Superconductivity for light beams?

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SUMMARY

The discussion centers on the concept of superconductivity and its applicability to light propagation. Participants clarify that while superconductivity refers to zero resistance in electrical currents, it does not apply to light, which propagates as electromagnetic waves. The consensus is that all materials, including optical fibers, introduce some level of loss when transmitting light. The term "lossless medium" is suggested as a more accurate descriptor for materials that minimize light attenuation, with space or vacuum identified as the most lossless medium for both light and electrical currents.

PREREQUISITES
  • Understanding of electromagnetic waves and their propagation.
  • Knowledge of superconductivity and its implications for electrical currents.
  • Familiarity with optical fibers and their characteristics.
  • Basic principles of light behavior in different media, including refractive index.
NEXT STEPS
  • Research "lossless medium for light propagation" to explore theoretical materials.
  • Study the principles of "gravitational lensing" and its effects on light paths.
  • Investigate "electron drift velocity" and its implications for electrical current propagation.
  • Examine the differences between "conduction" and "radiation" in electromagnetic theory.
USEFUL FOR

Physicists, electrical engineers, optical engineers, and anyone interested in the principles of light propagation and superconductivity.

  • #31
StandardsGuy said:
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]
 
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  • #32
StandardsGuy said:
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.
 
  • #33
rumborak said:
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.
 
  • #34
phinds said:
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 :smile:
 
  • #35
davenn said:
that's correct, but it doesn't stop a stream of electrons flowing ( controlled or otherwise) between two points in a vacuum :smile:
But is that current? Can it do work? (particularly sustained work?)
 
  • #36
phinds said:
But is that current? Can it do work? (particularly sustained work?)

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

Electron-Tube-EL34-B-6V6GT-6146B-6L6GT-6146-EL34-B-.jpg
or the older TV picture tube ?

monito6.jpg


There is a current flowing from the cathode to anode across the vacuum :smile:Dave
 
  • #37
AAAGGG. Tubes. I hate tubes. Bah humbug.
 
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  • #38
phinds said:
AAAGGG. Tubes. I hate tubes. Bah humbug.

They were wonderful things for keeping the radio shack warm on cold winter nights :smile:
 
  • #39
davenn said:
They were wonderful things for keeping the radio shack warm on cold winter nights :smile:
Yes, and they were TERRIFIC in Mcintosh amps and preamps but I still hate them. It's a long story.
 
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  • #40
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
 

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