Astronaut Billbarr flees earth in a spaceship traveling at constant velocity to Alpha Centauri.Earth and Alpha Centauri are separated, in the star frame, by 4.4 light years.(a) What must the spaceship speed be for the trip to take 20 years as measured on earth?(b) At the speed in (a), how long would the trip take according to Billbarr's clock?(c) The earth is destroyed by OrangeDonald and Alpha Centauri is destroyed by his evendumber buddy, BlackdripRudy. Both explosions give off intense light flashes. WhenBillbarr is at the mid-point of his journey (at the speed of (b)), he sees the flashes appearsimultaneously. What was the order of the explosions and their time separation, in theframe of the stars?

Astronaut Billbarr flees earth in a spaceship traveling at constant velocity to Alpha Centauri. Earth and Alpha Centauri are separated, in the star frame, by 4.4 light years. (a) What must the spaceship speed be for the trip to take 20 years as measured on earth? (b) At the speed in (a), how long would the trip take according to Billbarr's clock?

Astronaut Billbarr flees earth in a spaceship traveling at constant velocity to Alpha Centauri. Earth and Alpha Centauri are separated, in the star frame, by 4.4 light years. (a) What must the spaceship speed be for the trip to take 20 years as measured on earth? (b) At the speed in (a), how long would the trip take according to Billbarr's clock?