Saturday, September 28, 2013

Most amazing Universe precious moment


New form of photon-based matter is essentially a lightsaber

By  Sep. 26, 2013 9:30 am
lightsaber
Modern physics has taught us quite a lot about light and how it behaves, but some of what we thought we knew might not be entirely accurate. A team of scientists from MIT and Harvard have been herding photons through a cloud of super-cold atoms in an attempt to get them to do something that was once considered impossible — bind together. According to a new paper, they may have succeeded in creating a new form of matter entirely from photons, which is basically a lightsaber.
Conventional wisdom holds that photons are massless particles that don’t interact with each other, so how can they form molecules? The key was to create a special medium in which photons can interact strongly enough that they attract one another as if they have mass. This so-called “photonic matter” has been theorized for some time in scientific circles, but only in the abstract.
The team used a vacuum chamber filled with rubidium atoms to facilitate the formation of photonic matter. The cloud of gas was cooled to within a few degrees of absolute zero using (fittingly)lasers. Short laser pulses were then used to send individual photons into the cloud where the chilled gas sapped energy away from them, causing the photons to slow down considerably by the time they exited the cloud. If more than one photon was sent in at the same time, the researchers found the particles would lose so much energy that they emerged together as a single molecule.
Photons
The Harvard and MIT scientists believe this newly observed interaction between photons could be of great importance in the field of quantum computing. Photons have been studied as a medium for doing quantum calculations, but one of the principal challenges has always been that they don’t interact with each other. Well, now there might be a way to make that happen in the context of a quantum computer. The process still needs to be refined, but it’s an exciting proof-of-concept.
A few photons sticking together is a long way from a lightsaber, but we can still dream, can’t we?

El casco de Dios ,una explicación al mundo de la esquizofrenia


La superpoblación, a debate en 'CM'

Monday, September 23, 2013

The Moon Is 100 Million Years Younger Than Thought

The Moon Is 100 Million Years Younger Than Thought
This artist's conception of a planetary smashup whose debris was spotted by NASA's Spitzer Space Telescope …

The moon is quite a bit younger than scientists had previously believed, new research suggests.
The leading theory of   holds that it was created when a mysterious planet — one the size of Mars or larger — slammed into Earth about 4.56 billion years ago, just after the solar system came together. But new analyses of lunar rocks suggest that the moon, which likely by this monster impact, is actually between 4.4 billion and 4.45 billion years old.
The finding, which would make the moon 100 million years younger than previously thought, could reshape scientists' understanding of the early Earth as well as its natural satellite, researchers said. [ ]
"There are several important implications of this late moon formation that have not yet been worked out," Richard Carlson, of the Carnegie Institution for Science in Washington, D.C., said in a statement.
"For example, if the Earth was already differentiated prior to  , would the impact have blown off the primordial atmosphere that formed from this earlier epoch of Earth history?" added Carlson, who is presenting the new results Monday (Sept. 23) in London at a meeting organized by the Royal Society called "Origin of the Moon."
Scientists know the solar system's age (4.568 billion years) quite well. And they can pin down the formation times of relatively small bodies such as asteroids precisely, too, by noting when these objects underwent extensive melting — a consequence, in part, of the heat generated by the collision and fusion of these objects' building-block "planetesimals."
For example, analysis of meteorites that came from the asteroid Vesta and eventually rained down on Earth reveals that the 330-mile-wide (530 kilometers) space rock is 4.565 billion years old. Vesta cooled relatively quickly and is too small to have retained enough internal heat to drive further melting or volcanism, Carlson explained.
But it's tougher to nail down the age of larger solar-system bodies, he said.
"Ask the same question of the Earth or moon, and you don't get a very precise answer," Carlson said. "Earth likely took longer to grow to full size compared to a small asteroid like Vesta, and every step in its growth tends to erase, or at least cloud, the memory of earlier events."
Scientists keep getting better and better estimates, however, as they refine their techniques and technology improves. And those estimates are pushing the moon's formation date farther forward in time.
 is thought to have harbored a global ocean of molten rock shortly after its dramatic formation. Currently, the most precisely determined age for the lunar rocks that arose from that ocean is 4.360 billion years, the researchers said.
And here on Earth, scientists have found signs in several locations of a major melting event that occurred around 4.45 billion years ago. So, evidence is building that the catastrophic collision that formed the moon and reshaped Earth occurred around that time, rather than 100 million years or so before, the researchers said.