Flying Snake

The image of airborne snakes may seem like the stuff of nightmares (or a certain Hollywood movie), but in the jungles of South and Southeast Asia it is reality.Flying snake is a misnomer, since, barring a strong updraft, these animals can’t actually gain altitude. They’re gliders, using the speed of free fall and contortions of their bodies to catch the air and generate lift.Once thought to be more parachuters than gliders, recent scientific studies have revealed intricate details about how these limbless, tube-shaped creatures turn plummeting into piloting. To prepare for take-off, a flying snake will slither to the end of a branch, and dangle in a J shape. It propels itself from the branch with the lower half of its body, forms quickly into an S, and flattens to about twice its normal width, giving its normally round body a concave C shape which can trap air. By undulating back and forth, the snake can actually make turns. Flying snakes are technically better gliders than their more popular mammalian equivalents, the flying squirrels.There are five recognized species of flying snake, found from western India to the Indonesian archipelago. Knowledge of their behavior in the wild is limited, but they are thought to be highly arboreal, rarely descending from the canopy. The smallest species reach about 2 feet (61 centimeters) in length and the largest grow to 4 feet (1.2 meters).Their diets are variable depending on their range, but they are known to eat rodents, lizards, frogs, birds, and bats. They are mildly venomous snakes, but their tiny, fixed rear fangs make them harmless to humans.Scientists don’t know how often or exactly why flying snakes fly, but it’s likely they use their aerobatics to escape predators, to move from tree to tree without having to descend to the forest floor, and possibly even to hunt prey.One species, the twin-barred tree snake, is thought to be rare in its range, but flying snakes are otherwise quite abundant and have no special conservation status.

Hafele-Keating experiment

During October, 1971, four cesium atomic beam clocks were flown on regularly scheduled commercial jet flights around the world twice, once eastward and once westward, to test Einstein's theory of relativity with macroscopic clocks. From the actual flight paths of each trip, the theory predicted that the flying clocks, compared with reference clocks at the U.S. Naval Observatory, should have lost 40+/-23 nanoseconds during the eastward trip and should have gained 275+/-21 nanoseconds during the westward trip ...

Relative to the atomic time scale of the U.S. Naval Observatory, the flying clocks lost 59+/-10 nanoseconds during the eastward trip and gained 273+/-7 nanosecond during the westward trip, where the errors are the corresponding standard deviations. These results provide an unambiguous empirical resolution of the famous clock "paradox" with macroscopic clocks.

Walton Ford

Hall of Human Origins

All species consist of individuals that differ at some level. In Homo sapiens, population diversity arose as small groups occupied varied environments around the world. Localized populations changed due to genetic drift and natural selection. For example, some populations eventually showed more susceptibility to certain diseases, or more ability to digest certain foods. Superficial differences in stature and hair, eye, and skin color also arose among individuals and populations.Although these population changes take place at a genetic level, it does not mean that genes define "race." Race is cultural and social, not biological.Small, isolated groups are less and less prevalent in the human population. Our population is now abundant, consisting of larger, varied groups that intermingle and overlap. Since humans reproduce both within and between groups, we constantly mix genetic information. As a result, genetic differences between people of the same "racial" group can be greater than the those between people of two different groups. Furthermore, influences other than genes—such as hormones and environmental factors—also contribute to individual variation (go).

The Secret Life of the Brain

THE SECRET LIFE OF THE BRAIN reveals the fascinating processes involved in brain development across a lifetime. The five-part series, which will premiere nationally on PBS in winter 2002, informs viewers of exciting new information in the brain sciences, introduces the foremost researchers in the field, and utilizes dynamic visual imagery and compelling human stories to help a general audience understand otherwise difficult scientific concepts (go).

Averroes' commentary on De Anima

On the Soul (Greek Περὶ Ψυχῆς (Perì Psūchês), Latin De Anima) is a major treatise by Aristotle, outlining his philosophical views on the nature of living things. His discussion centres on the kinds of souls possessed by different kinds of living things, distinguished by the different life-processes those organisms go through. Thus plants have the capacity for nourishment and reproduction, the minimum that must be possessed by any kind of living organism. Lower animals have, in addition, the powers of sense-perception and self-motion (action). Humans have all these as well as intellect.
The notion of soul used by Aristotle is only distantly related to the usual modern conception. He holds that the soul is the form, or essence of any living thing; that it is not a distinct substance from the body that it is in; that it is the possession of soul (of a specific kind) that makes an organism an organism at all, and thus that the notion of a body without a soul, or of a soul in the wrong kind of body, is simply unintelligible. (He speculates that some parts of the soul--the intellect--may be conceived to exist without the body, but most cannot.) It is difficult to reconcile these points with the popular picture of a soul as a sort of spiritual substance "inhabiting" a body. Some commentators have suggested that Aristotle's term soul is better translated as lifeforce.

Averroes (Ibn Rushd) (1126-1198) was an Andalusian-Arab philosopher and physician. He wrote commentaries on most of the surviving works of Aristotle. These were not based on primary sources (it is not known whether he knew Greek), but rather on Arabic translations. On each work, he wrote the Jami, the Talkhis and the Tafsir which are, respectively, a simplified overview, an intermediate commentary with more critical material, and an advanced study of Aristotelian thought in a Muslim context. The terms are taken from the names of different types of commentary on the Qur'an.

