Gravity Explained

[Farsight]

You probably think of gravity as curved spacetime. Surprisingly Einstein didn’t, not quite. And neither should you. To understand gravity you have to take the ontological view. You have to learn to see what’s there. And to do that, you have to put time to one side, because time isn’t the same kind of dimension as the Dimensions of space. Yes, an object passing a planet traces a curved path, but you don’t stare up at a plane and decide that it’s a silver streak in the sky. You take a mental snapshot, flash, a picture of it in a timeless instant. It’s the same with gravity. Take the time-derivative of that curved spacetime. What you get is a gradient. And it’s a gradient in space, not curved spacetime.

 

 

But let’s tackle it an easier way, via an old favourite. Think about a cannonball sitting on a rubber sheet. The cannonball is heavy, and it makes a depression that will deflect a rolling marble, or even cause the marble to circle like an orbit. It’s a nice analogy, but it’s wrong. It’s wrong because it relies on gravity to pull the cannonball down in the first place. It uses gravity to give you a picture of gravity.

 

 

To get a better handle on it, imagine you’re standing underneath the rubber sheet. Let’s make that a silicone rubber sheet. It’s transparent, like my snorkel and mask. Grab hold of the rubber around the cannonball and pull it down further to give yourself some leeway. Now transfer your grip to the transparent silicone rubber itself. Gather it, pull it down some more. Now tie a knot in it underneath the cannonball, like you’d tie a knot in the neck of a balloon. Now pull it all the way down and let go. Boinggg! The cannonball is gone. Forget it.

 

 

Now, what have we got? We’ve got a flat rubber sheet with a knot in it. The knot will stand in for a region of stress, where the rubber is under pressure. Stress is the same as pressure. It’s force per unit area, and force times distance gives us the units for both work and energy. So energy is stress times volume. The knot represents energy. Or matter if you prefer. OK here’s the deal. Surrounding the small central region of stress is a much larger region of tension extending outwards in all directions. Whenever you have a stress you always have a tension to balance it. It isn’t always obvious, but it’s always there, like reaction balances action, and force balances force. The tension gradually reduces as you move away from the stress. If you could measure it, you would measure a radial gradient. But measuring it is trickier than you think. Because in this analogy we can’t use a marble rolling across a rubber sheet. This rubber sheet represents the world, there’s no stepping outside of it. Our “marble” has to be within the rubber sheet, and a part of it, made out of the same stuff as that knot.

 

We need an extra dimension. So turn your top hat upside down and tap it with your magic wand. Abracadabra! A flash of light and a puff of smoke, and that rubber sheet is now a solid block of clear silicone rubber extending in all directions. And you’re standing inside of it. Let’s make you a ghost so you can glide around unimpeded, for the purposes of gedanken. Our knot is now three-dimensional, like a moebius doughnut, maybe a little silvery like a bubble underwater. It’s not really made out of anything, it hasn’t got a colour, and it hasn’t even got a surface. It’s a soliton, a topological defect, a travelling stress that’s basically a photon, but going nowhere fast because it’s twisted round on itself. So E = hc/λ = pc = mc² means the momentum is now inertia, and we call it an electron.

 

 

Our electron has replaced our cannonball, and now we need a photon to stand in for that rolling marble. Let’s conjure one up, and send it propagating across our rubberworld so that it passes by our electron. We could run after it and take some snapshots with our ontological camera, but let’s save that for another day. For now our photon is just a shear-wave ripple, travelling at a velocity determined by the stiffness and density of the medium. There’s an equation for it in mechanics that goes like this:

 

v = √(G/ρ)

 

The G here isn’t a gravitational constant, but is the shear modulus of elasticity, to do with rigidity. It’s different to the bulk modulus of elasticity, because it’s a lot easier to bend something rather than compress its volume. The equation says a shear wave travels faster if the material gets stiffer, and slower if the density increases. In electrodynamics the velocity equation is remarkably similar. You’ve probably seen it before:

 

c = √(1/ε0μ0)

 

Here ε0 is permittivity and μ0 is permeability. The two are related by impedance √(μ0/ε0). High permittivity means a material will take a larger charge for the same voltage, for example Barium Titanate has 1200 times the permittivity of air, so we don’t make capacitors out of air. High permeability means a material exhibits more magnetism when you change the charge. Iron has lots of it, wood doesn’t, so magnets are made of iron. There are some marvellous similarities between mechanics and electrodynamics, though confusions abound too. With the piezoelectric effect you subject a material to mechanical stress and you get an electrical stress, a voltage, but high voltage is called high tension, which is negative stress. And electric current goes from negative to positive, so things are backwards. But let’s come back to that another time, and just say higher impedance means lower velocity.

