3 ms·
Liquid nitrogen is much easier and cheaper to work with than liquid helium (probably most US high schools see freeze and break a banana or similar experiments r
by ptero 10y ago
Liquid nitrogen is much easier and cheaper to work with than liquid helium (probably most US high schools see freeze and break a banana or similar experiments regularly; it costs very little).
IMO it would still be a major real world breakthrough when this is ready for engineering use. But while this research may be a big step to that goal, it does not yet move the problem from science to engineering.
- jeffwass 10y agoI used to do a lot of cryogenics work during my PhD. The statistic one of the professors often quoted was that "LN2 is cheaper than milk". Although LN2 is cheaper and more abundant, it's also 20 times warmer than LHe. That matters a lot for applications. To get an idea of ability to restrict thermal excitations, LN2 at 77K is only 4x 'colder' than room temperature. But LHe (4.2K) is 18x 'colder' than LN2, or 72x 'colder' than room temperature!
- bryondowd 10y agoThe 4x 'colder' here really threw me. Took me a minute to realize you meant 1/4 the temperature. Strikes me as an odd phrasing, like saying "airplanes fly 23x 'lower' than LEO".
- witty_username 10y agoIt's odd but correct because temperature has a minimum. We're just used to Celsius/Fahrenheit temperatures where you can't say that.
- spyder 10y agoThere is already a short (1 km long) high voltage, nitrogen cooled superconducting cable in use in Germany: http://www.extremetech.com/extreme/182278-the-worlds-first-superconducting-power-line-paves-the-way-for-billions-of-dollars-in-savings http://www.extremetech.com/extreme/182278-the-worlds-first-s...
- mzs 10y agoThanks: http://www.nexans.de/eservice/Germany-de_DE/fileLibrary/Download_540144810/Germany/files/Nexans_Superconducting_cable_systems.pdf http://www.nexans.de/eservice/Germany-de_DE/fileLibrary/Down...