When this star exploded the universe was only 10% the size that it is now.
How did the earth get to where it’s at now 13 billion years before this Gamma radiation arrived?
When that star exploded, the earth did no exist. The solar system did not exist. The parent star that exploded that eventually gave us the debris that became our sun probably didn’t exist as probably it’s parent star didn’t yet exist, either. 13 billion years it took the gamma ray burst, traveling at the speed of light (which is very slow for such a big universe) to reach the spot where one day a planet full of life would observe it............