In string theory, there are 10 or 11 dimensions, most of which are rolled up and very small. Could some of these rolled up dimensions be timelike?
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I’m not trying to be pedantic, and I didn’t mean to sound rude, but “infinite” has a precise mathematical definition, and accordingly something cannot be “near” to it. And while something that is infinite may be both immeasurable and inconceivable, just because something is immeasurable or inconceivable does not make it infinite. Mere astronomical numbers, while being well beyond the realms of human comprehension, are next to nothing compared to infinity.
The number of possible universes in the Many Worlds Interpretation as a rough approximation may be something like the number Planck volumes in the entire observable universe raised to the power of the number of units of Planck time since the big bang, which should be ((4/3)(pi)(r^3))^(age of universe). Using some values I got off the web, I get ((4/3)(3.14)((15x10^9 lightyears)(9.47x10^15 meters/lightyear)(6.19x10^34 Planck lengths/meter))^3)^((15x10^9 years)(5.85x10^50 Planck times/year)), which, if I haven’t dropped any decimals, is about (6.8x10^182)^(3.7x10^61). Now, since I’ve crashed all the machines I’ve tried to make calculate this number, and I really need to get back to work at some point, I’m just going to call this number (10[sup]183[/sup])[sup]10^61[/sup]. The point is that this number, which is so large that it is hard to even calculate or express symbolically, is just a regular (albeit large) integer, and is therefore precisely as far from zero as the number one. It is absolutely no nearer to infinity. Infinity is, in fact, still an infinite distance away from this number.
It seems to me that on a message board dedicated to stamping out ignorance, this is a perfectly legitimate nit to pick. YMMV.
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You get a finite number of universes under Many-Worlds if every quantum decision has two or more discrete possible outcomes. Not every interaction falls into this category. For example, a photon can impact an atom, knocking an electron from it and also giving off another photon. The electron can have a continuum of possible velocities. I’m not sure how Many-Worlds handles this case, but it would seem that you would have an infinite number of possible universes branching off.
Granted, and that’s fine. I don’t know which Many Worlds predicts, and whether everything is quantized, or what. My only point is that it can only be one or the other – infinite or finite. Just because the number may be really, really, really big doesn’t make it infinite. In fact, as I was trying to show, even inconceivably big numbers are downright titchy compared to infinity.
Ok I apologise - when i used the term near infinite i was just trying to convey a sense of an unimaginably large number. The number branching off may well be infinite - i don’t know.
I know you can’t really have a near infinite amount of things, i just meant it in a literary way, and not a (more correct) mathematical way.
hangs head… I promise not to do it again…
ZenBeam,
I also recall hearing that there were something like 12 dimensions that had been proven to exist, and that they were working on proving the 13th. I can’t remember the details, but there was an experiment that involved measuring something, the distance of which halves with each dimension. By the time you get to the 13th, the measurement is so small that it can’t be significantly measured. I think this is the basis for the multiverse theory. I may have read this in James Gleick’s book Chaos, but I’m not sure of that.
Anyone else read about this experiment?
Bald Taco your thinking about the 10 dimensions of superstring theory, this theory has not been proved properly yet.
For whatever it’s worth, in his unfinished novel The Dark Tower, a man is accidentally transported to a parallel universe which has numerous weird parallels to our own. For instance, The “tower” of the title is a fortress-like structure in that other universe which looks precisely like a building at Oxford, and stands at the same place on that Earth’s surface. Individual people have their twins; the hero is assumed to be someone else entirely, even by that other man’s fiancee.
People in this parallel universe have only a dim, confused grasp of distance, and have trouble understanding how far one locality is from another. At the same time, they have a much better grasp of time than we do, and understand it not as a line, but as a plane–our universe is on a line in that plane parallel and adjacent to the line their universe occupies.
Since the universes are confined to a single line in the plane, while time is two-dimensional, it is generally experienced as a one-dimensional phenomenon except by unfortunates such as the hero of the novel who become displaced.
The only exception to this principle appears to be with respect to dreams. The people in that parallel universe never invented railroads. For over a hundred years, children there have had nightmares about large monsters which charge along set paths. Researchers eventually determined that, in a parallel universe (that is, here) there are long systems of rails along which conveyances travels. These systems generally form paths which run to places analogous to the major cities in their universe.
A number of other fantasy writers appear to have touched on pretty much the same idea, but in less explicit terms. Examples which come ot mind are Jorge Luis Borges’ story The Garden of Forking Paths, and J. B. Priestly’s wonderful work The Other Place.
BTW, these hypothetical “extra” dimensions of string theory: are they supposed to be finite and of very small interval, or is it rather the case that they are supposed to be very expansive–even infinite–and our perception of them is supposed to be limited to a very small interval?
To use the analogy of The Dark Tower, is it supposed to be the case that an extra dimension is like the width of a string, and there is nothing beyind that narrow span, or is an extra dimension supposed to be like a vast plane, and our universe only occupies a narrow span on it, like the width of a string with, possibly, lots and lots of other strings to either side of it?
Oops:
I meant to write, “in his unfinished novel The Dark Tower C. S. Lewis describes…”
Wouldn’t it be proper to say that there is only 0.5 dimensions of time, as perceived by us, since there is a definite arrow to the progression of time, at least how i’ve so far noticed things going?
These extra dimensions are ‘curled up’ on a very tiny scale.
ataraxy, no, there was a thread on this in GD (Hawking’s theories), in relativity and quatum physics there is no arrow of time.
Come back cronos you sound like you actually understand this 
One instance in which it would make sense to me to consider an extra time dimension is a meta-time, described by anology. (For the purposes of this I’ll treat space as 3d and flat. The argument’s much the same otherwise,)
If I have a movie film cut into frames and stacked, to the characters there is a time dimension z (causes go forward in movie time, or up in my space). The whole film moves in my time as a whole, and I can see and alter a frame at any movie time at will. Imagine God viewing our time like this, and having a 5th dimesion of time to, uhh, have time.
Quoth ZenBeam:
In all of the current string theories, the extra dimensions (however many of them there are) are all spacelike. You can construct mathematical models of more timelike dimensions easily enough, but no sensible physical interpretation yet exists for them.
The usual interpretation, by the way, of these extra dimensions is that they’re all curled up on scales comparable to the Planck scale. It’s possible, though, that they’re as large as a millimeter or so. If this is the case, then the reason that we don’t perceive them is that the electromagnetic and nuclear forces don’t propagate through the extra dimensions. Gravity, though, (probably) would, so there have been a number of experiments recently to attempt to probe the behaviour of gravity at extremely short ranges.
There is also Heinlein’s novel Number of the Beast, which is based upon a idea of three time dimensions.
:eek: :eek: :eek:
So you’re saying that Stephen Kind pretty much ripped of the idea from Lewis :eek: !
Anyway, Hawking in his book: The Universe in a nutshell describes the possibility of a 2nd time dimension pointing “90 degrees” away from real time that he calls Imaginary Time. That is one of the great many of points in that book that I could not even begin to grasp.
He also mentioned that Real Time starts at the big bang and continues to expand forever while I-Time is like a sphere.
Err Stephen King Even