Cocktail Party Physics

on the road again

We are madly traveling about the world at the moment, en route to Doha, Qatar, for the World Conference of Science Journalists. So there is very little time to blog, and rather than make myself nuts, I'm likely to just take a hiatus for the next week or so. But in the meantime, in honor of the recent observation of neutrino oscillations at Japane's T2K experiment, here's a bit of particle physics history for your reading pleasure: the discovery of the tau neutrino!

“Neutrinos, they are very small/ They have no charge and have no mass/ And do not interact at all,” John Updike wrote in his 1960 poem, “Cosmic Gall.” Neutrinos were a fairly recent discovery then, and within two years physicists would discover that they were only just beginning to understand this mysterious “ghost particle.” For instance, there was more than one kind of neutrino, and it would take physicists another 40 years to find them all.

Wolfgang Pauli first proposed the existence of neutrinos in 1930 while investigating the conundrum of radioactive beta decay, in which some of the original energy appeared to be missing after an electron was emitted from an atomic nucleus. He hypothesized that in order to abide by the laws of energy conservation, another, as-yet-undetected neutral particle might also be emitted, accounting for the missing energy.

Pauli was reluctant to publish a paper on this unusual hypothesis, but he penned a letter to a group of prominent nuclear physicists gathering for a conference in Tubingen, Germany in December asking for input regarding means of detecting such a particle experimentally.  “I have done something very bad today by proposing a particle that cannot be detected; it is something no theorist should ever do,” he wrote, describing his idea as “a desperate remedy.”

Among the physicists who took Pauli’s idea seriously was Enrico Fermi, who developed the theory of beta decay further in 1934, coining the name “neutrino” (“little neutral one”) in the process. It became clear that if such a particle existed, it must be both very light – less than 1% the mass of a proton -- and interact very weakly with matter, making it very difficult to detect. But in 1956, Frederick Reines and Clyde Cowan succeeded in doing just that, sending a telegram to Pauli informing him of their discovery. “Thanks for message,” Pauli telegrammed back. “Everything comes to him who knows how to wait.”

Pauli died two and a half years later, and thus missed the discovery in 1962 of a second type of neutrino, dubbed the muon neutrino, corresponding to the surprising discovery of the charged muon lepton. (The latter caused I.I. Rabi to famously exclaim, “Who ordered that?”) In 1975, a third charged lepton, tau, was discovered, and subsequent experiments hinted strongly that there should also be a third kind of neutrino. While scientists at CERN uncovered further proof in 1989 of the tau neutrino’s existence, it would take another 25 years before the technology was available to detect this elusive particle directly.

In the 1990s, Fermilab designed the DONUT (Direct Observation of the NU Tau) experiment to search specifically for tau neutrino interactions. The scientists used the Tevatron to produce an intense neutrino beam, predicting it would contain at least some tau neutrinos. After deploying an elaborate system of magnets and iron and concrete to eliminate as many background particles as possible, the beam was fired at a three-foot-long fixed target: iron plates alternating with layers of a special emulsion sandwiched between them.

Those emulsions captured the tracks of any electrically charged particles produced by the extremely rare (about one in one million million) tau neutrino interactions, which were then electronically recorded by scintillators. The emulsions were then photographically developed so that scientists could analyze the data, looking for the telltale distinctive short track with a kink that indicates a tau lepton, the result of a tau neutrino interacting with an atomic nucleus. They were literally connecting the dots: small black dots left by particles passing through, which could then be connected to retrace the particles’ paths.

After the experimental run in 1997, it took three years of painstaking analysis to sift through all the data, winnowing some six million signatures down to 1000 candidate events. On July 21, 2000, scientists from the DONUT collaboration announced they had identified four tau neutrino signatures demonstrating an interaction with an atomic nucleus. The experiment also validated a number of new techniques for neutrino detection, most notably the emulsion cloud chamber, which significantly increased the number of neutrino interactions.

