astralavista

French biologists say thay have proof that immortality is impossible. Single-celled bacteria like E. coli, and even some humans, have long nutrured hope that they may eascape aging and death. No so, says Eric J. Stewart of the Institut des Hautes Etudes Scientifique in France. "No life strategy is immune to the effects of aging and suggest that this may be because immortality is too costly or is mechanistically impossible," he writes. "This may be bad news for people who had hoped that advances in science might eventually lead to human immortality."
Scientists have assumed that cells that divide symmetrically do not age and are functionally immortal. Stewart and his colleagues tested this idea by analyzing repeated cycles of reproduction in Escherichia coli, a bacteria that reproduces without a juvenile phase and with an apparently symmetric division.
E. coli is a rod-shaped organism that reproduces by dividing in the middle. Each resultant cell, Stewart writes, inherits an old end or pole and a new pole, which is made during the division. The new and the old pole contain slightly different components, so although they look the same, they are physiologically asymmetrical.
Stewart found that the cells "inheriting old poles had a reduced growth rate, decreased rate of offspring formation, and increased risk of dying compared with the cells inheriting new poles. Thus, although the cells produced when E. coli divide look identical, they are functionally asymmetric, and the old pole cell is effectively an aging parent repeatedly producing rejuvenated offspring."
That may take some wind from the sails of transhumanists and others who believe in the possibility of immortality in some shape.
At least Stewart did try to offer some solace. He said his research provides "an excellent genetic platform for the study of the fundamental mechanisms of cellular aging and so could provide information that might ameliorate some of the unpleasantness of the human aging process."

European astromomers at the Calar Alto Observatory in Spain have caught a dazzling supernova on film. The exploding star resides near the edge of the spectacular "grand spiral galaxy" NGC 6118 some 80 million light years away. The supernova blew up on August 1, 2004. Acccording to the astronomers, this particular kind of supernova resulted from the demise of a massive star that has lost its entire hydrogen envelope.
The supernova was classified Type Ib or Ic, which means it was part of a binary star system. A binary system involves a regular star,like our sun, and a super dense star called white dwarf. The heavy dwarf sucks away hydrogen from the neighboring star, fattening itself until it suffers from a massive case of indigestion (reaches critical density) and blows off. Such stellars explosions fuse hydrogen into helium, oxygen, carbon, iron, and so on, forging all the elements you, I, even the beer in your fridge are all made of.
Click on the headline for a picture.

Astronomers from the European Southern Observatory reported that our neighbor the Andromeda Galaxy and most other spiral galaxies are the result of titanic galactic collisions that took place some 8 billion years ago. The reigning theory has been that galaxy formation ended by then.
They also say that at least half the starts visible in the night sky were produced four to eight billion years ago in "episodic bursts of intense star formation," during the galactic mergers when the galaxies were still active star hatcheries.
In a twist, they also say that our own Milky Way somehow escaped these crashes. Click on the headline for collision details.

Researchers at the University of California, Berkeley applied mathematical models normally used to spot trends in the stock market, weather and other complex random events to track "electrical storms" in the human brain during epileptic seizures. They hope that the results will point them to methods to stop seizures and move treatment beyond lobectomies.
The researchers found that during a seizure, "a strong pattern of electrical signals suddenly emerges from the random fluctuations that characterize normal brain activity." The strong waves moving across the cortex may cause sudden, unpredictable sensations or uncontrollable movements. "Normal brain waves would resemble jagged lines with no apparent pattern or order on an electroencephalogram (EEG)," said Andrew Szeri, UC Berkeley professor of mechanical engineering and applied science and technology, and principal investigator of the study. "But in the brains of epilepsy patients, the spreading of a seizure is made manifest by strong coherent waves of electrical activity in the cortex."
The mathematical model used stochastic partial differential equations to describe the architecture of the brain. "The model could provide insight into the pathophysiology of the spread of a seizure," said Heidi Kirsch, assistant professor of neurology at UC San Francisco's Epilepsy Center. "Further down the line, this could also help us model the impact of medications and other interventions, to theoretically test how drugs with certain mechanisms will impact the brain."
Examples of potential therapies to stop seizures include "focal cooling, in which the part of the brain experiencing a seizure is literally chilled to dampen the seizure, and electrical stimulation of the affected area of the brain to counter the seizure as it's forming."

