Is a black hole the strongest thing in the world?

Answer 1

When people speak about "strong" usually they refer to tensile strength, the ability to resist compression, torsion, shearing force, etc. These particular forces don't really apply to black holes since they are in one sense mostly a "region in space". In the black hole's center the matter is concentrated, and believed to occupy zero volume and be of infinite density; as such, in the practical realm, it would be impossible to exert a distorting force upon it, since there would be no linear direction in which to measure any distortion. Even in theory, the nature of this matter is not fully described by our current physics and hence the idea of tensile strength would probably still not apply. Certainly in the metaphorical sense the gravitational force of a black hole is unparalleled - strong enough to distort and rip apart even the strongest known materials; in addition, anything with mass could be crushed by this gravity into the singularity. Lastly, one point of note is that "in the world" might be a confusing phrase - the nearest enduring black hole is of stellar mass and thought to be thousands of light years from Earth, hence isn't really in the world. One possible exception is that microscopic black holes may be created when the highest energy cosmic rays collide with particles in our upper atmosphere, although this kind is thought to have a very brief life-span.