It could be correlated to something very symbolic, but I'm hesitant to just say what it is. When I figured it out, it was an amazing, revelatory moment, and I just wouldn't want to rob anyone of that. 

 There are lots of probable reasons, including that it is approximately as big as it can be for a double integer while limiting the risk of rounding errors.  

 Oh yeah, that sounds familiar... Both can be true! I want muh participation trophy, lol