You are working in an observatory meant to look for anomalous astronomical events. One day, you record an event that takes place 65 billion kilometers away from the Earth. Exactly one day later, you record another event that takes place 40 billion kilometers away. In the following problem, assume that these two events took place at approximately the same orientation in the sky, such that you only have to work in 1 + 1 dimensions.
a) Is it possible that the first event could have caused the second? Why or why not?