Astronomers from Cardiff University in England have discovered an invisible galaxy. The galaxy is made of dark matter, the mysterious stuff that accounts for 25% of the universe. No one has ever seen dark matter. It's existence has only been inferred from the motion of galaxies.
The scientists used radio emissions to identify the object. The galaxy, called VIRGOHI21, is about 50 million light years away in the Virgo cluster. It's basically a giant invisible whirlpool that rotates like our Milky Way but contains no stars. "When you have eliminated the impossible, whatever is left - however implausible - must be the truth," said team member Mike Disney, quoting Sherlock Holmes.
Roughly 5% of the universe is made of visible matter, the stuff that makes you and I, your mother-in-law, and the stars, about 25% is dark matter and the rest is dark energy. No one has ever seen the latter two and we have no idea what they are. Even our galaxy is chock full of the mysterious stuff since otherwise it would fly apart like a carousel that's spinning too fast.

A team of scientists led by the University College of London have discovered a frozen sea near the Martian equator. Although water on Mars has been in the news a lot lately, this is apparently the firts direct evidence that there has been liquid water on the planet "not so long ago." (The water flowed some 5 million years ago when we've just started evolving from apes to hominids.) This discovery is pretty important because water means life and chances are, the scientists say, that some of that life may still be surviving.
The water that formed the sea appears to have sprung from beneath the Martian surface, just like Earthly brooks. It fowed down in a catastrophic flood from a series of fractures known as the Cerberus Fossae. It inundated an area about the size of the North Sea and was initially 45 metres deep on average.
Because of the freezing weather on Mars, the water immediately turned to ice. The pack-ice floes have drifted into obstacles, and in many places have become grounded on islands when the water level dropped. Ice is unstable at the surface of Mars because of the low atmospheric pressure, and sublimes away (changes straight from ice to vapour without passing through the liquid state) into the atmosphere, but volcanic ash and dust can preserve it. Thick ice trapped within enclosed craters suggests that most of the ice is still there.
Click on the headline to see pictures.

Robert Laughlin,winner of the Nobel prize in physics, is publishing an edgy little book called A Different Universe. The book takes on prominent theoreticians like Columbia's astrophysics star Brian Greene, cosmologist David Schramm of the University of Chicago and many others. Laughlin's beef with the scientists is their belief that all fundamental principles of science have been already discovered and that we just need to "fill in the details." He fumes that this view is "completely wrong and completely below the belt."
Laughlin argues that it's more important to look at how things are organized than what they are made of. "A field of flowers rendered by Renoir or Monet strikes us as interesting because it is a perfect whole while the daubs of paint from which it is constructed are randomly shaped and imperfect," he says. "The imperfection of the individual strokes tells us that the essence of the painting is in its organization."
He points out that this hierarchy exists everywhere in nature - just look at at atoms and how they can be broken down. He says that we don't need to chase emphemeral particles in supercolliders or understand the details of the string theory to make sense of the world. He posits that hierarchical organization "renders the most fundamental laws, whatever they are, irrelevant and protects us from being tyrannized by them," he says. "It's the reason we can live without understanding the ultimate secrets of the universe."

A group of neuroscientists at the University of California, Los Angeles and the University of Parma discovered "mirror neurons" that basically allow humans engage in mindreading. They say that the neurons let us understand what other people are thinking and anticipate the behavior of others.
The researchers said that these neurons code "some aspects" of future actions. "In this interpretation, an action observed within a familiar context activates mirror neurons for 'logically related' actions, those that most likely will follow the observed one," they wrote. "This suggests the mirror neuron system is intimately involved not only with understanding the behavior of others, but predicting it as well."
The researchers showed their test subjects a series of film clips inside a functional MRI machine. The clips were carefully edited for context, action, and intent. They found that an area known to be involved in the mirror system, the inferior frontal cortex, was activated only by scenes in which intent could be inferred.

