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The light of Sirius (Alpha Canis Majoris) projected by a solar furnace's hundreds of mirrors on a white sheet of paper

Optics Off-topic
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Danny Caes avatar
Danny Caes avatar
Imagine… instead of a piece of white hot metal on the focal point of the sun's light, projected by hundreds of mirrors, we could hang a sheet of white paper on te same focal point, to project the combined light of Sirius. How bright should that look? What would happen if someone's head is placed on that focal point, to look at the hundreds of mirrors, each one of those showing its own projected image of Sirius. A dazzling multi-twinkling "sea" of Sirius images!
Is this kind of optical experiment already performed? Am I the very first person on our planet to think that way?
Engaging
John Hayes avatar
John Hayes avatar
No, you are not the "very first person on our planet to think that way."  You've basically described how JWST and the Keck 10 m telescopes in Hawaii work but in those cases, precision mirrors are used to form high quality images that perfectly overlay in both space and time (temporal coherence) to form diffraction limited images.

John
Well Written Insightful Concise
Danny Caes avatar
Danny Caes avatar
John, I understand what you describe, but what I want to know is how the hundreds of (naked eye observed) images of Sirius are seen at the focal point of the solar furnace. I can imagine that, because of turbulence in Earth's atmosphere, no one of these reflected points of light look exactly the same (the visual effect of the continuous scintillation: the twinkling star effect). It must be great so see hundreds of pointlike twinkling Sirius images scattered all over the hundreds of mirrors! I don't know if these solar furnaces (hundreds of mirrors around a central tower) are still used to investigate the combined heat coming from the sun.

What would happen if the light of the Full Moon was reflected by these hundreds of mirrors, and projected on a sheet of white paper? What would be the "LUX" of such a multi-projected "moonbeam"? (not as bright as the sun, but... bright enough to read a book at night, I guess).
John Hayes avatar
John Hayes avatar
Solar power stations are common around the southwest.  There are three very large stations south of Las Vegas and another to the NW in a pretty isolated area, but those are just the one's that I regularly fly over.  They use a large array of tracking mirrors to reflect light onto a tower to heat water to drive steam turbines.

The radiometry of this king of system is straightforward to calculate so that's where you might start.

John