Please reopen this question per the discussion we had in the comments. What is the maximum possible temperature of a 1mx1mx1m cube that is the focal point of an array of mirror reflected, concentrated beams of sunlight?
Also, a link says it has been asked, which is untrue. The question asks what particular physics will limit what could be achieved in practice in an Alabama field (under earth’s atmosphere for one thing, without 360-deg access etc) on a specific object. It also asks how number of mirrors would scale. That would be affected by things that wouldnt affect the asymptotic limit to the radiating body, such as finding a way to differ the emissivity across the body. The linked question asks about the theoretical limits of solar furnaces approaching the temperature of the radiating body. Different question altogether
The question has the following unique twists (which are relevant because it was closed as being a duplicate):
1.Discussing the number of mirrors:
My new answer added physics but not engineering issues about this (nothing about materials or how to achieve it, but the concept of differential emissivity for example). From a physics standpoint will be the exponential increase in mirrors needed per Kelvin increase. I was about to add this to an answer. People have mentioned in related questions that the temp of sun is a limit, but this is an asymptotic limit.
- Asking about practical implications in an Alabama field:
Engineering questions aside, what hard limits might there be in the physics of doing this on earth (other than the second law limiting it to the temperature of the sun which has been discussed). For example, is there a limit imposed by losses through the atmosphere? If we assume constant atmospheric absorption, what does that do? What the atmosphere changes frequency profile?