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Lasers and lightning

Posted: Thu Jul 22, 2021 10:00 pm
by monkey
This is fun. They're going to shoot the sky with a massive laser on top of a mountain to make lightning go where they want (if it works).

clicky

Can't find much more detail on it, might do a bit more searching later.

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 6:16 am
by Grumble
Wouldn’t the laser itself get hit all the time?

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 12:51 pm
by monkey
Grumble wrote:
Fri Jul 23, 2021 6:16 am
Wouldn’t the laser itself get hit all the time?
Looks like they fire the laser close to a tower. I assume that this is so the lightning hits that, rather than the (currently hypothetical) important tower that you have.

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 12:59 pm
by dyqik
The laser would presumably be pulsed, and generating an ionized column into the sky. That will only be a fairly weakly conducting trail for the lightning to follow, and could be generated close to a much more conductive lightning conductor - maybe only a few inches away. Probably the ionized trail would short itself to the lightning conductor even before the lightning stroke followed it.


I'm disappointed you didn't mention the name of the company. The Trumpf Laser would definitely get a bunch of crowdsourced funding in the US...

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 1:18 pm
by monkey
dyqik wrote:
Fri Jul 23, 2021 12:59 pm
The laser would presumably be pulsed, and generating an ionized column into the sky. That will only be a fairly weakly conducting trail for the lightning to follow, and could be generated close to a much more conductive lightning conductor - maybe only a few inches away. Probably the ionized trail would short itself to the lightning conductor even before the lightning stroke followed it.


I'm disappointed you didn't mention the name of the company. The Trumpf Laser would definitely get a bunch of crowdsourced funding in the US...
It is, at 1 kHz. The "Terawatt scale" mentioned in the article would be the peak power of the pulses, rather than the average power, because otherwise you'd need a fair few very large power stations to make it go. Still puts my laser to shame though, that's only ~145 kW (and only 2W average).

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 1:55 pm
by Grumble
Presumably you could even fire it through a hole in a tower.

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 2:06 pm
by monkey
Grumble wrote:
Fri Jul 23, 2021 1:55 pm
Presumably you could even fire it through a hole in a tower.
And if there's not one there already, the laser would probably sort that out.

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 6:17 pm
by dyqik
monkey wrote:
Fri Jul 23, 2021 2:06 pm
Grumble wrote:
Fri Jul 23, 2021 1:55 pm
Presumably you could even fire it through a hole in a tower.
And if there's not one there already, the laser would probably sort that out.
Giant lasers, is there any problem that they can't solve?

(see the design of one of my T-shirts here. I bet a giant laser can help with that.)

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 6:23 pm
by Grumble
monkey wrote:
Fri Jul 23, 2021 2:06 pm
Grumble wrote:
Fri Jul 23, 2021 1:55 pm
Presumably you could even fire it through a hole in a tower.
And if there's not one there already, the laser would probably sort that out.
On a serious point you must have to position them away from air routes.

Re: Lasers and lightning

Posted: Fri Jul 23, 2021 8:47 pm
by dyqik
Grumble wrote:
Fri Jul 23, 2021 6:23 pm
monkey wrote:
Fri Jul 23, 2021 2:06 pm
Grumble wrote:
Fri Jul 23, 2021 1:55 pm
Presumably you could even fire it through a hole in a tower.
And if there's not one there already, the laser would probably sort that out.
On a serious point you must have to position them away from air routes.
One of the use cases mentioned was for protecting airports. I think the idea is that the lasers can make lightning rods effective over a much wider area than otherwise for the same height of rod.

With the laser guide stars the people up the hill use for adaptive optics for optical astronomy, there's a direct channel from air traffic control to the telescope operators to allow the guide stars to be cut if a plane wanders into the area.