Physicists, rejoice! I have arrived to geek with you!

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Been quiet for a while, actively studying the various methods currently being worked on for constructing simplical spacetimes.

This is a 4-simplex, a pentachoron, sort of a triangular analogue of a tesseract.



The central ball/struts are the same dimension (radius/thickness) as the others, but as it is further away along the 4th dimension it appears smaller.

There are ways to orient these, and assign the 10 parts of a specific GR Tensor to the individual struts, representing a spacetime in some computations.

I'm not as big of a fan of the 4-simplex triangulations though, preferring the hamiltonian lattice models currently.

http://arxiv.org/abs/gr-qc/9603030

Your Alteration of GR, Justmax, does that not imply that if something can affect something in the past, (even if just briefly past) then that something can then go on to transfer information to another point at the speed of light, thus in effect propagating information faster than the speed of light?

I have to ask this before I can really read anymore on it... There are too many corollaries that I have to keep in mind if this in fact so.
It has something to do with the way I see it, although I'm quite good at mathematics, I need to "visualize" it before the math does me any good, and often if i learn the math first, it interferes with my ability to "visualize" Like learning a song in Chinese first, then trying to learn it in English... The Chinese words just don't wanna stay out of your head long enough to sing in English.

Almost finished with Six Easy Pieces. Brilliant! Most of the physics is stuff I learned my first year of college, but the way he treats the subject is just beautiful, more like a love story. Except I don't read love stories. But you know what I mean.

Not exactly.

If you touch both ends of two pieces of wood together, does information get transmitted at any rate, or is it simply an extended region of simultaneous contact?

If I have two entangled coins, which are spread a second into the future and the past from my perspective, I give you one, we both flip them, and then at random one of us checks our coin.

What you observe determines what I see, and vice versa, it's an overly simplified description, but it will suffice for explanation purposes.

In the non-local interpretation of QM, your coin and mine are both "spread" spatially, in such a way that the paths they take towards the observed outcome depend on the paths they didn't take canceling out, and each coin can "reach across" an arbitrary distance to influence the paths the other coin doesn't take.

As I'm stating it, the point where they were entangled in the past is within their "present" moment, both coins treat it as being simultaneous with the points where we flip them, and with our observations of the result.

When you adjust the state by canceling out the possible paths, picking a definite outcome, the state of the coins in the past is decided as well, producing the observed result for the other observer.

When you use a delayed choice eraser type experiment, you interrupt the adjustment in a manner that lets you "re-flip" the coins based on the new observation.


The extent to which an object can extend into the past/future is based on it's mass, and the orientation of it's structure in spacetime. Electrical charge emerges as the observable outcome of the past > future or future > past orientation differences. Depending on how massive an object is, or equivalently, the distance it is interacting with due to accelerating, the temporally spread portion is constained by the spatial interaction.

Accelerate an electron, which normally has a significant future > past spread, and you distort it's overall structure. Speed it up enough, and the temporal interaction is traded more and more for spatial interaction, with the sum of the two being the speed of light.

With no mass, you have "fully extended" temporal interaction, time does not appear to pass at the speed of light, it is more like a spatial axis for a massless particle.

As a particle gains mass, it is trading the temporal interaction for spatial interaction, gaining more defined position, and the related velocity constraints due to gravity.

As you cross the planck mass, you enter a purely causal realm, where light cones are boundaries for interactions, and as you push up towards c you lose more temporal interaction. Time dilation can be observed at this point, but attempting to trade all temporal interaction for spatial interaction is a losing battle, and you bump into the light speed barrier.



Basically it's just something that struck me about the equations for gravitational redshift. It mentions that "Since the rate of clocks and the gravitational potential have the same derivative, they are the same up to a constant. The constant is chosen to make the clock rate at infinity equal to 1. Since the gravitational potential is zero at infinity:" which seems fine.

Then you think about what this means, the variation between our observed time dilation (something like 0.97 on the earths surface I think), and that of the most massive bodies in the Universe follows smoothly the relationship between the masses from this point upwards.

There is far more difference between our mass, and the mass of an electron, than there is between our mass, and a supermassive black hole.

