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ron ll
03-30-2010, 06:04 PM
I'm fascinated by the Large Hadron Collider so have been reading most of what I can find about it in the news today. But the Washington Post article stated that the LHC was "the coldest place in the universe at slightly above absolute zero." I can't find a confirmation of that. Could that possibly be true? The coldest place in the UNIVERSE? Any physicists here that can confirm or refute that?

"Two beams of protons were sent hurtling in opposite directions toward each other in a 17-mile (27-kilometer) tunnel below the Swiss-French border - the coldest place in the universe at slightly above absolute zero."

Mrleft8
03-30-2010, 06:13 PM
An ex-girlfriend's mother's heart is where they put the Hadron Collider?!!!!! :eek:

Gerarddm
03-30-2010, 06:19 PM
Absolute zero is zero degrees Kelvin, IIRC.

Can humans manufacture a space that cold? I would think you'd only get that temp in deep intergalactic space, or something...

ron ll
03-30-2010, 06:27 PM
Appears to be true. I found a backup here.

http://www.smithsonianmag.com/science-nature/phenom-200801.html

htom
03-30-2010, 07:02 PM
A tiny bit colder would appear to be possible, perhaps in some far-off star's physics lab. "Tiny" being in the order of 0.0000000001F colder. That's the limit, unless we really upset the laws of physics.

ron ll
03-30-2010, 07:18 PM
Good point. There may be many distant physics labs. For Cern to claim the record may be a little premature.

Covite
03-30-2010, 09:00 PM
There are two different things going on here.

The ultra low temperature researchers such as Wolfgang Ketterle of MIT, whose work is discussed in the Smithsonian Magazine article cited above, are exploring the behavior of very small amounts of matter at temperatures a few billionths of a degree above absolute zero (degrees Kelvin) or a little less, in a space about a millimeter across. Such experiments produce temperatures far lower than are observed anywhere in nature.

The equipment for such experiments typically occupies a lab room or two. Such research groups typically involve one or two dozen people.

That's not what is being done at the Large Hadron Collider (LHC) at CERN.

The LHC uses about 1600 superconducting magnets to send extremely energetic particle beams through a circular tunnel with a circumference of 27 kilometers. Superconducting magnets are used because they can achieve higher magnetic fields than normally conducting magnets and require less power.

The LHC uses about 96 tons of liquid helium to cool the magnets, many of which weigh over 27 tons each, to their operating temperature of 1.9 degrees Kelvin. That's a lot hotter than the ultra low temperature experiments discussed above, but still fairly chilly. (These numbers are from Wikipedia).

Over 10,000 people from over 100 countries and hundreds of universities and laboratories have collaborated in the construction and operation of the LHC. It is the largest cryogenic facility and the most complex machine in the world.

Breakaway
03-31-2010, 02:36 AM
In the physics reading I've done, it seems that any extreme--coldest, hottest fastest, etc--is really just a theoretical reference; a means of establishing a baseline. In any event, that collider is pretty chilly!