Olbers' Paradox is an observation regarding the
darkness of the night sky, specifically,
that stars in every possible direction, as could be imagined
in a universe that is infinitely large with an infinite
number of randomly-distributed stars,
would not show as a dark sky: it would all be bright.
The "paradox" was named
for Heinrich Wilhelm Olbers, an early writer on the conception.
The fact that the sky is dark is taken as evidence that
the universe does not extend homogeneously in all directions.