San Martin de Fromista

3D Virtual Visit at the temple "San Martin de Fromista" in Spain
(Visit)

Super-Kamiokande

It is believed soon after the big bang, when the universe was at a very high temperature, many neutrinos were produced. In addition, when a star explodes as a supernova, many neutrinos are emitted. Neutrinos are also copiously produced in nuclear reactions in the core of the sun. Also cosmic rays which come into the earth's atmosphere and interact with oxygen or nitrogen nuclei produce neutrinos. Purposes of the research are to elucidate the source of energy of the sun and detect the properties of the enigmatic neutrinos by observing these neutrinos with considerable precision.The detector consists of an inner volume and an outer volume which contain 32,000 tons and 18,000 tons of pure water respectively. The outer detector is used to veto entering cosmic ray muons and is used as a buffer to keep radiation emitted by the surrounding rock and walls from entering the inner volume. The inner detector has 11,200 photomultiplier tubes (PMTs) attached to the bottom, top and sides facing inward. The PMTs collect the pale blue light called Cerenkov light which is emitted by particles travelling fast as light in the water. By measuring the direction and intensity of this light,information about particle interactions such as neutrino interactions or proton decay can be determined (Official Website).

Simple Creatures, Intriguing Finds

Researchers look to fruit flies and tiny worms for greater understanding of neurodegenrative diseases such as Alzheimer's and Parkinson's. Fruit flies have many genes in common with higher animals, including humans. Researchers can easily transplant genes from humans into fruit flies. Finding mutations and observing the characteristics they produce are easier in fruit flies than in other types of animals.
Feany’s laboratory has bred a strain of the fruit fly Drosophila melanogaster that models Parkinson’s disease. Her team implanted mutant genes in the flies for a protein called alpha-synuclein.
Flies carrying the mutant genes lose dopamine-producing neurons in the brain’s substantia nigra, just as humans with Parkinson’s do. Also, fibrous bundles of alpha-synuclein form in the insects’ neurons. Bundles of the same structure and composition (called Lewy bodies) develop in the brain cells of people with Parkinson’s.
Cellular changes in the flies correlate with behavioral changes. Normal fruit flies climb up the sides of plastic vials. Middle-aged flies carrying the transplanted, mutant gene lose that ability.

28 New Exoplanets Discovered

Astronomers have discovered 28 new planets outside of our solar system, increasing to 236 the number of known exoplanets, revealing that planets can exist around a broad spectrum of stellar types-from tiny, dim stars to giants.
"We added 12 percent to the total in the last year, and we're very proud of that," said one of the study team members Jason Wright of the University of California at Berkeley. "This provides new planetary systems so that we can study their properties as an ensemble."
The planets are among 37 new objects spotted within the past year. Seven of the objects are failed stars called brown dwarfs, with masses that dwarf the largest, Jupiter-sized planets but too small to sustain the nuclear reactions necessary for stellar ignition.
John Johnson of the University of California at Berkeley and his colleagues presented the findings here today at a meeting of the American Astronomical Society (AAS).
Astronomers don't directly spot extrasolar planets, but rather look for stellar wobbles caused by orbiting planets. The planet's size and distance from the parent star affect how strong or weak of a wobble, and more sophisticated techniques for measuring the stellar wobbles has led to an ever-lengthening list of such outer planets. Now they can detect wobbles of a meter per second compared with the 10-meter limit just 15 years ago.

Astronomers Find First Earth-like Planet in Habitable Zone

The new planet known as Gliese 581 c (L) orbiting a red dwarf star

Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.
This exoplanet - as astronomers call planets around a star other than the Sun - is the smallest ever found up to now and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581, is smaller and colder than the Sun - and thus less luminous - the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid! The planet's name is Gliese 581 c.
The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another 'Trio of Neptunes'
The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs (video).

Photographs from The Met

See one hundred of the best photograph collection works of art from The Metropolitan Museum online.

Charles Nègre (French, 1820–1880). The Refectory of the Imperial Asylum at Vincennes, 1858–59

Gathered in the light-drenched refectory of a newly constructed convalescent hospital on the outskirts of Paris, patients and staff alike turned their eyes and attention to the man with the enormous camera at one end of the room, Charles Nègre. The resulting image, here in a rare unmounted and unretouched proof print from the artist's studio, is the largest and most engaging in a series of photographs that Nègre was commissioned to make as documentation and celebration of the Imperial Asylum at Vincennes. The hospital was established by Emperor Napoléon III to provide those injured on the construction site or in the factory—"the worker's true field of honor," in the words of one of Napoléon's ministers—with care comparable to that given to the nation's military veterans.
Trained as a painter in the same studio as Roger Fenton and Gustave Le Gray, Nègre was one of the era's most skilled photographers of architecture, possessing a particular sensitivity to the ways in which light and shadow animate the surfaces of centuries-old monuments. Here, he seized upon the streaming sunlight as a vehicle to enliven the structure and texture of his picture and to suggest enhanced activity and health in the hospital inhabitants.