Time Dimension To Become Space-like 587
KentuckyFC writes "The Universe is about to flip from having three dimensions of space and one of time to having four dimensions of space. That's the conclusion of a group of Spanish astrophysicists who have calculated that observers inside such a Universe would see it expanding and accelerating away from them just before the flip (abstract, full paper pdf on the physics arXiv). 'We show that regular changes of signature on brane-worlds in AdS bulks may account for some types of the recently fashionable sudden singularities. Therefore, the fact that the Universe seems to approach a future sudden singularity at an accelerated rate of expansion might simply be an indication that our braneworld is about to change from Lorentzian to Euclidean signature. Both the brane and the bulk remain fully regular everywhere.'" Update: 10/09 16:06 GMT by Z : A few readers have written in to point out that the article is not peer-reviewed; your mileage may vary.
Mayan Calender (Score:5, Funny)
Re:Mayan Calender (Score:5, Funny)
Assumptions (Score:5, Funny)
You're assuming that there is only one time dimension. But actually, from a non-linear, non-subjective viewpoint, it's more like a big ball of wibbly-wobbly, timey-wimey... stuff.
Re: (Score:3, Funny)
Thank you, Doctor (Score:5, Funny)
(for those of you who didn't recognize the Doctor Who quote in the parent, turn in your geek badge!)
Re:Assumptions (Score:5, Funny)
Time speeding up (Score:5, Interesting)
Time in our frame of reference is slowing down.
The only way that seemed possible was if we were traveling at speeds close to c, but that didn't sound feasible since we were observing objects that were moving away from us, in all directions. Then another weird thought occurred to me...
Our observed universe is self-contained within the event horizon of a giant black hole.
We're closer to the singularity, and accelerating towards it faster than objects closer to the edge of the event horizon. Time will move slower for us, and far away objects will appear to speed up. An outside observer (if such a thing could possibly exist) would perceive our universe as shrinking, but in our current frame of reference, we still think of it as expanding.
One other observation that lends to this possibility is the fact that we have not seen evidence of other "Big Bangs" or other "Universes". If the Big Bang happened once, shouldn't it be a repeatable occurrence in the limitless void of space?
Okay, that's my rant. You can slap the straitjacket on me now and ship me off to the funny farm.
Solomon Chang
Re:Time speeding up (Score:5, Funny)
Re:Time speeding up (Score:4, Funny)
Re: (Score:3, Funny)
Re:Time speeding up (Score:5, Interesting)
One of the unintuitive properties of a black hole is that as mass increases the average density inside the Schwarschild radius decreases... even though the radius itself increases. Anyways as Mass goes to infinity, Density inside the Schwarschild radius goes to Zero and of course the Radius goes to infinity.
The radius of the known Universe along with the mass that is hypothesized almost satisfy the Schwarschild radius equation and is only off by a factor of 2 or 3.(Which isn't much in Astronomy)
Re: (Score:3, Informative)
Re:Time speeding up (Score:5, Informative)
One suggestion was that two branes within the bulk colided, and all that energy that has to go somewhere goes into a big bang in a 4d brane (the bulk is either 10 or lately 11 dinentions while we are just in 4)
If those theories are correct, both time and space existed before the big bang, and also at some point in the future our brane will collide with another again and cause another big bang. This happens through out all the branes at different times and repeats forever.
Note that I word my post as if "this is", when it should be pointed out that my wording is this way "if these theories are right", so please take it as such.
Re: (Score:3, Insightful)
What was time like before the (4-space) big bang?
That said, this is probably a junk paper, but what you identify isn't a problem.
Re: (Score:3, Informative)
Does that help?
Re: (Score:3, Interesting)
Re: (Score:3, Funny)
Re: (Score:2, Funny)
Re:M-Theory is bad science (Score:5, Funny)
M-Theory was the brane child of a bunch of mathematicians
[tips hat]
Well, I for one welcomed our five dimentional (Score:5, Funny)
Breaking "time's arrow" will really fuck with our verb tenses.
But I worried about that tomorrow...
Re:Eternal Life (Score:5, Funny)
Don't look now, but it's already happened in Washington, D.C.
