We think of time as a sequence of events that happen in one universe. But there are different ways to look at time. And that leaves room for other interpretations. Like the idea that time is travel through universes.
Let me explain.
Physicists describe time as an increase in entropy, or disorder. Your kitchen gets messy over time if you don’t clean it. But it won’t get clean. Disorder runs in one direction. That is the forward direction of time.
Neuroscientists describe time in terms of brain function. The brain’s perception of time enables complex language. For example, in this sentence words follow others with brief pauses between. The sequence and pauses convey meaning. Without them, you get a bag of words and spaces. So perception of time may be essential for complex language. Creatures with complex language may therefore also always have a concept of time. (This includes birds, by the way.)
But I had a thought about time inspired by reading books on multiverse theories and the many-worlds interpretation of quantum physics. (I know, I know. Armchair physicist warning.) What if instead of time as a sequence of events, we think of it as a travel through universes?
If there are infinite universes, then there is (at least) one exactly like the one you’re in now. And the one you’re in now. And the one you’re in now. Did you just travel through three sentences in one universe? Or did you travel through three universes, in each having read an additional sentence?
I’m not sure you could ever prove which were true. They would be physically indistinguishable. And if two things are physically indistinguishable we can think of them as the same.
This doesn’t mean that the multiverse and many-worlds interpretation are true. It doesn’t mean there are infinite universes. But if there are, then I struggle to see how traveling through time or traveling through equivalent different universes are physically distinguishable.
Granted, I’m not a physicist and I really need (and want) to improve my math skills. But I wonder if we’ll see new perspectives on the nature of time influenced by multiverse theories and the many-worlds interpretation.