If a person 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 the transmission would this person have to wait for a reply?
A) 8.4 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 approximately 4.2 light-years away. A radio message would take 4.2 years to reach it, and the reply would also take 4.2 years to return, totaling 8.4 years.

If a Person Sent a Radio Message Toward the Star