Re: (Score:3, Funny)
Ode to the new way (Score:5, Funny)
Oh, I'm living in a tesseract,
a four dimensional box.
It's bigger on the inside,
what why my four-space rocks!
When you get on the inside,
the outside becomes the in,
Dimensionally speaking,
it's all about the spin.
E=MC^2 (Score:4, Funny)
Re:E=MC^2 (Score:5, Funny)
Re:E=MC^2 (Score:5, Funny)
Would that be spin-up or spin-down?
Re:E=MC^2 (Score:4, Funny)
My advice (Score:4, Funny)
Avoid poetry, coastal cities, and the Catskill mountains. Seriously. [wikipedia.org]
I wasn't expecting that... (Score:4, Funny)
Quack alert! (Score:3, Funny)
You still haven't produced the code for COSA, its been more than a month. Do you have it?
I suggest you read Relativity by Albert Einstein. He explains Special Relativity in simple mathematics that even somebody who has taken Algebra in US public school system can understand.
I will refer you to the following questionnaire: Are you a quack? [sunysb.edu]
But what does that mean? (Score:3, Interesting)
Not just what, but when? (Score:2)
In our lifetime?
In the lifetime of our species?
In the lifetime of our sun?
Before the expected "heat death" of the universe?
Re:Not just what, but when? (Score:4, Funny)
Re: (Score:3, Insightful)
Re:Not just what, but when? (Score:5, Funny)
Re: (Score:3, Funny)
Re:Not just what, but when? (Score:5, Funny)
Should this research be correct, the only question left will be: "This?" Now and always and forever, this?
Re:Not just what, but when? (Score:5, Funny)
Dark Helmet: What the hell am I looking at? When does this happen in the movie?
Sandurz: Now, you're looking at now, sir. Everything that happens now is happening now.
Dark Helmet: What happend to then?
Sandurz: We passed then.
Dark Helmet: When?
Sandurz: Just now. Were at now, now.
Dark Helmet: Go back to then!
Sandurz: When?
Dark Helmet: Now.
Sandurz: Now?
Dark Helmet: Now!
Sandurz: I can't.
Dark Helmet: Why?
Sandurz: We missed it.
Dark Helmet: When?
Sandurz: Just now.
Dark Helmet: When will then be now?
Sandurz: Soon.
Dark Helmet: How soon?
Re:Not just what, but when? (Score:4, Funny)
Re: (Score:2)
Because our biology and minds are tied to a three dimensional existence...
Would we know when/where it does happen?
Re: (Score:3, Insightful)
Re: (Score:2)
Namely - if you see an action in forward and reverse, both make sense. As opposed to macroscopic, where if you show a picture of a man falling from a roof in reverse, most people can tell you its in reverse.
Re: (Score:2)
Re: (Score:2)
Done.
Re: (Score:2)
ow ow my brane hurts! (Score:4, Funny)
Re:But what does that mean? (Score:5, Interesting)
In "Slaughterhouse Five", Vonnegut wrote about creatures who perceived time as a geometric dimension. They could perceive their entire lives as a wide landscape, stretching from past to present to future... and they could move freely within it, to relive the better moments and fast-forward over the unpleasant ones.
One of the implications that these creatures could see, but which we could not, is that the universe can only play out one way. Whatever happens, has always happened, and always will happen, it is unavoidable. The creatures could see their future with absolute certainty, and so they knew that choice is an illusion (or, in my understanding, a mis-connotated word that belongs in the realm of epistemology rather than of metaphysics).
In any case, if the universe experiences this sort of "signature change", then we'll never know it. Consciousness will abruptly cease, like a paused DVD player or a saved Diablo game, waiting forever for time to resume. But, a new sort of consciousness could arise, to which physical movement is the equivalent of temporal progression. Somehow, if it could gather information and then ruminate upon it, by means of movement rather than time, it could become self-aware.
Re: (Score:3, Funny)
Re: (Score:3, Interesting)
Movement is change, and change requires time. To move from one time to another, you need some kind of "metatime". To move through that, you'd need "metametatime" and so forth. Without change, y
Re: (Score:3, Interesting)
But you'd have no control over where in the realm of time you choose to move any more than you have control where in space you choose to move. You can will what to do, but you can't will what to will.
