Which statement best describes Schwarzschild's contribution?

• A. He showed that mass concentrated into a small space creates a boundary
• B. He proved black holes cannot form
• C. He discovered dark energy
• D. He developed the theory of special relativity

Answer: (A)

Schwarzschild showed that Einstein’s equations admit a solution for a simple, non-rotating mass, and that when such mass is squeezed into a small enough region, spacetime develops a boundary known as the Schwarzschild radius (the event horizon). This boundary marks the point beyond which nothing can escape, not even light, which is the essence of a black hole. That idea—that mass confined to a small space creates a boundary in spacetime—is the best description of his contribution in the options.

The other statements aren’t correct descriptions of Schwarzschild’s work: he did not prove that black holes cannot form—in fact, his solution describes how they form when mass is compacted within the Schwarzschild radius. He did not discover dark energy, and he did not develop the theory of special relativity.