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What if the sun was a bunch of parallel laser beams? Then you could focus them all into a single point.
by randyrand 8y ago
What if the sun was a bunch of parallel laser beams? Then you could focus them all into a single point.
- jstanley 8y agoRight, but that point would be exactly as hot as the surface that the light was coming from, and no hotter. (Is the argument as I understand it).
- jplee 8y agoIf this is true, how do laser cutters work? The focused beam can melt through steel, but surely the temperature of the gain medium is much lower than the melting point of steel? But the thermodynamics argument seems like it makes sense too...
- landryraccoon 8y agoLasers have negative temperature. The light emitted from the sun is nothing like laser light. https://en.wikipedia.org/wiki/Negative_temperature#Lasers https://en.wikipedia.org/wiki/Negative_temperature#Lasers
- whatshisface 8y agoLike the other commenter said, lasers are not black-body emitters. They "pump" light out and are very far from equilibrium.
- DuskStar 8y agoWouldn't that kind of make the National Ignition Facility [0] impossible? 0: https://en.wikipedia.org/wiki/National_Ignition_Facility https://en.wikipedia.org/wiki/National_Ignition_Facility
- jstanley 8y agoFrom what I've read in the other comments, the argument doesn't apply to lasers.
- whatshisface 8y agoLasers are kept far from equilibrium by design, unlike blackbody radiators which are in equilibrium with the electromagnetic field they are radiating in to.