Farsight

John, yep, the equation is c = √(1/ε0μ0) where ε0 is permittivity related to capacitance and μ0 is permeability related to magnetiseability, and these can also be combined as impedance √(μ0/ε0). Higher impedance means lower velocity, and I think it's unreasonable to say impedance can never change. PS: I tried to use math but had problems with the ε and μ characters. Fredrik: I have somewhat unusual and speculative ideas concerning time. This is perhaps not the place to discuss them.

Fredrik: apologies, I'm not clear on the above post and cannot respond with any worthwhile contribution. Swansont: no, he was clearly talking about a change in c. Your first link is very interesting but in no way conclusive, and your second link rather fudges the issue and IMHO confuses longer distance with longer time. Distance and time are both confounded on light. See GRAVITY EXPLAINED. Lekgo: re the original question, time has been demonstrably proven to pass more slowly in a high-gravity environment. The official definition of a metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second. If the metre in the high-gravity environment is the same length as the metre in the low-gravity environment, and if time passes more slowly in the high-gravity environment, it means that the speed of light in the high-gravity environment is less than the speed of light in a low-gravity environment. Note however, that in both environments, you will still measure c to be 300,000km/s. It's just like measuring the length of your shadow, but the only thing you can use to do this is the shadow of your ruler.

Here's an animation of the Shapiro effect: http://www.geocities.com/newastronomy/animate.htm Here's a wikipedia-style article: http://www.answers.com/topic/shapiro-delay Obviously the above can't be taken as 100% reliable, but I imagine this Einstein quote is correct: "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) The relative speeds of source and observer is something different, and as Special Relativity tells us, has no bearing on c.

IMHO: Light doesn't actually travel at a constant speed, not even in a vacuum. Check out the Shapiro effect: http://www.geocities.com/newastronomy/animate.htm However we always measure it to be doing 300,000km/s because light defines our seconds and our metres, and c is a conversion factor between the thing we call distance and the thing we call time. Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. This definition refers to a caesium atom at rest at a temperature of 0K… The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second... When c is reduced it affects the photons electrons and atoms of our bodies brains clocks and rulers. So we can never measure it directly. Trying to measure a reduced c would be like expecting to find less than sixteen ounces to the pound. Instead we experience the thing that we call gravity.

All: I'll be grateful for any feedback you can give me. Even if somebody delivers a showstopper. Fingers crossed I'll buff it up with the input I get, and do a version 2. Otherwise: enjoy!

GRAVITY EXPLAINED 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 ρ is the density. 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 rest 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, relativistic mass. The other half goes into rest 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 rest 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:

Genuine question? Let's see now, clearly you haven't read up on Pound-Rebka and Shapiro. If you had, you might appreciate why the object had to come from somewhere is a copout to avoid explaining where the kinetic energy comes from. And given that copout, your no need for a change in c is a refusal to take a rational look at the options. Bah, what was it you said above, you've stated nothing but hokey drivel. LOL, it's embarrassingly obvious that you haven't got a genuine bone in your body, and you're the wind-up merchant here. Don't waste my time snail. If you've got some physics to contribute fine, otherwise take your insults somewhere else.

I'm the guy who wrote TIME EXPLAINED, and I've though long and hard as to why time is not a Dimension and why we do not move through it. But this lajtner link talks about auras and mysticism, and is not science. Here's an excerpt: According to gravitational red shift and the sections above, the units of time and the distances between time impulses in a field are longer if they are nearer to a mass. This phenomenon appears in every field dimension and forms field skins around the mass. These skins have different thicknesses. Thickness depends on the distance between the mass and the skin. (Field skins can also be expressed as time skins)... Astonishing Mystical and Spiritual Relations of Lajtner Theory. By opening up a whole new way of looking at physics, Lajtner Theory can explain a number of previously unexplainable items. Take the following few examples: Auras - Everything has an aura. On the basis of the Lajtner Theory, now we know why. Auras are really the manifestation of the phenomenon of gravity. Healing through the Laying on of Hands, Self-Healing through the Power of Thought. According to modern Western medical knowledge, this is impossible. Not so. Energy radiates from the hands, the mind, and the body. This outpouring of energy can even be measured. One of the simplest tools for this purpose is the flitlat. To view the video, click here. ( If you cannot see the video, click here for... There's a similar new lajtner link on another physics forum.

