Author: Discover Main Feed

You’re watching a video of a needle piercing an anonymous hand, sinking slowly into the web between the thumb and index finger. You wince as you imagine the pain that the other person must feel, and for good reason. As you watch, you nervous system essentially duplicates the experience, responding as if you were vicariously feeling the pain yourself. This is typical of what happens when people see others in pain, but Italian scientist Alessio Avenanti has found an important exception to the rule. Racial bias can negate this ability to feel the pain of someone from a different ethnic group.

Avenanti recruited white and black Italian volunteers and asked them to watch videos of a stranger’s hand being poked. When people watch such scenes, it’s actually possible to measure their brain’s empathic tendencies. By simulating how the prick would feel, the brain activates the neurons of the observer’s hand in roughly the same place. These neurons become less excitable in the future. By checking their sensitivity, Avenanti could measure the effect that the video had on his recruits

He found the hallmarks of an empathic response only when the hands in the videos were prodded by a needle rather than a blunt piece of plastic, and only when he took measurements at the same part of the hand. But most interestingly of all, he found that the recruits (both white and black) only responded empathetically when they saw hands that were the same skin tone as their own. If the hands belonged to a different ethnic group, the volunteers were unmoved by the pain they saw.

So are we all just naturally and worryingly prejudiced? Far from it – Avenanti actually thinks that empathy is the default state, which only later gets disrupted by racial biases. He repeated his experiment using brightly coloured violet hands, which clearly didn’t belong to any known ethnic group. Despite the hands’ weird hues, when they were poked with needles, the recruits all showed a strong empathic response, reacting as they would to hands of their own skin tone.

The purple-hand experiment is a vital part of Avenanti’s study. Other scientists have suggested that people are less responsive to the pain of other ethnic groups, simply because their skin tones are less familiar and harder to identify with. But what could be more unfamiliar and less identifiable than a violet hand? It’s strong evidence that the lack of empathy from the first experiment stems not from mere novelty, but from racial biases.

Avenanti also found that the stronger these biases are, the weaker their empathic response. Each of his recruits did an ‘Implicit Association Test’, which looks for hidden biases by measuring how easily people make positive or negative connections between different ethnic groups. For example, white Italians are typically quicker to associate positive words with the term “Italian” and negative ones with the term “African”. And the faster they make those connections, the greater the differences in their responses to the stabbed black and white hands.

The recruit’s bodies betrayed their prejudices in other ways. On seeing the penetrating needles, their skins became moist and better at conducting electricity, a reflexive sign of emotional arousal. The needles evoked the same effect regardless of the hand they pierced, but the response was longer in coming if the hand belonged to a different ethnic group.

All in all, Avenanti says when we see pain befall a person from our own racial group, it immediately triggers resonant activity in our own nervous system. When we see the same event happening to someone of a different race, these simulations are weaker and take longer to form.

It’s a sad state of affairs but probably not an unpredictable one. After all, other studies have found that racial prejudices can make us dehumanise members of a different ethnic group. But more promisingly, Avenanti’s experiments suggest that things don’t have to be this way. Our default reaction, freed from the shackles of prejudice, is empathy with our fellow people, even if they do have freaky violet hands.

Reference: Current Biology http://dx.doi.org/10.1016/j.cub.2010.03.071

More on race:

• Williams syndrome children show no racial stereotypes or social fear
• Even on mute, TV can perpetuate racial bias
• How light or dark is Barack Obama’s skin? Depends on your political stance…
• Social status shapes racial identity
• People overestimate their reactions to racism
• They don’t all look the same – could better facial discrimination lead to less racial discrimination?

Yesterday morning, about 70,000 feet over the Pacific Ocean, the Boeing-designed X-51A Waverider “scramjet” set a new record. Reaching Mach 5 (almost 4,000 miles per hour), it wasn’t the fastest jet flight, but by burning for over 200 seconds it became the longest flight of its kind. The previous scramjet record, held by the NASA X-43, was 12 seconds.

A scramjet is similar to a simpler engine called a ramjet, but faster. The engines on most commercial jets have turbines to push air inside, but a ramjet is basically a tapered tube. As air flows through it, the shape of the tube compresses the air and, once the engine mixes this air with fuel, it ignites.

Unlike well-understood ordinary ramjets, which slow the air passing through them to subsonic speeds, the X-51 is intended to maintain combustion in a supersonic internal airflow — hence the name scramjet, for supersonic combustion ramjet — a feat often likened to “striking a match in a hurricane”. [The Register]

Since it needs moving air to fire, a ramjet can’t start from a standstill. Yesterday, a NASA-operated B-52 Stratofortress took the unmanned jet under its wing and dropped it at about 50,000 feet. Then a solid rocket booster accelerated the X-51 to about Mach 4.5. Then, on its own power, the scramjet climbed 20,000 feet, accelerated to Mach 5, and burned it engine for a total flight time of about 200 seconds.

“We are ecstatic to have accomplished most of our test points on the X-51A’s very first hypersonic mission,” said Charlie Brink, a X-51A program manager with the Air Force Research Laboratory at Wright-Patterson Air Force Base, Ohio. “We equate this leap in engine technology as equivalent to the post-World War II jump from propeller-driven aircraft to jet engines.” [U.S. Air Force]

NASA’s X-43A scramjet still holds the record for fastest jet engine flight, achieving about a 12 second run at Mach 9.6 in 2004. But the X-43A used hydrogen, which would require huge tanks if the jet found commercial use. The X-51A does not have this liability; it uses an easier-to-carry hydrocarbon fuel.

