Physicist Claims Time Has a Geometry 447
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."
time curves (Score:2, Interesting)
Lorentz transform anyone? (Score:5, Interesting)
For kicks, check out one way to visualize the spacetime wheel. [colorado.edu]
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.
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.
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 expresses a change. That is time.
So perhaps time would be best understood not as a straight line, but as water sloshing around in a bathtub.
Another aspect of space-time may be a non-uniform fabric. We understand gravity as a curvature of space time. Perhaps there are multiple space times expressed via the three of the fundamental forces. Different fundamental particles are either affected or immune via these overlapping space-times. Particles affect one another via strong nuclear forces. These particles in turn affects the behavior of the whole as expressed across the three space times: gravity, electro-magnetism and weak nuclear.
Those were my thoughts.
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).
Wow, maybe the Unverse just changed (Score:1, Interesting)
Of course maybe this fits better. Maybe 3-D space is the only space that is universal or maybe like the m-theory tiny dimentions even 4-D space is twisted and warped.
That would make wormholes not these odd tubes between locations as we think of them, but just places were the warped and twisted dimensions of the Universe intersect each other.
Anyway... I looked at the main presentation and while I will never get the math, the model and how it applies to some known results makes sends. Fun Fun Fun... Did we really think Einstien would be the last to redefine the universe on this scale?
Re:Actually... (Score:1, Interesting)
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, familiar with valleys, and other such features. One would not be too familiar with globes, and any planets one is aware of appear to be flat discs in the sky. Wouldn't it be more logical to blame the curve on such things as hills or valleys, which are known things, then conclude a globe, which isn't well known?
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.
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 measurements. In fact, when Columbus was convincing the Spanish to fund his voyage, he had to lie to convince them that the earth was smaller than it actually was.
I don't think any culture that had a concept of "gravity" (even though Aristotle thought it was an inherent downward tendency of heavy objects, rather than a mutual attraction) that didn't also understand that the earth is roughly spherical. Hell, if you have sailboats it's almost impossible not to notice it.
Re:Lorentz transform anyone? (Score:2, Interesting)
I did not mean to assert that time experienced by objects was identical in all frames, nor that some frame had a particularly special interpretation. When I referred to a single time axis, I meant the single time term in the 4-vector (x,y,z,t). This is obviously valid for the two particle system used in the typical derivation of the Lortenz transformations since regardless of the motion of the object/observer, we could reduce it to a single space-like dimension and a single time-like dimension (x,t) (and, obviously, as you mentioned, identically valid co-ordinates (x',t') for other frames which can be viewed as a transformation in the direction the axes point).
However, his suggestion of a temporal geometry seemed to imply, on my first reading, that he was suggesting additional temporal dimensions - (x,y,z,t1,t2,t3) for example - which would add complications to situations where we could not transform the system we were considering to a two-dimensional one.
But having re-read what he says, I fear you may actually be correct in your observation, and that he is merely presenting Special relativity as his own, new, remarkable idea. A shame such things can manage to get book deals (although that really should've been a clue, I suppose). Maybe when I'm more awake I'll watch his presentations to see if they actually have any substance.
(And sorry about the 'professor' confusion, I had misread which section of 'visiting staff' he fell under on the stanford website...)
Re:damn it, no one ever thought the earth was flat (Score:1, Interesting)
Re:More information on this theory (Score:1, Interesting)
Re:Lorentz transform anyone? (Score:3, Interesting)
And in other news it's discovered how come so many poor patent applications are approved...
(apologies to A. F. Mayer as I have no reason to suspect he's not good at his job, but if they're all vying to be the next Einstein it does explain things)
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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:The Number of the Beast (Score:3, Interesting)
His universe had 6 totally straight dimensions with no curvature (at least to the extent it was important to the story. This article talks about curvature in the time dimension, which was pretty fundamental to relativity 100 years ago, so this is not a new idea.
I don't think RAH's idea of rotating to make use of unused dimensions would work because most of the theories currently around which use extra dimensions assume that we can see the extra dimensions, but don't use them because the universe is closed and very short in that direction.
Also I think the waffle factor got to be a bit too much in that book. Friday was his last great book, IMHO.
