Shapiro delay measures general relativistic time dilation of signals passing near massive bodies.
- True - confirmed by Cassini/radar ranging
- False - Newtonian effect
- True - only for light not radio
- False - disproven by LIGO
Answer: True - confirmed by Cassini/radar ranging
Signals traversing curved spacetime experience extra delay proportional to gravitational potential; Cassini solar conjunction test verified GR to 10⁻⁵ precision.