We plan a trip to the nearest star, Proxima Centauri, which is 4.2 ly (light years) away (in the reference frame of the earth). We travel on a spaceship at a speed of 0.866 c. While at Proxima Centauri, we spend one year exploring its planetary system before returning to earth.(a) How long does the entire round trip take according to our clocks? Assume that while at Proxima Centauri our velocity relative to earth is negligibly small.years (± 0.2 years)(b) How long does the entire round trip tak