Joe Vogel, Boeing’s director of hypersonics, said, “This is a new world record and sets the foundation for several hypersonic applications, including access to space, reconnaissance, strike, global reach and commercial transportation.” [Washington Post]

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80beats: Super-Green, Algae-Derived Jet Fuel Passes Tests With Flying Colors
80beats: DARPA Loses Contact with Mach 20 “Hypersonic Glider” During Test Flight

This is not an “eat dirt for your health and happiness” study. You don’t need to shovel soil in your mouth. Just go outside.

Biologist Dorothy Matthews and company wanted to test a particular bacteria, Mycobacterium vaccae. It’s found commonly in the soil and carried widely through the air, so if you take a walk in the park you’ll probably breathe it in. Previous studies have shown that the bacterium increases serotonin in the brain, and have even suggested that the bacterium has antidepressant qualities. Since the neurotransmitter serotonin is also involved in cognition, the team wanted to see if the bacterium could have a direct effect on learning. Indeed it did, Matthews’ team announced at the General Meeting of the American Society for Microbiology in San Diego.

In a classic test of learning ability, Matthews gave mice a treat – white bread with peanut butter – as a reward to encourage them to learn to run through a maze. When she laced the treat with a tiny bit of Mycobacterium vaccae, she found that the mice ran through the maze twice as fast as mice that were given plain peanut butter [New Scientist].

The uptick in learning ability lasted as long as the researchers kept giving their mice the laced peanut butter.

But here’s a caveat: When they tested bacteria-fed mice three weeks after removing the single-cell organisms from their diet they found that these mice were still faster than the mice who never received the bacteria. The difference, however, was not significant. So the results are temporary [Scientific American].

And this is just a mouse model, too, so take that for what you will. But the least it’s another blow struck for the good name of bacteria, for the hygiene hypothesis, and for going outside, Matthews says.

“It just shows that we evolved with dirt as hunter-gatherers,” she says. “So turn off your TV and go work in your garden, or walk in the woods” [New Scientist].

Related Content:
DISCOVER: Is Dirt the New Prozac?
80beats: Special Seaweed-Chomping Bacteria Found in the Guts of Japanese Diners
80beats: Scientists Sequence DNA from the Teeming Bacterial Universe in Your Gut
80beats: Let Kids Eat Dirt: Over-Cleanliness Linked to Heart Disease
Discoblog: Let Them Eat Dirt! It Contains Essential Worms

Image: iStockphoto

This is a guest post from Vanessa Woods, author of the new book, Bonobo Handshake. Vanessa is a Research Scientist in Evolutionary Anthropology at Duke University and studies the cognition of chimpanzees and bonobos in Congo. When I wake up this morning, someone might try to kill me. I live 10 minutes from a small town called Durham, NC, where according to the last statistics, 22 people were killed, 76 women were raped, and there were 682 cases of aggravated assault. When a chimpanzee wakes up in the morning, they probably have the same thought. In fact, if you’re a male chimpanzee, you’re more likely to be killed by another chimpanzee than anything else. If you’re a female chimpanzee, expect to be beaten by every adolescent male who is making his way up through the ranks. People often ask me why humans are so intelligent, as in, what is it other apes lack that makes us so unique. I’ll tell you this: I would swap every gadget I own – my car, my laptop, the potential to fly to the moon – if I could wake up as a bonobo. No bonobo has ever been seen to kill another bonobo. There is very …

A while back, a young blogger named Jaden wrote about his college biology teacher who used the opportunity of his class to teach creationism and abstinence:

He started off his discussion by saying that there are two ideas (not theories, but ideas) of how life became how it is on Earth. He closed the classroom’s door. Once the door was closed, he glossed over the scientific explanation very quickly (less than 20 seconds), then explained Creationism for about five minutes (5000 year old Earth, no evolution, etc). He then said that accepted scientific thought is the first, and that’s what the school wants him to teach, “…but we all know which one is right.” WHOA! […] After he finished his Creationism lecture, he opened the classroom door again.

Yegads. That post was from April 23. Now that classes are over and grades finalized, on May 21 Jaden gave details. He did what I would’ve: approached the Dean of Science and told her the biology teacher was a crackpot.

What happened?

[The Dean] acted like I was being unreasonable. She said two things that really sit poorly with me. She told me that he is completely entitled to share his opinions in class. Then, she said eluded to the fact that I’m being intolerant of his beliefs and need to show more respect for him.

Ha!

First, this is not public high school, so the teacher can, if he so pleases, teach that Thor created the Universe by cracking an ostrich egg in two and then dancing around nude on one foot while swinging a lawn mower blade around his head (being careful not to nick his winged helm, of course). He can do that, but should he do that there should be repercussions. Just as there should be if he teaches creationism, a provably wrong idea that goes counter to everything a science class represents.

But clearly the Dean disagrees. Here’s what Jaden learned:

What I took away from this meeting with Dr. Williams was that my school didn’t care about science content in its science classes.

He’s right. The next step I would take would be to talk to the people that accredit colleges in Oklahoma. I am not saying that Jaden’s college should have their accreditation taken away, but I certainly think a focused and deep investigation is warranted. What other wacky (and useless) stuff is being taught there?

I’m pleased to announce that beginning today and running for a week at the Intersection, we will have daily guest posts from Vanessa Woods, author of the new book, Bonobo Handshake. Vanessa is a Research Scientist in Evolutionary Anthropology at Duke University and studies the cognition of chimpanzees and bonobos in Congo, and her posts will be about her new book. I’ve already seen the content, and it is spectacular….so, let bonobo week begin! The first post appears later today.

A new paper is out which drills down a bit on the genetic substructure in Spain. Genetic Structure of the Spanish Population:

Background
Genetic admixture is a common caveat for genetic association analysis. Therefore, it is important to characterize the genetic structure of the population under study to control for this kind of potential bias.