One step at a time, and we tripped up on the first (Score:2, Interesting)
Now, as to his claims, there are many. Most, if not all, seem to me to rely on his concept of "gravitational transverse redshift" GTR, which in turn (he claims) follows from "a simple thought experiment" on slide 6 of his first lecture, "A Correction to the Gravitational Model" [stanford.edu]. A little though shows his conclusions on slides 6 and 7 to be incorrect. If A sees B's clock running slowly and B sees A's clock running slowly this leads inevitably to a contradiction - an inescapable paradox.
Say both A and B set their clocks simultaneously to zero, according to an observer at rest at a point O, halfway between A and B, while the spacecraft is at rest. The observer at O also sets their clock to zero at the same time. At this point both Mayer and Einstein would say that all three clocks are observed by A, B and O to be running at the same rate.
Let the spacecraft accelerate at rate g for t seconds according to the clock at O, which continues to be halfway between A and B. Then let the spacecraft coast - becoming an inertial frame again. Now all three clocks are again observed to be running at the same rate. According to Mayer though, O sees the clocks at both A and B to be lagging the clock at O, A sees the clocks at O and B to be lagging the clock at A, B sees the clocks at O and A to be lagging the clock at A.
We now move the observers and clocks at A and B to the location of O, taking great care to do so completely symmetrically, so that there is no reason to distinguish between A and B. Here is the paradox - according to Mayer, A continues to see B's clock lagging A, and B continues to see A's clock lagging B.
This is not the same as the twins paradox. According to O, who has been sitting in the middle all this time, the movement of A and B has been completely symmetrical and there is no reason to favour one over the other.
Since the rest of Mayer's argument, especially GTR, seems to me to depend on this thought experiment, and since his conclusions from the thought experiment are wrong, his remaining theoretical arguments will fall, unless they follow from other principles.
There is some uniqueness (Score:3, Interesting)
1) time is non-linear within the same object, when the object is accelerating (and all objects are accelerating at all times; there is no restful object in the universe--relativistically), so measurements that were thought to be predictable through redshifts are not in fact predictable through the means we've been using and
2) these new domains of time can be thought of not as time-coherency but rather non-red shift, individual object domains. Calculating domains then becomes possible, as newly defined 'red shifts among red shifts' rather than the simplistic comparison from Einstein's equations. Einstein's equations were right, but didn't consider all objects can have their own relativistic differentials in time; hence the new 'geometric' concept. I like the idea, and will mosh it through my Mathematica constructs to see what happens.
Comment removed (Score:3, Interesting)
Re:damn it, no one ever thought the earth was flat (Score:3, Interesting)
Re:time curves (Score:3, Interesting)
Re:The Number of the Beast (Score:2, Interesting)
According to the Chaos Magician Peter Carroll, the way magic works is thus: at any given point, there are infinite 'alternate dimensions', with the 'present' being the one that we generally experience, necessarily created by the three dimensions of time, resulting an infinite number of alternate universes existing concurrently with this one, but that we can never interact with. However, there is a cone of possibility extending into both the past and the future, of different possible pasts and futures that could conceivably have created this present or conceivably result from this present. The trick to getting magick to work is in judging accurately the cone of possible realities and working towards the potential future that you're after. Most people in this society call that working towards an end. Of course, most people don't know just how wide a range of possible futures there are, and disbelieve in the power of mental effort to effect change by itself, and thus have little to no perception or experience of reality bending to their will.
Heinlein's book expresses the idea of what you might find yourself interacting with if you were able to transfer into those other concurrent realities. His concept of world-as-myth is mostly just a pleasant flight of whimsy for a professional author, based largely on the general concept of magick-- that belief creates reality. Yet also he's expressing the concept that the author is both tapping into a world already in existence AND creating that world simultaneously.
Undoubtedly this sort apparently paradoxical thinking will be found to some degree confusing and wrong-headed, yet sufficient meditation on the subject will invariably reveal its pure logic. Though I don't feel that either Heinlein or Wilson (or Carroll) really effectively described what's going on, it's easy enough to grasp ahold of the same intuitive Truth that they all wrapped their books around.
Is this new idea actually new? Decidedly not. The question is whether it'll garner any greater degree of support in this round, imo.