Tuesday, May 31, 2005

Strongest Source of Gravitational Waves?

Stellar tango. These tightly orbiting white dwarfs, doomed to collide, churn space with gravitational waves in this artist's illustration.

At the American Astronomical Society meeting now under way in Minneapolis, Tod Strohmayer (NASA/Goddard Space Flight Center) reported on periodic X-ray pulsations from a source known as RX J0806.3+1527. The pulsations, found with the Chandra X-Ray Observatory, agree with earlier, visible-light observations indicating that the source is a pair of white-dwarf stars orbiting each other in a tight binary system. The two collapsed stars are separated by only 80,000 kilometers (50,000 miles, or one-fifth the Earth-Moon distance) and circle each other every 5.36 minutes. No known binary star has a shorter orbital period.

article in Sky and Telescope.

White Dwarfs in a Death Spiral in Science.

Female spiders exploit double-barrelled sperm storage

Redbacks use cannibalism and conniving to select the best mates.

Large female redbacks can collect sperm from more than one mate.
© Maydianne Andrade

Females seem to hold all the cards in this species.
Maydianne Andrade
University of Toronto, Canada

Female redback spiders are not the most sympathetic of lovers: they routinely begin to eat their suitors before they've had a chance to finish mating. And now research shows that their internal anatomy also helps them get one over males, by influencing which mates get to fertilize their eggs.

The female redback has two organs for storing sperm ...
The two sperm sacs help to prevent a male from stealing a mating advantage simply by being the first to court a female ... A male has two sperm-depositing organs, called palps, that correspond to the female's two sperm sacs, although he can use only one palp in a mating session.

A male tends to break off the end of his mating palp inside the female's sperm sac, partly blocking its entrance, the researchers say. "This functions as a plug, a kind of chastity belt," explains Paul Hillyard, curator of arachnids at the Natural History Museum in London.

Having two sperm sacs may therefore give females extra choice over who fathers her young ... If one of the sacs is blocked by a mate, a subsequent partner can still be given the opportunity to deposit his sperm in the other.

article in Nature News

Fertilizer from the stars

Could a gamma-ray burst have provided nutrients for early plants?
article in Nature by Philip Ball.

Twin beams of gamma rays are thought to burst from the supernovae of giant stars. Click here to see the animation.

The explosion of a star in our cosmic neighbourhood may not sound like good news for life on Earth. But a team of US researchers says that just such a catastrophe could have showered our planet with fertilizer that helped plants to colonize the land about 440 million years ago

a previous Gamma-ray burst post

Andromeda's Stellar Sprawl

Big surprise. . The classic starry disk of Andromeda (left, and central red section on right) extends far deeper into space than astronomers thought (yellow and green, right).
CREDIT: NOAO/AURA/NSF (left); R. Ibata et al./Isaac Newton Telescope (right)

The results are convincing but hard to understand, says astronomer Wallace Sargent of Caltech, who was not part of the study. "I find it very impressive, but I didn't expect to see ordered motion so far out," he says. Some unknown influence must settle the orbits and make them persist for billions of years, Sargent says.

article in Science Now

Galactic neighbour gets supersized in Nature News.

Bringing Up Baby a film by Howard Hawks

has finally come out on DVD. A classic screwball comedy starring Cary Grant and Katharine Hepburn and a great way to spend a rainy afternoon. Just to hear Hepburn pronounce the word "can't" is a delight.

Grant is an earnest paleontologist , Hepburn is his far from earnest nemesis. She loses his brontosaurus intercostal clavicle: audio clip

Quantum Weirdness: A Readers Guide

Einstein (and just about everyone else, for that matter) found some aspects of Quantum Mechanics profundly disturbing. Heisenberg's Uncertainty Principle and the probabilistic nature of quantum theory provoked him to the make the famous statement: "God Does Not Play Dice with the Universe". The EPR thought experiment of the 1930's (Einstein was the E), crystalized some of the strange elements of quantum mechanics, which almost (but not quite!) seems to violate relativity - (see however the post below).

Some of the strangeness of quantum mechanics was nicely isolated in Bell's Theorem, proposed in 1964 by John Bell, which seems to indicate there's a fundamental nonlocal nature to reality - according to quantum theory.

The simplest and most straightforward exposition of quantum weirdness I've found is in the article Quantum Mysteries for Anyone reprinted in "Boojums All the Way Through" by David Mermim.

can be downloaded as an ebook. Has a lot of quantum theory mixed in with very well-written biography by a physicist and long-time contributor to the New Yorker magazine.