Results
In this study we have sampled over 800 unrelated individuals from the population of Spain, and have genotyped them with a genome-wide coverage. We have carried out linkage disequilibrium, haplotype, population structure and copy-number variation (CNV) analyses, and have compared these estimates of the Spanish population with existing data from similar efforts.

Conclusions
In general, the Spanish population is similar to the Western and Northern Europeans, but has a more diverse haplotypic structure. Moreover, the Spanish population is also largely homogeneous within itself, although patterns of micro-structure may be able to predict locations of origin from distant regions. Finally, we also present the first characterization of a CNV map of the Spanish population. These results and original data are made available to the scientific community.

They used a 160 K SNP-chip for this, though for the PC charts below they were constrained to ~100,000 SNPs. Nothing too revolutionary in the paper. The fact that Spaniards have more haplotype diversity vis-a-vis the “CEU” sample in the HapMap, which consists of Utah Mormons, isn’t too surprising, since those individuals are Northern European and Northern Europeans tend to be a touch less diverse than Southern Europeans (more heterozygosity in Southern Europe than in the North). A common explanation for this is that Northern European populations emerged as subsets of Southern populations which expanded out of Ice Age “refugia” within the last ~10,000 years or so, and this migratory process would have induced some bottlenecks and so reduced their diversity. The findings in this paper are broadly consistent with the idea that Spain was a refugium, and so one of the sources of the population of Northern Europe. But, note that there are lots of controversies about recent European demographic history right now, so I wouldn’t take the aforementioned model as a given. Also, one major issue which sticks out is the lack of Basque populations in the sample, since that’s a group which has long been of interest, and some aspects of many demographic scenarios hinge on their nature. No surprise that Visigoths, Berbers and Arabs didn’t perturb these results too much. I believe that these groups did arrive in Iberia in large numbers, but on a relative scale their proportions were small and they probably didn’t alter Spain’s basically genetic character.

Below are some charts of note.

First, dimensions of genetic variation in the Spanish population using 100,000 SNPs by locality where the sample was collected.

If some of the localities were as obscure to you as me, here is the PC chart with a subset of them rotated and superimposed upon a map of Spain.

Finally, here are the Spanish samples plotted in relation to two HapMap populations, the CEU (American whites of Northern European ancestry) and TSI (Tuscans from Italy).

There are a few outliers here in relation to their putative population cluster, but in general the three groups are nicely separated as expected. Spain is bounded by water and a rather imposing mountain range. These serve as natural barriers to gene flow. But within the peninsula it’s dominated by a high plateau. I really don’t have an intuitive understanding of whether the spatial distribution of Spain’s people (which for ecological reasons probably can be extrapolated back to antiquity) should homogenize it through a circular pattern of gene flow, but perhaps that’s what these data are showing. I am a bit wary of saying that Spain is internally homogeneous without referencing other European populations of the same scale in detail. Perhaps what this group found is what you’d find on this scale with this chip; not much.

Cite: BMC Genomics 2010, 11:326doi:10.1186/1471-2164-11-326

H/T Dienekes

The folks at 3 Quarks Daily are taking nominations for their second annual Prize in Science. The judge this year will be Richard Dawkins.

Here are the details for how to nominate a blog post from the past year, written after May 23, 2009. The deadline is May 31.

Some Loom readers have already nominated some posts–thanks! Here are a few other of my favorites…

Full-Spectrum Genomes

The X-Woman’s Finger Bone

A Day Among the Genomes

Kinkiness Beyond Kinky

Skull Caps and Genomes

The Origin of Big

Ardipithecus, We Meet At Last

A group of new blogs have launched at NYU’s Science, Health, and Environmental Reporting Program. In my capacity as Visiting Scholar there, I helped some of the students think through how to work blogs into their training at NYU. Mainly, I urged them to think about how to not be boring. I suggested they set up blogs that they themselves would actually want to write, and that weren’t like a lot of other blogs.

And they did! Kids these days.

So check out the whole blog roll, and offer your deeply insightful and constructive critiques. They’re waiting for you.

It’s BMJ week (again) on NCBI ROFL! After the success of our first BMJ week, we decided to devote another week to fun articles from holiday issues of the British Medical Journal. Enjoy!

“OBJECTIVE: To investigate the risks of mild traumatic brain injury and neck injury associated with head banging, a popular dance form accompanying heavy metal music. DESIGN: Observational studies, focus group, and biomechanical analysis. PARTICIPANTS: Head bangers. MAIN OUTCOME MEASURES: Head Injury Criterion and Neck Injury Criterion were derived for head banging styles and both popular heavy metal songs and easy listening music controls. RESULTS: An average head banging song has a tempo of about 146 beats per minute, which is predicted to cause mild head injury when the range of motion is greater than 75 degrees . At higher tempos and greater ranges of motion there is a risk of neck injury. CONCLUSION: To minimise the risk of head and neck injury, head bangers should decrease their range of head and neck motion, head bang to slower tempo songs by replacing heavy metal with adult oriented rock, only head bang to every second beat, or use personal protective equipment.”

Read the full article here.

Image: flickr/y-its-mom

Related content:
Discoblog: NCBI ROFL: Injuries due to falling coconuts.
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Discoblog: NCBI ROFL: Pink Floyd hallucinations: not just for druggies.

WTF is NCBI ROFL? Read our FAQ!

That’s not cloud cover. It’s polar ice on Mars, about 600 miles across and covered with deep etchings. The dark valley on the right, named Chasma Boreale, is about the size of the Grand Canyon.

This riven Martian arctic was a mystery to scientists for over forty years. But data from NASA’s Mars Reconnaissance Orbiter has given researchers some important clues to how the ice spirals formed. Their findings appear in two papers published in the journal Nature.

