What is the boundary around a black hole beyond which nothing can escape?

What is the boundary around a black hole beyond which nothing can escape?

• A. Singularity
• B. Event Horizon
• C. Accretion Disk
• D. Pulsar

Answer: (B)

The main idea here is the boundary that defines the point beyond which nothing can escape a black hole. This boundary is called the event horizon. It’s not a solid surface, but a limit in spacetime where the escape velocity equals the speed of light. Once something crosses this boundary, even light cannot get back out, so information from inside can’t reach the outside universe. Inside the horizon, all possible paths lead inward toward the center, toward the singularity. The other terms refer to different features: the singularity is the infinitely dense point at the center, the accretion disk is the rotating disk of gas that often surrounds the black hole outside the horizon, and a pulsar is a rapidly spinning neutron star, not a black hole. The event horizon is the boundary that matters for what can leave the black hole.

The main idea here is the boundary that defines the point beyond which nothing can escape a black hole. This boundary is called the event horizon. It’s not a solid surface, but a limit in spacetime where the escape velocity equals the speed of light. Once something crosses this boundary, even light cannot get back out, so information from inside can’t reach the outside universe. Inside the horizon, all possible paths lead inward toward the center, toward the singularity.

The other terms refer to different features: the singularity is the infinitely dense point at the center, the accretion disk is the rotating disk of gas that often surrounds the black hole outside the horizon, and a pulsar is a rapidly spinning neutron star, not a black hole. The event horizon is the boundary that matters for what can leave the black hole.