MASS EXPLAINED You know that energy is an intangible thing. You can’t hold energy in the palm of your hand. Because energy is to do with stress, which is the same as pressure, which is the same as negative tension, and you need a volume of stress to get the units right. Because stress is force per unit area and energy is force times distance. You know that mass is a tangible thing. You can hold a thing in your hand and feel the mass of it. You even know that E=MC2, and that the intangible thing called energy can be used to make the tangible thing called mass. But you don’t know how. I’ll explain how. The answer is all down to motion. Or the lack of it. You have to think in terms of momentum and inertia. You have to stop thinking that momentum is something that a mass has, because a thing can have momentum without having the thing you think is mass. Like a photon. You know this because you’ve read the physics. You also know this because you’ve felt it yourself, down on the beach, playing in the surf. Along comes a massive wave. You know it’s a travelling stress and you think it has no mass because it’s the water that has the mass. But the wave does have momentum, enough to knock you and your girlfriend flat on your back, laughing and screaming with salt water up your nose. You can’t grab hold of it, but it can grab hold of you. And realising this is the first step in grasping how intangible energy can become tangible mass. Please Register or Log in to view the hidden image! You can get a better feel for this with a gyroscope. Waggle it back and forth. See how light it feels. Now wind the string round the spindle, grasp it tight, and pull. You pulled tension out, so you put energy in. Your gyroscope is now humming, maybe precessing a little. When you try to waggle it you can feel the angular momentum working against you. And you’re beginning to get a feel for mass. Something that has a lot of mass is harder to move. Or harder to stop. Because it’s got a lot of inertia. Or a lot of momentum. And a lot of energy. And these things aren’t quite as different as you might think. energy E=mc2 kinetic energy KE=½mv2 momentum p=mv inertial mass=m Consider a 10 kilogram cannonball travelling at 1 metre per second in space relative to you. Brace yourself, then apply some constant braking force by catching it in the midriff. Ooof, and you feel the energy. Kinetic energy is looking at this in terms of stopping distance, whilst momentum is looking at it in terms of stopping time. The momentum is conserved in the collision because the two objects shared a mutual force for the same period of time. The kinetic energy isn’t conserved, because some of the mass-in-motion was redirected into deformation and heat and probably bruises, all of which involve mass-in-motion, but scattered motion instead of tidy vector quantities of masses moving relative to you. Or you moving relative to them, because all the while you were never too sure whether it was you moving or the cannonball. When we turn our attention from a cannonball to a photon, we have to express the energy and the momentum in a different way. There is no “mass”, so the energy is hf, and the momentum is hf/c. The h here is Planck’s constant of 6.63 x 10-34 Joule-seconds, and is an “action” which is a momentum multiplied by a distance. The f is the frequency per second, and our old friend c is distance over time, which converts a stopping-distance measure into a stopping-time measure. It’s just λ/c or wavelength over frequency, so you can also express the momentum as h/λ. And you can see how that momentum affects a mass via Compton scattering: Please Register or Log in to view the hidden image! When a photon collides with a free electron the electron gets a bump and goes flying off at an angle, while the photon is similarly deflected and its wavelength is increased. The electron has gained some kinetic energy and the photon has lost some momentum. Or vice versa. Their velocity vectors have changed, as have their relative velocities. You can play “photons” at home with a strip of carpet or better still a rubber mat. Lift one end, grip it tight, and give it a big shake. You can see a wave travelling down the length of the rubber. It’s a travelling stress that rides on the tension it creates, and you can toss “electrons” with it, be they dollies or eggs. Hours of endless fun. Better than an egg in the microwave for four minutes. Now imagine you’re the electron, only it’s you moving instead of the photon. Bump, and you’re sent flying off at an angle. It feels like you hit something solid instead of a volume of stressed space. Like a bad flight with so much turbulence it’s like riding over rocks. It would feel like the photon had inertia instead of momentum. But the photon isn’t sitting in one place, and you can’t nail it down like you can nail down your rubber mat. So how do you keep that bump of momentum in the same place? There’s only one tool in the box. More of the same. Imagine you’ve got a couple of table tennis bats and you’re good at topspin. If you bat that photon just right you can change its direction and give it some energy. It’s called an Inverse Compton, like the picture above but with the arrows going the other way. Then you can hit it with the other bat to change its direction again. Repeat in rapid succession until you’ve got a kind of hexagon going, a miniature electromagnetic vortex. Now keep batting away, but close your eyes, like you might close your eyes when you’re playing repulsion with a couple of magnets. You can feel something there between your bats. What you can feel is basically mass. You’ve made a mass. It isn’t a proper mass because if you stop batting your photon will be off like a shot. You need to bat faster and harder to get it down smaller and smaller. You’re packing more and more stress into a smaller and smaller volume. Then at 511keV, or 8.18 x 10-14 Joules, a funny thing happens. The volume will fit only a single wavelength, and the stress in your photon kind of tangles round itself like a moebius-strip bagel, spinning and rolling around itself like a smoke ring, and suddenly you’ve got yourself a self-sustaining vortex that you don’t have to bat any more. You’ve got yourself something that goes round twice to get back where it started, so it’s got spin ½. All the negative charge variation is on the outside, so it’s got negative charge. And most importantly, because it isn’t going anywhere, when you hit it, it’s you hitting the photon instead of the photon hitting you. It had momentum, and now its got inertia. It’s got mass. And you’ve got yourself an electron. Please Register or Log in to view the hidden image! It’s wrapped into tight little loop, and you can’t undo it. When you give it a little tap with a bat you can still think in terms of the Compton picture. But now the