Re: (Score:3, Interesting)
Re:But what does that mean? (Score:4, Interesting)
Also, why does time seem to flow into a single direction? Most of the equations of physics work fine both ways, but time only appears to flow in a single direction, only its "pace" changes. The best explanation is that there's a breaking of symmetry, a process which for some reason only occurs in one direction of the time dimension(s). The only such process we can observe at this time is entropy. In a closed system, it always increases, it can never decrease. So entropy seems to be linked to time in some intricate way, or maybe it's actually an extra time dimension linked to the first in some way. So what happens if time changes into a space dimension? What does that even MEAN? The only significant difference between time and space is that single direction in which time flows, so does it mean the second law of thermodynamics will stop applying? The flow of entropy will reverse or break its link to the time dimension? This would not necessarily be so "bad" but it would completely break down most of the laws of physics that depend on this phenomenon, thus destroying the universe, no?
Re:But what does that mean? (Score:4, Interesting)
In a closed system entropy can and does decrease from time to time. It is simply much more likely to increase, due to there being more possible states with high entropy than there are states with low entropy in known physical systems, and the likelihood of it decreasing in a given period decreases sharply as the complexity of the system grows. It never goes to zero, thought.
A classical example is a box with two separate gasses, initially separated by a dividing wall. If the wall is removed, the gasses will mix, eventually spreading equally to every part of the box. However, suppose that the box only contains a single molecule of both gasses. It is certainly possible, and even likely, that both molecules happen to be at their initial side of the box, and both gassed therefore separated back to their own sides, at some future point. Add another molecule to both gassed, and you'll have to wait a bit longer for all four to be at their initial sides, but still not too long. A third molecule, and it takes longer still, then fourth, fifth and so on.
The more molecules you add, the longer you'll have to wait. However, no matter how many molecules there are in the box, given a long enough time, the gasses will separate, simply due to random motion of the molecules happenign to take all the molecules of one gas to one side of the box at the same time, and all the molecules of the other gas to the other side at the same time.
It will take almost, but not quite, forever, but that's a far cry from "never".
Re: (Score:3, Insightful)
Free will is just an idea. It isn't some essential observed bit of the universe. From all scientific evidence we are complicated finite state machines. We are entirely physical, deterministic machines.
Oh crap,.....not again (Score:2)
So... Should I buy canned goods and water? (Score:2)
Re: (Score:2)
Be wise. Be safe. Be aware.
Re: (Score:3, Insightful)
Isn't "time" only subtlety different from a physical dimension?
This phrasing suggests that time is not a physical thing. Given that the variable "t" occurs in practically all dynamic equations of physics, I'd have to disagree with the assertion that time isn't physical.
Plagarism! (Score:4, Funny)
More of this is elaborated in his development of these themes: "Some More of God's Greatest Mistakes," and "Who Is This God Person Anyway?".
Re: (Score:2)
So how does this affect us? (Score:2, Interesting)
And mostly-OT but seemed related: I remember a couple of SF short stories about something like this... one was "Mimsy were the Bogroves" or something like that, where two kids discover 4-dimensional toys from the future, then read "Jabberwocky" and figure out how to move in time.
The other one was about a kid who befriends a
Re:So how does this affect us? (Score:5, Informative)
I believe that's The Boy Who Reversed Himself [amazon.com]. I remember having read that when I was in highschool.
Re: (Score:2)
Of course, it's kind of hard to tell how that would actually work out, as we still don't really understand time.
Re: (Score:2)
But if our space-time will flip to 4D, then it will be a sad future for the Earth. For one thing, there's no stable planetary orbits in 4D...
This can mean but one thing (Score:4, Funny)
Misleading summary (Score:2)
That being said, what is the best way to handle the signature change? Should I stand in a doorway or head for the storm cellar?
Explanation? (Score:2)
Re: (Score:2)
Can anyone explain, by way of analogy, what having four time-like dimensions and no time-like dimensions would entail? Would everything just . . . stop? Would our current motion through time carry forward through Newton's Laws, so that we don't even notice the switch? I did RTFA, and it's light on details. I attempted to RTF paper, and immediately zoned out. So, anyone understand this well enough to attempt to clarify?
Clearly, this means you will end up sleeping with your grandma and becoming your own grandfather.
