Could we possibly live in a universe with more than one dimension of time?
I’ve tried to imagine what two time dimensions would feel like…
What is chemical reactions went at a different ‘rate’ then nuclear or something? (pardon my ignorance of science and try to understand the spirit of what I am thinking and compensate/substitute words for chemical/nuclear )
So, in the past chemical reactions occured at a higher/lower rate than compared to nuclear. So, in respect to one process, the other seems to be speeding up or slowing down.
Would this be an accurate representation of more than one time dimension? Could it be possible?
First off, no, your hypothetical wouldn’t be a good model for two dimensions of time. You really want to think in analogy with distance here; a second dimension of time would be sort of like moving from a line to a plane.
For this reason, I would tend to think that the answer to your question is “God, I hope not.” It would be really cool, since you’d be able to move much more freely, but I think it would play merry hell with causality and for all I know you could wind up being your own father and all sorts of deep Freudian things like that.
I’m no physicist, but isn’t it entirely possible there are actually 2 dimensions of time?
We know of 3 space dimensions, and one time, but we are always moving forward at 1 second per second in the time dimension. Suppose there were 2 dimensions of time. This would mean time is like a flat sheet, rather than a line. We would always have to move forward, but we could move side to side in the other time dimension. In this case, our path though time would be like a wiggly line on a sheet. We couldn’t visit the past, because we would be always going forward.
Of course, to us, our path though time would seem like a straight line, and thus we wouldn’t even notice that there were 2 time dimensions…
For practical purposes, if we can’t ever observe extra dimensions or do anything with them, then we really oughtn’t to talk about them as real. I mean, yes, you can envision an extra dimension of time to which we have no access and which acts for all intents and purposes as just the one dimension we’re familiar with, but then how would we ever know there are two? It’s simpler to assume that things which cannot be observed and which don’t add any explanatory power don’t exist, although that’s an assumption, of course.
As to how exactly a second dimension of time would work, I really don’t know; I’m not into that kind of physics. Perhaps you’d be forced to have ever increasing t[sub]1[/sub] and t[sub]2[/sub] both, but I seem to recall that this isn’t the case. People who know more about this than me are free to deliver the smackdown, however.
I’m not willing to say absolutely that there can’t be an extra timelike dimension, but I will say that it plays merry Hell with the math, and nobody has figured out how to make physical sense out of the notion. You can add as many spacelike dimensions as you like, though, and still make a sensible model out of it (this is rather popular in modern physics, as a matter of fact: Some up-and-coming theories require as many as 26 dimensions).
On the other hand, a Universe with three (or more) timelike dimensions and only one spacelike dimension actually would make sense, and in fact would be essentially identical to the one we actually have.
Would we always be moving forward at a constant rate in the space dimension then? Would such a situation be in any way different to the one we’re in now?
Maybe in your example movement along the “other” time dimension would correspond to movement into other parallel universes somewhat different from our own. Don’t like your life? Just move “sideways” in time and maybe you’ll enter a universe where you are rich and happy…
Ok, but what if you had no freedom of movement in either time dimension like you do now with one. It would still look like a line but, over time, some aspects of reality would ‘speed up’ compared to others. (like chemical vs nuclear I brought up in my OP)
So in a sense you would still be moving through alternate universes but with no freedom to control movement in “imaginary time” or whatever you would call it. As you moved in i-time the universal constants would be changing slowly and the perceived universe would change sublty over “time” reckoned as a 45 degree line through real and i-time. Is that the idea?
Footnote: I actually have heard physicists use the term “imaginary time”.
The many world interpretation of quantum mechanics basically says what you’re talking about. Every moment there are near infinite amounts of universes branching off our one, in which every single possibility is played out. The interesting thing about this is that it is an interpretation of the equations, and thus at the moment, cannot be ruled out as a real description of the universe.
I’m not sure exactly where these alternate branching off universes are meant to be though - in other space dimensions, or time ones or what…
[hijack]You can’t have “near” infinite. Something is either infinite, or it is not. If you mean really big, just say “really big.” Sorry – pet peeve.[/hijack]
‘the universal constants would be changing slowly and the perceived universe would change sublty over “time” reckoned as a 45 degree line through real and i-time. Is that the idea?’
That is one idea, but there are many degrees of movement possible in two dimensions-
the universe could move forward in a wave of increasing amplitude, or spiral around a central point, or describe a curve or an ellipse- these are some of the most simple possible motions in two dimensions.
The plane of 2time could be filled with universes, and the paths of these universes could cross for infinitesimal periods of time, perhaps imperceptible to the inhabitants (if any.)
More difficult to imagine would be a universe where any particle could take any concievable path in 3+2 space- causality could be reversed, and fields of force might have to follow an inverse cube law.
Fun isn’t it?
1 : extending indefinitely : ENDLESS <infinite space>
2 : immeasurably or inconceivably great or extensive : INEXHAUSTIBLE <infinite patience>
3 : subject to no limitation or external determination
4 a : extending beyond, lying beyond, or being greater than any preassigned finite value however large <infinite number of positive numbers> b : extending to infinity <infinite plane surface> c : characterized by an infinite number of elements or terms <an infinite set> <an infinite series>
Seems to me that mooka’s use of “near infinite” fits just fine with definition (2). Sorry – incorrect pedantic nitpicks are a pet peeve.
[/hijack rejoiner]
I want to emphasize again that if you’re stuck on a single path, like, say, along the circumference of an ellipse or something, you’re moving in one dimension; I only need one coordinate (the angle, in this case) to specify your position.
Having two dimensions of time in a meaningful way would mean that at least in some restricted sense you could move freely in both. It’d be like the difference between being able to walk only in a circular path (1D) or anywhere inside the circle as well (2D).
And that’s why it’s so hard to try to make sense of it.
I’ve read that our universe can be thought of as a giant static four dimensional object, with 3 space dimensions, and one time one. If our universe begins with a big bang, and ends with a big crunch, then it would look like an elongated sphere with 2 pointy ends - the big bang and big crunch being the two ends. As conscious beings we experience a succession of 3 dimensional snapshots of this 4 dimensional object, which give us the impression of time passing and things happening, when in fact the 4 dimensional universe is static.
If there were 2 time dimensions then the universe would be a 5 dimensional object, instead of a 4 dimensional one. However its difficult to see how conscious beings with a conception of time passing could exist in such a universe. Theres no obvious ‘path’ to move along to take 3 dimensional snapshots of this object. You could argue that a passage of time is needed for consciousness to exist. Hence why we’re not in such a universe. Maybe there are universes with 2 time dimensions, but there aren’t any intelligent observers in them to appreciate them!
Crossing paths… I’m picturing one dimension of space and two of time. The line universes move about the 2time plane. When they intersect they might, at that point, in fact be the same universe. Alternately, each universe might be a different kind of matter from all the others and not have an effect. The weirdest thing would be if all the universes were all the same kind of stuff. Then, for a brief time they would each experience each other’s matter “winking” in and then right out of their space.
If time is not a constant, as Stephen Hawkings says in “A Brief History Of Time” (and I am trying to fully grasp, btw) then what of time being an infinite number of dimensions?
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