My sister won the science fair with a "frictionless puck" using CO2, two jars, and two hockey pucks. This is not that:
More like this
Since yesterday I talked about blinking I figured that today I would re-post something from the old
Tom and Jerry, or Fetch! with Ruff Ruffman?
Answer: Tom and Jerry.
Liz and Celeste are on vacation, so we're re-posting some content from our old site.
By Celeste Monforton, originally posted 11/4/09
Wow ... I wish I had a superconducting puck that size.
[OT] FSF is looking for signatures on a petition to keep future PCs with UEFI Secure Boot capable of booting other systems:
http://www.fsf.org/campaigns/secure-boot-vs-restricted-boot/statement
Apparently this isn't the Meissner effect but something more subtle involving magnetic field lines getting "caught" in the superconductor. I don't really understand what this means. The physics seems more complicated than the usual Meissner effect. Sure is cool though.
I checked with Jim Kakalios on this just now (we were at an event) and this is a quantum phenomenon, according to him. Personally, I'm still thinking its fake, but what do I know?
Good, quick explanation of what's going on here: http://jtotheizzoe.tumblr.com/post/11590151866/if-this-video-doesnt-mak…
Flux tubes!
The most amazing part:
Quantum Levitation
Posted on: October 20, 2011 10:05 AM, by Greg Laden
and we're commenting on the 19th. Take that, Einstein.
Mu: Yeah, that's because, just for fun, I wrote this post using those new extra-fast neutrinos.
i first saw this at a colloquium in the late 80's when high Tc superconductors were first discovered. pretty cool. (ha!)
it's been over 20 years, and there still is no good theory about how high Tc superconductors work. then again, it took over 40 years before BCS theory described ordinary superconductivity.
i still want a jetpack.
Catch this one?
http://www.ted.com/talks/aaron_o_connell_making_sense_of_a_visible_quan…
Even if it's fake, the technology they're using to fake it seems pretty amazing itself.
I've heard some controversy over whether or not it's actually "quantum," but that's kind of an afterthought as far as I'm concerned. If it works and it's replicable, they can call it what they please, so long as I get my freaking hover car.
The superconductor seems to stay superconducting for longer than I would expect. Anyone have info on the type or whether there are any other tricks to how they have kept it cool?
@ glen (#10)
To get the 'locking' effect they use a superconductor that is only 1 micron thick.
That means that most of the 'puck' can simply be thermal insulation - so even though most of the outer part of the puck will be approaching room temperature - but the inner section of 1 micron can still be nice and chilly.
That's my guess anyway.
Mac
at Mac #11: the "locking" effect if magnetic flux tubes getting pinned by defects in the crystal. when the superconductor superconducts, external magnetic fields are expelled. mostly. some get pinned, and cause the leveitation effect. this effect can happen with thicker crystals too. the first one i saw in the 80's was about 3/4" diameter and 1/4" thick. it could levitate and hang upside down from the pinned flux.