26. What is dark matter?
a) Matter that emits no light or other electromagnetic radiation
b) Matter that is not visible due to being obscured by clouds of gas and dust
c) Matter that has been artificially created by humans
d) Matter that is made up of anti-particles
27. What is a black hole?
a) A celestial body that emits no light or other electromagnetic radiation
b) A celestial body that has collapsed to a point of infinite density, creating a region of spacetime with gravity so strong that nothing, not even light, can escape
c) A celestial body that emits only radio waves
d) A celestial body that is so large it warps spacetime
28. What is a supernova?
a) A star that has exploded
b) A planet that has collided with another planet
c) A black hole that emits large amounts of radiation
d) A galaxy that is on a collision course with another galaxy
29. What is the Big Bang Theory?
a) The theory that the universe was created in a massive explosion about 13.8 billion years ago
b) The theory that the universe has always existed and will always exist
c) The theory that the universe is constantly expanding and contracting
d) The theory that the universe is composed of an infinite number of parallel universes
30. What is a quasar?
a) A star that emits large amounts of radiation
b) A galaxy that emits large amounts of radiation
c) A black hole that emits large amounts of radiation
d) A planet that emits large amounts of radiation
