Headscratchers / Justice League S 2 E 19 And 20 Hereafter

• Vandal Savage's explanation of why he couldn't travel back in time to fix his own mistakes felt half-done. Okay, he can't travel back to anytime that he exists in, and he's existed since the Stone Age. But there was some point in pre-history when the caveman who would become Vandal Savage hadn't been born yet. What's stopping him from traveling back then, and taking The Slow Path back to the modern day? Depending on the way causality works in the DCAU, he can either stop his young self from becoming immortal, or let it happen and give his younger self strict warnings about causing apocalypses. Heck, he can even take over the primitive world if he hasn't outgrown that obsession.
  • While he certainly could do that, I figure he just pegged it as not a fruitful plan since, after 25,000 years living through the same events all over again, he'd be too insane to really be able to stop Vandal Savage in the present. Of course, he could go back and kill himself (Or just prevent himself from becoming immortal), since he'd only need to live through something like twenty years to get to that point, and I can't think of why he wouldn't try that.
  • Initial troper here. Just realized that Savage could have reused the plan than that he almost won WWII with. He just has to send a message back to Savage about not playing with the force of gravity. I love that episode to bits, but I can't get the Fridge Logic out of my head.
    • Its possible he tried that and Past-Savage didn't listen to the message, or decided to go ahead with the experiment while taking "precautions", modifying his experiments with safety measures that of course failed.
  • In the comics DCU, it's impossible to intersect your own light-cone. Vandal Savage was physically unable to travel back to his own past and interact with his younger self, slow path or no.
• There was something else about Hereafter that always bothered me. So Vandal Savage creates a machine that gives him control over gravity. Sure. He uses this machine to kill the Justice League and "disrupts the gravitational balance of the entire solar system". Okay, so that's why we can see what looks like Saturn in the sky that big. Did these gravitational disruptions also somehow age the Sun the several billion years necessary for it to enter the red giant stage? I mean I get that a powerless Superman creates more drama and tension to the story but... what?
  • Actually, yes, since the stage a star is in is directly related to its mass; changing the gravity (Perhaps removing much of a stars mass) will certainly alter its state.
  • More precisely, the physical configuation of a star is driven by a balance between radiation pressure pushing outward and gravity pulling inward. If something altered the force of gravity, this equilibrium would shift.
• Why did they not reveal Superman's secret identity since it would seem pointless to keep it (as far as they know)?
  • Why would they? All it would result in is a media blitz of Ma and Pa Kent, and/or supervillains targeting them directly.
  • Does the public think that Superman has a secret identity to begin with?