 

Back in rubberworld, our photon-marble is passing our electron-cannonball. We notice it veers towards it a little. That’s because where the rubberworld tension is slightly greater, the real-world impedance is slightly higher, so the velocity is slightly lower. What we’re seeing is refraction.

 

 

Here’s the crucial point: our real world is like that rubberworld with the knot in it plus an extra dimension, and we’re made out of this stuff, along with our rulers and clocks. So we don’t see the tension. We don’t measure the change in c. But we can infer it. Like in the Pound-Rebka experiment, where a photon is blue-shifted at the bottom of the tower because c there is lower. Or in the Shapiro experiment, where the light takes longer to skim the sun because the c there is lower too.

 

There’s an equivalence going on here between General Relativity and Special Relativity, but it’s tricky to spot. Imagine that I stay here on earth while you travel to Alpha Centauri in a very fast rocket travelling at .99c. We can use 1/√(1-v²/c²) to work out that you experience a sevenfold time dilation. (Multiply .99 by itself to get .98 and subtract this from one to get a fiftieth, which is roughly a seventh multiplied by a seventh). We normally think of time dilation as being matched by length contraction, but that’s only in the direction of travel. Hold up a metre ruler transverse to the direction of travel and it’s the same old metre. Your metre is the same as my metre, and your time is dilated by a factor of seven, which means it takes a beam of your light seven times longer to traverse your transverse metre. Looking at it another way c = s/t and your t changed, your s didn’t, so your c did. Your c is a seventh of mine. Don’t get confused about this. Don’t tell yourself that your lightbeam is following a diagonal path and has to cover a greater distance. That’s introducing an absolute reference frame, mine. Stay in your own frame. Then when you come back after your year-long round trip, I aged seven years, but you only aged one. You aged less because your c was slower than mine, but you never noticed it at the time. The equivalence comes in because I could have slid you into a black box and subjected you to high gravity instead of sending you to Alpha Centauri. We know that “clocks run slow” in a high gravity situation, just as they do when you’re travelling fast. And it’s for the same simple reason. The c is reduced. But you won’t measure it as reduced, because it’s just a distance/time conversion factor. Just like you when you go to the moon you don’t get three ounces to the pound.

 

 

I know it’s difficult to stop thinking c is a constant. Yes it’s always measured to be the same in all frames. But when you step back to see the big picture that is the whole gallery, when you look at all the frames side by side, you see what distinguishes them is the way c changes. It’s a constant, but it isn’t constant. Once you realise that c changes in a “gravitational field” you can allow yourself the epiphany of understanding gravitational potential energy. We know that E=mc², so a cannonball sitting quietly in space represents maybe 1011 Joules of energy. If the earth now trundles on to the scene, the cannonball will fall towards it, and just before impact will also have kinetic energy of say 109 Joules. Now hold it right there. Freeze frame. Where did that kinetic energy actually come from? Has it been sucked out of the earth? Has it been magically extracted from some zero-point bottomless bucket? Has it come from the “gravitational field”? No. There’s no free lunch from Mister Gravity. The energy came from the cannonball. And it hasn’t come from its mass because mass is “invariant”. Only it isn’t invariant because the mass has actually increased, check the Pound-Rebka experiment. So E=mc² and we’ve got a pile of kinetic energy that hasn’t come out of the m. There’s only one place left it can have come from. The c. The c up there is greater than the c down here, and there’s a gradient in between.

 

There’s always a gradient in c when there’s gravity. Even across the width of an electron. Yes, the gradient might be very small. But it isn’t negligible. If you think it is, as per the General Relativity Equivalence Principle, you’ve just thrown the baby out with the bathwater. An accelerating frame with no tidal gradient isn’t the same as a proper gravity situation. There’s always a tidal force. The gradient has to be there. There can be no Uniform Gravitational Field. Because without that gradient, things don’t fall down.

