Slashdot Log In
Physicist Claims Time Has a Geometry
Posted by
ScuttleMonkey
on Sat Feb 04, 2006 08:33 PM
from the high-time-to-check-it-out dept.
from the high-time-to-check-it-out dept.
sciencenews writes to tell us that a physicist at Stanford has just recently published a peer review website for several physics lectures focusing on a single underlying idea that "time is not a single dimension of spacetime but rather a local geometric distinction in spacetime." The science is presented quite clearly and originally uses GPS systems as a point of focus. From the article: "Not too long ago, people thought the Earth was flat, which meant they thought that gravity pointed in the same direction everywhere. Today, we think of that as a silly idea, but at the same time, most people today (including most scientists) still think of spacetime as if it were a big box with 3 space dimensions and 1 time dimension. So, like gravity for a flat Earth, the single time dimension for the 'big box universe' points in one direction, from the Big-Bang into the future. A lot of lip service is given to the idea of "curved spacetime", but the simplistic 3+1 'box' remains the dominant concept of what cosmic spacetime is like."
Related Stories
[+]
One Big Bang, Or Many? 492 comments
butterwise writes "From the Guardian Unlimited: 'The universe is at least 986 billion years older than physicists thought and is probably much older still, according to a radical new theory. The revolutionary study suggests that time did not begin with the big bang 14 billion years ago. This mammoth explosion which created all the matter we see around us, was just the most recent of many.'"
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
More information on this theory (Score:3, Funny)
Re:More information on this theory (Score:3, Funny)
However, I'm surprised we're not going into a flamewar over John Titor [johntitor.com] in this one, since we've got a good opportunity.
Re:Point(s) of interest (Score:5, Insightful)
What has testing got to do with it? It will always be a theory, because that's all science can produce. If you want something definate you want mathematical theorems - those are known to be true. Theories never will be - they can just be very reliable at predicting things, nothing more.
Re:Point(s) of interest (Score:5, Informative)
Re:Point(s) of interest (Score:5, Informative)
What is this 'reality' you speak of?
Mathematics isn't constrained by our perceptions of what it 'should' be or what feels right. It's constrained by the axioms and principles we build it from. And in this case, 0.9 recurring is exactly equal to one. As you demonstrated, there are countless proofs of it (the one you selected being one of the less rigorous ones), and since the proofs are not incorrect, it means that their conclusion is wholly true, from a mathematical point of view.
Looked familiar (Score:3, Funny)
Re:More information on this theory (Score:3, Funny)
proof (Score:5, Funny)
Re:proof (Score:5, Funny)
Lorentz transform anyone? (Score:5, Interesting)
For kicks, check out one way to visualize the spacetime wheel. [colorado.edu]
Re:Lorentz transform anyone? (Score:3, Insightful)
Re:Lorentz transform anyone? (Score:5, Interesting)
In other words not only is there are redshit if we fire a lazer up into space from the earth (i.e. light leaving a gravity well) but even if we just shine a laser from one point on the earth's surface to another there should be a small redshift as well. His argument is that one would expect to see such a reshift in a accelerating frame because the light is traveling farther than it would at constant velocity.
Personally I'm skeptical of this argument at the moment because whether or not one would see a redshift is going to depend on the effect of that acceleration on the clocks. As the rocket speeds up the time dilation from SR increases as well, perhaps the right amount to compensate for the increased difference. At the very least the thought experiment doesn't produce a clear result (and it is always possible that multiple solutions are compatible with it).
As an aside the question of whether there is a global constant progression of time or it differs from location to location is just a matter of naming. The scientific community has decided to call the effects from acceleration/velocity changes in the passage of time because such a description seems to be more productive and simpler. However, one could describe the same phenomena by saying time progresses at the same rate everywhere but all physical processes slow down/speed up. Or to say it another way the Lorentzian theory of an ether with shrinking rulers and faster clocks is experimentally equivalent to SR and the same thing should be possible to do with GR (so long as there are no closed curves in time e.g. time travel)
Re:Lorentz transform anyone? (Score:4, Interesting)
Conversely, what I think this professor is suggesting that it's not quite so simple as dealing with a single axis, but rather a collection of them, which would mean it's not possible to consider our motion through time with regard to one solitary axis, which would have an effect on many aspects of relativity (although not in the Lorentz derivation shown at the link in your post, I don't think, since in that case our spatial and time axis are simply defined as being the directions of relative motion anyhow, so there this point is moot).