Please do. I do. Yes I have, and I'm satisfied that I don't. And if the object was sitting there in space as the earth came trundling up? You're ducking the issue and defending it with this primary school slur. When an object falls, the reduction in c is what accounts for the kinetic energy. It also accounts for an increase in mass. You should be aware that I'm a firm adherent to the energy book must always balance. This is why I've been asking where the kinetic energy comes from. I hope you're aware that this means gravity is not a force. When a photon falls it is blue-shifted. It appears to gain energy, but in truth it doesn't. The reason is that reduced c. I didn't assume that the object is created at the height it was dropped from. See above, where I talk about the object sitting there in space as the earth comes trundling up. Also look up the Shapiro effect and the Pound-Rebka experiment: http://en.wikipedia.org/wiki/Shapiro_effect http://www.circlon-theory.com/HTML/poundRebka.html Wikipedia is not 100% reliable, and I don't know what this circlon theory is, please do your own independent browsing.

What, did I misquote you? Utmost apologies. Now let me see, where's your "little merit" post? Here's your first comment on my first-cut TIME EXPLAINED, semantics: http://www.scienceforums.net/forum/showpost.php?p=309275&postcount=25 Here's your first comment on this thread, metaphysics: http://www.scienceforums.net/forum/showpost.php?p=319037&postcount=33 Here's a spectacularly wrong: http://www.scienceforums.net/forum/showpost.php?p=319827&postcount=55 Here's a psuedoscientific: http://www.scienceforums.net/forum/showpost.php?p=323919&postcount=85 Perhaps you might care to reread your posts. Catch the drift. Even of your two posts above. They are yet more digs instead of open honest discussion. And let's remember I only said start here as regards the pmb link to gravity and curved spacetime. I didn't say it was some conclusive proof in support of my position, after all, it's merely an essay.

What logical fallacies? What false premise? What invalid logic? No you haven't. You gave a couple of sentences on binding energy. What I don't specifically understand is how a mass is reduced when it falls to earth, or how energy need not be conserved, or come to think of it, perpetual motion machines.

What data is that exactly? What advice? Like your post above? Geddoutofit. And what errors? Nobody has pointed out any errors. Edtharan's had a try, in his straw-man drown-out axiomatic fashion, but you certainly haven't, and neither has Swansont. Swanson won't even read it, because its "worthless psuedoscience". No, the real problem is that people who know a bit of physics convince themselves that they know it all, despite the fact that they can't give any answers. And when offered some answers, what do they give? Constructive comment? Earnest dialogue? No. Just juvenile insults.

Swansont: I don't like to hear you saying "so what" about Einstein in defense of your view. Or that energy need not be conserved. And apologies in advance if it was my misunderstanding, but you seemed to be a little hazy about mass. IMHO the things you're coming out with sound more like the things you might expect to hear coming from me. Think about it. Anyhow, please can you clarify where, in your view, the kinetic energy of a falling body actually comes from? [math]E=mc^2[/math] Edtharan: Sorry I didn't get back to you yesterday, there was a website problem. I asked you what gives if c=s/t and the t is dilated, and you said space, even though the transverse metre rule is not length-contracted. You say of my ideas every single one has been shot down. I beg to differ. I have to say you seem to be rejecting everything out of hand, and moreover creating obscuration and confusion with your very long posts. Please make smaller posts, raising points individually so that I can demonstrably deal with them.

Start with this: http://xxx.lanl.gov/abs/physics/0204044 Pete Brown is pmb, I'm sure he'd be perfectly happy if you emailed him for more details. Like you dismiss my essays? No, I'm not happy to be dismissed so trivially. I didn't mean to be trivial about Feynman, it's just that it was the end of lunchtime and the website was playing up. I work for a living, and now I've got to go do some.

I'll defend it in the Mass Explained thread. Don't dismiss it as psuedoscientific until you've actually looked at it. Whoa. Mass is nowadays defined to be invariant in all frames. There's been a lot of debate about this. You'll find yourself in big arguments with your colleagues if you say a photon "has mass". Note though that I view rest mass as the special case and would prefer to see relativistic mass used as the definition. I know gravitational redshift is real. Yes, the energy is different. But remember a photon has no rest mass. It has relativistic mass, which equates to energy, see above. But let's put mass to one side: the excited nucleus has more energy at the top of the gravity well than at the bottom because the c is lower at the bottom. The difference in c accounts for the kinetic energy of a falling body. It's where the potential energy can be found. If you disagree with this, give me an alternative: where does the kinetic energy of a falling body come from? Your "energy need not be conserved" really doesn't cut it. Sorry, I'm afraid this lecture employs the wrong concepts. I know that sounds arrogant, because Feynman was a smart guy and a good egg. But there you go.

