Due to the interest in Cryogenics from the previous post, I will now discuss extremely low temperatures and their applications.
First I want to talk about super low temperatures, not actual Cryogenics. Don't worry, it isn't a history lesson. Bose (yes the same guy with the particle named boson) and Einstein (Einsteinium, right!?) proposed after working together that at extremely cold temperatures (near absolute zero) a certain behavior of particles would happen. This is called the Bose-Einstein condensate. Normally, as most of you know, gases move around chaotically in all directions (this is what provides atmospheric pressure, atoms hitting your skin constantly bumping around). However, their theory proposed atoms would move as if you were holding a bunch of pieces of string and waving them together (a uniform wave motion).
In 2001 3 scientists shared the Nobel prize in Physics, 2 from CU Boulder, CO and one from MIT for being the first to demonstrate this condensate. Know what temperature it took to observe it? 1 billionth of 1 degree Kelvin (1 x 10^-9). To fully understand how close that is, they gave the following analogy. If the distance from London to Colorado were the last 1 degree K, they got within a pencil lead's thickness of absolute zero. That's very cold! They did it by keeping the gas within a magnetic field, amongst other things.
But, here is what is really cool about it. Light always moves at 2.9979 x 10^8 m/s in a vacuum, but when it passes through a medium of any kind it has to 'energize' and then pass from one atom to another, so the observed speed is slower. However, it is still moving at the 2.9979 x 10^8 m/s, it just pauses at each atom. Hopefully that makes sense. Now, it was so cold, that light actually passed through the condensate at the speed of a bicycle! That is completely insane. Scientists are now looking at ways to use this, including things such as data storage within light itself due to being able to almost suspend it. Fascinating!
Now onto Cryonics. As some of you may know, in the US and most other parts of the world you have to be legally dead before you are allowed to be frozen. The temperature at which they do it prevents the body from breaking down and incurring further tissue damage (the boiling point of liquid N). One of the first problems, was crystallization of water between cells. Water is a polar molecule and thus has an interesting property all of you are aware of but might not understand. Ice expands and is less dense than water (thus floats). It is caused because the water molecules form circular type chains with space between them rather than all crunched up like liquid water. Well, that type of thing happening in your body is obviously bad.
So, in 1990 some scientists invented something that prevents the freezing of water between cells to help preserve transplant organs. This substance is called a vitrification fluid. It works fine on many tissues, but the brain has more sensitive tissues, so the effects are not completely understood. Animal brains have survived, but characteristics of personality and memory recall are unknown. Additionally, loading the body with vitrification fluid can be bad. In large quantities it is known to be toxic. How toxic? We don't know, because no one has been frozen and woken up.
Regardless, it is believed that by the time the much more complex medical issues which caused the individual to die are solved, the vitrification toxicity and/or cellular damage will be no problem. Works for me, since I'd rather be 150 years in the future anyways :)
Comments welcome as always!