Of course, I could be completely wrong, as it's nearly 2am, I haven't looked at his slides, and my report is turning my brain to mush. I'll have to have a look in the morning when it works again.
Re:Lorentz transform anyone? (Score:3, Insightful)
Re:Lorentz transform anyone? (Score:5, Informative)
Re:Lorentz transform anyone? (Score:5, Funny)
Re:Lorentz transform anyone? (Score:5, Funny)
I was pointing out his employement as a patent examiner as an explanation of why he might not know all that much about general relativity, but I just now realized how ironic [wikipedia.org] that is.
Re:Lorentz transform anyone? (Score:4, Informative)
Re:merit of mayer's argument (Score:5, Insightful)
Given that caveat, I found Mayer worth a serious look. He's got a number of references showing measurements that GR does not explain. The most convincing stuff is from GPS satellite measurements which show an unexplained sawtooth pattern with a period of two cycles per day and an amplitude of several feet (or nanoseconds). GPS satellites and ground stations explicitly correct for the general relativistic effects of the earth's gravity well, so any anomalies would be very interesting. But he's also got anomalies in measurements of hydrogen 21 cm radiation and in the effect of Ganymede on signals sent from the Galileo spacecraft.
If Mayer faked the anomalies (but I believe they're real), he would be shot down in no time. Assuming the anomalies are real, then any theory that can explain them in addition to the rest of the effects explained by GR (precession of Mercury's orbit, redshift of a gravity well, etc) deserves a serious look.
One other point. In grad school, when we students complained about the many annoyances involved in writing and publishing our work, my advisor would say "50% of science is communication." There's alot of wisdom in that. There are plenty of cranks (or not so cranky folk) out there tugging on physicists' sleeves and saying "Einstein was wrong and I have a notebook full of equations to prove it!" I know such a fellow myself, but it would take weeks to examine his equations and maybe months to explain his errors. What he and his ilk lack is the ability to communicate like a scientist. Anyway, where I'm going with all this is that Mayer suffers no such lack. His 'Lecture 1' document is much better than average writing by a scientist. While this doesn't prove his equations are better than Einstein's, it is further reason why he deserves a serious look.
hmm... (Score:5, Insightful)
Close (Score:5, Interesting)
Spacetime perceives time as a one dimensional vector that is orthogonal to all other vectors. Because relativistic equations for time, distance, mass, etc, use a sqare root function, you get imaginary distances and imaginary time when an object exceeds C. Usually, an imaginary quantity means that you're looking at the wrong axis.
(Trivial case in point: when solving a quadratic equation, if the parabola doesn't intersect the X axis, you will get a complex number. If you break that down into real and imaginary components, the imaginary components correspond to the displacement in the Y axis for that solution's real component value in the X axis.)
Ergo, if a tachyon exists, it would experience a spacial axis as "time" and the time axis as space, UNLESS "time" is not a single axis, in which case all bets are off.
In consequence of not having a telephone-number IQ, I can only speculate wildly, but I'm going to guess that the relativistic equations do indeed refer to some measure of bleeding between space and time and that no further dimensions are required - for GPS or for any other phenomena governed by relativity. (Superstrings being about the only exception I can think of.)
I personally think that part of the problem is that time IS regarded as "special", whereas perhaps it would be better if it were regarded as special "only as far as absolutely necessary". To the extent that specialness is an extra parameter, you want to eliminate all extra parameters as far as possible (and no further).
Re:Close (Score:3, Informative)
Time is just one aspect. (Score:5, Insightful)
In his paper "On the Cause of Geodetic Satellite Accelerations and Other Correlated Unmodeled Phenomena", via the American Geophysical Union in December 2005, he outlined specific modifications to general relativity. The paper's Abstract begins:
"An oversight in the development of the Einstein field equations requires a well-defined amendment to general relativity that very slightly modifies the weak-field Schwarzschild geometry yielding unambiguous new predictions of gravitational relativistic phenomena."
