According to Levin, what did Einstein realize about gravity?

• A. It is a fundamental force transmitted by particles
• B. It has something to do with falling
• C. It bends light only
• D. It is independent of mass

Answer: (B)

Gravity, in Einstein's view, is the curvature of spacetime caused by mass and energy, and objects in free fall simply follow straight paths (geodesics) through that curved geometry. The motion toward a mass isn’t a force pulling on you in space; it’s the natural path you take when spacetime is warped by mass. That makes falling toward massive bodies the direct expression of gravity in this framework, which is why this idea best fits Einstein’s insight. The other descriptions describe aspects or remnants of the same phenomenon but don’t capture the core shift to geometry: gravity isn’t just a force carried by particles, light bending is one consequence but not the whole story, and mass-independence is a corollary of the equivalence principle rather than the central realization.