Gactimus wrote in message ...
How many people can the earth support?

Assume exponential growth.
If you assume all humans stay on earth and imagine that there is a
'super science' of progress
solving all social, political, economic and logistics problems. Then
in an article in:

"Population, Evolution, and Birth Control, A Collage of Controversial
Ideas, Ed. Garret Hardin; W.H. Freeman, 1964, ISBN 0716706709, (381p).
"

(I don't have my copy at hand.)

I believe the upper limit is roughly 20 people per square meter! Or
about 2E15 people! The reason for this limit is that the earth would
consist of a single metal sphere and which would start
to melt due to the inability of the sphere to radiate all combined
body heat (by black body radiation) of that many people. This happens
around the year 9000 or so?
I can't remember who wrote this article.

Issac Asimov has an essay somewhere about population exponential
growth , but he lets humans expand into space , limit there seems to
about the year 13,000 (I think?) when human expansion by space ship
fleet would be a sphere expanding at the speed of light.