For the more mathematically minded:

Quantum Theory, Concepts and Methods by Asher Peres, was the most helpful single reference for me.

The Feynman Lectures on Physics: Volume III is a classic.

Quantum Computation and Quantum Information
by Isaac L. Chuang, Michael A. Nielsen is a clear exposition of those topics.

Superluminal telecommunication: an observable contradiction between quantum entanglement and relativistic causality

Authors: Ruo Peng Wang

I present a schema for a superluminal telecommunication system based on polarization entangled photon pairs. Binary signals can be transmitted at superluminal speed in this system, if entangled photon pairs can really be produced. The existence of the polarization entangled photon pairs is in direct contradiction to the relativistic causality in this telecommunication system. This contradiction implies the impossibility of generating entangled photon pairs.

preprint in the physics archive

see also Quantum State of Entangled Photon Pairs by the same author.
I show that the photon pairs used in experimental tests of quantum non-locality based on Bell's theorem are not in the entangled quantum state. The correct quantum state of the ``entangled'' photon pairs is suggested. Two experiments for testing this quantum state are proposed.

The author expresses skepticism about quantum entanglement, which is the basis for many of the mind-boggling phenomenon of quantum mechanics. Unfortunately I don't have the background to evaluate his claims.

Quantum Physics from A to Z

Quantum Physics from A to Z in the Physics archive.

"This is a collection of statements gathered on the occasion of the Quantum Physics of Nature meeting in Vienna."

Since philosophers are beginning to discuss the “Zeilinger principle” of quantum physics [1, 2, 3] it appears timely to get a community view on what that might be. The interpretation in question seems to have been developed over a period totalling 60 years to the day and does not only concern quantum mechanics but physics as a whole.

One of the statements attributed to Zeilinger is "Good papers have to be sexy." This is apparently what passes for sexy in the world of quantum information theory.

A Quantum Constraint for the Physical Viability of Classical Traversable Lorentzian Wormholes

Authors: Kamal K. Nandi, Yuan-Zhong Zhang, Nail G. Migranov

The physical viability of classical wormholes can be ascertained by computing if the total volume of exotic matter needed to maintain the wormhole is finite. Using this value as the lower bound to the quantum ANEC integral, we confirm that only Planck size wormholes can be supported by the massless quantum Klein-Gordon field. Some known wormholes seem to be physically unrealistic.

preprint in the physics archive

The Planck length is the scale at which classical ideas about gravity and space-time cease to be valid, and quantum effects dominate. This is the ‘quantum of length’, the smallest measurement of length with any meaning.

And roughly equal to 1.6 x 10 to the -35 meters or about 10 to the minus 20 times the size of a proton.

Pretty useless, and that's all this paper wants us to have.
This is more like it!

Can't we please have our wormholes?

Volcano of Colima Erupts in Mexico

Smoke and ash from the Colima volcano, on May 25 2005, 430 miles northwest of Mexico City, in what was the largest eruption in 14 years. (Photo: AP)

October 2004 from Volcano of Colima Mexico, photos

Photograph courtesy of Abel Cortes, Colima Volcano Observatory,
University of Colima, November 22, 1998.
Aerial view of Colima Volcano moments after a lava flow on the upper flank of the volcano collapsed; the photograph is tilted slightly (horizon is in upper right). The white plume is rising directly from the summit of the volcano. The tan-colored ash cloud on the volcano's flank (left side in this view) is rising from a pyroclastic flow. The fast-moving pyroclastic flow was caused by the collapse of a thick lava flow that was extruding from the summit area and oozing down the volcano's steep upper cone. When the lava flow collapsed, the hot lava broke apart into fragments ranging in size from boulders to tiny ash particles and swept down the volcano under the influence of gravity to form the pyroclastic flow; the flow reached a maximum distance of 4.5 km from the summit.

More images and information on Colima at Volcano World (Colima)

SI / USGS Weekly Volcanic Activity Report

A Romantic Love Poster

This poster explains Romantic Love (sorry all you poets)

Article in the New York Times: Watching New Love as It Sears the Brain

co-author Helen Fischer
her web site

Casablanca has been called the most romantic film ever ...
but that was before brain scans.

Spitzer Captures Fruits of Massive Stars' Labors

Check out the Spitzer Space Telescope website at Caltech for more information and spectacular images of the massive star Eta Carinae and the surrounding nebula at Spitzer Captures Fruits of Massive Stars' Labors.

