Earth-50, or more accurately, Universe-50, is the universe in which several series take place.
Below is a list of timelines in this Earth. Not all events are listed, only some of the ones deemed notable.
For clarity's sake, the REF tags below are used to reference episodes in which something is being retconned in these timelines.
Timelines 1 - 5
Timelines 6 - 10
Timelines 21 - 25
Timelines 56 - 60