Data from Mars now points to both the canyon and spiral troughs being created and shaped primarily by wind. Rather than being cut into existing ice very recently, the features formed over millions of years as the ice sheet grew. By influencing wind patterns, the shape of underlying, older ice controlled where and how the features grew. [NASA]

This image was made using Mars Orbiter Laser Altimeter data. A shaded-relief image, it shows clearly the pole’s gorges. Chasma Boreale is a mile deep in some places.

Related content:
Bad Astronomy: A marvelous night for a Moon (and Mars) dance
Bad Astonomy: Sand dunes march across Mars
Bad Astronomy: Mars craters reveal ice
80beats: Mars Rover Sets Endurance Record: Photos From Opportunity’s 6 Years On-Planet

Image1: NASA/Caltech/JPL/E. DeJong/J. Craig/M. Stetson
Image2: NASA/GSFC

After years of denial, Floyd Landis–the cyclist who was stripped of his winning title to the 2006 Tour de France after failing a drug test–admitted last week that he did take performance enhancing drugs. And his confession is causing a stir, partly because he also implicated former teammate Lance Armstrong, seven-time-winner of the Tour de France (Armstrong denies the accusation), and partly because of the particular drugs he fessed up to taking:

Mr. Landis said in [several emails to cycling officials] that during his career, he and other American riders learned how to conduct blood transfusions, take the synthetic blood booster Erythropoietin, or EPO, and use steroids. All these practices are banned in cycling. Mr. Landis said he started using testosterone patches, then progressed to blood transfusions, EPO, and a liquid steroid taken orally. [Wall Street Journal]

EPO shook the cycling community in the 1990s, when police raids during the 1998 Tour de France (dubbed the “Tour de Dopage“) found that several riders were using EPO. It looks like the drug, believed to be thwarted by drug tests, has returned.

Our kidneys produce most of our natural erythropoietin, a hormone that leads to the creation of red blood cells. Since red blood cells carry oxygen, more cells means more oxygen in the blood. More oxygen means longer, harder workouts.

Anemics, who suffer from fatigue, naturally have low levels of the hormone. Dopers, who take a synthetic version, have high levels, which can give them endurance but also lead to dangerous side effects such as blood-thickening (and thus strokes).

Regulatory agencies like the International Cycling Union and the World Anti-Doping Agency have developed tests to combat the use of such drugs in competitive sports. For example, the biological passport program, unveiled in 2007, uses repeated sampling to make an electronic record of the cyclist’s natural levels of various hormones, which become benchmarks to test against before a particular race. And since a urine test introduced in 2000 could determine EPO levels, apparent use of the drug declined over the past decade.

But Landis’s confession forces regulatory agencies to face a loophole that helped riders pass urine tests. It’s called microdosing:

“In 2003, the athletes started to use a new procedure together with blood doping,” said Francesca Rossi, the director of antidoping at the International Cycling Union, the sport’s governing body. “I know that this microdosing strategy can be difficult to detect.” Working with doctors, cyclists discovered that carefully controlled, small doses of EPO eluded the urine test while still raising their red cell count. Microdoses of EPO let athletes put in superhuman hours of training without suffering the natural consequence of fatigue. [New York Times]

The debate over how much EPO doping is going on in competitive cycling will certainly continue in the messy aftermath of Landis’s claims. In one allegation, Landis claimed that Armstrong was caught with EPO in 2001 Tour de Suisse, but that officials had covered it up.

Landis suffered another blow to his credibility. The International Cycling Union said no riders tested positive for EPO at the 2001 Tour de Suisse, disputing comments made by the disgraced cyclist. [Boston Globe]

Related Content:
80beats: Can “Biological Passports” Save Sports From Doping?
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80beats: Warning All Competitive Male Cyclists: Less than 5% of Your Sperm May Be Normal

Image: flickr / whileseated

Sorry for the radio silence around here of late. I don’t know about anyone else, but I’ve been traveling like a mad person. The good news is that I just got back from UC Davis, where I had the chance to meet John Conway for the first time in person.

The bad news is: no time for blogging. But I recently received an email pointing out that some links have died in an old post, which I proceeded to update. And that gave me the idea of stooping to a classic blogospheric move in times of sparse content: reposting old stuff! So here is the post in question, from several years ago. If people don’t complain too loudly, maybe we’ll dig up some more ancient blogging and bring it back to the surface.

————

Quantum mechanics, as we all know, is weird. It’s weird enough in its own right, but when some determined experimenters do tricks that really bring out the weirdness in all its glory, and the results are conveyed to us by well-intentioned but occasionally murky vulgarizations in the popular press, it can seem even weirder than usual.

Last week was a classic example: the computer that could figure out the answer without actually doing a calculation! (See Uncertain Principles, Crooked Timber, 3 Quarks Daily.) The articles refer to an experiment performed by Onur Hosten and collaborators in Paul Kwiat’s group at Urbana-Champaign, involving an ingenious series of quantum-mechanical miracles. On the surface, these results seem nearly impossible to make sense of. (Indeed, Brad DeLong has nearly given up hope.) How can you get an answer without doing a calculation? Half of the problem is that imprecise language makes the experiment seem even more fantastical than it really is — the other half is that it really is quite astonishing.

Let me make a stab at explaining, perhaps not the entire exercise in quantum computation, but at least the most surprising part of the whole story — how you can detect something without actually looking at it. The substance of everything that I will say is simply a translation of the nice explanation of quantum interrogation at Kwiat’s page, with the exception that I will forgo the typically violent metaphors of blowing up bombs and killing cats in favor of a discussion of cute little puppies.