For background information on Eta Carinae try this link

Two of my favorite books about stars are both by James B. Kaler,
The Hundred Greatest Stars and Extreme Stars, both of which discuss Eta Carinae.

Sunday, May 29, 2005

How Did House Bands Become a Filipino Export? by John Bowe

An very droll article indeed in the New York Times Magazine, May 29, 2005.

Songbird performing at a resort in Danang, Vietnam

Gan's success depends on knowing his clients' taste. In Thailand, the most requested song is ''Hotel California.'' Taiwan is lately cuckoo for the macarena. The Chinese, he said, ''have not gone to the state of loud music. They are still at the state of like the early rock 'n' roll music, 60's music, Petula Clark, Burt Bacharach, evergreens, you know? 'Born Free,' 'Yesterday,' 'Unchained Melody,' 'I Can't Stop Loving You.''' The most commonly requested song in both China and Japan is Sinatra's ''My Way.'' And yet in the Philippines, Gan said, unless you're at an oldies club, audiences only want the current Top 40. ''If you request 'My Way,' you get shot. I'm not kidding. That actually happened.''

Frank's popularity varies among Asian audiences

Wednesday, May 25, 2005

Nuclear approach may help climate researchers pinpoint volcanic eruptions

Slice of tree showing rings with sample wedge removed.

"There's gold in them thar rings. Tree rings that is, and Penn State researchers are using the Breazeale Nuclear Reactor to measure gold and link the rings to volcanic eruptions."

"When Peter I. Kuniholm, professor of archaeology and dendrochronology and director of the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology at Cornell, saw which tree rings held the highest gold levels, he quickly recognized that they dated to years of known volcanic eruptions.

Because trees add a ring a year to their trunks, if researchers know the cutting date of a tree or can calibrate the tree's rings against a previously dated tree, researchers can assign each ring accurately to a specific year. By isolated wood from just one ring, neutron activation analysis can measure the gold that the tree took up during that year with parts per billion sensitivity.

Neutron activation analysis uses the neutrons produced by a nuclear reactor to create temporary radioactive isotopes in a sample. Because each isotope has its own gamma radiation signal, the gamma radiation signal strength indicates the amount of that element present. "

"The preliminary results of analysis of one tree for the years 1411 through 1988 were presented in a recent issue of the Journal of Radioanalytical and Nuclear Chemistry.

Working with Kuniholm and John J. Chiment, another researcher at the dendrochronology laboratory, and Corrnell undergraduate students Pam Sullivan, Meg Underwood and Danielle Hauck, Unlu analyzed 577 rings from a Bosnian or palebark pine from Greece.

"We are looking at the last 500 to 600 years to gain confidence in the procedure," says Unlu. "The volcanic eruptions during that time are known, so we can make correlations. Then we will go back and look at the past 6,000 years."

Six thousand years into the past is the depth of the samples currently at Cornell's dendrochronology laboratory. The lab has already dated approximately 4.5 million tree rings to this time.

The researchers found that they successfully matched gold peaks to volcanic eruptions beginning with an eruption of the Soufriere Hills volcano in 1440 and including a 1480 eruption of Mt. St. Helens. However, the researchers also had high gold peaks for a number of years between 1480 and 1580 when there were no known volcanic eruptions.

"When we see major gold peaks but no volcanoes, it could be forest fires," says Unlu. "We cannot really tell if we are seeing a global signal or a regional or local signal when we are looking at only one tree."

How can a forest fire be confused with a major volcanic eruption? If the researchers are correct, easily. Unlu believes that the increased gold uptake during volcano years occurs because the volcanoes put large amounts of particulate matter into the atmosphere and change the environmental acidity as well as the rainfall, sunshine and temperature patterns creating a stressful situation for trees. The trees, to compensate for a lousy year, try to take up more nutrients, including copper, an essential element for tree growth and health. The gold is indiscriminately absorbed along with the copper, but the copper is used for tree metabolism while the gold remains in the new growth.

Another possible cause of the increased gold uptake could be through the leaves because of direct fallout from the volcanic eruptions, but Unlu believes it is the darkness and stress that push the trees to search for copper among other elements. To eliminate forest fires and other local events, the researchers want to look at other trees from other areas. They are currently looking at two dated trees from Turkey and one from California.

"The main problem in atmospheric science is they do not have enough data," says Hauck, now a graduate student in nuclear engineering at Penn State. "We want to correlate tree ring data with climate cycles to get a much better indication of what is natural and what is anthropogenic. Tree rings can help."