There is no curvature. Gravity is not curved spacetime. Einstein did not agree with the view that it was. Yes, mass and energy are interchangeable, but a mass really doesn't create energy for any objects in the vicinity. And since you think it does, I don't think I'll be convincing you of anything much.

Don't dodge the issue. This is like I've asked you describe an elephant and you're fobbing me off by asking me what type of elephant. Come on, if you really do think you understand energy, explain it. Give a description of the underlying property that is common to electromagnetic energy, kinetic energy, or any other type of energy that you choose. Don't give me some non-explanation that tells me what Energy does. Tell me what it is. If you can't, then you don't understand it, and you need to stop kidding yourself.

Pay attention Snail. Time Explained says time is not fundamental, and we must consider spacetime to be space. It's only the path of an object that is curved over time. The space is not curved. You have to take the time derivative of your "curved spacetime" to see that what's actually there is a gradient in space. It's a local tension gradient orthogonal to the mass/energy stress. This gradient is expressed as a gradual change in c. That's what the gravity is. The problem is this: where does that potential energy actually reside? Where does the kinetic energy actually come from? Don't just say the gravitational field, because that's a brush-it-under-the-carpet non-answer. This is the TIME EXPLAINED thread, and the link I posted for Swansont was to MASS EXPLAINED. Cylindrical Universe? Spring idea? What is this? Energy is stress, and a volume of it. Oh come on, you don't need mathematics to think about it and give reasoned feedback. That's just an excuse. One day maybe some of you will realise just how important these essays are, and how they totally knock spots off some of the stuff under Physics. One day maybe somebody will say Oh My Gawd He's Right and move them out of Speculations and slap them into Physics where they belong. PS: I'm on holiday for a week from tomorrow and will probably be incommunicado.

The plain vanilla variety, insane alien. Yes, energy is stored and delivered in many different ways, eg chemical, nuclear, radiation, kinetic. But there is a common underlying explanation of what it is. I'm on holiday for a week from tomorrow, and will probably be out of touch for a while.

I'm sorry, but I don't like potential ability to cause change. It doesn't say what energy is. It tries to say what energy does, but I can cause change, and I'm not energy. You don't have to be able to define it, or define it accurately. Nor do you have to stick to fifty words. But you ought to be able to describe what it is rather than what it does, and give the gist of it at least. If you can't, then you have to appreciate that actually, despite what you think, you don't really understand it after all.

My simple electron is not bound in some nuclear embrace with the earth. So binding energy is not the answer here. On the micro scale one needs the intuitive grasp of how energy is stress x volume and relates to momentum via c, and then how momentum is localised into inertia. If it takes energy to pull your proton and your electron apart, this must end up localised as additional mass. On the macro scale mass is considered to be invariant - an object doesn't change mass when it falls to earth. That's because gravity is different to Electromagnetism. You can cut a travelling electromagnetic stress, a photon, so that it forms two stable loops thereby creating an electron and a positron - each with mass. You just can't do the same sort of thing with gravity. To reiterate, if E=MC2 and the mass doesn't change, that kinetic energy has to come from a change in C.

Don't blame me. People talk about "pure energy" when they don't have any real notion of what it is. Can you explain what energy is in a sentence or two? Can you give something better than the capacity to do work because, see essay, that's a circular definition that doesn't get to the heart of it. If you can't put it down succinctly, then whatever you might think, you don't actually understand it. I feel that I do understand energy, and judging from some of the responses on this thread, I rather feel that people who don't understand it, don't want to. With the exception of jck I haven't seen any constructive input or any correction or alternative.

And where is that potential energy situated before the falling object starts falling?

Consider a very simple case involving a single electron - you have no neutron or protons to attract one another. But perhaps you first of all need to understand what mass is, so see MASS EXPLAINED: http://www.scienceforums.net/forum/showthread.php?t=24320