So the curve holds nicely between millions of solar masses (0.00000000...1) and the mass of the earth (0.97), then flattens almost completely for virtually no change between the mass of the earth, and zero mass?

I couldn't explain why this should be like that, except when I considered that Einstein thought causality and locality must be preserved. He knew GR protected locality, but it does not do the same for causality, unless you set the rate of time constant to equal 1 at infinite distance from a gravity well (zero mass). He hid it pretty well, people accept non-local weirdness easier than causal violations.

I've been struck before by an idea that wave/particle duality is indicative of such particles vibrating or oscillating in another dimension, and thought time was a perfectly viable alternative for it.

That and I keep getting hooked on the concept that time and light are in fact the same thing. (light in the broadest sense, meaning the photon) I know it's not what you're saying either, but I know that what I just said isn't quite right.. there is more to it, but never could quite grasp what that more was.

If the photon is truly massless though, it would imply that it has an infinite temporal spread though, would it not?
Otherwise it would have to have a temporal spread of some arbitrary constant. And that I just don't like.

It does make sense, if time is a frictionless dimension, that a given mass particle at a given energy would be able to oscillate across it with a given amplitude. higher energy/lower mass would increase amplitude (temporal spread)

I guess what i'm suggesting, is I can "visualize" what you're saying, only I have to twist it slightly that rather than co-existing across the temporal spread, it oscillates across it... Coexisting would, to me violate the conservation of mass/energy. (or would it instead account for the missing 90%+ of the mass of the universe?)

Could an imbalance in this oscillation account for the forward arrow of time? With mass/velocity having an effect to counteract the imbalance (thus slowing time passage)

Not sure how serious i'm taking this idea here... I'm on the verge of falling asleep, and things are starting to ... drift.
But maybe it'll give you something to think about.

Photons have zero rest mass. That is why the move with the speed of light in every inertial frame of reference, regardless of how that frame moves with respect to other inertial frames. However photons have energy which is why they can knock electrons about.

ruveyn.

The Universe would need infinite temporal span to have infinite spread though, and the amount of energy present in photons should reduce it to a finite range covering a vast period of time.

The spread in general is the 4 dimensional structure of everything, my appearance from moment to moment is a 3 dimensional slice of my 4 dimensional shape.

In this case, I'm proposing that massive objects like ourselves are generally limited to interactions defined slice by slice, with all slices defined in a purely causal manner relative to the propagation of light. So I would claim that a beam of light crossing one light second takes no less than one second. If I'm in a frame with significant time dilation, an outside observer in a frame with far less dilation would claim my "second" spanned more than a second, possibly far more. To where I may observe thousands or millions of years as a second from my perspective.

While objects below the quantum/classical transition mass would have a wider slice that they define interactions with, in many cases spanning several slices of a more massive object simultaneously. Claiming that two, or three, or fifty seconds were all simultaneous events, and interacting with them accordingly would appear extremely acausal to an observer with a more narrowly sliced perspective.

He he he he!

I've got three of you in my house. Sometimes my eyes glaze over. The kids have taken to quizzing me periodically to see if I'm paying attention. Eyes are frequently rolled as I give lame answers. Sometimes I lock myself in my room. If only they were interested in the cool social sciences that I love, but no. I have a robotacist, an oceanographer and a mathemetician/historian. I do like the history stuff, and i do like argueing AI with eldest son.

I'm sure I'd enjoy hearing from you in real life, but would need time to ponder. I've never taken physics but it does seem interesting. I used to live near Princeton and had many friends who would try to explain things like String Theory and Plasma Physics. It's interesting, but sometimes they would use terminology that I didn't understand and weren't always very good at bringing it down to my level.

I accidentally made a double post here, so I'm going to edit this to ask my physics question. Pardon me for interrupting your thread with something very basic. I hope you'll enjoy answering.

Last night 2 of my kids nearly came to blows over something to do with the 4th dimension. I was very curious about what they were talking about but when I tried to get them to explain about it they would start fighting again.

What is the 4th dimension? Isn't it space/time?

Is there some big news about it, that involves the origin of the universe or something? I really wanted to hear more but had to put the general peace above my curiosity.