Large volcanic eruptions put particles into the wind, into the jet stream and have a global, rather than only local effect. Unlu would also like to go back and check the samples with high gold for other elements. Because neutron activation analysis is nondestructive, and the samples are no longer radioactive after about a month, this reanalysis for other elements is possible. Unlu now has a Nuclear Engineering Education and Research grant from the U.S. Department of Energy to continue his analysis of tree rings and correlation to volcanic activity and other climate events.

The original news release at Penn State University.

Tuesday, May 24, 2005

A Sensational Title

Carrying on with the theme of A Sensational Title coupled with quite serious research and scholarship, here are three titles for your consideration: Demonic Males; Sperm Wars; Women, Fire and Dangerous Things.

Demonic Males: Apes and the Origins of Human Violence is by Richard Wrangham and Dale Petersen. I first learned about the book after attending a performance of a George Bernard Shaw play at the ART in Harvard Square and sitting in on a subsequent panel discussion. Richard Wrangham was on the panel - he talked about his book, showed slides from his field research with Bonobos (a relative of chimpanzees) and even managed to somewhat tie it in with GBS. Bonobos are known as possibly the sexiest animals on earth and the slides didn't shy away from that fact. The next person on the panel commented that there was an old saying in theater, "never go on after children or animal acts" and it was true, the rest of the panel was at a serious disadvantage after Wrangham's spectacular presentation.

Sperm Wars: The Science of Sexby Robin Baker, combines research published in the most prestigious journals (by the author) with illustrative little scenarios that read like hard-core pornography. An "I buy Playboy/girl for the articles" kind of win-win.

Women, Fire and Dangerous Things: What Categories Reveal about the Mind by George Lakoff, is a quite serious work of Cognitive Science and Linguistics. Evidently there's a language (Australian?) with a grammar which groups the three categories of the title.

Sunday, May 22, 2005

"Middlemarch" a BBC production

One of the greatest books ever written leaps to life in this lavishly filmed BBC production, seen on Masterpiece Theatre. You’ll share the frustrations of George Eliot’s heroine (Dorothea Brooke, portrayed by a luminous Juliet Aubrey) whose desire to add meaning to her life conflicts with 19th-century provincial English culture. A turbulent, romantic epic shot on location in England and Italy.

My second favorite BBC series, exceeded only by the incomparable "I Claudius". Unfortunately, there was something wrong with the image, possbily due to my $40 Radio Shack DVD player (you get what you pay for, it seems). The image was stretched vertically and possbily chopped, which rendered the gentlemen's already tall black hats as monstrosities. Still it was a great production - I greedily finished the final three episodes in one sitting, last night.

Cooperate or Else!

"Go ahead, make my day." Dirty Harry succinctly informs a norm violator that he anticipates deriving satisfaction from inflicting altruistic punishment.

Why exactly do people - and other animals as well - so often cooperate instead of pursuing their individual goals independently, especially in circumstances when there are opportunities for short-term gain by cheating? "It's better to be nice", "For the Good of the Group", and other such sentiments are all well and good, but why isn't altruistic behaviour "selected against" in a world ruled by evolution and the survival of the fittest? Natural selection works directly on individuals, but only indirectly on groups, so group selection is rather tricky in practice.

There have been several interesting new papers in the past year on the role of punishment in maintaining cooperative behaviour: from evolutionary, game-theoretic and neurobiological perspectives.

First a trio of classic books touching on the subject of cooperative behaviour:

    The Evolution of Cooperation by Robert Axelrod. The Prisoner's Dilemma, Tit for Tat.

    The Selfish Gene by Richard Dawkins. Kin Selection.

    Sociobiology by E.O. Wilson. The Magnum Opus.

Next a newspaper article on one of the colorful pioneers of the evolutionary theory of behaviour, Robert Trivers.
Boston Globe (March 27, 2005)

While researching Trivers I stumbled across a wonderful blog by a very attractive thinker Teardrop Souffle.

From an economic, game theoretic point of view, the article that introduced "The Paradox of the Commons":

The Tragedy of the Commons
by Garrett Hardin
Science (13 December 1968)
"In economic affairs, The Wealth of Nations (1776) popularized the "invisible hand," the idea that an individual who "intends only his own gain," is, as it were, "led by an invisible hand to promote . . . the public interest" (5). Adam Smith did not assert that this was invariably true, and perhaps neither did any of his followers. But he contributed to a dominant tendency of thought that has ever since interfered with positive action based on rational analysis, namely, the tendency to assume that decisions reached individually will, in fact, be the best decisions for an entire society"

The rebuttal to the invisible hand in population control is to be found in a scenario first sketched in a little-known pamphlet (6) in 1833 by a mathematical amateur named William Forster Lloyd (1794-1852).

