Black Holes

A black hole is a region of space from which nothing, not even light can escape. Around a black hole there is an undetectable surface called an event horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.

Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work.