Last edited by Kiley on 19 May 2010, 12:57 pm, edited 2 times in total.

This really isn't an Aspie/NT thing at all, it's an intelligence/learning style thing. My gifts lean in other directions, but I'm pretty good at what I'm good at, it's just not physics. It's shocking how much of the human population really isn't that smart, or that interested in using their brains. I think being an Aspie does tend to focus one on using one's brain as one doesn't have some of the other mental distractions that social sense creates, but lots of NTs are in physics.

I'm not an Aspie, though NT probably isn't exactly the right label for me either. I'm very divergent and have ADHD. I'm also a verbal learner and need to talk and teach about problems to really work them over in my head. Writing or speaking, both work for me. It's annoying for some people especially when they aren't interested in whatever problem I'm working on.

When I get to the end of the thread I have a physics question for you.

Right now I could go all sorts of ways explaining 4D and whatnot.

If you can cross your eyes and see a stereoscopic picture, try this out.

[youtube]http://www.youtube.com/watch?v=iXYXuHVTS_k[/youtube]

Here's another still version: http://www.pitt.edu/~jdnorton/teaching/ ... ereo_1.gif
See how the small cube is "inside" the bigger one?

The small cube is actually the same size as the big one, it's just further away along a 4th axis, often described as ana or kata, inwards/outwards.


Those "tubes" are all the same thickness, and length. All the angles are 90 degree angles, all the gold balls are the same size, and two cubes meet at each square face. That is actually 8 identical cubes folded together in a higher spatial dimension, just as a cube is 6 identical squares folded together in a higher spatial dimension.

http://www.pitt.edu/~jdnorton/teaching/ ... index.html

That page should be understandable regardless of how far into the subject you've gone, look it over for yourself some, it's fascinating stuff, and will help explain a lot of the more arcane terms your kids may use.


Your youngest, the math one, will probably love this site: http://www.pitt.edu/~jdnorton/teaching/ ... index.html, and it's written out at a pretty accessible level in comparison to some of the stuff you can find. I'm constantly suggesting it for people curious about relativity and physics and stuff.

As for spacetime itself, this isn't completely accurate, but it may help visualize it a bit better.

Oh! It's like that cool candle thing where it looks like it's a box but it's really a long shape, it just depends on the angle you're looking at it from. Really fun, no eyes glazing over...but the kid is having a hard time getting his eyes to cross. I'll go read that stuff. At least I'm getting a second chance at a lot of this stuff with my kids.

Yeah, I like to use the geometrical concepts to get people into things easier, without the brainkersploding effect.

I gave some tips for the stereoscopic images in the other thread, it's kind of an odd muscle group to activate deliberately, most of the time we aren't even aware we can do this til we figure out how to cross our eyes in the mirror or whatnot.

Even then it doesn't always click that crossing your eyes can let you pinpoint a nearby spot in space without anything to actually focus on at that spot.


Just be careful about eyestrain, you can give yourself a headache doing it too much if you aren't used to it.

After all the playing around I've done with this stuff, I can move one eye in towards my nose by itself, then turn the other outwards, then back in, tap the side of my head to "shake them straight", and whatnot.

Babies are pretty universally amused by this.

Interesting concept there... they would not be AS biased by the 3d nature of space as we are, their brains ripe and fresh. I might start showing stuff like this to my 12.5 week old son. Hopefully it'll given him counter-action to prevent him from blocking such thoughts from his mind... Then maybe i'll have someone to talk to about stuff like this someday.
I need someone to tell me i'm crazy... if i don't get a daily dose, i might start thinking i'm sane, after all.. and we can't have that!

Edit: Or did you mean the moving your eyes this way and that?

The eyes, but getting kids used to handling higher dimensional geometry young is never a bad idea.

Thanks for the eye crossing tips.

I'm sure my son will figure it all out before I do. I should show it to all the kids and see what they make of it. My eldest has a fairly ordinary IQ, around 120, but in the spacial-reasoning catagory he's way up there...I forget the number 146 maybe? He may be able to explain it to me.

Middle son isn't all that into math, but he might take an interest if we do it together.