Answer to Question 1
The escape velocity of a celestial object is the speed that an object on its surface needs to escape the gravitational field. A black hole is so dense that the escape velocity is greater than the speed of light, so light cannot escape the black hole; hence, the term black.
Answer to Question 2
It became known as the Copernican Revolution because it was not just the adoption of a new idea but a total change in the way astronomers, and, in fact, all of humanity, thought about Earth and its place in the Universe. In fact, our modern use of the words revolution and revolutionary to describe philosophical, political, and social upheavals comes from the title of Copernicus's book, De Revolutionibus, which means On Revolutions.
Zebras are several species of African equids (horse family) united by their distinctive black and wh
Black Knapweed
Bergmann’s and Allen’s rules expressed in two rabbit species. (a) A snowshoe hare. (b) A desert-livi
Clay Lohmann, Black Lung.
Black and white patients enrolled in Medicare do not receive the same medical treatment, even when ...
Children with disabilities used to be sent to special schools. In a process called mainstreaming or ...