 

Let’s go back to rubberworld. But it’s time we did a Reverse Image and made the rubber the ghost. Now you’re back to normal again take a look at that electron once more. It’s a travelling stress localised because it’s going round in a circle. Stick this ring of light in a real gravity gradient, caused by a zillion other electrons some distance downaways. What’s going to happen? Flash, take a picture. At a given instant we have a quantum of light travelling down like this ↓. There’s a gradient top to bottom, but all it does is gives the photon a fractional blueshift. A little later take another picture. Flash. Now the photon is moving this ← way, and the upper portion of the photon wavefront is subject to a slightly higher c than the lower portion. So it bends, refracts, curves down a little. Later it’s going this ↑ way and gets fractionally redshifted, and later still it’s going this → way and curves down again. These bends translate into a different position for our electron. The bent photon path becomes electron motion. Only half the cycle got bent, so only half the reduced c goes into kinetic energy. The other half goes into mass, but it’s only a scale-change falling out of the clear blue sky:

 

 

So here’s your free lunch:

 

 

Now you can understand why gravity is not some magical, mysterious, action-at-a-distance force. There is no curvature of spacetime, no hidden dimensions, no gravitons sleeting between masses. There’s no energy being delivered, so gravity isn’t even a force. It’s just the tension gradient that balances the stress that is mass/energy. And we’re just rubberworld Fatlanders getting to grips with our wrinkles and bumps.

 

No energy delivered, extra mass to use as collateral... that means there’s no energy cost. So if we could somehow contrive a gradient that goes the other way... whoo, it’ll be The Stars My Destination. But first of all we must also understand the thing we call Space. We must learn how light is a ripple of nothing, and how all the somethings are made from it. It’s a tale of something and nothing, and since nothing comes for free, there will be a Charge...

 

 

Acknowledgements: thanks to J.G. Williamson and M.B. van der Mark for Is the electron a photon with toroidal topology? http://members.chello.nl/~n.benschop/electron.pdf, to Peter M Brown for his many papers on his excellent website http://www.geocities.com/physics_world/, to Robert A Close for for Is the Universe a Solid? http://home.att.net/~SolidUniverse/]home , to Reg Norgan for http://www.aethertheory.co.uk/pdfRFN/Aether_Why.pdf, to G S Sandhu for The Elastic Continuum http://www.geocities.com/gssandhu_1943/index.html to all the forum guys with their relevant posts and links, Wikipedia contributors, and to anybody who I’ve forgotten or whose pictures I’ve used. Thanks guys. Oh, and thanks to:

[Farsight]

All: I'd appreciate any feedback you can give on the above to straighten me out. Even if it's some kind of photon torpedo that sinks the whole essay. Otherwise, enjoy!

 

:eek:

 

PS: I'm also known as Farsight.

[kalesh]

Interesting Read.

I'm still trying to digest the info. Some if it actually reflects a theory of time I have. I'll soon post some comments on to improve this.

[Farsight]

Kalesh: Have a read of TIME EXPLAINED v2.1

 

http://hypography.com/forums/search.php?searchid=139231

[Boerseun]

Interesting, however, I think you're unnecessarily complicating matters.

 

The original 'rubber sheet' analogy serves perfectly well in a 2-dimensional world where the cannon ball warps the sheet into a third dimension that's utterly inaccessable to 2D-worlders unless a heck of a lot of mass is supplied. The fact that a rubber sheet will be 'pulled down' by a cannonball in real life due to gravity, is simply coincidental, but that's not the idea behind the analogy. It's not using gravity to prove gravity, it's illustrating how a n-dimensional world can change in the n+1 dimension under certain circumstances. Mass does indeed change the time dimension locally. An extreme example of this would be a black hole inside of which time comes to a grinding halt. That is screwing around with spacetime, which certainly exist.

 

I do, however, like the idea of local stress gradients, but following that specific line of thought to its ultimate conclusion will bring you straight back to ether, which, according to Michaelson-Morley does not exist. Your stress gradient has to exist in something, surely. If it simply exist as an ethereal 'stressed space', then you've simply ended up in describing spacetime by another name, and you're back to square one.

 

You're also attempting to recreate the 'rubber sheet' world in 3D, which isn't the intention of the rubber sheet analogy. The intention is simply to illustrate how an 'invisible dimension' can be affected through happenings on the lower dimensions. Seeing as we can only see 3 dimensions, we have to have a 2 dimensional analogy so that the changes in the 4th dimension can be displayed in the 3rd dimension.

[Farsight]

Thanks for that, Boerseun. I do need to talk properly about space and charge to really get to the bottom of this stress and tension. Then perhaps I could persuade you that it's those extra dimensions that complicate things unnecessarily. Especially the "time" dimension. Yes, it does rather end up with a type of aether. But different. See Einstein's 1920 Leyden address. This is Aether 2, the sequel. And it's a horror movie!

