Posts Tagged ‘antimatter’
Pamela discovers antimatter belt around Earth
A thin band of antimatter particles called antiprotons enveloping the Earth has been spotted for the first time.
The find, described in Astrophysical Journal Letters, confirms theoretical work that predicted the Earth’s magnetic field could trap antimatter.
The team says a small number of antiprotons lie between the Van Allen belts of trapped “normal” matter…
The antiprotons were spotted by the Pamela satellite (an acronym for Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) – launched in 2006 to study the nature of high-energy particles from the Sun and from beyond our Solar System – so-called cosmic rays…
Among Pamela’s goals was to specifically look for small numbers of antimatter particles among the far more abundant normal matter particles such as protons and the nuclei of helium atoms.
The new analysis, described in an online preprint, shows that when Pamela passes through a region called the South Atlantic Anomaly, it sees thousands of times more antiprotons than are expected to come from normal particle decays, or from elsewhere in the cosmos.
The team says that this is evidence that bands of antiprotons, analogous to the Van Allen belts, hold the antiprotons in place – at least until they encounter the normal matter of the atmosphere, when they “annihiliate” in a flash of light.
The band is “the most abundant source of antiprotons near the Earth“, said Alessandro Bruno of the University of Bari, a co-author of the work…
Dr Bruno said that, aside from confirming theoretical work that had long predicted the existence of these antimatter bands, the particles could also prove to be a novel fuel source for future spacecraft – an idea explored in a report for Nasa’s Institute for Advanced Concepts.
One of the crankier pundits I work with has held for decades that antimatter can’t [and doesn't] exist. I’ll have to ask him if this and other recent work has served to change his mind.
I might end up with more spare time. 
Physicists building bigger ‘bottles’ of antimatter
If you wondered why our military sponsors this research?
Once regarded as the stuff of science fiction, antimatter—the mirror image of the ordinary matter in our observable universe—is now the focus of laboratory studies around the world.
While physicists routinely produce antimatter with radioisotopes and particle colliders, cooling these antiparticles and containing them for any length of time is another story. Once antimatter comes into contact with ordinary matter it “annihilates”—or disappears in a flash of gamma radiation.
Clifford Surko, a professor of physics at UC San Diego who is constructing what he hopes will be the world’s largest antimatter container, said physicists have recently developed new methods to make special states of antimatter in which they can create large clouds of antiparticles, compress them and make specially tailored beams for a variety of uses…
Surko said that since “positrons”—the anti-electrons predicted by English physicist Paul Dirac some 80 years ago—disappear in a burst of gamma rays whenever they come in contact with ordinary matter, accumulating and storing these antimatter particles is no small feat. But over the past few years, he added, researchers have developed new techniques to store billions of positrons for hours or more and cool them to low temperatures in order to slow their movements so they can be studied.
Surko said physicists are now able to slow positrons from radioactive sources to low energy and accumulate and store them for days in specially designed ”bottles” that have magnetic and electric fields as walls rather than matter. They have also developed methods to cool them to temperatures as low as that of liquid helium and to compress
them to high densities.
“One can then carefully push them out of the bottle in a thin stream, a beam, much like squeezing a tube of toothpaste,” said Surko, adding that there are a variety of uses for such positrons…
Surko and his colleagues are building the world’s largest trap for low-energy positrons in his laboratory at UC San Diego, capable of storing more than a trillion antimatter particles at one time.
I have to chuckle over this research – since one of the other blogs where I’m an editor is the property of a pundit who denies the existence of antimatter.
“Denial” is a funny political quantity. The always-politically-correct Right Wing in America [for PC is their invention] has succeeded in appending the concept of skeptic to denial. It’s like putting an unrecovered alcoholic in charge of the advertising for your barroom because he can claim to have no problems with drink – that he would ever admit to. The word has no place in science; but, then, the pundits who espouse denial as emblematic of skepticism are generally too lazy to read more than a paragraph or two of a scientific study.
Non-scientists don’t realize the persistent conservatism, the need for repeated testing and verification for conclusions considered at least reasonable. I followed the discussion, tests and reviews followed by more discussion in the published papers of the Max Planck Institute for 2 years at the beginning of this millennium – on the question of climate change. It took that long for just one of the hundreds of peer institutes and research centers on Earth to come to the conclusions that grounded the IPCC Report – regardless of whatever politics follow those few pages around. The scenario was repeated inside each of those bodies and continues today.
And those who deny climate change, as some deny the existence of anti-matter and any number of revelatory advances in science will continue to base that denial on little or nothing of value. Much less scientific methods. Much less reading a report.
In a world first, physicists trap atoms of antimatter
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.”
Bravo!