The result of this amendment is an additional relativistic effect. As you may know, in general relativity, the velocity of light is a constant. Thus one's velocity relative to a photon can result in a shift of measured frequency, i.e. the red-shift, or blue-shift of spectra. Also, since the theory claims that accelerated reference frames are identical, this shift is also observed due to gravitational acceleration.
The author claims that gravitationally induced red-shifting is also dependent on the angle through which a photon travels in a gravitational field. In addition, the theory discusses gravity and angular momentum. An accelerating electric charge emits electromagnetic energy. Though long theorized, a similar gravity wave has never been observed. The author suggests that angular momentum, e.g. spinning and orbiting masses emit electromagnetic energy as well. Thus, orbits even in a perfect vacuum will decay. As a spinning body slows, or orbital momentum decays, this energy will be balanced by radiation in the microwave range.
The additional source relativistic red shift, and the additional changes with respect to conservation of momentum, have profound cosmological import, if true. The theory passes the simplicity and beauty tests admirably. What I particularly like about his presentation has to do with testability.
He discusses numerous problems with the GPS and geodetic satellite systems, various puzzling data from several deep space missions, the orbits of planets and moons, and show how his equations account for the discrepancies in the data. He also proposes a number of simple experiments which could prove or disprove his theory. He predicts what to look for in terrestrial microwave radiation, and suggests experiments that could be run using existing satellites which could prove or disprove his theory. He also suggest that other scientist look at data which has already been collected but which he has never seen, and predicts what patterns might confirm the theory.
From the ground up, the ideas are well reasoned, and his approach seems scientifically sound.
Time gets into the mix, because the broader ramifications of the theory are large. Imagine a space ship under constant acceleration. On the floor (aft bulkhead) place two clocks communicating via pulses of light. He shows how each clock (even though they share the same acceleration reference frame) will each view the other as slow. By virtue of general relativity, pairs of clocks on earth should likewise each view the ticks of another clock as slow. Thus, there is no common, universal time. The rate of time is a local attribute at each location.
The cosmological implications if this theory are also impressive.
There is no need to posit dark matter or dark energy. They are discussed only to account for missing matter and the expansion of the universe. However, if this theory is true, the universe is not expanding, thus removing the need to postulate dark energy. The matter needed to keep galaxies from flying apart is no longer needed. Rotating galaxies are radiating microwaves and slowing down, not being gripped by dark matter. The universe finite and unbounded. It is neither expanding nor contracting.
No big bang would have happened. Remember the history of the theory? It was attempting to account for red shifted stellar spectra and for the microwave background. If the red shift is a relativistic phenomenon (not the result of unive
1+1=2 solves problems, too... (Score:3, Insightful)
The novel idea that there are an infinite number of time dimensions in the Universe revolutionizes gravitational theory and much of modern science with it. A number of outstanding scientific mysteries are definitively solved, including observations that lead to the concepts of 'dark energy' and 'dark matter'.
A number of outstanding scientific mysteries are also solved with my new unpublished theory that 1+1 = 2. Doesn't mean that the idea holds water, though.
I think that many problems in academia are because of "publish or perish" advancement. I think this is an example in point.
Stepping sideways in time... (Score:5, Interesting)
It sure seems like time goes forward only, from my own day to day observations. My mind can't even comprehend what going another direction (except for "backwards") would even mean as a concept.
Cohesion of forces ... (Score:3, Interesting)
Unless you're editing a movie, it really doesn't make sense considering time as a an axis. It's almost as if time is a cohesion of forces expressed cumulatively across all forces in the universe. As objects move, the relative difference in forces express
Re:Stepping sideways in time... (Score:3, Insightful)
The "arrow" of time is a consequence of the second law of therm
Re:Stepping sideways in time... (Score:3, Insightful)
It might be that from a different perspective, everything can be 'happening' at once, so to speak. Some
Re:Stepping sideways in time... (Score:3, Interesting)
I've never understood this argument. I mean in the way past you would be familiar with hills, and familiar with mountains,
Re:Stepping sideways in time... (Score:4, Interesting)
I can't say whether I agree or disagree with him. I'd have to see his maths.
