[alancalverd]

For what it's worth, you can make x-rays by unreeling Sellotape / Scotch Tape / other sticky plastic tapes very rapidly. The hazard, as with switching off your torch,  is negligible.

[clueless (OP)]

Thanks paul cotter and alancalverd. I am a bit more optimistic now. I'll try to expand my idea, make it clearer and easy to understand, offer it to my cousin, and if He refuses and thinks it is total baktag, or has other projects, I still might send a private message to one of You, dear Naked Scientists, for your opinion and suggestion, possibly partnership. After all, hope dies last, and humanity needs hope more than ever, where pollution is potentially apocalyptic.

[alancalverd]

Save your typing fingers! "Free electricity" is not possible. The work done separating the ends of the wire will exceed any energy available to make electrons leave it.

The answer to a sustainable future for homo sapiens is to reduce our standard of living or reduce our population. The latter is obviously more desirable, saves a lot of effort, and costs nothing.

[varsigma]

Apologies, the semiconductor device I mentioned is called a cleaved-coupled x-ray diode or somesuch. A free-electron laser uses alternating magnetic fields. And it's a lot bigger than a diode.

I wouldn't worry too much about producing x-rays because both types of laser are pretty high power and high current, generally not in the milliamp region of most electronics.

[evan_au]

I'm afraid that electrons won't travel a few millimeters after you cut the wire, because electrons are always bumping into the atoms of the copper wire, which effectively halts their forward motion.

The references below suggest that:
- An electron will collide with an atom about every 10^-14 seconds
- An electron will travel about 10^-8 meters between collisions with an atom

If you remove the electrical field, the electrons will not regain their drift speed after this collision.

https://www.wyzant.com/resources/answers/770983/what-is-mean-free-path-for-the-conduction-electrons-in-copper-assuming-that
https://www.wyzant.com/resources/answers/770982/what-is-the-mean-free-time-between-collisions-for-the-conduction-electrons-

Electrons do have momentum: Electrons colliding with atoms in a conductor causes the atoms to shift position, a process called electromigration.
- This is a major problem in the most advanced semiconductor chips, where current must flow through finer and finer wires (down to as little as 5nm wide, in the latest chips).
https://en.wikipedia.org/wiki/Electromigration

All of this changes in superconductors, where electrons (or electron pairs) can propagate through the material without interacting with the superconducting material, so they have a long mean free path, and mean free time.
- But the chemical reactions driving AA batteries stop at the extremely low temperatures required by current superconductors!