FAQs About Black Holes

Black holes are among the most mysterious of stellar objects. Though they are, or were, stars, black holes emit no light. Their massive size and near-invisibility has lent them a substantial mystique in popular culture and science fiction. Read on to learn answers to some common questions about black holes.

Q: Can you escape from a black hole?

A: Black holes have extraordinarily strong gravity. The escape velocity of a black hole, the speed at which one must travel to escape its gravity, is extremely high; beyond the point called the event horizon, the escape velocity exceeds the speed of light. Anything which falls past the event horizon of a black hole cannot escape.

Q: Could the sun turn into a black hole?

A: No, only stars larger than a certain size (called the Chandrasekhar limit) collapse into black holes as they age. The Sun is considerably smaller than the Chandrasekhar limit. It cannot go into supernova or turn into a black hole. As the Sun ages, it turns into a white dwarf.

Q: Are black holes gateways to another universe?

A: Physicists are still studying exactly what happens, and what exists, beyond the event horizon of a black hole. The idea that black holes could connect to hypothetical white holes as gateways is considered; however, black holes are a hotly-contested area of research within astrophysics, and no one completely understands how they work, or even what they are.

Q: Could a black hole swallow the Earth?

A: If there was a black hole nearby, it could certainly swallow the Earth. Black holes do consume stars and other stellar bodies; however, there are no black holes within many light-years of Earth, making it impossible for any black hole to swallow the Earth for millions or billions of years.