If I did, I'd have to conclude that I couldn't say whether I agreed or disagreed with him -- I'd have to understand his maths.
If I did that, I probably couldn't say whether I disagreed or agreed with him. I'd only be able to make strange aardvark-like noises.
However, as for my own current understanding of time, I'd have to say that time appears to be a log of the order of interactions, and secondary derivative interactions, and so on... thus making it locally constant, and globally pointless.
As Ford Prefect said... (Score:5, Funny)
Warning : possible silly science (Score:3, Insightful)
Basically if it was the genuine article, I would expect the website to list his position with Standford (he appears not be facutly) and his previous work. I didnt see that. The power point presentation has all the signs such as lots of pretty graphs and pictures which "prove" this (although admittedly this is better than most) and a lot of big words. What I would expect to see is a bit of hard maths and maybe one example, he's coming on far too eager. Also he focuses on what it fixes, what does it break? I want some predictions for experiments to measure. Its easy to explain one or two effects with a theory, the real test is what does it predict. I would also expect a link to a preprint explaining this and its abstract. I would go so far that any serious scientist would post a preprint on xxx.lanl.gov as the first step of going public.
I'm very doubious about any werid and wonderfull theory coming from somebody who is outside the world of science, as theres a lot of chafe out there. Just go the poster session of the APS annual meeting to see what I mean. Okay its helpfull to keep an open mind, Einstein came from the outside with his really werid seemly crackpot theories but that happens rarely.
Now just to point out I'm not saying its junk, I havnt read it yet, just saying it appears to raise of a few of the warning flags.
Science vs. Engineering (Score:5, Funny)
In my experience, scientists who work with such issues are quite clear on this point (and, so far as I can tell, have been for eighty some years).
But for other sorts of scientists (e.g. biologists), engineers, and the rest of us, who only need to calculate things to five or ten decimal places or so, assuming that the time points in the same direction throughout the area of interest (and generally that space is flat and such) is reasonable--so reasonable, in fact, that we'd be nuts not to work with that as an assumption.
If I'm tracking the migration of some sort of beetle or planning a system of trusses to support a load or deciding if I should walk or drive to the store for milk, I would have to be mad to start out treating spacetime as a fine-grained network of plank-scale events with information flow between them determining the local geometry of space time (and thus the direction of time). Likewise with the effects of nearby astronomical bodies--if they were big enough and close enough to seriously distort spacetime I'd have a lot bigger problems to worry about. On average, to the level I'd ever need to deal with in these sorts of cases, it is now and the future is coming up later and the past is what already happened.
--MarkusQ
Flat Earth (Score:4, Insightful)
Re:Flat Earth (Score:3, Interesting)
Really? I don't remember his measurements in his writings, but two generations before him Thales had measured the diameter of the earth within a few percent of our modern measu
Revolutionary stuff (Score:4, Insightful)
I am a bit skeptical towards those who make revolutionary claims like this and publish it to the general public instead of in scientific journals.
Tor
damn it, no one ever thought the earth was flat! (Score:4, Informative)
direction(s) of time (Score:5, Informative)
There is definitely a good case to be made that the past-versus-future arrow of time is not fundamental. Basically our psychological sense that the past is different from the future comes from the direction of the thermodynamic arrow of time, but the second law of thermodynamics doesn't come from the basic laws of physics (which are essentially time-reversal symmetric) but from the boundary conditions of the universe: for some reason unknown to us, we had a low-entropy big bang. The meaning of "past" is really "that way to the big bang."
