the same zone as the most pious of Western nations (along with Poland and Malta). In many ways the American Republican party today is probably analogous to moderate Islamists of the AKP; though I would suspect that the AKP has a larger “tail” of social conservatism than the Republican party.

COMMENTS NOTE: Any comment which misrepresents the material in this post will result in banning without warning. So you should probably stick to direct quotes in lieu of reformulations of what you perceive to be my intent in your own words. For example, if you start a sentence with “so what you’re trying to say….”, you’re probably going to get banned. I said what I tried or wanted to say in the post. Period.
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By Razib Khan in Data Analysis