Leon Lederman, who shared the 1988 Nobel Prize in Physics with Jack Steinberger and Melvin Schwartz for the discovery of the muon neutrino, called the achievement “an important and long-awaited result. Important because there is a huge effort underway to study the connections among neutrinos, and long awaited because the tau lepton was discovered 25 years ago and it is high time the other shoe was dropped.”

Among the questions physicists were still pursuing was whether neutrinos might have a tiny bit of mass, which could dramatically alter scientists’ estimation of the overall mass of the universe, because they are so plentiful. This in turn has implications for estimating the rate of expansion of the universe. And if neutrinos do have mass, whether they could oscillate and change flavors over time as they traveled through space. For instance, would it be possible for a muon neutrino to change into a tau neutrino via oscillation?

That question was answered with a resounding yes in 2010. Scientists with the OPERA experiment at Gran Sasso National Laboratory reported that they had found four instances of the telltale signature of the tau neutrino among a stream of billions of muon neutrinos generated at nearby CERN -- the first direct observation of a neutrino transforming from one type into another. Experiments are ongoing to further explore this phenomenon and determine specific masses for neutrinos.

With the discovery of the tau neutrino, only one more particle remains to be found to complete the Standard Model of Particle Physics: the elusive Higgs boson. Fermilab’s soon-to-be-retired Tevatron is racing against the clock to make one more significant discovery before it exits the particle physics stage, competing with the Large Hadron Collider at CERN. It will herald the dawn of a new era in physics – and possibly yield a few more unexpected surprises.

 

drunken masters of lingua franca

We're having a bit of a thematic installment of Friday Fodder this week. See, I regrettably missed this year's Acoustical Society of America meeting in Seattle, but I still managed to rifle through their impressive collection of lay language papers covering talks presented at the meeting. I already covered the watershed work on muting the noise of flushing low-flow toilets a couple of weeks ago. But there were also tons of papers relating to speech: researchers at looking at the voice physiology of transgender people; how men and women imitate each other and what this might tell us how gender, emotion and just plain old acoustics impact those imitations; and how to identify the sexual orientation of speakers based on just their voices.

There was even a paper on "understanding casual speech," which I guess must be, like, hard and stuff for some folks. And now I'm happy to report that Abby Kaplan, who works in the linguistics department at the University of Utah, had some interesting things to say about drunken speech patterns -- namely, whether it's harder to pronounce certain sounds or words when intoxicated.

This might strike many readers as "Duh!" science, but as Kaplan discovered, actually demonstrating in a rigorous fashion what we all instinctively feel to be true -- based on personal experience -- isn't quite as simple as it seems. (Nor is she the first to be intrigued by this question. Via Language Log, I learned that there is a 1902 treatise by a guy named Edward Wheeler Scripture, The Elements of Experimental Phonetics, that toys with the notion of studying the phonetics of drunken and other unusual speech patterns through recordings.)

Let's start with the assumption that certain sounds and words are more difficult to pronounce than others (an effect that is exacerbated if, like me, your vocabulary was acquired through extensive reading -- I habitually put my emPHAsis on the wrong syllABle). "Intuitively, it seems obvious that some sounds are harder to pronounce than others," Kaplan writes. She points to the "th" sound, as in "think" as being rather rare in the world's languages, and a stumbling block for many ESL students.

Linguistic theory holds -- so far -- that some phonetic speech patterns involve substituting easier sounds for harder ones. The most common example is how [p] is ponounced [b] in some languages (Korean, Malaysian) when it occurs between two vowels, while in other languages [b] is pronounced [v] when between two vowels. But how do we know if these quirks occur because one sound really is easier than another? Well, you can always conduct a controlled experiment with participants reading a list of words first while sober, and then while intoxicated, since the latter sate impairs verbal (and other) functions.

