The laws of our universe allow for a strange exotic type of material far different from the kind that dominates the world as we know it.  This material, antimatter, has its own unique characteristics, the most notable of which is its ability to annihilate normal matter, releasing energy.

Scientists at CERN, Europe's particle-physics lab near Geneva, Switzerland, have taken an important step forward to better understanding and perhaps one day using antimatter.  They have created the long lasting manmade antihydrogen-1 (more on this later) particles in the history of experimental particle physics.

What is Antimatter?

Antimatter was theorized as early as Arthur Schuster in a paper entitled "Potential Matter -- a Holiday Dream" published in the journal Nature in 1898.  In the piece, Schuster speculated on antiatoms and the possibility of "antimatter", a special kind of atom which could destroy normal matter.  Even earlier papers from the 1800s speculated on similar concepts.  These works proved prescient.

Material in the universe is asymmetric in that it is divided into unequal amounts of antimatter and matter, matter being the dominant material.  Matter is composed of protons, neutrons, and electrons.  Antimatter is composed, respectively, of antiprotons, antineutrons, and positrons.  Just as protons, neutrons, and electrons form matter atoms, antimatter's elementary particles form antimatter atoms.  A one-antiproton antimatter atom is dubbed antihydrogen-1, a two antiproton (plus one antineutron) antihelium-3, and so on.

When matter and antimatter collide, they undergo a process known as annihilation, which can  produce a massless photon, imbued with energy, if the collision substituents are certain kinds of particles/antiparticles.  There are plenty of caveats, though.  At high energy, they can instead produced exotic particles -- so energetic annihilation does not always occur.  

And the process can work in reverse -- photons can decay into matter and antimatter.  In fact, this is how physicists first observed the antimatter atom.

Positrons, which are positively charged antielectrons, so to speak, were first observed experimentally in a gas chamber by Carl David Anderson at the California Institute of Technology in 1932.  In 1955, Emilio Segrè and Owen Chamberlain -- working at the University of California, Berkeley Bevatron – collided two protons together at 5 GeV, releasing a photon with enough energy to decay into a proton and antiproton.  The field of antimatter was born.

Record Survival Times at CERN

Even as production techniques of antiparticles and antimatter atoms have refined, the problem of annihilation remains the biggest obstacle to studying antimatter and using it.

Researchers on two rival CERN teams -- ALPHA and ATRAP -- are trying to get enough antimatter atoms to survive for a great enough timespan to get a spectroscopic energy measurement.  

That energy measurement would allow them to compare the energy in a hydrogen-1 atom to that of an antihydrogen-1 atom.  Despite the charges being flipped, the energy, under the standard model, is hypothesized to be the same.  If either team can achieve this measurement, they would effectively have offered a piece of conclusive evidence in support of the standard model, one of the fundamental models of modern physics.  Or they might disprove it, showing that a more complex model was necessary -- an equally valuable discovery.

To do that, though, they need to trap 100 antihydrogen-1 atoms for long enough to take a measurement.  They're having trouble just trapping one now.

But the ALPHA team has devised a clever solution.  They take advantage of weak magnetic interactions created by spins of the constituent particles to trap the antihydrogen within a magnetic chamber with a field created by an octupole (eight wire) magnet.  While the particles don't get sucked into the field as strongly as a charged particle might, the apparatus was sufficient to trap an antihydrogen atom within the field for 38 out of 335 trials.

The antihydrogen atoms remained trapped, and thus in existence for more that 170 milliseconds, before escaping and annihilating matter within the walls of the containment vessel.

The ALPHA team is billing the success as the most important breakthrough since ATRAP and an earlier experiment, ATHENA produced large quantities of extremely short-lived antihydrogen in 2002.  That discovery showed that mass-production of antiparticles was feasible.  Now the ALPHA team believes they've answered a critical second question -- how to trap them.

Jeffrey Hangst, spokesman for the ALPHA collaboration at CERN comments, "We're ecstatic. This is five years of hard work."

The results were published in the journal Nature, perhaps fitting given that it was the journal in which antimatter was first theorized in over a century prior.

Don't Count Out ATRAP

The ATRAP points out that the ALPHA team isn't out of the woods yet.  They've just trapped one particle and they need 100 simultaneously trapped.  

The ATRAP team is trying a different tack, attempting to leapfrog the ALPHA team's breakthrough.  They are using positrons to cool antiprotons within a magnetic trap (a so-called nested Penning Trap) and then recombining the cool positrons (which are cooled separately via radiation cooling) with antiprotons.

This approach relies on making a cool, more easily trapped atom, rather than using a higher-energy, more complex trap to snare high-energy antihydrogen atoms.

Their plans and progress is published in the journal Physical Review Letters.

Both teams feel they're on the verge of getting enough trapped particles to get the spectroscopic measurement.  Thus, within the next year or two, expect a major announcement as evidence is delivered either supporting or invalidating the standard model.

What's Next -- Antimatter Guns and Spaceships

Positrons are useful in medical imaging.  Thus mass production and storage of antimatter could offer imaging advances to better detect disease.

But more exciting (or scary), perhaps, is the possibility of using antimatter to produce weapons.  An antimatter bomb could literally destroy the buildings, whole, and destroy the atmosphere over a city, creating a secondary pressure implosion, causing yet more destruction.  Smaller scale weapons could be used to destroy heavily armored, slow moving vehicles like tanks, mechas, or battleships.  In space antimatter weapons would be even more dangerous as premature annihilation would be less of an issue.

Another exciting, more peaceful use would be to use the energy created by annihilation to generate a huge amount of thrust, propelling a rocket to near lightspeed.  Thus antimatter, a material that typically is only found in small quantities in the stars, might someday allow an enterprising future man to get to those stars.