Multiple choice general knowledge science & technology

A boundary in spacetime through which matter and light can only pass inward towards the mass of the black hole and not outward is known as ___.

  1. event horizon

  2. black boundary

  3. loop horizon

  4. gravity boundary

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The event horizon is the boundary marking the point of no return around a black hole - beyond this boundary, nothing, not even light, can escape the black hole's gravitational pull. It's a one-way membrane in spacetime where all future-directed paths lead inward toward the singularity. The other options ('black boundary', 'loop horizon', 'gravity boundary') are not standard physics terminology.