And here is where the fun begins, because in order to test this hypothesis, Kaplan had to get her study participants quite drunk. I'm guessing she had quite a few volunteers. They were plied with equal parts vodka and orange juice until they reached a blood alcohol content level of between .10 and .12, just above the legal driving limit in the US of .08) -- until, one assumes, they started to sound like the title character played by Dudley Moore in the original Arthur from the 1970s:

Kaplan's findings: (a) drunken speech is indeed different from sober speech (the "Duh" aspect); and (b) "the overall range of sounds that people pronounce is smaller in drunken speech than in sober speech," which is consistent with Kaplan's original thesis, with one caveat: the participants didn't always choose the easier sounds when they were drunk. Sometimes they pronounced more of their [p]'s like [b]'s when drunk, but then, they also pronounced more of their [b]'s like [p]'s. So you can't really say, based on her study, that one sound is easier than the other. And this, says Kaplan, has some interesting implications for the prior assumptions made by linguists:

"If drunken speech really does involve saying `easier' sounds, then these results are a challenge for what linguists have traditionally believed about the sound patterns described above.  These results suggest that neither [p] nor [b] is easier to pronounce between vowels, but rather that some sound intermediate between the two is easier than both.  If it's not true that [b] is easier to say between vowels than [p], then there must be some other reason languages replace [p] with [b] in this context.... One important goal for future research is to try other methods of studying 'easy' and 'hard' sounds, and see whether the results of those methods are consistent with the results of this experiment."

Arthur's slurred speech is made more difficult to understand, one presumes, by his pronounced British accent. Over at The Last Word on Nothing, Sally Adee has an amusing post on why a British accent makes phrases like "chuffed" and "can't be arsed" -- even random dialogue from Jersey Shore -- sound posh, whereas when Adee herself attempts those phrases, her native-German-laced-with-Long-Island-and-a-bit-of-Baltimore accent simply isn't up to the "can't be arsed" challenge: "When a Brit delivers the phrase, those three little words are transformed into gleaming pearls of wit. But in my mouth, that 'r' is like hitting a ten-foot pothole in a clown car.”

I think we should all be able to say "chuffed" and other amusing Britishisms if we feel so inclined, even if it makes our friends roll their eyes -- possibly even with a fake British accent. C'mon, it could be funny, as well as pretentious. Jen-Luc Piquant deliberately puts on airs for her fellow avatars in Cyberspace; she thinks it makes her sound more sophisticated to affect zee 'eavy Gallic accent, n'est-ce pas? I don't have the heart to tell her that it just makes her seem like a prat. Who am I to judge?

Heck, sometimes I find myself imitating (badly) people's regional accents in casual conversation in spite of myself. I recall as a teenager, during church fellowship hour, finding myself in conversation with a well-spoken, articulate high school senior girl, who was making a valiant effort to reach out to the shy, socially awkward sophomore (i.e., me -- people don't believe me today, but I was painfully shy through much of college), fidgeting before her and struggling to maintain eye contact. I did my best to match her liveliness, her vocal inflections -- except then she got a strange look on her face and abruptly walked off. She thought I was mocking her (I wasn't). It was one of many failed attempts to fit in with my church's social structure.

The tendency of people to imitate tone of voice, gestures, and other elements of conversational style is something that is well-documented by linguistic studies, according to Sara Phillips, a linguist at Ohio State University. Phillips and her collaborators decided to explore one commonly imitated factor in particular: regional dialects, most notably, how certain vowels are pronounced. Northerners, for instance, might flatten out the vowel sound in "block" such that it seems closer to "black," and make a subtle distinction in vowel sound when they say "caught" or "cot," compared to Midland speakers. "We wanted to see if speakers imitate only idiosynchratic properties of the talker's voice, or if they imitate properties of the talker's dialect, too," writes Phillips.