It is... inevitable.
Re: (Score:2)
explanation (Score:2)
It isn't slashdotted, it is just frozen in time.
Re:Explanation? (Score:5, Interesting)
Doctor Who was right after all (Score:2)
the intersection of mathematics and cosmology (Score:5, Funny)
great (Score:2, Funny)
Peer review (Score:5, Funny)
Re: (Score:3, Funny)
Math does not equal PROOF!! (Score:2)
How many goddamned times do we have to have this discussion on here?
Math is a language. It is a means whereby describe things to the best of our comprehension in a manner that best conveys our impressions to others.
Just because a bunch of numbers add up does not mean it is proof of anything. Otherwise, Creationists are right and the world began in 4004 BC.
This would be Bad (Score:2)
"... about to ..." (Score:5, Insightful)
When you say "about to" in sports, something generally happens pretty fast.
When you say "about to" in geology, something generally happens pretty slow.
Generally speaking, saying "about to" in cosmology is to geology as geology is to sports.
But not always. At some points in time, the volcano under Yellowstone does go off. Likewise, supernovas happen, and perhaps brane changes too. But to say "about to" or "soon" is just meaningless to human scales of time.
no more time: end of universe? (Score:2)
hopefully The Chaos will save us [wikipedia.org]!
And YOU can profit! (Score:2)
Sure, it sounds bad, but with every big change comes winners and losers and you can be one of the winners if you act now!
Oh, wait, that's how to profit from that other singularity...
My time-tail is bigger than yours (Score:2)
Define "about to"? (Score:5, Insightful)
Are we talking about something they see as imminent -- could happen at any moment?
Or are we talking about geological time scales -- it'll happen in a few hundred thousand years, give or take?
Or do they mean cosmological scales -- where 'about to happen' means somewhere in the next ten or twenty million years?
Or is the whole question of when a silly thing to ask, given that they're talking about the end of time as sequential/chronological?
It has to be linked (Score:2)
This explains [xkcd.com] the rudiments of string theory.
Old, old old news (Score:2, Informative)
Relativity talks of space and time as a single 4-dimensional 'spacetime'.
M-Theory, Superstrings, p-Branes, and a billion other theories all say there are 10 (or 11) dimensions, including things like two-dimensional "time" and "imaginary-time" dimensions, smaller "curled-up" spacial dimensions, etc.
Next thing you know youre going to tell me (Score:2)
maybe mamas and papas got it right.
The 1960's called... (Score:2)
New rule of web hosting (Score:2)
All you D & D players (Score:3, Funny)
Lorentzian to Euclidian transformations... (Score:4, Funny)
Yeah, I said it.
Mileage? (Score:5, Funny)
Hope not. (Score:5, Interesting)
Comment removed (Score:5, Informative)
My crude guess (Score:4, Interesting)
It appears to me that this is a purely mathematical result. They are basically saying that an anti-de sitter bulk, the interior of anti de Sitter (AdS) space which is a constant negatively curved (or constant positive cosmological constant) with one time-like dimension (Lorentzian space) can be glued to a euclidean space smoothly along the boundary of the two spaces. Classically, this is of little relevance since time-based trajectories would stop at the boundary (either take infinite time to arrive or the system would "rip" itself apart at the boundary). Instead there could be (though not addressed in the paper) observable quantum effects from having something past the boundary even if it is purely spatial. Space-time states might extend over the boudary into this other space. So you might end up with the strange situation where parts of the universe are interacting beyond the end of time.
This paper doesn't tell you whether that occurs or not. But it does indicate that it is possible for quantum systems to have both Lorentzian and Euclidean space components seamlessly connected.Consequences (Score:4, Insightful)
Re: (Score:2, Funny)
and there was much rejoicing.
(holy crap we have close #'s too)
Re:So. . . . (Score:5, Funny)
Re: (Score:2)
Well, when you consider that one second ago is one light-second awa - i.e. abut 300,000 kilometers - then getting to one second ago would be about as difficult as getting to the Moon from Earth...
In other words, we possibly could move about in time "much as we 3D space" - but we don't move around in that all that well, either. At least when compared to the speed of light...
Re: (Score:2)
Re: (Score:2)