The tragedy of the commons develops in this way. Picture a pasture open to all. It is to be expected that each herdsman will try to keep as many cattle as possible on the commons. Such an arrangement may work reasonably satisfactorily for centuries because tribal wars, poaching, and disease keep the numbers of both man and beast well below the carrying capacity of the land. Finally, however, comes the day of reckoning, that is, the day when the long-desired goal of social stability becomes a reality. At this point, the inherent logic of the commons remorselessly generates tragedy.

As a rational being, each herdsman seeks to maximize his gain. Explicitly or implicitly, more or less consciously, he asks, "What is the utility to me of adding one more animal to my herd?" This utility has one negative and one positive component.

1) The positive component is a function of the increment of one animal. Since the herdsman receives all the proceeds from the sale of the additional animal, the positive utility is nearly +1.

2) The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effects of overgrazing are shared by all the herdsmen, the negative utility for any particular decision-making herdsman is only a fraction of 1.

Adding together the component partial utilities, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another. . . . But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit--in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all.

Finally, a selection of recent articles on the role of sanctions in cooperative behaviour.

Emotion expression in human punishment behavior
by Erte Xiao and Daniel Houser
PNAS May 17, 2005
Evolutionary theory reveals that punishment is effective in promoting cooperation and maintaining social norms. Although it is accepted that emotions are connected to punishment decisions, there remains substantial debate over why humans use costly punishment. Here we show experimentally that constraints on emotion expression can increase the use of costly punishment. We report data from ultimatum games, where a proposer offers a division of a sum of money and a responder decides whether to accept the split, or reject and leave both players with nothing. Compared with the treatment in which expressing emotions directly to proposers is prohibited, rejection of unfair offers is significantly less frequent when responders can convey their feelings to the proposer concurrently with their decisions. These data support the view that costly punishment might itself be used to express negative emotions and suggest that future studies will benefit by recognizing that human demand for emotion expression can have significant behavioral consequences in social environments, including families, courts, companies, and markets.

Altruistic punishment and the origin of cooperation
by James H. Fowler
PNAS May 10, 2005
How did human cooperation evolve? Recent evidence shows that many people are willing to engage in altruistic punishment, voluntarily paying a cost to punish noncooperators. Although this behavior helps to explain how cooperation can persist, it creates an important puzzle. If altruistic punishment provides benefits to nonpunishers and is costly to punishers, then how could it evolve? Drawing on recent insights from voluntary public goods games, I present a simple evolutionary model in which altruistic punishers can enter and will always come to dominate a population of contributors, defectors, and nonparticipants. The model suggests that the cycle of strategies in voluntary public goods games does not persist in the presence of punishment strategies. It also suggests that punishment can only enforce payoff-improving strategies, contrary to a widely cited "folk theorem" result that suggests that punishment can allow the evolution of any strategy.

Human behaviour: Egalitarian motive and altruistic punishment (reply)
Nature (06 January 2005);
Fehr and Gächter reply - Fowler et al. raise an important question. They correctly argue that the desire to reduce inequality may motivate cooperators who altruistically punish free riders in our experiments. Also, the evolutionary history of humans suggests that egalitarianism shaped many human cultures and that egalitarian motives may, therefore, be a powerful force behind the punishment of free riders. In addition, recently developed proximate theories, which formalize the notion of inequality aversion, also suggest that egalitarian desires may be important. Fowler et al. contrast their egalitarianism hypothesis with our view that negative emotions against free riders drive punishment.

Human behaviour: Don't lose your reputation
Nature (06 January 2005);
Collective action in large groups whose members are genetically unrelated is a distinguishing feature of the human species. Individual reputations may be a key to a satisfactory evolutionary explanation.

Getting to Know You: Reputation and Trust in a Two-Person Economic Exchange
by Brooks King-Casas, Damon Tomlin, Cedric Anen, Colin F. Camerer, Steven R. Quartz, P. Read Montague1
Science (1 April 2005)
Using a multiround version of an economic exchange (trust game), we report that reciprocity expressed by one player strongly predicts future trust expressed by their partner—a behavioral finding mirrored by neural responses in the dorsal striatum. Here, analyses within and between brains revealed two signals—one encoded by response magnitude, and the other by response timing. Response magnitude correlated with the "intention to trust" on the next play of the game, and the peak of these "intention to trust" responses shifted its time of occurrence by 14 seconds as player reputations developed. This temporal transfer resembles a similar shift of reward prediction errors common to reinforcement learning models, but in the context of a social exchange. These data extend previous model-based functional magnetic resonance imaging studies into the social domain and broaden our view of the spectrum of functions implemented by the dorsal striatum.

