Question

A UFO (unidentified flying object) being piloted by an alien appears in the sky. It moves in a straight line with a large, constant velocity, then it vanishes. These events are witnessed by a farmer who is stationary on the ground. For the motion of the UFO, from the moment it appears until the moment it vanishes, which of the following is true?

(a). The alien and the farmer both measure the proper time and the proper distance

(b). The alien measures the proper time and the proper distance

(c). The farmer measures the proper time and the proper distance

(d). The farmer measures the proper time and the alien measures the proper distance

(e). The alien measures the proper time and the farmer measures the proper distance

Answer 1