A region of spacetime where gravity is so strong that nothing, not even light, can escape.

A dense object with a gravitational pull so strong that it can bend light.

A collapsed star that has exhausted its nuclear fuel.

A point in spacetime where the laws of physics break down.

The radius of the event horizon of a black hole.

The radius of the singularity at the center of a black hole.

The radius of the largest orbit that can exist around a black hole.

The radius of the smallest orbit that can exist around a black hole.

A point of infinite density and gravity.

A region of spacetime where the laws of physics break down.

A point where all matter and energy are concentrated.

A point where time and space come to an end.

By the collapse of a massive star.

By the collision of two neutron stars.

By the merger of two black holes.

All of the above.

Ripples in spacetime caused by the acceleration of massive objects.

Waves of energy that travel through space at the speed of light.

Disturbances in the gravitational field of a massive object.

All of the above.

Albert Einstein.

Isaac Newton.

Stephen Hawking.

Max Planck.

2015.

2016.

2017.

2018.

The merger of two black holes.

The collision of two neutron stars.

The collapse of a massive star.

The explosion of a supernova.

It confirmed the existence of gravitational waves.

It opened up a new window on the universe.

It allowed us to study the properties of black holes.

All of the above.

To study the properties of black holes.

To study the properties of neutron stars.

To study the properties of white dwarfs.

All of the above.

Gravitational waves are very weak.

Gravitational waves are very difficult to distinguish from other types of noise.

Gravitational wave detectors are very expensive to build.

All of the above.

Developing more sensitive gravitational wave detectors.

Studying the properties of black holes in more detail.

Using gravitational waves to study the early universe.

All of the above.

Black holes are the source of gravitational waves.

Gravitational waves are produced by the motion of black holes.

Black holes can be detected by gravitational waves.

All of the above.

The boundary of a black hole beyond which nothing, not even light, can escape.

The boundary of a black hole within which nothing, not even light, can escape.

The boundary of a black hole beyond which nothing, except light, can escape.

The boundary of a black hole within which nothing, except light, can escape.

A point of infinite density and gravity.

A point of infinite density and zero gravity.

A point of zero density and infinite gravity.

A point of zero density and zero gravity.