Brain Study Shows Why Revenge Is Sweet
by John Roach
for National Geographic News
National Geographic New (August 27, 2004)
Revenge is sweet. Many of us have felt that way, and now scientists say they know why.

A new brain-imaging study suggests we feel satisfaction when we punish others for bad behavior. In fact, anticipation of this pleasure drives us to crack the whip, according to scientists behind the new research.

The findings, reported in today's issue of the journal Science, may partly explain a behavior known as altruistic punishment: Why do we reprimand people who have abused our trust or broken other social rules, even when we get no direct practical benefits in return?

The Neural Basis of Altruistic Punishment
by Dominique J.-F. de Quervain, Urs Fischbacher, Valerie Treyer, Melanie Schellhammer, Ulrich Schnyder, Alfred Buck, Ernst Fehr
Science (27 August 2004)
Many people voluntarily incur costs to punish violations of social norms. Evolutionary models and empirical evidence indicate that such altruistic punishment has been a decisive force in the evolution of human cooperation. We used H2 15O positron emission tomography to examine the neural basis for altruistic punishment of defectors in an economic exchange. Subjects could punish defection either symbolically or effectively. Symbolic punishment did not reduce the defector's economic payoff, whereas effective punishment did reduce the payoff. We scanned the subjects' brains while they learned about the defector's abuse of trust and determined the punishment. Effective punishment, as compared with symbolic punishment, activated the dorsal striatum, which has been implicated in the processing of rewards that accrue as a result of goal-directed actions. Moreover, subjects with stronger activations in the dorsal striatum were willing to incur greater costs in order to punish. Our findings support the hypothesis that people derive satisfaction from punishing norm violations and that the activation in the dorsal striatum reflects the anticipated satisfaction from punishing defectors.

Sweet Revenge?
by Brian Knutson
Science(27 August 2004)
Revenge feels good! Most of us take satisfaction in punishing violators of social norms and may even incur costs to do so. In a Perspective, Knutson takes us on a joy ride through the brain to seek the areas involved in the exacting of revenge. Intriguingly, it is the striatum, a key subcortical brain structure involved in feeling satisfaction, that is activated in human volunteers subjected to PET imaging as they play a game designed to elicit acts of revenge (de Quervain et al.).

Friday, May 20, 2005

Microsocopic Images

at The Micropolitan Museum of microscopic art forms.

The fragile wing of a mosquito. If you smash a mosquito very carefully you can enjoy the beauty of its wings!

Bell animalcules are common in fresh water but can also be found in the sea. These colonial Ciliates live attached to a stalk. Find out more about their fresh water relatives on the smallest page on the web

Monday, May 16, 2005

The Poggendorff Illusion

Fig. 1. The Poggendorff illusion and its behavior. (A) When an obliquely oriented straight line is interrupted by a vertical occluder, the line segment on the right appears to be shifted downward with respect to the line segment on the left. (B) A similar effect occurs when the orientation of the interrupted line is reversed. In this case, the collinear extension on the right appears to be shifted upward. (C) When an oblique line is interrupted by parallel horizontal lines, the oblique line segments appear to be shifted horizontally with respect to each other. (D) The magnitude of the effect increases as the interrupted line is made more vertical. (E) The magnitude also increases as the width of the interruption increases. (F) The illusion is largely abolished when only the acute components of the stimulus are presented, but the effect is maintained when only the obtuse components are shown. (G) The illusion is diminished when the standard configuration is rotated so that the interrupted line is horizontal.

A new explanation for this illusion has just been published.

The Poggendorff illusion explained by natural scene geometry by Catherine Q. Howe, Zhiyong Yang, and Dale Purves in Proc. Natl. Acad. Sci. USA.
One of the most intriguing of the many discrepancies between perceived spatial relationships and the physical structure of visual stimuli is the Poggendorff illusion, when an obliquely oriented line that is interrupted no longer appears collinear. Although many different theories have been proposed to explain this effect, there has been no consensus about its cause. Here, we use a database of range images (i.e., images that include the distance from the image plane of every pixel in the scene) to show that the probability distribution of the possible locations of line segments across an interval in natural environments can fully account for all of the behavior of this otherwise puzzling phenomenon.