So they had participants repeat words and phrases of certain regional dialect talkers, recording the utterances of both. These were designated A, B and X, in which B was the speaker's normal pronunciation, A was the speaker prnouncing the same word in imitation of a dialect speaker, and X was the original dialect speaker's pronunciation. Then they played the recordings back for a control group of listeners who were asked to determine whether A or B sounded more like X. (There are sound files so you can hear for yourself.) Anyone who chose A seemed to be picking up on the imitated accent of the dialect. Or were they? Phillips et al. coupled their study with an acoustic analysis, and came to a somewhat different conclusion:

"It appears that speakers were imitating aspects of pronunciation that are not known to mark dialect, such as the duration of the vowel or final consonant of the word. In our experimental materials, the Northern talkers produced longer vowels and consonants than the Midland talkers.  This difference may have resulted in the appearance of dialect imitation, even though participants were really only imitating idiosyncratic features of the talkers’ speech. If they were imitating dialect features, we would have expected to find effects of vowel pronunciation instead.  While we did find weak evidence for vowel imitation, the effect was not significant.

Taken together, these results suggest that while speakers imitate characteristics of individual talkers’ speech, they do not necessarily imitate well-known dialect markers. It may be that our effect of dialect on imitation was due to peculiarities of our speakers rather than real differences between the Northern and Midland dialects.

Okay, but has anybody bothered to study what it is about foreign accents that makes the speakers so difficult to understand? Mais, oui! I give you graduate student Alison Trude and her faculty advisor, Sarah Brown-Schmidt, both of the University of Illinois in Urbana-Champaign's psychology department, who conducted a series of studies looking at a listener's ability to understand a native English speaker and a native Quebecois speaker both speaking English words and phrases.

A classic illustration of the difference is the respective pronunciations of "bee" and "beet." While a native English speaker will pronounce the "ee" in both the same, the Quebecois will pronounce "beet" with a short "i" sound, so that it sounds like "bit." It was an elaborate experimental setup involving tracking eye movement as participants viewed computer images of various objects while listening to accented and unaccented words describing those images. Supposedly this told the researchers how quickly they understood the words.

The prediction: "Previous research has shown that participants spend more time looking at pictures whose names sound more alike, so it was predicted that participants would look at the picture of the beet more when hearing the English speaker say 'bees' and would look at the picture of the beet less often when hearing the French speaker say 'bees,' because in the French accent, 'bees' and 'beet' sound less similar."

The actual result was just the opposite. Participants looked at the wrong picture more often when listening to the French speaker, and adapted more easily if they heard each of the accented words pronounced with the same ending ("beet", "seat", or "feet"). It also helped if the accented words didn't sound like another English word, since there was less room for further confusion. So Trude and Brown-Schmidt concluded from their experiments that (a) if you're talking to someone with  foreign accent, having that person utter a string of words that sound similar will help you adapt to their accent; and (b) you'll have more trouble if the accent causes you to confuse two real words in English, i.e., the "beet" vs "bit" example (or "beep"). Per Trude and Brown-Schmidt:

These findings show that we as listeners have very particular expectations about how speech should sound. Some theories say that when listening to a foreign speaker, we relax the rules of pronunciation and are more accepting of things that don’t sound quite right because we understand that he or she cannot speak the language perfectly. However, these results suggest the opposite: native speakers of a language are listening for well-formed words, regardless of who’s talking.

This might have a useful application in bringing foreign actors to Hollywood, for example. Arnold Schwarzenegger notoriously kept his lines to a bare minimum in Conan the Barbarian in his early acting days, all uttered in heavily Austrian-accented English. And Hong Kong martial arts master Jackie Chan's move to American films was hampered by his broken English and heavy Chinese accent; ditto for Jet Li, who had, like, three lines in Lethal Weapon 4. And thus we come full circle back to our theme of drunken speech with a look at a unique style of martial arts: Zui Quan, which loosely translates as "drunken boxing." (Yeah, it's just an excuse to bring up Jackie Chan and include an awesome video clip. What of it?)

Chan immortalized the style in two films, Drunken Master I and Drunken Master II, wherein his protagonist gains the upper hand in climactic fight scenes by becoming inebriated --although it's important to strike the right balance: earlier in DM-II, Chan's character becomes a bit too drunk after a fight with his father, slurring his speech and warbling a little ditty called "I Hate Daddy," before getting the crap beaten out of him by thugs because he's too inebriated to fight at all.) In reality, Zui Quan practitioners only imitate the physical movements of drunkards; they are not actually drunk.  Per Wikipedia:

"The postures are created by momentum and weight of the body, and imitation is generally through staggering and certain type of fluidity in the movements. It is considered to be among the most difficult wushu styles to learn due to the need for powerful joints and fingers. ... Zui Quan techniques are highly acrobatic and skilled and require a great degree of balance and coordination, such that any person attempting to perform any Zui Quan techniques while intoxicated would be likely to injure himself.

