In the frame of a space station two navigation buoys are at rest on the axis
PHYSICS · Multi-part · Fermi University Physics · Relativity & Gravitation · Special relativity: spacetime and kinematics · Special relativity: spacetime and kinematics
Relativity and Gravitation, Ch Minkowski spacetime, four-vectors and causal structure
Problem
In the frame S of a space station two navigation buoys are at rest on the x axis. Event A: at t=0 the buoy at x=3.00×108 m transmits a pulse. Event B: at t=1.50 s the buoy at x=9.00×108 m transmits a pulse. All coordinates and times are those of S; the buoys and the station are at rest in S, and everything happens in vacuum with gravity ignored. At the same time a cargo hauler is moving inertially directly away from the station along +x at 0.600c. Its beacon emits light of frequency 450 THz as measured in the hauler's own rest frame.
((a)) Predict, and then decide by calculating Δs2 (in m2), whether the pulse transmitted at A could have triggered the transmission at B.
((b)) Calculate the beacon frequency received by the station.