Question

calculate the time (in years) it would take to send a message to the Galactic Capitol located at the center of our Milky Way galaxy and then receive the reply. We live about 2.5x10^20 meters away from the Galaxy center. Assume the message leaves the Earth and travels at the speed of light and that they take 1 year to decide what to answer..

Answer 1

Answer:

The total time is $\bf{52850~Yr}$.

Explanation:

Given:

The distance between Galactic Capitol and Earth is, $d = 2.5 \times 10^{20}~m$

The speed of light is, $c = 3 \times 10^{8}~m/s$

The time taken by the message to reach and come back to Earth is given by

$t &=& \dfrac{2d}{c}\\~~&=& \dfrac{2(2.5 \times 10^{20}~m)}{3 \times 10^{8}~m/s}\\~~&=& 1.6 \times 10^{12}~s\\~~&=& \dfrac{1.6 \times 10^{12}~s}{(86400 \times 365)~s}~Yr\\~~&\approx& 52849~Yr$

In addition they take 1 year to decide to reply.

Thus, the total time is $25850~Yr$.