Even though the style seems irregular and off balance it takes the utmost balance to be successful. To excel one must be relaxed and flow with ease from technique to technique. Swaying , drinking, and falling are used to throw off opponents. When the opponent thinks the drunken boxer is vulnerable he is usually well balanced and ready to strike. When swigging a wine cup the practitioner is really practicing grabbing and striking techniques. The waist movements trick opponents into attacking sometimes even falling over. Falls can be used to avoid attacks but also to pin attackers to the ground while vital points are targeted."

You can see Zui Quan in action in this eight-minute choreographed fight scene from Drunken Master II, when Chan was at the height of his athletic prowess. (And remember, he does all his own stunts, so he really is falling backward onto a bed of hot coals. Ouch!) Definitely one of the Best. Fight. Scenes. Ever.

friday fodder #12

It's been a deadline-centric week so blogging has been light, with only the occasional foray into interesting things on the internet. For instance, Jen-Luc Piquant was tres desole to learn from the folks at Jezebel that caffeine-infused leggings won't make her ass get smaller; it's back to the Cyber-Elliptical for her! But we were thrilled to discover, via Isis the Scientist, that there is an entire blog devoted to a Jell-O Shots Test Kitchen. Also? Technology Review will be having an entire special issue devoted to science fiction stories -- we can't wait! But there were also more substantive bloggy items as well; we offer a sampling below for your weekend perusal.

Don't Toss Out Your Cell Phone Yet! It's baaack! The specter of cancer-causing cell phones! Folks are freaking out again over WHO's latest public service announcement regarding evidence for a correlation between cell phone use and brain cancer. Bear in mind that WHO is not making the claim that cell phones cause cancer; it knows full well that correlation is different than causation, and the biological and epidemiological evidence just doesn't meet (yet) the standard of causation -- unlike, say, smoking and cancer, where the link is very well established. Sadly, this distinction is being lost in much of the media coverage and public response. Orac lays it all out for you here and he's pretty fair as well as respectfully insolent; for a less personal take on the actual data, check out Ed Yong's piece at Cancer Research UK.

When Physics Gets Counter-Intuitive, Part I. Scientific American continues to pump out well-written, thought-provoking guest blog posts on fascinating topics, and this week they featured physicist Vlatko Vedral describing his latest research into a counterintuitive conundrum of quantum mechanics that appears to violate a principle (if not an actual law) of thermodynamics:

"Everyone who has ever worked with a computer knows that they get hotter the more we use them. Physicist Rolf Landauer argued that this needs to be so, elevating the observation to the level of a principle. The principle states that in order to erase one bit of information, we need to increase the entropy of the environment by at least as much. In other words we need to dissipate at least one bit of heat into the environment (which is just equal to the bit of entropy times the temperature of the environment).... Our new paper argues that in quantum physics, you can, in fact, erase information and cool the environment at the same time. For many physicists, this is tantamount to saying that perpetual motion is possible! What makes it possible is entanglement...."

When Physics Gets Counter-Intuitive, Part II. Over at Skulls in the Stars, Dr. SkySkull regales us with two related posts on the weirdness of water and the "Mpemba effect": namely, that under just the right circumstances, hot water can freeze faster than cold water. Per the Good Doctor: "In 1963, a Tanzanian secondary school student named Erasto Mpemba noticed that hot ice cream mix froze faster than cold ice cream mix.  He pointed this out to a visiting physics lecturer, and the two published their experimental observations in 1969." It's weird, and it's not entirely understood, which makes for some fascinating reading.

