A New Form of Matter

Scientists have created a new kind of matter: It comes in waves and bridges the gap between the everyday world of humans and the micro-domain of quantum physics.

It's not often that you get to be around for the birth of a new kind of matter, but when you do, the excitement is tremendous.

"To see something which nobody else has seen before is thrilling and deeply satisfying. Those are the moments when you want to be a scientist," says Wolfgang Ketterle, a physicist at MIT and one of the first scientists to create a new kind of matter called Bose-Einstein condensates.

Bose-Einstein condensates ("BEC's" for short) aren't like the solids, liquids and gases that we learned about in school. They are not vaporous, not hard, not fluid. Indeed, there are no ordinary words to describe them because they come from another world - the world of quantum mechanics.

Quantum mechanics describes the bizarre rules of light and matter on atomic scales. In that realm, matter can be in two places at once; objects behave as both particles and waves (a strange duality described by Schrodinger's wave equation); and nothing is certain: the quantum world runs on probability.

Image © 2002 The Nobel Foundation. more Nobel prizing-winning scientists used lasers and magnetic fields to create a new form of matter.

Although quantum rules are counter-intuitive, they underlie the macroscopic reality we experience day-to-day. Bose-Einstein condensates are curious objects that bridge the gap between those two realms. They obey the laws of the small even as they intrude on the big.

A BEC is a group of a few million atoms that merge to make a single matter-wave about a millimetre or so across. In 1995, Ketterle created BEC's in his lab by cooling a gas made of sodium atoms to a few hundred billionths of a degree above absolute zero - more than a million times cooler than interstellar space! At such low temperatures the atoms became more like waves than particles. Held together by laser beams and magnetic traps, the atoms overlapped and formed a single giant (by atomic standards) matter wave.