So here is our problem: a large box lies before us, and we would like to know whether there is a sleeping puppy inside. Except that, sensitive souls that we are, it’s really important that we don’t wake up the puppy. Furthermore, due to circumstances too complicated to get into right now, we only have one technique at our disposal: the ability to pass an item of food into a small flap in the box. If the food is something uninteresting to puppies, like a salad, we will get no reaction — the puppy will just keep slumbering peacefully, oblivious to the food. But if the food is something delicious (from the canine point of view), like a nice juicy steak, the aromas will awaken the puppy, which will begin to bark like mad.

It would seem that we are stuck. If we stick a salad into the box, we don’t learn anything, as from the outside we can’t tell the difference between a sleeping puppy and no puppy at all. If we stick a steak into the box, we will definitely learn whether there is a puppy in there, but only because it will wake up and start barking if it’s there, and that would break our over-sensitive hearts. Puppies need their sleep, after all.

Fortunately, we are not only very considerate, we are also excellent experimental physicists with a keen grasp of quantum mechanics. Quantum mechanics, according to the conventional interpretations that are good enough for our purposes here, says three crucial and amazing things.

• First, objects can exist in “superpositions” of the characteristics we can measure about them. For example, if we have an item of food, according to old-fashioned classical mechanics it could perhaps be “salad” or “steak.” But according to quantum mechanics, the true state of the food could be a combination, known as a wavefunction, which takes the form (food) = a(salad) + b(steak), where a and b are some numerical coefficients. That is not to say (as you might get the impression) that we are not sure whether the food is salad or steak; rather, it really is a simultaneous superposition of both possibilities.
• The second amazing thing is that we can never observe the food to be in such a superposition; whenever we (or sleeping puppies) observe the food, we always find that it appears to be either salad or steak. (Eigenstates of the food operator, for you experts.) The numerical coefficients a and b tell us the probability of measuring either alternative; the chance we will observe salad is a², while the chance we will observe steak is b². (Obviously, then, we must have a² + b² = 1, since the total probability must add up to one [at least, in a world in which the only kinds of food are salad and steak, which we are assuming for simplicity].)
• Third and finally, the act of observing the food changes its state once and for all, to be purely whatever we have observed it to be. If we look and it’s salad, the state of the food item is henceforth (food) = (salad), while if we saw that it was steak we would have (food) = (steak). That’s the “collapse of the wavefunction.”

You can read all that again, it’s okay. It contains everything important you need to know about quantum mechanics; the rest is just some equations to make it look like science.

Now let’s put it to work to find some puppies without waking them up. Imagine we have our morsel of food, and that we are able to manipulate its wavefunction; that is, we can do various operations on the state described by (food) = a(salad) + b(steak). In particular, imagine that we can rotate that wavefunction, without actually observing it. In using this language, we are thinking of the state of the food as a vector in a two-dimensional space, whose axes are labeled (salad) and (steak). The components of the vector are just (a, b). And then “rotate” just means what it sounds like: rotate that vector in its two-dimensional space. A rotation by ninety degrees, for example, turns (salad) into (steak), and (steak) into -(salad); that minus sign is really there, but doesn’t affect the probabilities, since they are given by the square of the coefficients. This operation of rotating the food vector without observing it is perfectly legitimate, since, if we didn’t know the state beforehand, we still don’t know it afterwards.

So what happens? Start with some food in the (salad) state. Stick it into the box; whether there is a puppy inside or not, no barking ensues, as puppies wouldn’t be interested in salad anyway. Now rotate the state by ninety degrees, converting it into the (steak) state. We stick it into the box again; the puppy, unfortunately, observes the steak (by smelling it, most likely) and starts barking. Okay, that didn’t do us much good.

But now imagine starting with the food in the (salad) state, and rotating it by 45 degrees instead of ninety degrees. We are then in an equal superposition, (food) = a(salad) + a(steak), with a given by one over the square root of two (about 0.71). If we were to observe it (which we won’t), there would be a 50% chance (i.e., [one over the square root of two]²) that we would see salad, and a 50% chance that we would see steak. Now stick it into the box — what happens? If there is no puppy in there, nothing happens. If there is a puppy, we have a 50% chance that the puppy thinks it’s salad and stays asleep, and a 50% chance that the puppy thinks it’s steak and starts barking. Either way, the puppy has observed the food, and collapsed the wavefunction into either purely (salad) or purely (steak). So, if we don’t hear any barking, either there’s no puppy and the state is still in a 45-degree superposition, or there is a puppy in there and the food is in the pure (salad) state.

Let’s assume that we didn’t hear any barking. Next, carefully, without observing the food ourselves, take it out of the box and rotate the state by another 45 degrees. If there were no puppy in the box, all that we’ve done is two consecutive rotations by 45 degrees, which is simply a single rotation by 90 degrees; we’ve turned a pure (salad) state into a pure (steak) state. But if there is a puppy in there, and we didn’t hear it bark, the state that emerged from the box was not a superposition, but a pure (salad) state. Our rotation therefore turns it back into the state (food) = 0.71(salad) + 0.71(steak). And now we observe it ourselves. If there were no puppy in the box, after all that manipulation we have a pure (steak) state, and we observe the food to be steak with probability one. But if there is a puppy inside, even in the case that we didn’t hear it bark, our final observation has a (0.71)² = 0.5 chance of finding that the food is salad! So, if we happen to go through all that work and measure the food to be salad at the end of our procedure, we can be sure there is a puppy inside the box, even though we didn’t disturb it! The existence of the puppy affected the state, even though we didn’t (in this branch of the wavefunction, where the puppy didn’t start barking) actually interact with the puppy at all. That’s “non-destructive quantum measurement,” and it’s the truly amazing part of this whole story.