The Physics of Blood Spatter. Via io9, we learned that physicists at Washington State University got all C.S.I. in the lab to investigate patterns that might indicate the exact height of the blood-spurting wound. And they did it with a couple of boards, some string, Ashanti chicken wing sauce and Ivory dish soap (the latter two ingredients were combined to get just the right consistency for the test droplets). Dexter would be so proud.

Truth is Stranger Than Webcomics. So, I'm assuming you all read Zach Weiner's Saturday Morning Breakfast Cereal regularly, so you saw this comic about how George de Hevesy used "aqua regia" to melt down Max von Laue's Nobel Prize medal during World War II to protect the gold from the invading Nazi hordes. But did you know it was a true story? I didn't! Fortunately, The Stray World was on the case and gives you the backstory, along with a nifty demo video for good measure.

The Natural Science of E.B. White. So, my pal Michael Sims has a new book out, The Story of Charlotte's Web, exploring the biographical back story to this childhood classic. And he's also written a fascinating article in the Chronicle of Higher Education about White's attitude towards animals and nature, which was far more nuanced than many critics have assumed to date. Sure, he could make a young child weep over Charlotte's inevitable demise, as if one had lost a true friend; but he wasn't prone to cheap sentimentality either (hence the power of his famous novel). Michael makes a strong case, and also delves into White's realization that science and fiction/storytelling do, in fact, make excellent bedfellows:

In writing Charlotte's Web, White developed much of his fanciful, empathetic story from what might seem the least likely direction—natural science. After watching a real-life spider spin an egg sac above his barn doorway, he determined a likely species for her so that he might learn her characteristics. Turning to scientific sources, both recent and antique, he carefully researched the life cycle of spiders: how they spin orb webs and egg sacs, how they trap prey and lay eggs, how in the spring the spiderlings balloon and disperse on filaments of web. "I discovered, quite by accident," he wrote, "that reality and fantasy make good bedfellows."

From the first, his scientific research and his whimsical imagination encouraged each other. He envisioned Charlotte performing certain actions in her web, such as writing letters that showed up well enough for people to see, and immediately he turned to scientists to learn by what chemistry and acrobatics she might accomplish what he had in mind. He pounced on an unexpected tidbit of information in a source book, such as the detail that stream-side spiders have been known to catch small leaping fish in their webs, and soon Charlotte was retailing these facts as anecdotes about her extraordinary family.

Double the Fun With Rube Goldberg Devices. Some folks are trying to raise money via Kickstarter to take their Life-Sized Recreation (a kinetic sculpture) of the popular kid's game, Mouse Trap, on the road in all its Rube Goldberg-ery goodness:

And because you can never have too much of these contraptions, we bring you (via Popular Mechanics) a video of the winners of the 24th Annual National Rube Goldberg Machine Contest held at Purdue University, who built the most complicated such device yet. To wit: "It starts with the Big Bang, re-creates the extinction of the dinosaurs, holds a jousting competition, flips over an album, and simulates World War II, a shuttle launch, the fall of the Berlin Wall, and even the alleged apocalypse in 2012. In its precisely executed review of history, "The Time Machine," a Rube Goldberg contraption built by members of the Purdue Society of Professional Engineers and Society of Hispanic Professional Engineers, incorporates a record-breaking 244 steps—all to water a single flower." It's Short Attention Span Science!

Journalism Train Wreck of the Week: Finally, John Rennie has a hilarious takedown of a "news story" -- Jen-Luc added the scare quotes in a pique -- at the Mail Online that he has dubbed "The Alpha Cavewoman Fiasco." Granted, the Mail is an easy target, but it's always a treat to watch John whip out the Scalpel of Sarcasm. His post also has the best lead of the week: "If a news story about human evolution mentions Raquel Welch or One Million Years B.C. in the lead paragraphs, you should lower your expectations for the rest because it is shallow and hackneyed. If it mentions The Flintstones, you should probably skip the rest because it is juvenile. But if it mentions both Raquel Welch and Wilma Flintstone twice in the first six paragraphs, you should sigh with relief: because you will never read anything more stupid in the rest of your life."