It is a scary thought. While walking down the road you meet someone who wants to shake your hand. But the stranger is made of anti-matter, and when your fingers touch -ka-boom.
Physicists believe the Big Bang created as much anti-matter as matter - the normal stuff of which we are made.
However, when the two meet they annihilate each other in a puff of energy. That makes capturing anti-matter atoms hard and raises the prickly question of why we and the universe exist at all.
Now scientists say they are close, for the first time, to making and snaring a complete anti-matter atom.
Working at the CERN European Laboratory for Particle Physics, in Switzerland, the scientists, led by Gerald Gabrielse, of Harvard University, believe they may have already created relatively slow moving anti-hydrogen atoms.
Using electric fields they slammed the building blocks of anti-matter, anti-electrons and anti-protons together to form anti-hydrogen. Chilled to minus 269 degrees C, the anti-matter atoms flew off at a fraction of the speed of light before colliding with the walls, destroying themselves.
"It is a fairly significant step," Professor Gabrielse said yesterday. "I believe we have made cold anti-matter atoms ... but I can"t really prove it."