Fireworks go off at the same time according to Earth clocks in two cities, Alum and Boron, that are 300 km apart. The people in a spaceship that is flying in a straight line from Alum to Boron at 0.80c also observe the fireworks. Do they see the fireworks in the two cities simultaneously? If the people in the spaceship say the fireworks were not simultaneous in Alum and Boron, how long before or after the fireworks flashed at Alum did the fireworks flash at Boron according to their calculations? (The spaceship is directly over Alum when the fireworks flash.)
A)Yes; 0
B)Before; 1.0 × 10−3 s
C)After; 1.0 × 10−3 s
D)Before; 1.3 × 10−3 s
E)After; 1.3 × 10−3 s

Question

Quizplus · Accepted Answer

Due to the relativistic effect of simultaneity, observers in the spaceship will not see the events as simultaneous. The time difference can be calculated using the formula for time dilation and the Lorentz transformation, resulting in the fireworks at Boron appearing before those at Alum by 1.3 × 10−3 s.

Fireworks Go Off at the Same Time According to Earth