Use Equation 33.6 to calculate the square of the spacetime interval between the events (a) of Problem 39 and (b) of Problem 40. Comment on the signs of your answers in relation to the possibility of a causal relationship between the events.

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Data From Problem 39 & 40

Repeat Problem 39, now assuming that civilization B lags A by 1.2 million years in the galaxy?s reference frame.

Data From Problem 39

You?re writing a galactic history involving two civilizations that evolve on opposite sides of a 1.0x10⁵ -ly-diameter galaxy. In the galaxy?s reference frame, civilization B launched its first spacecraft 45,000 years after civilization A. You and your readers, from a more advanced civilization, are traveling through the galaxy at 0.99c on a line from A to B. Which civilization do you record as having first achieved interstellar travel, and how much in advance of the other?

Transcribed Image Text:

(As)² = c²(At)² – [(Ax)² + (Ay)² + (Az)°] (33.6)