As we watch, a spaceship passes us in time $\Delta$t.The crew of the spaceship measures the passage time and finds it to be $\Delta$t'.Which of the following statements is true?
A)"$\Delta$t is the proper time for the passage and it is smaller than $\Delta$t'"
B)"$\Delta$t is the proper time for the passage and it is greater than $\Delta$t'"
C)"$\Delta$t' is the proper time for the passage and it is smaller than $\Delta$t"
D)"$\Delta$t' is the proper time for the passage and it is greater than $\Delta$t"
E)"None of the above statements are true."

Question

Quizplus · Accepted Answer

The proper time is the time measured in the rest frame of the event, which in this case is the spaceship. Therefore, $\Delta t'$ is the proper time and it is smaller than $\Delta t$ due to time dilation in special relativity.

As We Watch, a Spaceship Passes Us in Time Δ\DeltaΔ TThe Crew of the Spaceship Measures the Passage Time and T.The

As We Watch, a Spaceship Passes Us in Time $\Delta$ TThe Crew of the Spaceship Measures the Passage Time and T.The