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.
Black River Brookie
Black and Tan Coonhound
Charles Darwin may be dead and gone but a recent write-in campaign has pitted him against Republican
Ben Jones, Black Face and Arm Unit.
A black impact socket. Always use an impact-type socket whenever using an impact wrench to avoid ...
The synapse and synaptic transmission. (a) A thin cleft, called the synapse, separates one cell from