What If You Got Stuck in a Time Loop?

Monday. Tuesday. Wednesday. Wednesday. Wednesday. Again? Wednesday. I feel like we’ve done this before. Wednesday. Does anybody else notice this? Wednesday. How do I break this time loop? Could you tell if you’ve been living the same day all over again? How many times did today really happen? And if you were trapped in a loop, how would you get out of it?

You know that feeling of deja vu, when you just know you’ve seen this happen before? Now imagine if your entire day is a big deja vu moment. And tomorrow. And then the day after tomorrow. And nobody seems to notice it but you. What would you do to break the cycle? Would it reset each time? What would happen if you die? I understand you’ve got a lot questions. But before we start, I’d like to introduce you to some mind-blowing science.

As weird science theories often do, this one starts with Albert Einstein’s theory of general relativity. Basically, the idea is that the three dimensions of space, and a dimension of time, are joined together in a continuum called space-time. Gravity can bend this space-time, which, theoretically, makes time travel possible. That is, if you have access to a big enough black hole, or to a time machine like a Tipler cylinder. We included the instructions on how to build one in another video, you might want to check it out.

Without getting into too much detail, a time machine like a Tipler cylinder could create a closed timelike curve. In this system, a particle could go back in time to where it started. We don’t understand quantum physics enough to know if these closed timelike curves could, or couldn’t exist. But for the sake of this scenario, we’ll assume they are possible, and are a result of space-time folding upon itself. What would this mean for you?

For one thing, you could travel back into yesterday and start your day all over again. In that case, reliving the same day over wouldn’t be surprising to you. You’d be in control of when to go back to the future. And if you die during one of those travels, you wouldn’t wake up in your bed the morning before. That would be the real end for you. But you wouldn’t be restricted to only going back to yesterday. You could travel back to the time when you were born. Take a hell of a trip down memory lane.

No matter how far in the past you went, you wouldn’t change it in any way. You wouldn’t create any paradoxes, like killing your yesterday’s self, or whatever else you might come up with. Ironically, what’s preventing you from creating any time paradoxes is called a Predestination Paradox. In a closed timelike curve, when you travel to the past, you’ve always been a part of that past. Your presence wouldn’t change a thing.

At the same time, if you find yourself reliving yesterday, that could mean that somebody put you in a time machine, and sent you one day back. In that case, you should just go on with your day till it’s over, and the next day you’d be living in tomorrow. If you want to geek out on time traveling, here’s some food for thought.

Maybe closed timelike curves aren’t closed at all? What if, instead, an alternate timeline would appear every time you traveled to the past? Then you’d continue living in an alternate universe, and you wouldn’t be able to go back to your original one, unless you open some kind of portal to a parallel world.