X-Message-Number: 29404
From: "Chris Manning" <>
References: <>
Subject: Re: near absolute zero
Date: Mon, 9 Apr 2007 22:06:52 +1000

> Message #29401
> From: "Basie" <>
> Subject: Laser-cooling Brings Large Object Near Absolute Zero
> Date: Sun, 8 Apr 2007 15:37:39 -0400

[snip]

> "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," said Thomas Corbitt, an MIT
> graduate student in physics and lead author of the paper. "Nobody's
> demonstrated quantum mechanics at that kind of (macroscopic) scale."

I don't think quantum mechanics was even mentioned when I went to high 
school (in Australia between 1969 and 1974).

I do remember as a child reading about the peculiar behaviour of liquid 
helium. (This was something I read out of my own interest, not connected 
with school.) It said that liquid helium flows up the inside walls of its 
container and down the outside. Also, any object floating on it which is 
given a twist will continue rotating indefinitely. I don't remember whether 
any explanations were given.

>
> 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 degrees Kelvin, -237 
> degrees
> Celsius or -460 degrees Fahrenheit), atoms lose all thermal energy and 
> have
> only their quantum motion.
>

Absolute zero is - 273 C. 

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