Sunday, May 15, 2005

"Cosmic Gall" by John Updike

Neutrinos, they are very small.
They have no charge and have no mass
And do not interact at all.
The earth is just a silly ball
To them, through which they simply pass,
Like dustmaids down a drafty hall
Or photons through a sheet of glass.
They snub the most exquisite gas,
Ignore the most substantial wall,
Cold shoulder steel and sounding brass,
Insult the stallion in his stall,
And, scorning barriers of class,
Infiltrate you and me. Like tall
And painless guillotines they fall
Down through our heads into the grass.
At night, they enter at Nepal
And pierce the lover and his lass
From underneath the bed—you call
It wonderful; I call it crass.

(Knopf) © 1960, 1988 John Updike.
Originally in The New Yorker. All rights reserved.

Note: in the meantime, it seems neutrinos do actually have some mass, alas - but that was a pretty big surprise.

John Hoyer Updike

Max Ernst: a Retrospective

exhibit at the Metropolitan in New York - April 7, 2005–July 10, 2005. See the review by John Updike in the New York Review of Books

"The Robing of the Bride", 1939 130 x 96 cm., Venice

Europe after the Rain II. Oil on canvas. 54 x 146 cm. 1940-42. Wadsworth Atheneum, Hartford, CT, USA

Europe after the Rain, we are told, was begun by Ernst in a European prison camp and finished in the United States—a precarious transit, in that dire time, for a crusty canvas two feet by five." says Updike in his review.

Adolf Hitler and Josef Goebbels view the exhibition of "degenerate art", Munich 1937

Hitler was definitely not a fan, Ernst happened to be Jewish:

Max Ernst (French, born Germany, 1891–1976)
The Blessed Virgin Chastises the Infant Jesus Before Three Witnesses: A.B., P.E. and the Artist, 1926
Oil on canvas; 77 1/4 x 51 1/4 in. (196 x 130 cm)
Museum Ludwig, Köln
© 2004 Artists Rights Society (ARS), New York/ADAGP, Paris

According to Updike's review, "The original exhibition including Ernst's assaultive painting The Blessed Virgin Chastises the Infant Jesus before Three Witnesses: A.B., P.E., and the Artist (1926) was closed by church pressure because of it; at the Met, alone on a large wall and protected by glass against possible Christian vandals, it exerts a sensuous spell."

"The House of Flying Daggers" a film by Zhang Yimou

now out on DVD.

Zhang Yimou's early films, "Red Sorghum" (1987), "Ju Dou" (1990), and "Raise the Red Lantern" (1991) were intimate, beautiful, devastating films centered around the oppression of women in pre-revolutionary China. His most recent films "Hero" and "House of Flying Daggers" are very different indeed. Martial arts spectaculars with big budgets and strong female fighters in lead roles, they are much less effective emotionally. The oppressed women in his earlier films were defiant, but they were completely powerless and their vulnerability made their strength of character impressive indeed. The newer films seem quite shallow in comparison.

However, "Hero" did have some of the most beautiful scenes I've ever seen in film, especially memorable were several scenes with ravishing depictions of water. Zhang Yimou's visual style is unmistakable, starting with the gorgeous shots of freshly dyed fabric sheets in "Ju Duo". But a big share of credit for the look of "Hero" has to go to cinematographer Christopher Doyle. He's shot so many stunning films, including "In the Mood for Love", directed by Wong Kar Wai.

The "Making of" documentary on the Flying Daggers DVD wasn't particularly striking, repetitiously filled with comments that all amounted to "Zhang Zimou is really, really good". However, it did explain one fairly odd transition in the film, the climatic fight scene takes place in a fairly substantial snow storm. But the scenes before it, essentially on the same day, were quite temperate. Apparently there was a freak October snow storm during the filming, totally unexpected of course, and the director just went with it.
Ang Lee is another talented director who succumbed to the lure of the big-budget martial arts blockbuster with his "Cringing Tiger". That film's critical and popular success was a total mystery to me. Chow Yun Fat is great in Hong Kong gangster movies, but he was utterly unconvincing in a costume period piece, never mind his deficiencies as a martial arts player.

The DVD cover

Beautiful watery scenes from "Hero"

Freak snowstorm in "Flying Daggers"

You can see a beautiful trailer for "Ju Dou", you might have to endure an annoying ad first, but it's worth it.

Saturday, May 14, 2005

Klein's quartic curve

This is called Klein's quartic curve. It can be turned inside out and it gets reflected in the process.