But it gets better. Note that, if there were a puppy in the box in the above story, there was a 50% chance that it would start barking, despite our wishes not to disturb it. Is there any way to detect the puppy, without worrying that we might wake it up? You know there is. Start with the food again in the (salad) state. Now rotate it by just one degree, rather than by 45 degrees. That leaves the food in a state (food) = 0.999(salad) + 0.017(steak). [Because cos(1 degree) = 0.999 and sin(1 degree) = 0.017, if you must know.] Stick the food into the box. The chance that the puppy smells steak and starts barking is 0.017² = 0.0003, a tiny number indeed. Now pull the food out, and rotate the state by another 1 degree without observing it. Stick back into the box, and repeat 90 times. If there is no puppy in there, we’ve just done a rotation by 90 degrees, and the food ends up in the purely (steak) state. If there is a puppy in there, we must accept that there is some chance of waking it up — but it’s only 90*0.0003, which is less than three percent! Meanwhile, if there is a puppy in there and it doesn’t bark, when we observe the final state there is a better than 97% chance that we will measure it to be (salad) — a sure sign there is a puppy inside! Thus, we have about a 95% chance of knowing for sure that there is a puppy in there, without waking it up. It’s obvious enough that this procedure can, in principle, be improved as much as we like, by rotating the state by arbitrarily tiny intervals and sticking the food into the box a correspondingly large number of times. This is the “quantum Zeno effect,” named after a Greek philosopher who had little idea the trouble he was causing.

So, through the miracle of quantum mechanics, we can detect whether there is a puppy in the box, even though we never disturb its state. Of course there is always some probability that we do wake it up, but by being careful we can make that probability as small as we like. We’ve taken profound advantage of the most mysterious features of quantum mechanics — superposition and collapse of the wavefunction. In a real sense, quantum mechanics allows us to arrange a system in which the existence of some feature — in our case, the puppy in the box — affects the evolution of the wavefunction, even if we don’t directly access (or disturb) that feature.

Now we simply replace “there is a puppy in the box” with “the result of the desired calculation is x.” In other words, we arrange an experiment so that the final quantum state will look a certain way if the calculation has a certain answer, even if we don’t technically “do” the calculation. That’s all there is to it, really — if I may blithely pass over the heroic efforts of some extremely talented experimenters.

Quantum mechanics is the coolest thing ever invented, ever.

Update: Be sure not to miss Paul Kwiat’s clarification of some of these issues.

Two things vacciney:

1) While it’s not due to antivaxxers, it’s still important: measles is making a comeback across the world. According to the article, the lack of funding is making vaccines hard to come by in Africa, Asia, and Europe, and measles is very opportunistic. With the antivaxxers still spreading their lies in America, Australia, and elsewhere, it’s all too easy for this awful disease to spread wildly anywhere it gets a toehold.

2) It’s a delicate task, talking about someone’s kid when it comes to autism and vaccinations. It’s a social minefield; you’re dealing with an innocent kid, but you’re also dealing with a parent who may be gravely misinformed and doing a lot of harm by spreading misinformation. Jenny McCarthy, though, put her son Evan front and center in the nonsense she spouts about autism, and is doing considerable harm to the public health. Skeptico has taken on her claims, and shows that her version of events seems to shape-shift according to her needs.

Tip o’ the syringe to my brother, Sid for the measles link.

It’s on.

Today the U.S. Coast Guard gave its approval to BP’s “top kill” plan to finally cap the oil spill, and at 2 p.m. Eastern time, the company got started. BP leaders warned that it may take a couple of days before they know for sure if it worked, but now say they will maintain the live video feed during the top kill attempt.

A successful capping of the leaking well could finally begin to mend the company’s brittle image after weeks of failed efforts, and perhaps limit the damage to wildlife and marine life from reaching catastrophic levels. A failure could mean several months more of leaking oil, devastating economic and environmental impacts across the gulf region, and mounting financial liabilities for the company. BP has already spent an estimated $760 million in fighting the spill, and two relief wells it is drilling as a last resort to seal the well may not be completed until August [The New York Times].

This procedure is no sure bet, because a top kill hasn’t been attempted 5,000 feet down in the sea before. BP’s CEO Tony Hayward estimates the percentage chance of success in the 60s.

The procedure requires an elaborate and precise orchestration among five vessels at the surface, whose duties range from housing pumping equipment to storing a total of 50,000 barrels of drilling mud, and several remote-controlled undersea robots. If all goes as planned, the dense mud will be pumped through a single 6-5/8-inch-diameter drill pipe from one vessel, which will then enter two 3-inch-diameter hoses. Those hoses will deliver the material to the sea floor, where they will intersect with the choke and kill lines of the damaged blowout preventer, which sits atop the well [Christian Science Monitor].

Whether this works may depend on whether the weight of the mud is enough to push the oil back into the well, which isn’t certain. If it fails, the junk shot option—trying to plug up the leak with tires and golf balls and other trash—is still on the table.

Recent posts on the BP oil spill:
80beats: Oil Spill Now on 65 Miles of Shoreline; BP Will Try a “Top Kill” to Stop the Leak
80beats: BP To Switch Dispersants; Will Kevin Costner Save Us All?
80beats: Scientists Say Gulf Spill Is Way Worse Than Estimated. How’d We Get It So Wrong?
80beats: Testimony Highlights 3 Major Failures That Caused Gulf Spill
80beats: 5 Offshore Oil Hotspots Beyond the Gulf That Could Boom—Or Go Boom

Image: BP

Remember the sunscreen speech? The Chicago Tribune column, which became an urban legend and then a bizarre spoken word hit for Baz Luhrmann, began

Wear sunscreen.

If I could offer you only one tip for the future, sunscreen would be it. The long-term benefits of sunscreen have been proved by scientists, whereas the rest of my advice has no basis more reliable than my own meandering experience.

