Can you put out a fuse (fire) with a laser?

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Discussion Overview

The discussion explores the feasibility of using lasers to extinguish a fuse or stop combustion, including the potential application of laser cooling in explosive scenarios. Participants examine theoretical principles and practical limitations associated with these concepts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that a sufficiently powerful laser could melt a fusible link, suggesting a potential method for extinguishing a fuse.
  • Others argue that lasers add energy to a system, making it unlikely they could stop combustion or halt an explosion, and may instead accelerate the process.
  • A participant notes that laser cooling is effective only at temperatures close to absolute zero and not applicable to room temperature or hot combustion gases.
  • One participant suggests that, in principle, it might be possible to stop combustion by using laser light to push oxygen away from the burning material, although this would require an expensive laser system.
  • Another participant questions the scale of fire being considered and emphasizes the need for sufficient energy in a laser pulse to disrupt combustion effectively.
  • It is clarified that 'laser cooling' refers to a quantum effect distinct from the combustion context being discussed.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of lasers in extinguishing fires or stopping combustion, with no consensus reached on the feasibility or practicality of the proposed methods.

Contextual Notes

Limitations include the dependence on the power and energy of the laser, the specific conditions of the combustion process, and the distinction between laser cooling and combustion dynamics.

J3J33J333
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TL;DR
I was wondering you if you could use a laser to put out a fuse or to stop combustion?
I was wondering you if you could use a laser to put out a fuse or to stop combustion? Could you use some form of laser/laser cooling to put out an explosion mid-explosion?
 
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Under what principle?
 
J3J33J333 said:
I was wondering you if you could use a laser to put out a fuse or to stop combustion?
Any laser with sufficient power could melt a fusible link. Lasers are used to cut thick sheets of steel.
https://en.wikipedia.org/wiki/Laser_cutting

J3J33J333 said:
Could you use some form of laser/laser cooling to put out an explosion mid-explosion?
A laser adds energy to the system, so it is unlikely to be able to stop combustion or halt an explosion. It would probably only increase the rate of the process.

Lasers can only cool things like single atoms that are held in a trap, at temperatures close to absolute zero. The laser can stimulate removal of the last quantum of energy from the trapped atom.
https://en.wikipedia.org/wiki/Laser_cooling
 
Baluncore said:
Any laser with sufficient power could melt a fusible link.
I thought he meant the kind of fuse on dynamite. A rapid oxidation reaction.
 
In principle? Yes.

But just shining any old laser at a fuse will do absolutely nothing.

J3J33J333 said:
Summary: I was wondering you if you could use a laser to put out a fuse or to stop combustion?

Could you use some form of laser/laser cooling to put out an explosion mid-explosion?
I wish. Laser cooling will not work on room temperature gases, much less hot combustion gases. Our "explosions" that get studied in atomic physics experiments occur at or below a thousandth or even a millionth of a degree kelvin above absolute zero.

I say it is possible in principle to stop combustion because radiative forces on molecules has been demonstrated (several times, like this example). You could use laser light to push the oxygen away from the burning fuse. It would just be a very, very expensive laser system.
 
J3J33J333 said:
Could you use some form of laser/laser cooling to put out an explosion mid-explosion?
You seem to be thinking along the lines of blowing out oil well fires with dynamite. I'd have to ask what scale of fire are you actually considering and what power of laser could be involved. Any laser pulse would need sufficient Energy to cause an 'explosion' to blast away enough oxygen from the fire to stop it burning and allow it all to cool down before it could re-ignite (fire triangle). So it's not just the Peak Power of the laser that counts (which could easily be GW) but the total Energy in a shortish interval. We could be talking in terms of a military weapon which could vaporise parts of an incoming missile.

As has been pointed out already, 'Laser cooling' is an entirely different (quantum) effect.
 

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