See John Baez's page for more information.

Friday, May 13, 2005

"High-energy physics: An emptier emptiness?" by Frank Wilczek

In Nature News & Views

A new experiment at Brookhaven using colliding gold ions provides surprising evidence about a fundamental concept in physics: the vacuum. It appears that you can get something from nothing, the vacuum is unstable and new particles can be spontaneously created in empty space. Gack.

A side view of one of the first high-energy collisions captured by the Solenoidal Tracker of the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The initial head-on collision of two gold ions, each consisting of a total of 197 protons and neutrons, occurs at the mid-point of the central tube (running across the image from right to left). The tracks indicate the paths taken by thousands of subatomic particles created in the fireball of energy set free in these collisions. Several layers of detectors, arranged concentrically around the central tube, and encased in a powerful magnet, allow the identification of these particles. (Courtesy of Brookhaven National Laboratory, STAR collaboration.)

Thursday, May 12, 2005

"Robotics: Self-reproducing machines" by Zykov et.al.

article in Nature May 12, 2005. See also Robots master reproduction by Andreas von Bubnoff, news article in the same issue of Nature and A Chip Off the Robotic Block by Adrian Cho in Science.

a, Basic module, with an illustration of its internal actuation mechanism. b, Snapshots from the first 10 s showing how a four-module robot transforms when its modules swivel simultaneously. c, Sequence of frames showing the self-reproduction process, which spans about 2.5 min and runs continuously without human intervention, apart from the replenishing of building blocks at the two 'feeding' locations (circled in red). (For movie, see supplementary information.)

The video is surreal, the motion of the little blocks seems very organic somehow.

A modular machine made of four swiveling blocks uses electromagnets to reproduce itself in a matter of minutes. You have to give it pre-made fresh blocks and put them in a convenient location. This is definitely lowering the bar for self-reproduction, the blocks are complicated little devices themselves. People manage to reproduce themselves using fairly simple chemicals as buidling blocks, though we too require seven essential amino acids that we can't fabricate ourselves. As the authors themselves point out: "We circumvent the long-standing hurdle of what counts as self-replication by suggesting that self-replicability is not a binary property that a system either possesses or not, but is a continuum dependent on the amount of information being copied." Hence a strategy leading to more convincing self-reproduction might involve incrementally simplifying a system of rather complex building blocks, rather than starting from scratch with a satisfyingly elementary substrate.

Tuesday, May 10, 2005

Hoag's Object

This bizzare object was discovered in 1950 by astronomer Art Hoag. It's a bright ring of hot blue stars surrounding a nucleus of yellow stars. Take a close look just above the nucleus - you'll see yet another ring galaxy.

Hoag's Object at Hubble

A recent paper: Hoag's Object a Soliton?

A NASA Hoag's Object page with an explanation and reference links.

Short Gamma Ray Burst on May 9th

Neutron-star cataclysm? A faint patch of light (green arrow) on the fringes a distant galaxy may mark the spot where two neutron stars collided, in this image taken on the morning of 9 May.
CREDIT: J. Bloom/UC Berkeley/WIYN Telescope

Science Online reported the first Short Gamma Ray Burst directly observed, by the NASA Swift satellite at midnight on May 9th. You can find up to the minute news on this and other Gamma Ray Bursters at NASA.


Link to a previous post about the December 27th Giant Gamma Ray Flash.

Nature article:
Swift satellite spies cosmic crash

Sunday, May 08, 2005

Shelia Chandra, vocalist

Beautiful, eerie, Indian influenced music: Shelia Chandra Official Site, Shelia Chandra at Amazon. She was featured on the soundtrack of "Lord of the Rings: The Two Towers", the "Breath of Life" track. Other tracks I've enjoyed:

"Speaking in Tongues III" - Moonsung 1999

"Speaking in Tounges I", "Ever So Lonely/Eyes/Ocean" - Weaving My Ancestors' Voices 1992
"Lament", "Strange Minaret" - The Struggle 1985
"Ever so Lonely"- Third Eye (Monsoon) 1982

"Notorious", a film by Alfred Hitchcock

with Ingrid Bergman, Cary Grant and Claude Rains. Claude Rains creepy mother is credited as Madame Konstantin, a perfect name for the part.

Hitchcock and Bergman.

One of the greatest films ever, story by Ben Hecht (who also wrote "Front Page"). The scene on the staircase at the end is marvelous.

On the staircase.

At the track.

The elegant Criterion DVD cover

What was in the coffee?