Levin states that gravitational waves squeeze and stretch which part of reality?

• A. The fabric of space
• B. The Earth's atmosphere
• C. The ocean of space
• D. The Sun's magnetic field

Answer: (A)

Gravitational waves are disturbances in the geometry of spacetime itself. As a wave passes, it alternately stretches space in one direction and contracts it in the perpendicular direction, so distances between freely falling objects change briefly. This is why Levin says they squeeze and stretch the fabric of space—the “fabric” is spacetime, not a physical medium like air, water, or a magnetic field. The atmosphere, oceans, or solar magnetic fields aren’t the thing being distorted; any direct interaction with matter is extremely tiny, because gravitational waves interact very weakly with ordinary matter. The observable effect is the changing distances that detectors measure, reflecting this wave-driven distortion of spacetime itself.