[Farsight]

Personally I think the Shapiro Effect is a cracker. Here's an animation and a wiki-style article.

 

Illustration of the Shapiro Effect

Shapiro delay: Information from Answers.com

 

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity ; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light)." - Albert Einstein (The General Theory of Relativity: Chapter 22 - A Few Inferences from the General Principle of Relativity)

[Uclock]

Popular

 

Have you worked out the math of this assumption that gravity is a form of stress and can this math mathematically match Newtonian gravity?

Also can you tell me what is being stressed exactly?

 

Tony

[Farsight]

Popular, have you worked out the math of this assumption that gravity is a form of stress and can this math mathematically match Newtonian gravity? Also can you tell me what is being stressed exactly? Tony

 

Sorry, no. But I wouldn't expect much different, for example

 

[math]F=GMm/r^2[/math]

 

still holds. I'll perhaps look further at this at a later date, but it hasn't been a priority to date because what I've been trying to do is describe what the axiomatic mathematical terms actually mean. See TIME EXPLAINED, MONEY EXPLAINED for a bit of fun, ENERGY EXPLAINED, and MASS EXPLAINED. In essence they're telling you about t £ E and m. Do read them in that order. It's all classed as speculation, but there appear to be no flaws in the logic.

 

Space is being stressed. There are subtleties here. I hope to explain how it works in the next essay, which will either be called SPACE EXPLAINED or CHARGE EXPLAINED.

[Uclock]

Popular

 

Sorry, no. But I wouldn't expect much different, for example

 

still holds. I'll perhaps look further at this at a later date, but it hasn't been a priority to date because what I've been trying to do is describe what the axiomatic mathematical terms actually mean. See TIME EXPLAINED, MONEY EXPLAINED for a bit of fun, ENERGY EXPLAINED, and MASS EXPLAINED. In essence they're telling you about t £ E and m. Do read them in that order. It's all classed as speculation, but there appear to be no flaws in the logic.

 

What seems logical to one person may seem illogical to another but unless you have the math to back up your idea most will just read your point of view of reality and move on.

 

 

Space is being stressed. There are subtleties here. I hope to explain how it works in the next essay, which will either be called SPACE EXPLAINED or CHARGE EXPLAINED.

 

So is space some kind of aether then in your view?

 

Tony

[Farsight]

Popular, What seems logical to one person may seem illogical to another but unless you have the math to back up your idea most will just read your point of view of reality and move on.

 

I know, Opmoc. I think it happens a lot. People are generally more comfortable when they see more mathematics than I've used here and in previous essays. But they don't appreciate the difficulty of using mathematics when the subject matter is in essence the very axioms used within mathematics. See my post above.

 

So is space some kind of aether then in your view?

 

Yes. But it isn't the sort of aether that the Michelson-Morley experiment was intended to detect. It's something different. I like to think I share Einstein's view:

 

"..according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it." Albert Einstein, Leyden address, 1920.

[arkain101]

Popular I have enjoyed all your essay's. They read well and keep me interested.

 

What Uclock said is true. "Most" will depend on the maths constructed from the logic. Not everyone is a very powerful logician.

 

However "most" is not all. With that said I think you stress some profound points in your essays.

 

I find a saying that makes sense related to this.

Logic without math is blind. Math without logic is lost.

 

I think it is just as important to interpret the logic properply as it is to have math that works.

 

Energy for example. The equations describe energy as a thing. You have pointed out that it is not a thing.

 

This I agree to. I am skeptical when I see something being called a fundamental, such as energy. I would be one to say there must be something that energy interacts with. I am not going to attempt at describing just what that is at the moment.

 

Though I hope this stresses my point that logic is important, and although it may be to some as "your" way of seeing it. There is more to it than that. It took a "way of seeing" to create modern science, its not always limited to a personal perspective.

 

 

Now with that said I think this model on gravity is a good way to illustrate an easy to understand concept that introduces you and prepares you for going to the next step.

 

I see one problem when we try to take this logic to the next step. This model implies that we can think of space as a position inside a thing, even if that thing is an invisible blob.

 

In respect to the fact that physics remains the same inside all frames of reference this should say it exludes physics where there is NO frame of reference. What this entails is that space and time is independent for each frame. Also, each frame should have its own seperate unite of space and time intimately intwined and as much as a part of the frame as the frame is a part of it.

