[Answer] What is a black hole?

Step 1 : Introduction to the question " What is a black hole? "

...

A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.

The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe directly.

Albert Einstein first predicted the existence of black holes in 1916, with his general theory of relativity. The term "black hole" was coined many years later in 1967 by American astronomer John Wheeler. After decades of black holes being known only as theoretical objects, the first physical black hole ever discovered was spotted in 1971.

More Info: www.nasa.gov

Step 2 : Answer to the question " What is a black hole? "

A planet:

Please let us know as comment, if the answer is not correct!

Step 3 : Disclaimer & Terms of Use regarding the question " What is a black hole? "

Our machine learning tool trying its best to find the relevant answer to your question. Now its your turn, "The more we share The more we have". Share our work with whom you care, along with your comment ...Kindly check our comments section, Sometimes our tool may wrong but not our users.

Are We Wrong To Think We're Right? Then Give Right Answer Below As Comment