716: Time Machine
Title text: We never see any time travelers because they all discover it’s a huge mistake. This is also why your friend at the lab suddenly looked a year older recently.
In this comic, Rob is about to discover time traveling but a future version of him comes back in time and hits him with a baseball bat before he can actually build his time machine.
A common theme in time travel fiction is going back into the past to fix some mistake or stop some tragedy before it happens. In this comic, it is implied that Rob's time traveling turned out to cause a tragedy of some kind, so in order to stop it, Future-Rob must go back in time to stop himself from time traveling in the first place. The last panel supports this by suggesting that at least once a month somebody discovers time travel, but inevitably ends up going back in time to prevent themselves from doing so.
The title text suggests that this is why we never see any time travelers since they would have stopped their own past selves from time traveling. After getting rid of their past selves they would assume their place in the timeline, hence why a friend would suddenly look older: they have aged, just in another timeline before returning to the past.
- Rob is working at a workbench. Future-Rob appears out of nowhere with a baseball bat.
- Future-Rob: Hi, Rob.
- Rob: Whoa, you're me!
- Future-Rob: You're about to have an idea for a time machine.
- Rob: I am?
- Future-Rob hits Rob over the head with the baseball bat.
- A friend approaches Future-Rob working at the workbench, with Rob nowhere to be seen. The baseball bat is stashed behind it.
- Friend: Hey, Rob. What's up?
- Future-Rob: Nothing.
- This happens somewhere roughly once a month.