Thursday, December 29, 2005

Speed of Light vs. Molasses

While on the topic of the speed of light over at Triton's I came across this article from the Harvard University Gazette about a group of physicists slowing a beam of light to 38 MPH (down from 186,000 Miles Per Second***)

It's a pretty cool expirement. They inject sodium into a vacuum (well, it was a vaccuum up to that point) and then use a laser to get all the atoms moving in one direction. Then they use lasers to get all the atoms to clump together in the middle with next to no movement. No movement equals energy equals temperature (basically) so no movement equals no temperature. In this case it was a fraction above absolue zero (minus 459.7 degrees F, colder than most of space) This formed what is known as an Einstein-Bose "condensate". This condensate acts as one big cell and presents huge resistance to the light wave which enabled the University to observe light at a mere 38 MPH (I've gone faster than that on my bike!) Their next project is to perfect the technology and get the speed down to a whopping 1 centimeter per second

*** Edited Changed from 186,000 MPH to MPS. Thanks Ted