Superconductivity for light beams?

[davenn]

But is that current? Can it do work? (particularly sustained work?)

yes it's current ... how do you think an tube works ?

or the older TV picture tube ?

There is a current flowing from the cathode to anode across the vacuum Dave

 

[phinds]

AAAGGG. Tubes. I hate tubes. Bah humbug.

 

[davenn]

AAAGGG. Tubes. I hate tubes. Bah humbug.

They were wonderful things for keeping the radio shack warm on cold winter nights

 

[phinds]

They were wonderful things for keeping the radio shack warm on cold winter nights

Yes, and they were TERRIFIC in Mcintosh amps and preamps but I still hate them. It's a long story.

 

[DrDu]

While superconductivity requires charged particles, in some special media, light can behave as a superfluid, i.e. propagate without losses. I think we had an article in the news section just some days ago:
https://phys.org/news/2017-06-stream-superfluid.html