Anti-matter is sort of the opposite of regular matter we see and interact with, except that the particles that make it up are opposite in charge. An anti-electron or positron is positive instead of negative and an anti-proton is negative instead of positive. Neutral particles such as a neutron also have an anti-particle with opposite properties such as baryon number. It i possible to combine anti-protons and anti-neutrons to form the nuclei of anti-atoms and even to get positrons to orbit around these nuclei, forming anti-atoms. Physicists have managed to create anti-hydrogen, but no anti-matter can exist for very long since it is destroyed on contact with matter.
At CERN in Geneva, scientists have managed to capture anti-hydrogen anti-atoms for an incredible 16 minutes. This may not seem very long, but on the scale of atoms and particles, this is an eternity.
“We’ve trapped antihydrogen atoms for as long as 1,000 seconds, which is forever” in the world of high-energy particle physics, said Joel Fajans, a University of California, Berkeley professor of physics who is a faculty scientist at California’s Lawrence Berkeley National Laboratory and a member of the ALPHA (Antihydrogen Laser Physics Apparatus) experiment at CERN.
Trapping antimatter is difficult, because when it comes into contact with matter, the two annihilate each other. So a container for antimatter can’t be made of regular matter, but is usually formed with magnetic fields.
In the ALPHA project, the researchers captured antihydrogen by mixing antiprotons with positrons — antielectrons — in a vacuum chamber, where they combine into antihydrogen atoms.
The whole process occurred within a magnetic “bottle” that takes advantage of the magnetic properties of the antiatoms to keep them contained. An actual bottle, made of ordinary matter, would not be able to hold antimatter because when the two types of matter meet they annihilate.
After the researchers had trapped antimatter in the magnetic bottle, they could then detect the trapped antiatoms by turning off the magnetic field and allowing the particles to annihiliate with normal matter, which creates a flash of light.
The team has now managed to capture 112 antiatoms in this new trap for times ranging from one-fifth of a second to 1,000 seconds, or 16 minutes and 40 seconds. (To date, since the beginning of the project, Fajans and his colleagues have trapped 309 antihydrogen atoms in various traps.)
And the researchers plan to improve on that, with the “hope that by 2012 we will have a new trap with laser access to allow spectroscopic experiments on the antiatoms,” Fajans said in a statement. Those experiments would give researchers more information on the antimatter’s properties.
In that way, it could help to answer a question that has long plagued physicists: Why is there only ordinary matter in our universe? Scientists think antimatter and matter should have been produced in equal amounts during the Big Bang that created the universe 13.6 billion years ago.
Maybe an anti-matter drive, like in Star Trek is just around the corner.
Oh, and see here for the coolest little particles in nature.