Physics Ch. 15 Study Guide

The path of light in a vertical "light clock" in a high-speed spaceship is seen to be longer when viewed from a stationary frame of reference. Why, then, does the light not appear to be moving faster?

It takes correspondingly more time.

What is the first postulate of special relativity?

The laws of nature are the same in all uniformly moving frames of reference.

Does light travel through space?

Yes

Is it possible for a person with a 70-year lifespan to travel farther than light travels in 70 years? Explain.

Yes, a person moving at speeds close to c lives longer.

Can you travel while remaining in one place in space? Explain.

Yes, while at rest, you are traveling only through time

What is time dilation?

The stretching of time due to motion in space

What is the second postulate of special relativity?

c is always the same whether the source, the observer, or both move.

What is the ratio of distance to time for light waves?

the speed of light

What are the present-day obstacles to interstellar space travel?

Fuel energy and radiation

Does light travel through space and time?

No

Does light travel through time?

No

If you were traveling in a high-speed rocket ship, would clocks on board appear to you to be running slow? Defend your answer.

No. In your frame of reference, there is no time dilation. Relative speed of you and clocks is zero.

If we view a passing spaceship and see that the inhabitants' time is running slow, how do they see our time running?

Slow also; each sees the same effect in the other.

What is space-time?

Space and time are two parts of one whole.