What is “Time” and how exactly does it work?
In: Physics
Asking two different physicists what time is and how it works is like asking a Hindu priest and a Presbyterian minister what “God” is and how god works. Both have probably spent a lifetime studying and thinking about that very question. They have very thought-through ideas about it that many many others believe as well. They may really believe that they have the one true answer. But the truth is that no one knows for sure. That’s not a very satisfying answer, but that’s how it is.
Here are the two most popular ideas:
Imagine an ant on the floor of an elevator. The ant can move left, right, forward, backward–any direction it wants, but only on the floor. To the ant, the floor is the only thing that exists. The elevator is moving up at a constant speed, and has been moving in that direction and at that speed for the ant’s entire existence, so the movement isn’t something it feels or notices. The two main ideas say that
1. the elevator floor is rigid and flat. The rocks and loose change on the floor just sit on top of the tiles. If the ant moves 1 tile left as fast as it can, the elevator has gone the same fixed distance up as when the ant moves its fastest a tile forward, back, etc.
2. the elevator floor is spandex with tiles printed right on the fabric. The rocks and loose change on the floor stretch it out where they’re sitting. Because the tiles aren’t all the same size and shape when they’re being stretched, if the ant moves its fastest one tile left, the elevator won’t have gone the same distance up as if the ant had gone one tile right. How much the elevator has gone up while the ant moves across a single tile depends on if/how stretched that tile is.
Time is the elevator shaft.
Edit: Thanks for the award!
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