Talk-Polywell.org

Once again I'll leave it to the well educated on the subject to say if this has any importance:

http://www.sciencedaily.com/releases/20 ... 132930.htm

The story sure sounds interesting...

Mike

Having near-zero resistance to electric current is very applicable to polywell, especially if this can be done at temperatures closer to room temperature...electron flow = magnetic field

Basically, they tried to break a superconductor in a known way, and it didn't break. So they came up with a model that explains this. A more fundamental question will be is their model correct, or is there some other way to explain the behavior.

In any case, it is a really nice discovery. Proves there is a hell of a lot we still don't know about how things work!

What interests me is the recent indications of superconductivity near 200K. That should be quite easy to support. Not room temperature, but a lot closer than 77K.

Yeah, that's mentioned in the Wikipedia article here: http://en.wikipedia.org/wiki/High-tempe ... rconductor

Mike

KitemanSA wrote:What interests me is the recent indications of superconductivity near 200K. That should be quite easy to support. Not room temperature, but a lot closer than 77K.

Superconductivity at liquid nitrogen temperatures would be a big improvement over liquid helium temperatures.

scareduck wrote:

KitemanSA wrote:What interests me is the recent indications of superconductivity near 200K. That should be quite easy to support. Not room temperature, but a lot closer than 77K.

Superconductivity at liquid nitrogen temperatures would be a big improvement over liquid helium temperatures.

You bet, and SC at dry-ice temperatures would be better still!

KitemanSA wrote:

scareduck wrote:

KitemanSA wrote:What interests me is the recent indications of superconductivity near 200K. That should be quite easy to support. Not room temperature, but a lot closer than 77K.

Superconductivity at liquid nitrogen temperatures would be a big improvement over liquid helium temperatures.

You bet, and SC at dry-ice temperatures would be better still!

assuming you don't use dry ice, solids are hard to pump, I'd wager.

Professor Science wrote:

KitemanSA wrote:You bet, and SC at dry-ice temperatures would be better still!

assuming you don't use dry ice, solids are hard to pump, I'd wager.

True.
In the NASA... forum that preceded this one there was a long discussion on using certian electronics cooling fluids as a preference to LN because they have a much higher specific heat, but it turns out they get gloppy at LN temperatures. I suspect they would be a lot less viscous at 200K than 77k.

Professor Science wrote:

KitemanSA wrote:You bet, and SC at dry-ice temperatures would be better still!

Assuming you don't use dry ice, solids are hard to pump, I'd wager.

Assuming dry ice as a refrigerant, alcohol or acetone might be circulated for heat transfer. But in any case, the higher your superconductor operating temperature, the easier the refrigeration.

Assuming dry ice as a refrigerant, alcohol or acetone might be circulated for heat transfer.

Back in college I wandered past a lab and saw some friends goofing around with dry ice and acetone. They did most of the same fun things (e.g. shattering roses) you see done with liquid nitrogen.

to be fair liquid nitrogen is somewhat overkill for things like that, as it's at 70 K, while dry ice would probably be around 220 K, maybe a bit lower. water freezes spontaneously at 233 K and the acetone likely just provided something to conduct the heat to and from readily.

edit: OK, bad use of the term spontaneously, i meant without crystaline seed. water can be chilled considerably below 0 celsius if it doesn't have something to form a crystal around. example.

Dry ice is 194.6K

http://www.economicexpert.com/a/1:E2:K.htm

I was working off of -50 celsius, guess i had a trivia point mis memorized. to be fair, the only time i needed a specific temperature on it was to figure out if i could use it as a coolant for my super chilled water runs and when i found out it was too cold i disregarded it all together.