Author Question: Explain why relativity allows us to travel, in principle, to the center of the Milky Way, but we ... (Read 52 times)

saliriagwu · **on:** Jul 27, 2018

Explain why relativity allows us to travel, in principle, to the center of the Milky Way, but we would never be able to tell our friends back home about it.

What will be an ideal response?

Question 2

Species are groups of organisms

A) with a common ancestor
B) that are genetically distinct
C) that look similar
D) that are capable of interbreeding with one another

ryhom · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

If we could build a very fast spacecraft that traveled within a tenth of a percent of the speed of light, then time dilation and length contraction allow us to travel the 28,000 light-years to the center of the Milky Way in what would seem like just a few years to us. However, back home on Earth, the trip would take about 28,000 years to go and another 28,000 years to come back: none of your friends would be around to listen to your tales of adventure when you returned. Note that even if you sent a radio message while you were at the center of the Galaxy, it would still take 28,000 years to arrive at Earth because the radio waves barely move faster than the spacecraft.

Answer to Question 2

B