Posts Tagged ‘matter’
Scientists claimed a breakthrough Thursday in solving one of the biggest riddles of physics, successfully trapping the first “anti-atom” in a quest to understand what happened to all the antimatter that has vanished since the Big Bang.
An international team of physicists at the European Organization for Nuclear Research, or CERN, managed to create an atom of anti-hydrogen and then hold onto it for long enough to demonstrate that it can be studied in the lab.
“For us it’s a big breakthrough because it means we can take the next step, which is to try to compare matter and antimatter,” the team’s spokesman, American scientist Jeffrey Hangst, told The Associated Press.
“This field is 20 years old and has been making incremental progress toward exactly this all along the way,” he added. “We really think that this was the most difficult step…”
Theory posits that matter and antimatter were created in equal amounts at the moment of the Big Bang, which spawned the universe some 13.7 billion years ago. But while matter — defined as having mass and taking up space — went on to become the building block of everything that exists, antimatter has all but disappeared except in the lab…
Scientists have long been able to create individual particles of antimatter such as anti-protons, anti-neutrons and positrons — the opposite of electrons. Since 2002, they have also managed to lump these particles together to form anti-atoms, but until recently none could be trapped for long enough to study them, because atoms made of antimatter and matter annihilate each other in a burst of energy upon contact.
“It doesn’t help if they disappear immediately upon their creation,” said Hangst. “So the big goal has been to hold onto them…”
“We have a chance to make a really precise comparison between a matter system and an antimatter system,” he said, “That’s unique, that’s never been done. That’s where we’re headed now.”
If we’re looking for alien life, we should look where they may be hanging out – especially if they ain’t meat machines like us!
Just a different kind of shiny
Seti, the Search for Extraterrestrial Intelligence, has until now sought radio signals from worlds like Earth. But Seti astronomer Seth Shostak argues that the time between aliens developing radio technology and artificial intelligence (AI) would be short. Writing in Acta Astronautica, he says that the odds favour detecting such alien AI rather than “biological” life.
Seti searchers have mostly still worked under the assumption – as a starting point for a search of the entire cosmos – that ETs would be “alive” in the sense that we know. That has led to a hunt for life that is bound to follow at least some rules of biochemistry, live for a finite period of time, procreate, and above all be subject to the processes of evolution.
But Dr Shostak makes the point that while evolution can take a large amount of time to develop beings capable of communicating beyond their own planet, technology would already be advancing fast enough to eclipse the species that wrought it.
“If you look at the timescales for the development of technology, at some point you invent radio and then you go on the air and then we have a chance of finding you,” he told BBC News. “But within a few hundred years of inventing radio – at least if we’re any example – you invent thinking machines; we’re probably going to do that in this century.
“So you’ve invented your successors and only for a few hundred years are you… a ‘biological’ intelligence…”
Dr Shostak says that artificially intelligent alien life would be likely to migrate to places where both matter and energy – the only things he says would be of interest to the machines – would be in plentiful supply. That means the Seti hunt may need to focus its attentions near hot, young stars or even near the centres of galaxies.
“I think we could spend at least a few percent of our time… looking in the directions that are maybe not the most attractive in terms of biological intelligence but maybe where sentient machines are hanging out.”
Makes sense to me. But, then, I made the transition to understanding our species as meat machines decades ago. Another transition to more durable construction is a natural.
A US-based physics experiment has found a clue as to why the world around us is composed of normal matter and not its shadowy opposite: anti-matter.
Anti-matter is rare today; it can be produced in “atom smashers”, in nuclear reactions or by cosmic rays. But physicists think the Big Bang should have produced equal amounts of matter and its opposite.
New results from the DZero experiment at Fermilab in Illinois provide a clue to what happened to all the anti-matter…
Researchers working on the DZero experiment observed collisions of protons and anti-protons in Fermilab’s Tevatron particle accelerator. They found that these collisions produced pairs of matter particles slightly more often than they yielded anti-matter particles.
The results show a 1% difference in the production of pairs of muon (matter) particles and pairs of anti-muons (anti-matter particles) in these high-energy collisions…
The dominance of matter in the Universe is possible only if there are differences in the behaviour of particles and anti-particles…
Indeed…previous observations were fully consistent with the current theory, known as the Standard Model. This is the framework drawn up in the 1970s to explain the interactions of sub-atomic particles.
Researchers say the new findings, submitted for publication in the journal Physical Review D, show much more significant “asymmetry” of matter and anti-matter – beyond what can be explained by the Standard Model.
If the results are confirmed by other experiments, such as the Collider Detector (CDF) at Fermilab, the effect seen by the DZero team could move researchers along in their efforts to understand the dominance of matter in today’s Universe.
The data presage results expected from another experiment, called LHCb, which is based at the Large Hadron Collider near Geneva.
It would be illogical to posit results from either the CDF or the LHCb experiments which counter the DZero experiment. Context, premises, will be identical.
Data and analyses in greater depth and accuracy should lead us to more understanding of the questions asked.
Phase transitions — changes of matter from one state to another without altering its chemical makeup — are an important part of life in our three-dimensional world. Water falls to the ground as snow, melts to a liquid and eventually vaporizes back to the clouds to begin the cycle anew.
Now a team of scientists has devised a new way to explore how such phase transitions function in less than three dimensions and at the level of just a few atoms. They hope the technique will be useful to test aspects of what until now has been purely theoretical physics, and they hope it also might have practical applications for sensing conditions at very tiny scales, such as in a cell membrane.
They worked with single-walled carbon nanotubes, extremely thin, hollow graphite structures that can be so tiny that they are nearly one-dimensional, to study the phase transition behavior of argon and krypton atoms…
Phase transitions change the density of atoms. In the vapor form, there are fewer atoms and they are loosely packed. Liquid has more atoms and they are more tightly packed. The solid is a crystal formed of very tightly packed atoms. To determine the phase of the argon and krypton atoms, the researchers used the carbon nanotube much like a guitar string stretched over a fret. A nearby piece of conducting metal applied an electrical force to oscillate the string, and the scientists measured the current to “listen” as the vibration frequency changed — a greater mass of atoms sticking to the nanotube surface produced a lower frequency.
“You listen to this nano guitar and as the pitch goes down you know there are more atoms sticking to the surface,” Cobden said. “In principle you can hear one atom landing on the tube — it’s that sensitive.”
Besides providing a test bed for physics theories, the work also could be useful for sensing applications, such as nanoscale measurements in various fluid environments, examining functions within cell membranes or probing within nerves.
“Nanotubes allow you to probe things at the subcellular level,” Cobden said.
Bravo! Working at this level of basic research can be a reward unto itself.
You always hope to see translation of your work into something expansive, a dialectic of operability recognized and put to use with sophistication and expansion. But, properly designed, context understood, you enjoy the contribution made and the function of learning.