UPSC | Prelims GS | 2026

What is the principal physical advantage of a nuclear clock over a conventional atomic clock, as described in the report?

  1. It uses transitions in an atomic nucleus, which is more shielded from environmental disturbances than electrons
  2. It measures time using gravitational waves from black holes
  3. It avoids any need for a frequency reference or feedback system
  4. It works because nuclei have no electromagnetic interactions

Answer

Correct Answer

It uses transitions in an atomic nucleus, which is more shielded from environmental disturbances than electrons

Explanation

A is correct: nuclear transitions are less exposed to electric, magnetic and thermal disturbances affecting electron-based atomic clocks. B describes neither clock principle. C is wrong because the experiments use laser-frequency checking and feedback. D is wrong because nuclei do interact electromagnetically; the relevant protection is shielding and transition physics.

Topics: nuclear clocks, precision measurement, science and technology, thorium-229 nuclear transition