The boundary beyond which nothing, not even light, can escape.

The center of a black hole where all matter is concentrated.

The region outside a black hole where its gravitational influence is felt.

The point of no return from which nothing can escape the black hole's pull.

A point of infinite density and gravity.

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

The point from which the black hole was formed.

The point where all matter and energy are concentrated.

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 region outside a black hole where its gravitational influence is felt.

The radius of the point of no return from which nothing can escape the black hole's pull.

Thermal radiation emitted by black holes due to quantum effects.

Gravitational waves emitted by black holes as they rotate.

Electromagnetic radiation emitted by black holes as they accrete matter.

X-rays emitted by black holes as they interact with surrounding gas.

A mechanism by which energy can be extracted from a rotating black hole.

A mechanism by which matter can be ejected from a black hole.

A mechanism by which black holes can merge with each other.

A mechanism by which black holes can evaporate.

The region outside the event horizon where matter and energy can still escape.

The region inside the event horizon where matter and energy cannot escape.

The region around a black hole where spacetime is distorted.

The region around a black hole where gravitational waves are emitted.

A theorem that states that black holes have no hair, meaning they are completely characterized by their mass, angular momentum, and charge.

A theorem that states that black holes have hair, meaning they can have additional properties beyond their mass, angular momentum, and charge.

A theorem that states that black holes can only exist in certain types of spacetime.

A theorem that states that black holes cannot exist in the universe.

A hypothesis that states that singularities in spacetime are always hidden behind an event horizon.

A hypothesis that states that singularities in spacetime can never be observed directly.

A hypothesis that states that black holes cannot exist in the universe.

A hypothesis that states that black holes can only exist in certain types of spacetime.

A hypothetical object that is formed by the merger of two neutron stars.

A hypothetical object that is formed by the merger of a neutron star and a black hole.

A hypothetical object that is formed by the merger of two black holes.

A hypothetical object that is formed by the collapse of a massive star.

An effect that causes black holes to emit gravitational waves.

An effect that causes black holes to emit electromagnetic radiation.

An effect that causes black holes to emit Hawking radiation.

An effect that causes black holes to emit X-rays.

A process by which energy can be extracted from a rotating black hole.

A process by which matter can be ejected from a black hole.

A process by which black holes can merge with each other.

A process by which black holes can evaporate.

A black hole that is rotating.

A black hole that is not rotating.

A black hole that has a singularity at its center.

A black hole that does not have a singularity at its center.

A black hole that is not rotating.

A black hole that is rotating.

A black hole that has a singularity at its center.

A black hole that does not have a singularity at its center.

A black hole that has both mass and charge.

A black hole that has mass but no charge.

A black hole that has charge but no mass.

A black hole that has neither mass nor charge.

A black hole that has both mass, charge, and rotation.

A black hole that has mass and charge but no rotation.

A black hole that has mass and rotation but no charge.

A black hole that has charge and rotation but no mass.