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).
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.
nope......
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 black plague does still exist today, however it is a really rare disease
Nope you may see hair that look really dark or black but it is actually very dark red hair
of course they do and there no different to white people
Black lions do not exist. Black leopards and black jaguars, however, do exist.
Racism-Exist-For-Black only i tryed how it goes a entry of exist.
No. He's a big black dog that isn't named Clifford.
Not much is really known about white holes... including the question whether they exist, or even can exist. The term "white" hole has simply been used in comparison with a "black hole", which is in some ways the opposite.
Yes, black widow spiders exist and they tend to be black in color (hence their name).
Bald eagles are endangered, but they really exist.