You’ve probably already heard of laser cooling if you’re up to date with your quantum physics and Nobel Prize winners. The winners of the Nobel Prize in Physics 1997 were three researchers that had developed a method of freezing sole atoms using lasers. Scientists at MIT (Massachusetts Institute of Technology) has now managed to take this one step further and cool down entire objects using lasers, not just single atoms. They’ve been able to freeze down a dime-sized mirror to 0.8K (-272°C/-460°F) and by doing this they hope to observe the quantum properties and effects of objects, but to be able to do so they need to lower the temperature even more.
“You always learn in high school physics that large objects don’t behave according to quantum mechanics because they’re just too hot, and the thermal energy obscures their quantum behavior,/…/Nobody’s demonstrated quantum mechanics at that kind of (macroscopic) scale.” – Thomas Corbitt, graduate student.
Laser cooling is quite simple in its theory; you bombard an item with photons but instead of being absorbed the photons bounce of with more energy than they had with them. To be able to study the quantum effects of objects of this size you have to eliminate as many of the regular mechanical effects as possible, whereof heat is a major source of interference. The secret is to combine two of the previous known techniques; optical trapping and optical damping.
Optical trapping means that you shoot an intensive ray of light towards the mirror holding it at place. No that you have the mirror where you want, free from other mechanical interactions you can use optical damping to remove the heat using lasers. They are forced to it like this because any kind of mechanical setup consists of atoms by itself and these atoms have their own built-in heat and mechanical energy that would interfere with the study.
If and when they will push the temperature to even lower levels they will be to study the quantum properties of entire objects and you can count on the entire physics world will be locked in and paying attention then. There are a few obstacles on the way, but the people at MIT are very optimistic about the future and believe they are close to accomplishing a heroic achievement.
