If we sent a radio message toward the star nearest to the Sun,and intelligent beings from a planet near the star sent back a reply immediately on receipt of the message,how long after our transmission would we have to wait for a reply?
A) 8.6 years
B) 1 light-year
C) 1 year
D) 20,000 years

Question

Quizplus · Accepted Answer

The nearest star to the Sun is Proxima Centauri, which is 4.22 light-years away from us. This means that it would take 4.22 years for our radio message to reach the star. And if the intelligent beings respond immediately upon receiving the message, it would take another 4.22 years for their reply to reach us. Therefore, we would have to wait a total of 8.6 years for a reply.

If We Sent a Radio Message Toward the Star Nearest