Black Holes

2. an almost perfect vacuum, nearly void of matter and with extremely low pressure
3. any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources
7. what happens when a star has reached the end of its life and explodes in a brilliant burst of light
12. the boundary where the velocity needed to escape exceeds the speed of light (black hole's surface)
14. a disklike flow of gas, plasma, dust, or particles around any astronomical object
15. the distance between the center of a Schwarzschild black hole and its event horizon

1. born when extremely massive stars collapse and typically weigh between five and 10 times the mass of the Sun
4. the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun
5. the force by which a planet or other body draws objects toward its center
6. electromagnetic radiation which, according to theory, should be emitted by a black hole
8. the theoretical stretching of an object as it encounters extreme differences in gravitational forces
9. a region of space having a gravitational field so intense that no matter or radiation can escape
10. includes all of space, and all the matter and energy that space contains
11. a place where matter is compressed down to an infinitely tiny point, and all conceptions of time and space completely break down
13. the measure of the amount of matter in a body