- #1
edpell
- 282
- 4
What is the longest focal length practical for a lens and/or shaped mirror?
I ask because it would be good if we could put a mirror at GEO and shine sunlight at one spot on the Earth 24 hours per day for energy production. The problem is sunlight is dispersing 1% so from 36,000km it would spread to 360km. Whence the lens or shaped mirror.
I ask because it would be good if we could put a mirror at GEO and shine sunlight at one spot on the Earth 24 hours per day for energy production. The problem is sunlight is dispersing 1% so from 36,000km it would spread to 360km. Whence the lens or shaped mirror.
Last edited: