Time
2024-12-08 to 11
We move through the three space dimensions. SR shows that our motion affects how we perceive motion and time.
We measure our own motion within our frame of reference. In fact, measuring motion defines a frame of reference. We ride in a car sitting still. But the car moves at 100 kph along the highway, so we are moving at 100kph along the highway, too. And the Earth spins, and orbits the sun, and the solar system moves within the local star cluster, which moves within the spiral arm that orbits the Galaxy. The Galaxy spins, and moves towards Andromeda. And so on.
Within us, the blood moves, air moves, muscles expand and contract, molecules move about and react with each other. Within larger molecules, groups of atoms move this way and that as the molecule changes shape. The atoms themselves move, and within the atom, the electrons and nucleus move. In fact, they move so much that the best we can do to specify their motion is to describe it as a cloud of possibilities, using a wave function that’s said to collapse when we measure those motions.
Heisenberg says the more precisely we measure the motion of electrons etc, the less precise the measurement of their location. Or the more we know about how the electron moves, the less we know about where it is. Which interpretation of the math is correct? I don’t know. Take your pick.
Why do I emphasise motion? Because all motion “takes time.” That is, any change in a space dimension entails a change in the time dimension. This seems to me the intimate integration of space and time that Einstein formalised as General Relativity. I hope this interpretation Einstein’s insight is correct.
So the other day I was thinking about time as a dimension, for about the 777th time. It had occurred to me that if we move through space, what would it mean to say that we move through time?
We normally think of time as “passing”, and point to clocks that measure that passage one tick at a time. Where a tick is a small motion of something. In the international standard of time measurement that tick is a single cycle of the vibration of caesium:
The second [...] is defined by taking the fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s−1.[1]
That “.... one tick at a time...” is either evidence of our brain’s conceptualising limits, or else proof that time is real in the same sense that space is real. Take your pick. I mention this puzzle because recently Carlo Rovelli and other physicists have wondered whether time is real or an illusion. Maybe space is all there is, and the feeling that time passes is created by our brains. The question may have been instigated by the awareness that being aware means being aware of time passing.
We speak of “spending time”, and continue with the terrifying thought that once we’ve spent a chunk of time, we can’t (unlike with money) earn an equivalent chunk of time to replace what was spent. Heraclitus supposedly said that we never step in the same river twice, since the water has flowed on between steps. Time, he said, is like that river. There’s a hymn that includes the phrase “time, like an ever-flowing stream”, which is a cliche by now. These ways of thinking all imply that time is some kind of entity. It’s not like space. Which may be why we have trouble dealing with Einstein’s concept of spacetime.
Does thinking of time as something we move through solve these conceptual problems? Maybe. Let’s try it.
Begin by supposing that there’s more than one time dimension. We happen to be confined to a line within that space, our timeline. Specify a frame of reference and you specify a timeline. We move through time along that line whenever we move through space. And as I’ve sketched above, we are always moving with respect to some other entity. Utter repose is impossible. Even death entails motion: as our body decays, its bits and pieces move in all directions, transported by the critters that eat them or the wind and water that carries them away. The skeleton that remains moves with the Earth.
Now suppose that we could move off that timeline, in any direction, sideways, up and down, at an angle, in a circle. Just as in space we can take a shortcut, we could take a shortcut in time, and arrive at a future point on out timeline without passing through the intermediate ones. Time travel the would be moving off our timeline, moving around in time, and rejoining our timeline.
If time is multidimensional, would there be some way of writing a formal theory that could be tested? I’ll leave that up to the people who can handle the math. But the concept could work as a premise for sci-fi story. I’m sure the idea has occurred to someone else. If not, I hereby claim first invention (or discovery), and grant a non-transferable licence to anyone who wants to use it. Just give me a cut of the royalties.
© W. Kirchmeir
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