As a matter of fact, fuel on the universe runs out, so it's definitely impossible for it to have run eternally, also if there were an infinite amount of time before us, our time wouldn't take place, since there is an infinite there, it never ends, so we never come to be. It's similar to Zenos paradox, only that zenos paradox was about a fixated distancy that couldnt be ran because each time there was one more half to advance (in case anybody wants to actually go and claim that it is like that, it isn't, its totally different).