|MadSci Network: Astronomy|
You are right---under ordinary circumstances, the only "objects" which collapse under their own weight are stars. Not just any stars, either: stars like our Sun do not contain enough matter to overwhelm the chemical forces pushing atoms apart. Only stars with around ten or more solar masses may collapse when they run out of nuclear fuel in their cores; and such stars are very rare.
You may read science fiction stories about mad scientists who create (very small) black holes in the laboratory. We don't have the technology to do that today, but who knows what we'll figure out a few hundred years from now?
[There are two other classes of black holes: primordial and supermassive. Primordial black holes have masses of perhaps the size of a large mountain to the size of an asteroid. If they exist, primordial black holes formed from fluctuations in the matter density in the first instants of the Universe. I stress though that these are, at this point, entirely theoretical as a primordial black hole has never been observed. Supermassive black holes, like Sgr A* at the center of the Milky Way Galaxy, have masses of millions to billions of solar masses. It is not yet clear how these form. Moderator]
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