Superconductivity for light beams?

[berkeman]

As I recall, someone on this forum said that light doesn't require a medium. I argued, and put forth a "theory" of how vacuum was a medium. My post was deleted by an "official" of this forum.

Sounds appropriate. Personal speculation is not allowed here. If you had a problem with the Moderation, per the PF Rules you should contact the Mentor involved. [/off-topic]

 

[ZapperZ]

As I recall, someone on this forum said that light doesn't require a medium. I argued, and put forth a "theory" of how vacuum was a medium.

I'm not impressed. "theories" like that are a dime a dozen on the 'net. Publish it, then you can boast about it on here. Otherwise, join the queue.

Something no one mentioned is that non-focused light dissipates as the square of the distance, even if there is no loss from the medium.

What does this have anything to do with a "medium"? It is simply a geometric effect due to 3D space. An electrostatic field from a point source has the same 1/r² dependence. Has nothing to do with space being a medium or not.

Zz.

 

[phinds]

I'm a bit surprised to not see the obvious answer here: the most lossless medium for current and radiation is ... space.

No, space is not a good conductor of electric current at all.

 

[davenn]

No, space is not a good conductor of electric current at all.

that's correct, but it doesn't stop a stream of electrons flowing ( controlled or otherwise) between two points in a vacuum

 

[phinds]

that's correct, but it doesn't stop a stream of electrons flowing ( controlled or otherwise) between two points in a vacuum

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

 

[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