Comment by ben_w

14 days ago

> I wonder if that principle applies here or not

It applies, but also in practice the maximum temperature is lower than the theoretical upper bound.

https://what-if.xkcd.com/145/

I'm confident that the physics is correct, but I hate when things are translated for the lay public:

> "In general, there's no way to "overlay" light beams on each other, because the whole system has to be reversible".

Behold, my two torches.

Oh funny, my intuition when I was writing that was “there’s probably an xkcd what if about this”, but I imagined it be about surrounding the sun with mirrors. Same idea though in the end