It's also probably true that in a complete theory of quantum gravity, the picture of three space dimensions plus one time dimension (3+1) would break down completely at small scales. The whole idea of distance and dimensionality is probably a large-scale approximation that loses its validity at small scales. There is a strong argument [wikipedia.org] to be made that for fundamental reasons, spacetime must be discrete, not continuous, at the Planck scale. The only people seriously trying to construct discrete theories of quantum gravity right now seem to be the people doing loop quantum gravity (not string theory, which uses a flat 3+1 background of spacetime). For a good popular-level account of this kind of stuff, see Smolen's Three Roads to Quantum Gravity. In loop quantum gravity, they are able to construct an infinite set of possible universes (each one is a type of knot), but the problem is that none of them can be proved to resemble flat 3+1 spacetime, even asymptotically. In other words, there's no way you can even take this tangle of events and figure out whether it has anything like time and space that you can define on it. It's like being a flea living in a world that consists of threads woven together. On your scale, can't be sure whether it's a one-dimensional piece of yarn, a two-dimensional piece of fabric, or a three-dimensional wad of wool.
Lecture2Signed, page 25 (Score:5, Informative)
Jump to page 25 of the second set of slides, where the author shows two time vectors at an angle to each other. If you have two observers, one with each time vector, then each observer thinks that the other is slowed down. Each sees redshifted light from the other.
This angle between time vectors can be caused by gravity or by the curvature of the universe.
In the gravity case, it is used to explain discrepancies in all sorts of measurements, from the Pioneer spacecraft, to the changes in the orbits of various celestial bodies, to discrepancies in the GPS, to the apparency that a U.S. atomic clock and a French one will each think the other is ticking slower. This is what most of the first slide show is about.
In the cosmological case, the idea is that the universe is round (see page 28 of the second presentation) and that the redshift that we think is due to the expansion of the unverse is actually due to the curvature of the universe, i.e., a galaxy around the universe from us will appear to have slower time, because its time vector is going in a different direction than ours. A galaxy ninety degrees around would appear to have time completely stopped, so it would be invisible to us (frequency of zero). Galaxies further away than that would be going backwards in time from our perspective, but we can't see them.
This is an idea I have not seen before. It seems really neat to me. It seems plausible but then (a) I can't personally verify the observations that he claims validate his theory; he could have produced fake graphs and they would fool me, but I would think it would be easy for him to get caught at that, and (b) even though I've had calculus up to differential equations, I never had non-Euclidean geometry or higher-dimensional stuff, so I can't actually follow his calculations very well. Then again, I didn't try very hard.
We shall soon see if he has made a significant error. The numbers and the observations will tell the story; either they work out, or they don't.
I read Heinlein, too. (Score:4, Funny)
What's with people questioning who he is? (Score:4, Informative)
If you look at his colleagues,
i ng.html [stanford.edu]
http://www.scu.edu/spo/spring_03_2.htm [scu.edu]http://www.stanford.edu/dept/physics/people/visit
then cross-reference a few of them:
http://www.gf.org/lfellow.html [gf.org]
Douglas N. C. Lin, Professor of Astronomy and Astrophysics, University of California, Santa Cruz: 1991
If you look him up he is all over about Astrophysics and applied mathematics.
Betty Young, Santa Clara:
Now if you research Betty you find this:
u ng.cfm [scu.edu]
http://www.scu.edu/cas/physics/facultyandstaff/yo
Now whatever becomes of this Alex Mayer and his credentials are yet to be determined. However, I doubt Stanford would even allow him web space under the Physics department if he didn't have the credentials to back it up.
Beats per Beast (Score:3, Funny)
Did you even read the book? (Score:3, Informative)
Re:Maybe time is Spherical (Score:3, Funny)
And my response to it.
I have seen the light! (Score:3, Funny)
Yet, today, as I read the teachings o
But - you haven't proved that (Score:5, Funny)
Re:I have seen the light! (Score:4, Funny)
Re:Perhaps this may finally vindicate.... (Score:5, Funny)
Ignorance of the Time Cube, Life Cube &
Ineffable Truth Cube, indicts you Stupid.
Ignoring Cubic Creation indicts you evil.
Singularity God impossible.
>>>>
Bizarre syntax indicts you schizophrenic.
Re:lipservice to spacetime? (Score:3, Informative)
...that's like saying ther's no "up" separate from "east". The real question is if they are orthogonal [wikipedia.org].
Re:The implications (Score:3, Funny)
This might work in theory, but I've never observed it.
What? You've never experienced