BLACK HOLE FACT SHEET
1. The concept of a “dark star” was first introduced in 1783 by John Michell
from England and Pierre-Simon Laplace from France.
2. John Archibald Wheeler coined the term “black hole” in 1967. He also coined
the term “worm hole.”
3. A “worm hole” is a black hole connected to a white hole.
4. A white hole is the reverse of a black hole. If gravity causes matter to fall into
a black hole, then matter gets spit out of a white hole.
5. A star must be three times bigger than our Sun to explode as a supernova and
then collapse as a stellar black hole.
6. The closest black hole to Earth is Cygnus X-1, safely 8,000 light years away.
7. Most spiral galaxies have Supermassive Black Holes in their centers.
8. Supermassive black holes can be millions or billions of times more massive
than our Sun.
9. The center of mass of a black hole is called a “singularity.”
10. The critical distance at which nothing can escape a black hole is called the
“event horizon.”
11. We live in a world with four dimensions: length, width, height, and time.
12. According to Einstein’s Theory of General Relativity, matter curves spacetime and the result is gravity.
13. A stellar black hole is a collapsed star that is wrapped in infinitely curved
space-time, is infinitely dense, and has infinite gravity.
14. Any object falling into a black hole would be torn to pieces by tidal forces
(the uneven pull of gravity).
15. Astronomers call the extreme tidal forces acting on an object in a black hole
the “Spaghetti Effect.”
16. From side to side, the tidal forces in a black hole would be enough to squeeze
coal into diamond.
17. From top to bottom, the tidal forces in a black hole would be enough to
stretch an object thin like a piece of atomic spaghetti.
18. Nothing can escape a black hole, but black holes release X-rays. Over time,
they shrink and will eventually disappear, or “evaporate.”
19. Time becomes so warped inside a black hole that time comes to an end.
20. Objects falling into a black hole travel faster and faster, approaching the
speed of light, which is 186,000 miles per second.
21. The escape velocity of a black hole is faster than the speed of light. Matter
cannot travel faster than the speed of light, so nothing can escape.
22. Time goes by at a slower rate for someone traveling fast compared to an
observer who is stationary (not moving).
23. The “Twins Paradox” explains the above: An Earth-bound twin would age
faster than the fast-moving rocket-bound twin.
24. The Twins Paradox has been proven using precise atomic clocks, one on a
runway and the other on an airplane in flight. (Ask your teacher.)
25. Black holes are epically awesome!
Black Hole Sizes - Data Table:
Black Hole Mass
(in solar masses)
Diameter of Black
Hole in Miles
Diameter of Black
Hole in Kilometers
Comment
3
11
18
Smallest stellar
mass black hole
10
37
60
Medium stellar
mass black hole
100
370
600
1000
3700
6000
1 million
3.7 million
6 million
Largest stellar
mass black hole
Intermediate
mass galactic
black hole
Black hole at
galactic center of
the Milky Way
1 billion
3.7 billion
6 billion
Black hole in a
quasar
The Spaghetti Effect: spaghettification