A space age take on ancient children's story of naughty monkey - poking your nose at certain places can be harmful! Humans have found a gravitational wave generator on Mars of alien origin, abandoned for eons. At its heart is a "quantum black hole" - device vibrates it to generate gravity waves. Careless poking around has released it into the mars' interior - mars will soon be a black hole!
Fact sheet.First published: Analog, January 1974.
Note: Why is this post so short?