Probably the fact that they can't be seen, in any wavelength, and that their properties can be inferred
only by observation of their effects on their surroundings.
Probably the fact that they can't be seen, in any wavelength, and that their properties can be inferredonly by observation of their effects on their surroundings.
The biggest obstacle for proof of existence of black holes has always been our inability to observe them directly, due to their nature of absorbing light and never emitting it (since the escape velocity of a black hole exceeds the speed of light). However, there is abundant evidence of their existence. For example, studies of the orbits of stars near the supermassive black hole at the Milky Way's core have shown that no object other than a black hole could explain their path - otherwise, the stars in orbit would hit the object (i.e., it is so small and so massive, that there is no other possible explanation).
He was desciminated because he was black.
Black History
A black hole? well scientist are not sure. Black holes is a theory, not proving to be true. But there could be.
By natural selection. (Some natural obstacle prevent the other rhinceros to mix with the black.)
Emily gibb is the biggest black eyed peas fan in the world
The biggest asiatic black bear living in china weighed 720 pounds.
the biggest thing in the universe that isn’t A galaxy is a black hole
Black Friday
it is in the "black river"
black