In theory, antimatter dropped over the surface of the Earth should fall down. However, the issue has never been successfully experimentally tested. The theoretical grounds for expecting antimatter to fall down are very strong, so virtually all physicists expect antimatter to fall down; however, some physicists believe that antimatter might fall down with a different acceleration than that of ordinary matter. Since this has never been experimentally tested, it's important to keep an open mind.
What should we expect theoretically?
Based on what we currently know, we would expect that the only significant force acting on a piece of falling antimatter is gravity; by the equivalence principle, this should make antimatter fall with the same acceleration as ordinary matter. However, some theories predict new, as yet unseen forces: these forces would make antimatter fall differently than matter. But in these theories, antimatter always falls slightly faster than matter; antimatter never falls up. This is because the only force that would treat matter and antimatter differently would be a vector force (mediated by the hypothetical gravivector boson). Vector forces (like electromagnetism) repel likes and attract opposites, so a gravivector force would pull antimatter down toward the matter-dominated Earth, while giving matter a slight upward push.

Most self-respecting starships in science fiction stories use antimatter as fuel for a good reason – it’s the most potent fuel known. While tons of chemical fuel are needed to propel a human mission to Mars, just tens of milligrams of antimatter will do (a milligram is about one-thousandth the weight of a piece of the original M&M candy).

However, in reality this power comes with a price. Some antimatter reactions produce blasts of high energy gamma rays. Gamma rays are like X-rays on steroids. They penetrate matter and break apart molecules in cells, so they are not healthy to be around. High-energy gamma rays can also make the engines radioactive by fragmenting atoms of the engine material.

One technical challenge to making a positron spacecraft a reality is the cost to produce the positrons. Because of its spectacular effect on normal matter, there is not a lot of antimatter sitting around. In space, it is created in collisions of high-speed particles called cosmic rays. On Earth, it has to be created in particle accelerators, immense machines that smash atoms together. The machines are normally used to discover how the universe works on a deep, fundamental level, but they can be harnessed as antimatter factories.

Originally posted by bluemooone2
One heck of a lot of work went into this , thats for sure. So apparently anti-matter is real. Cool find) it says it will fill the container with Positronium in a matter of seconds. hmmm....... en.wikipedia.org...

At issue is a van-sized device called the Alpha Magnetic Spectrometer, which scientists hope will tell them more about the universe and its beginnings. The AMS is scheduled to fly aboard Endeavour in July to be installed aboard the International Space Station, but a potential design flaw has forced NASA to consider postponing the mission.

The spectrometer will be installed on the exterior of the space station to study high-energy cosmic rays in the hunt for elusive antimatter and dark matter.