Scientists at the European Center for Nuclear Research in Geneva plan to make miniature black holes this year, according to a new book by science writer Arthur I. Miller. The book, Empire of the Stars, about the life of the Indian astrophysicist Subrahmanyan Chandrasekhar who proved mathematically that stars can collapse into black holes, says that the experiment is "scheduled to be carried out in 2005" by smashing protons and antiprotons. Miller says that the black holes will be million times smaller than an atomic nucleus and will have the mass of a proton. Looking ahead, Miller writes that scientists at the Large Hadron Collider, also at CERN, "are already talking about 'black hole factories,' in which they hope to produce a black hole a second." The LHC is currently under construction and is scheduled to be completed in 2007. With circumference of 17 miles (27 kilometers), it will be the largest collider on earth.
Apparently, there's no need to fear that Switzerland will be sucked into a supermassive singularity with the rest of the planet in tow. Such mini black holes are supposed to be highly unstable and will immediately evaporate. According to quantum mechanics, empty space is frothing with matter and antimatter particles which pop in and out existence, so called quantum foam. But near a black hole one of the matter-antimatter particles can pulled inside the hole by its gravity and the other escape. According to Einstein, the fugitive particle removes energy from the black hole.
When the black hole is tiny this mechanism removes its entire mass in a fraction of a second. The evaporated black hole leaves behind a flash, so called Hawking radiation, predicted by the British astrophysicist Stephen Hawking. Miller writes that studying the flash may allow physicists to "pry open information about how black holes are formed as well as the structure of the space on the tiniest level."
Let's hope that Messrs Einstein and Hawking got their equations right.

Scientists at Princeton University's Department of Ecology and Environmental Biology say they've figured out how large groups of animals coordinate their movement and behavior. They say that large groups easily make accurate decisions about where to go even when no individuals are regarded as leaders and very few individuals have any pertinent information."It demonstrates the power of the little guy," said Daniel Rubenstein, chair of ecology and evolutionary biology at the university. "You don't need avowed leaders, you don't need complex signaling."
The researchers assumed that group coordination stems from two fundamental instincts: the need to stay in group and the desire by some members to act on their own information about where to go. Using computer modeling, the team endowed their simulated animals with the basic "urge" to stay close other members of the group without running into them. As predicted, this bunched the animals into close, evenly spaced groups "like those of real animals, which pay a high price - such as being eaten - if they stray from their group."
In the next step, some members of the herd were given a drive, such as knowing where to find food. The software then told this enlightened bunch to balance their urge to find food with their desire to stay in the group. Yet, in repeated simulations, the entire group ended up with full stomachs. What more, the same small number of informed animals, as little as 10 members in a group of 200, was equally effective in leading small and large groups.

The speeding up of the universe may be caused by gravitational leaks, says Georgi Dvali, physicist at New York University. Dvali believes that gravity leaks out into extra space dimensions like water from a strainer. The depleted gravity then exerts less pull on stars and galaxies and allows them fly apart from each other. "The cosmic acceleration of the universe indicates that the laws of General Relativity get modified not only at very short but also at very large distances," Dvali says. "It is this modification, and not dark energy, that is responsible for the accelerated expansion of the universe." Dark energy is the mysterious force currently considered the most likely culprit behind the speeding up of the universe.
The stuff that's leaking out are gravitons. They are theoretical messenger particles of the gravitational force predicted by the string theory. That's a unified theory of the universe, which says that nature is made of one-dimensional filaments called strings. The string theory also postulates that space has more than three dimensions. "Virtual gravitons exploit every possible route between the objects, and the leakage opens up a huge number of multidimensional detours, which bring about a change in the law of gravity," he says.
One problem with gravitons: so far, no one has been able to find one.