 

Electromagnetic radiation appears to have two of three components in the universal perspective. It has null charge with (i)Electric and (ii)magnetic properties, but appears to be missing the (iii)time component, which would include a space compnant.

 

I suspect that logic must begin to introduce itself to the concept that space and time is also not a thing, as you would describe energy is not a thing.

 

If you are confused to what I mean by this allow me to use an analogy.

 

With our human mind we look out to the skies and we see a vast universe surrounding us that has special relativistic behaviours. Or do we?

 

However, we (our perspective) is nowhere beyond the atoms that make up our bodies, both in relation to distance and time. So we must constrict ourselves to this location.

 

So the analogy would be to propose that there is countless universes. Each universe is a functioning idependent unit of charged-mass-space-time. Let that be an example of an atom. Each unit is constant, this goes further than to say in respect to its own frame, but because it is the emobiment of a frame, a bubble of time and space.

 

This analogy is only one of, I suppose could be many possible forms to apply this logic that space and time are not of form.

 

I hesitate to get into descriptions but I will attempt to throw out some fundamental things that could be derived from this logical proposal.

 

Allow a black hole to represent a unit of space-time where time has been set to nearly zero for the exchange of something else. Such that energy has been shifted from the side that creates events to the side that slows events.

 

In such a way that is similar to where matter can take on a different state at absolute zero in a bose-einstein condensate, except possibly at the other side of the scale.

 

 

Overall, I am interested in focusing on how you would like to support the rubber world analogy or replace it.

[Farsight]

I'm not sure about the above, arkain. For now maybe the best I can say is this:

 

Energy is in essence stress, light being the closest thing to "pure energy".

 

Light is a travelling stress. It's travelling through space, and has energy and momentum.

 

If you nail down the light in one place by twisting it into a loop, that momentum is translated into inertia, and you've got mass.

 

If matter is made out of light, everything is something like Rimmer the "hard light hologram" from Red Dwarf, meaning we live ina kind of Rimmerworld. If you mentally collapse this to two dimensions like an ordinary movie projection, you can grasp how the length of anything depends on the projection.

 

Hence space starts to look less than absolute too. But I need to think this all through with respect to and permittivity and charge.

[arkain101]

Interesting. I enjoy reading any idea that is out there when it is layed out in such an understandable way. These ideas may never be correct but they will always have the capacity to act as tools for expanding ones thought. One of the most difficult things to do is to think of something that may never have been thought about before. Like a round earth, like the sun at the center of the solar system, like a color you have never seen before, or like time is not a galactic universal grandfather clock.

 

These insanities of logic that can be incredible difficult for even the incredibly gifted individuals who discover them, but they have continually offered us to generate order out of the most jumbled pile of measurements, observations and thoughts.

 

I want to quote Einstein from this particular article:

 

In 1950 A psychologist by the name of R.S. Shankland asked Einstein how long he had worked on the Special Theory of Relativity before 1905. Einstein told him that he had started on the problem at the age of 16, already as a student when he could devote only part of his time to it. and worked on it for tend years. He made many fruitless attempts to develope a theory consistent with the experimental facts, but they had to be abandoned, 'until it came to me that time was suspect!'.

Einstein, in his conversation with Shanklad , commented at length on the nature of mental processes, and emphasized that our minds do not seem to move step by step to the solutions of a problem; rather, they take a devious route. 'It is only at the last that order seems at all possible in a problem,' said Einstein.

[arkain101]

Back to your gravity.

 

How would one explain with any kind of aether; Radar signals passing near a massive object takes slightly longer to travel to a target and longer to return (as measured by the observer) than it would if the mass of the object were not present, if while those signals do not take longer for an observer who is located inside that particular gravitational field?

 

ie: measureing the speed of light on the surface of the planet.

 

That is, what properties would an aether require in order to have light succumb to an increase delay as it passes through a gravitational field relative to an observer outside of this field, while at the same case succum to an decrease in delay relative to an observer inside the particular gravitational field?

 

I suppose the question is only logical if my understanding of these events is accurate.

[Farsight]

Good one about Einstein, arkain. Yes, time is definitely suspect. That "aether" would have the property of increased permittivity - capacitance. That's what the gravity is. Note that the observer who is within the zone wouldn't be able to measure anything different to 300,000km/s. He wouldn't see a decreased delay. See the bit in TIME EXPLAINED where I give the definition of seconds and metres. They're both defined by light. So if light goes slower you don't notice it.

[arkain101]

Interesting.. I will consider.