whole thing is tied into a single wavelength and since it isn’t kept in place by some atomic nucleus acting like a tetherpole, you can’t stretch it with a little tap. All you get is the deflection. That deflection is a change in the photon velocity vector, it adds to all the velocity vectors in the moebius loop. It translates into motion, so the electron as a whole moves with respect to you. You can do the same sort of thing to make a positron. It’s got the twist wrapped the other way, with the positive charge variation on the outside. But there’s no table tennis bats in particle physics. In practice you fire a mega-electron-volt photon at an atomic nucleus, whereupon it splits into two to create an electron and a positron at the same time for conservation of charge. The positron won’t last long because it will meet an electron, and the two will annihilate to create a pair of 511keV gamma-wave photons flying off in opposite directions. It’s like the electron is a twist in your fishing line and the positron is the mirror image twist. Slide them together, and voila, twang, gone. Now when we go back to your cannonball we can see how it’s a whole heap of whirling stress, a trundling bundle of energy. But is the cannonball moving or is it you moving, and what’s its mass? Is the rest mass calculated from the transverse velocity vector of those racing photons, or is it the relativistic mass of whatever path they trace through space? Take your pick, but I pick the latter. Which means in my eyes photons have momentum, and energy, and mass too. It’s all relative really, because we’re made out of these things, they’re like our light clocks. If you’re racing past me, yours look like this /\/\/\ to me and mine look the same to you. But our own look like this | to each of us. Our length contraction of 1/√(1-V2/C2) is relative, like our time dilation, and our momentum and energy, so I think our mass might as well be relative too. Anyhow. That’s why a moving mass is rather like a spring. It looks like a spring stretched out rather than a spring compressed. That’s why a moving mass has something that looks like tension, sorry negative tension volume, that thing called energy. I will talk some more about these things. I will talk about electromagnetism and space, and whether energy is a property of space or makes it the thing that it is. And I will talk about particle physics and string theory, and matter. But first, I need to try to explain a matter of some gravity... Acknowledgements: thanks to J.G. Williamson and M.B. van der Mark for Is the electron a photon with toroidal topology? see http://members.chello.nl/~n.benschop/electron.pdf to Peter M Brown for his many mass papers on his excellent website http://www.geocities.com/physics_world/ , to Robert A Close for The Other Meaning of Special Relativity A New Interpretation of Special Relativity, to R F Norgan likewise see http://www.aethertheory.co.uk/pdfRFN/Aether_Why.pdf, 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. And Paul Dirac. Thanks guys.
If anybody can give me some feedback to this layman's explanation I'd be grateful, even if it sinks it.
A poster called Good Elf on another forum showed me this. I really liked the way Qiu-Hong talks about grasp and intuition as opposed to the abstraction of mathematics. Note what he says about mass being action (=momentum) constrained by curved spacetime. "The Nature of the Electron" by Qiu-Hong Hu http://arxiv.org/pdf/physics/0512265
the photon is massless in relation to the sun as people are massless in relation to the universe. I mean big deal...one human and huge universe.
I read it again closely and I didn't miss anything that I saw the first time. However, now that u mention that it's sarcasm.......
...there was a story in China, about a man who dared to go against the slaughter of other Chinese people who did not want to obey the ruler. "Hero" is the movie detailing this story. Well after many assassination attempts, the man reached the ruler and had the sword against the emperor's throat. But he never killed the emperor. Because the emperor told him that 1000's dead will allow 100000's to be spared. So one man is nothing, now?
Please Register or Log in to view the hidden image! my view of the electron is slightly different... but... your views are just as well... it would seem. -MT
>> now its got inertia. It’s got mass. Hand waving.... What is "inertia" ? IMO mass is a variable. What is "mass" ? Until you really understand these concepts we use for unexplained observations, your foundation thoughts are castles in the air.
Re the electon Love that pdf, good work I have found the ultimate equation that defines energy, from electrons to planets etc is energy = N / [(pi^2)^n] where N is the wave number.. between pi and 2pi and n is the integer quantum number. It seems that an electron's energy can be described by n =3 and N = pi All are logical geometric representations in Euclidean space.
I've been thinking about that, but I can't give an answer as yet. I plan to write a CHARGE EXPLAINED essay at some point. Uri: What do you mean hand-waving? Do you want me to insert a definition of inertia? I thought I'd explained mass adequately. Please elaborate. If you're happy to define energy via an equation, please describe what is is, in English. If you can't, you have to face up to the fact that you don't understand it.
Thanks for the interest, Prince James, though they don't qualify as theories. They're just essays for the layman, by a layman, hopefully with an ontological slant that's heavy on insight and grasp. I hope that sitting down and trying to explain things like this helps my own understanding, though of course I need rational feedback to have any confidence of this. It certainly increases my enjoyment of Physics, and it seems to be more productive and rewarding than 100% chitchat. Anyhow, they follow on from one another in logical progression: TIME EXPLAINED MONEY EXPLAINED ENERGY EXPLAINED MASS EXPLAINED The next one in the series is GRAVITY EXPLAINED. It's written, but only on paper, courtesy of a poolside sunbed in FuerteVentura. It'll take me a few days to get it finished off. Naturally I have others in the pipeline.
Money and Energy do exist So you say money does not exist ..... just like energy. But it does. Just because it is not physical does not mean it does not exist. Words are symbols/lingustic models of ideas/concepts and both are very real. Inflation does not exist ? Unemployment does not exist ? Energy does not exist ? You get the point. Back to money ..... you got it right in an early paragraph when you said the word 'promise' .... a promise to exchange something for the paper. For the currency form of money; in the recent past that something was gold ;now it is the promise to coerce your creditors to accept the note to settle debts.