But is even this sage advice subject to the “it’ll cause cancer, no wait, it’ll cure cancer” back-and-forth that plagues medical studies? Reading some headlines today, you might think so. Don’t toss out your tube of Banana Boat just yet, though.

The non-profit Environmental Working Group released another of its reports on the sunscreen industry, coming down hard on the chemicals it uses and the claims it makes in its advertising. Some stories about the report drew headlines like “Sunscreen May Hurt, Not Help;” “Your Sunscreen May Give You Cancer: Study;” and “Study: Many Sunscreens May Be Accelerating Cancer.”

EWG’s report claims that a Vitamin A compound called retinyl palmitate, used in some 40 percent of sunscreens, breaks down and causes skin damage under exposure to sunlight. The report cites research done under the Food and Drug Administration. But, according to dermatologist Henry W. Lim of Henry Ford Hospital:

These claims, says Lim, are based on a study in mice, which are far more susceptible to skin cancer than humans. “It’s dangerous to apply a finding in mice to humans, and I’ve spoken with a number of my colleagues about this and we all agree that it’s very premature to even cast doubt about the safety of this chemical.” The EWG also flagged products with oxybenzone, which it calls a “hormone-disrupting” compound. This, too, is based on mice data, says Lim; the animals were fed significantly greater amounts of the chemical than what’s commonly applied in sunscreen. Other research found no significant changes in blood hormone levels in human volunteers who were told to apply sunscreens containing oxybenzone every day for two weeks [U.S. News & World Report].

I called up dermatologist Darrell Rigel at New York University, who argues that since Vitamin A is used in skin cancer treatment, the claim that it’s a cancer-causer is a dubious one. As the old graduation speech notes, the benefits of sunscreen have been shown for the millions of people who’ve used it to protect their skin for the last quarter-century. Rigel’s worry is that cancer fear-mongering would lead people to go without sunscreen this weekend and throughout the summer, subjecting themselves to damaging burns. “That’s what the real danger is,” he says.

Besides, the Vitamin A compound isn’t the whole story. Back to Dr. Lim:

Interestingly, the EWG gave its green or favorable rating only to products that contain zinc oxide or titanium dioxide, two blockers that don’t get absorbed into the skin and are considered pretty innocuous. But Lim says that some dermatologists have expressed concerns about the use of these compounds in people who have inflammatory skin conditions like eczema. Tiny cracks in the skin of people with eczema could allow these compounds to enter the bloodstream [U.S. News & World Report].

So do pay attention to the ingredients if you have skin conditions. And if you’d prefer find a sunscreen without the Vitamin A ingredient anyway, the EWG’s database can give you a hand with that.

Just don’t stop wearing sunscreen, please. In fact, use more: The EWG reinforces some helpful points we already knew, including that high SPF numbers can lead people into a false sense of security so they don’t use enough sunscreen, or don’t reapply it when necessary. In addition, they argue, sunscreens should come with more information about their ability to block UVA radiation, and not just UVB.

This is partially the fault of the FDA, which has promised–and failed to deliver on–regulations for sunscreen. The organization claims that regulations might be issued as soon as next October, but manufacturers will have at least a year to comply [Fast Company].

Finally, the EWG reminds the public that sunscreen shouldn’t be a primary protector—that is, don’t stay out shirtless all day in the blazing heat because you slathered on some SPF 45 in the morning.

Related Content:
DISCOVER: The Biology of Sunscreen
DISCOVER: Outrunning Melanoma
Discoblog: Sunscreen: Healthy Habit for You, Bringer of Death for Coral Reefs
Discoblog: Lather Up: New Sunscreen Could Be Inspired By Hippo Sweat

Image: flickr / Indexorama

They change their clothes frequently. They shower repeatedly, sometimes using a whole bar of soap in one go. Some even swallow perfume.

They think they smell bad, but they don’t.

Olfactory reference syndrome is a rare psychiatric disorder, but it can lead to isolation, depression, and suicide. It’s also a little-noticed, little-studied syndrome. But now a study to appear in Depression and Anxiety has looked at twenty sufferers and reviewed current literature on the disorder to determine its general characteristics.

Psychiatrists have known about the disorder’s symptoms for over a century, but treatment and diagnosis are difficult, in part because the syndrome doesn’t currently have its own classification in Diagnostic and Statistical Manual of Mental Disorders (DSM)–the handbook of mental health professionals. The manual combines the syndrome with other disorders, such as social phobia, delusional disorder, body dysmorphic disorder, and obsessive-compulsive disorder. The new study gives recommendations for updating the next version of the manual, and suggests adding this disorder to an appendix of conditions that need further research.

As reported by HealthDay News, nineteen of the study’s twenty volunteers exhibited at least one compulsive behavior, like repeated self-sniffing or showering. On average, they spent eight hours a day thinking about their smell. Fearing social interactions, forty percent had been housebound for over a week.

Many patients thought the smell came from their mouth, but they were also concerned with their armpits, genitalia, anus, feet, and skin, according to a MedPage Today article.

Katharine Phillips, a coauthor of the study and a professor of psychiatry and human behavior at Brown University, presented these and other findings on Tuesday at the American Psychiatric Association annual meeting. She told Reuters Health:

“I think it’s a very secret and hidden disorder, because these patients tend to be very ashamed of themselves…. I have been so struck by the intense suffering that the patients experience.”

