Gravitational waves in recent observations were produced by the merger of which astronomical objects?

• A. Electromagnetic waves
• B. Merging black holes
• C. Neutrinos
• D. Dark matter halos

Answer: (B)

Gravitational waves are ripples in spacetime produced by the acceleration of massive objects, with the strongest signals coming from compact, relativistic binaries. When two black holes orbit each other, they twist spacetime and radiate energy as gravitational waves. As they lose energy, the orbit tightens and the waves grow in frequency and amplitude in a characteristic chirp, culminating in the merger and a final ringdown of the merged object. This waveform is the telltale signature that detectors like LIGO/Virgo pick up, matching the pattern expected from binary black-hole coalescences. Other options describe different messengers—electromagnetic radiation is light, neutrinos are tiny particles, and dark matter halos don’t produce the rapid, strong bursts of gravitational waves seen in these events.