# Bose–Einstein condensate

(Redirected from Bose Einstein Condensation)

Bose–Einstein condensate (BEC) is what happens to some things when they are made very cold. It forms when the particles that make up something are made to have very low energy. Only special particles called bosons can make a Bose–Einstein condensate and they can only do this if they are very close to the coldest temperature possible, close to 0 K (or- 273° C, or −459.67 °F); this is called absolute zero. A Bose–Einstein condensate is a type of change of state, like when water turns into ice. And like when water turns to ice, it gets slippery; things that are Bose–Einstein condensates have 0 viscosity. This means they are as slippery as possible.

## Theory

Particles can only have a set amount of energy. They either have the energy to bounce around in gases or just the energy to flow like a liquid or be fixed like a solid. If you take enough of the particle's energy away you get to the tiniest or the smallest amount of energy possible. This is a Bose–Einstein condensate. This makes all of the particles exactly the same and instead of bouncing around randomly in all different directions, they all bounce up and down in exactly the same way, forming something called a 'giant matter wave'.[1]

## History

The Bose-Einstein Condensate was first thought up by Satyendra Nath Bose and Albert Einstein in 1924–25, but we then had to wait seventy years for somebody to prove that it existed. Eric Cornell and Carl Wieman made the first Bose–Einstein condensate in 1995 at the University of Colorado. Cornell, Wieman, and Wolfgang Ketterle at MIT were then given the 2001 Nobel Prize in Physics.[2]

## Experiments

Usually to get anything cold enough to make a Bose–Einstein condensate you have to first trap the stuff using magnets and then, by bouncing lasers off them, take all of their energy away through red shift. This still does not get things quite cold enough. Some of the particles will still be bouncing around a lot and only some will be lying down nicely. The magnetic field is then slowly lowered bit by bit to let the faster bouncing particles out. This just leaves us with the coldest and slowest atoms inside.[3]

## References

1. "Bose-Einstein condensation". physicsworld.com. Retrieved October 21, 2011.
2. http://www.nist.gov/public_affairs/releases/BEC_background.htm
3. "Bose-Einstein Condensate". YouTube. Retrieved October 21, 2011.