Related content:
Discoblog: Bad Breath? Body Odor? Don’t Bother Applying to China’s Space Program
Discoblog: Doctor, Is My Diabetes Medicine Supposed to Smell Like Gym Socks?
DISCOVER: Finding the Right Word Odor
DISCOVER: The Brain: The First Yardstick for Measuring Smells

Image: flickr / mysza831

Florida Today is reporting that Space X is planning to launch their first Falcon 9 rocket as early as this week, May 27 or 28! [Update: I just found out that the launch has been delayed to Jun 2/3 due to a slip in the schedule of a launch of a Delta IV.]

I am an unabashed fan of Space X, one of many commercial companies building rockets to make access to space easier, more reliable, and less expensive. They have already shown themselves to be capable of putting rockets into space, and being resilient while doing so. The Falcon 9 is the next in their series of rockets; this one capable of getting supplies to the Space Station, sending astronauts into orbit, and eventually, being able to put a 20 ton payload into geosynchronous orbit.

You can keep up-to-date with what’s what on the Space X updates page. I’ll be keeping a close watch on events as well. This is the future of space exploration, quite literally, and I’m very excited about it.

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Related posts:

Obama lays out bold revised space policy
Falcon 9 getting ready for maiden voyage
Falcon 1 launch a success!
Falcon 9 standing tall
High roller



Image credit: Space X.

In the Canadian Rockies, a horde of 91 squid-like animals have risen from the depths, millions years after their demise. This isn’t the plot of a terrible B-movie; it’s the doing of Martin Smith and Jean-Bernard Caron from the University of Toronto. Together, they have solved a mystery some 500 million years in the making.

Smith and Caron have been giving a makeover to an enigmatic creature called Nectocaris. Until recently, only one specimen had ever been found. Its poor state and puzzling combination of features made it nigh impossible to classify. But not anymore – by finding a staggering 91 extra specimens, Smith and Caron have revealed that Nectocaris is the earliest known cephalopod. It’s the great-great-great-(etc)-granduncle of today’s octopuses, squids and cuttlefish.

Nectocaris pteryx or “swimming crab with wings” was first described by Simon Conway Morris in 1976. It’s one of the stars of Canada’s Burgess Shale formation, arguably the planet’s most important collection of fossils. Its rocks preserve an extraordinary diversity of animals from the Cambrian period, some 505 million years ago. It was a time of great evolutionary experimentation, when the ancestors of all of today’s animal groups mingled with bizarre creatures that have left no living descendants.

Until now, Nectocaris’s allegiances have shifted all over the place. Conway Morris himself had no idea where to place it. Some scientists suggested that it was an early arthropod, a relative of crabs, shrimp and the like. Others placed it within the chordates, the group that includes us and all other back-boned animals. But Smith and Caron think that both of these possibilities are unlikely. Their new specimens reveal a host of features that are distinctly cephalopod-like.

Around four centimetres in length, Nectocaris had a soft, flattened, kite-shaped body with two fins running down its sides. Its small head was adorned with two long tentacles and two stalked eyes. Unlike the compound eyes that were common among Cambrian animals, probably had the camera-like structure that modern cephalopods use. From its neck protruded a flexible funnel, which opened into an internal cavity containing pairs of gills.

The funnel lay behind some of the earlier confusion about Nectocaris. In the original specimen, it was flattened so that it looked like a shield-like plate behind the eyes, reminscent of a crustacean’s body armour. The new specimens put paid to that interpretation. The structure is clearly a funnel, similar to those used by modern cephalopods. Nectocaris probably used it to swim the same way, giving it an extra boost of jet propulsion to complement the beating of its large fins.

It was either a predator or a scavenger, grabbing small, soft-bodied animals with its long tentacles. And it probably spent most of its time close to the seabed; some specimens had sediment-filled gill chambers, suggesting that they were caught by a sudden fatal mudslide. The sediment helped to preserve their bodies with such quality that 500 million years later, their position in the animal tree of life has suddenly become clearer.

Nectocaris’s new status pushes back the rise of the cephalopods by 30 million years, telling us that this popular group arose far earlier in earth’s history than previously thought. Smith and Caron think that two other Burgess Shale oddities – Vetustovermis and Petalilium were also members of the same family.

The revised family tree also repaints our picture of the group’s origins. Until now, scientists had thought that the group’s first representatives – the nautiloids – evolved from a group of creeping snail-like creatures called monoplacophorans, whose backs were covered with cap-like shells. These casings were gradually modified so that the animals could float. The living nautiluses and the extinct (but frequently fossilised) ammonites belong to the same shell-bearing group.

But Nectocaris had no shell despite being the earliest known cephalopod and an active swimmer. If Smith and Caron’s interpretation is right, the cephalopods didn’t inherit hard coverings from a monoplacophoran ancestor. These shells were a later innovation all their own.

There are a few parts to the puzzle that haven’t been fitted yet. For example, did the cephalopods start off with two tentacles as in Nectocaris only to evolve more over time, or were Nectocaris’s arms formed by fusing multiple pairs? Also, all modern cephalopods have a sharp, horny beak and a nightmarish, rasping tongue called the radula; it’s unclear if Nectocaris shared these features, for its mouthparts have never been well preserved.

The radula is a particularly big deal – it’s a uniting feature of all molluscs (the group that includes cephalopods, monoplacophorans, snails and others), including some that are supposedly more primitive than Nectocaris. Finding a radula would be the clincher for Smith and Caron’s argument; failing to do so puts their analysis in a tricky position.

Reference: Nature http://dx.doi.org/10.1038/nature09068

Images: reconstruction by Marianne Collins; fossil photo by Jean-Bernard Caron

More on cephalopods:

• Scientists solve millennia-old mystery about the argonaut octopus
• Glowing squid use bacterial flashlights that double as an extra pair of “eyes”
• What the stomach contents of sperm whales tell us about giant squid and octopuses
• Camouflaged communication – the secret signals of squid
• A squid’s beak is a marvel of biological engineering