Free Republic
Browse · Search
General/Chat
Topics · Post Article

Skip to comments.

Laser-cooling Brings Large Object Near Absolute Zero
Science Daily ^ | April 8, 2007 | Massachusetts Institute of Technology

Posted on 06/23/2007 9:46:43 PM PDT by SunkenCiv

To see quantum effects in large objects, they must be cooled to near absolute zero. Such low temperatures can only be reached by keeping objects as motionless as possible. At absolute zero (0 Kelvin, -273 degrees Celsius or -460 degrees Fahrenheit), atoms lose all thermal energy and have only their quantum motion... the researchers report that they lowered the temperature of a dime-sized mirror to 0.8 degrees Kelvin... But in order to observe quantum behavior in an object of that size, the researchers need to attain a temperature that is still many orders of magnitude colder, Mavalvala said. To reach such extreme temperatures, the researchers are combining two previously demonstrated techniques-optical trapping and optical damping. Two laser beams strike the suspended mirror, one to trap the mirror in place, as a spring would (by restoring the object to its equilibrium position when it moves), and one to slow (or damp) the object and take away its thermal energy... Using light to hold the mirror in place avoids the problems raised by confining it with another object, such as a spring, Mavalvala said. Mechanical springs are made of atoms that have their own thermal energy and thus would interfere with cooling... "That last factor of 100 will be heroic," she said.

(Excerpt) Read more at sciencedaily.com ...


TOPICS: Astronomy; Science
KEYWORDS: stringtheory

Assistant professor Nergis Mavalvala, left, and Ph.D. student Thomas Corbitt are part of an international team that has devised a way to cool large objects to near absolute zero. (Credit: Donna Coveney)

Laser-cooling Brings Large Object Near Absolute Zero

1 posted on 06/23/2007 9:46:46 PM PDT by SunkenCiv
[ Post Reply | Private Reply | View Replies]

To: AdmSmith; bvw; callisto; ckilmer; dandelion; FairOpinion; ganeshpuri89; gobucks; KevinDavis; ...
The truth is, string theory news has been pretty slow, so there haven't been many, uh, forget it.

2 posted on 06/23/2007 9:48:10 PM PDT by SunkenCiv (Time heals all wounds, particularly when they're not yours. Profile updated June 23, 2007.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: SunkenCiv
The truth is, string theory news has been pretty slow, so there haven't been many, uh, forget it.

Uh, threads?

3 posted on 06/23/2007 9:55:47 PM PDT by cardinal4
[ Post Reply | Private Reply | To 2 | View Replies]

Laser Cooling
Department of Physics and Astronomy, Georgia State University | post-1985 | Carl R. (Rod) Nave
Posted on 12/28/2004 12:57:07 PM EST by SunkenCiv
http://www.freerepublic.com/focus/f-bloggers/1309656/posts


4 posted on 06/23/2007 9:59:15 PM PDT by SunkenCiv (Time heals all wounds, particularly when they're not yours. Profile updated June 23, 2007.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: cardinal4

You touch it with a needle.


5 posted on 06/23/2007 9:59:40 PM PDT by SunkenCiv (Time heals all wounds, particularly when they're not yours. Profile updated June 23, 2007.)
[ Post Reply | Private Reply | To 3 | View Replies]

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
General/Chat
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson