Superman used to time travel. He still does now but apparently needs Flash's treadmill to fine tune it.
My questions are regarding the 'physics' of his time travel. Was it a random power back then or was it the relativity thing where faster then light travel somehow makes one a time traveller. Was it explained? Speed may explain moving forward in time. But how on earth can one go back in time by speed? Perception of time slows down for the faster then light time traveller. So the only possible diirection is forward.
Next question is about the effects of time travel. I think it applies to the whole DC universe as well. Was it even explained how time travel is strange in that by doing so you essentially change something which shouldn't have happened.
And are there any fun stories with Superman's time travel? The obvious answers must be LoSH.
And finally do you want Superman's time travelling powers used more often? I find it quite incredible that you don't even need a time machine when you are Superman. Not only space but even time can be one's playground.