GPS satellites must correct for relativity because:

  1. they move faster than light
  2. they have no clocks
  3. their clocks run at a different rate from clocks on Earth
  4. light doesn't reach them
Answer

C) their clocks run at a different rate from clocks on Earth

Otherwise positions drift by kilometres per day. SLO P-11-F-03 · Understanding

Physics MCQ · More Special Relativity MCQs · Practise