Final answer:
The correct answer to the effects of traveling near the speed of light is 'All of the above,' which includes time dilation, length contraction, and increased mass. These relativistic effects result in different observations for moving and stationary observers, as demonstrated by changes in clock rates, lengths, and mass.
Step-by-step explanation:
When considering the effects that occur as a result of traveling through the galaxy near the speed of light, the correct answer is: d) All of the above. This encompasses time dilation, length contraction, and increased mass.
Specifically, time dilation implies that a moving clock, when observed from a stationary frame of reference, will seem to tick slower. Length contraction indicates that an object in motion will appear shorter along the direction of motion to a stationary observer. Increased mass means that as an object's velocity approaches the speed of light, its mass appears to increase, making it require more energy to accelerate further.
So, for an astronaut moving at a significant fraction of the speed of light relative to the Earth:
- (a) He does not observe his own clock rate to have slowed because that is his proper time, which is always constant for him.
- (b) He sees Earth-bound clocks ticking slower.
- (c) He does not observe his ship to have shortened, but Earth-bound observers would notice the length contraction.
- (d) The distance between stars lying parallel to his direction of motion would appear contracted to him.
- (e) He and an Earth-bound observer may agree on the relative velocity in numerical terms, but their observations of time and space will differ due to relativistic effects.