swansont Posted February 14, 2007 Posted February 14, 2007 when an object falls to earth where does the kinetic energy come from? Here's a clue: E=MC2 and M didn't change. It didn't? Mass changes when objects attract due to a nuclear potential or an electrostatic one. e.g. a neutron and proton attract each other, and will release energy to form a bound state; the mass will have decreased. Why wouldn't mass wouldn't change due to a gravitational potential?
Farsight Posted February 15, 2007 Author Posted February 15, 2007 It didn't? Mass changes when objects attract due to a nuclear potential or an electrostatic one. e.g. a neutron and proton attract each other, and will release energy to form a bound state; the mass will have decreased. Why wouldn't mass wouldn't change due to a gravitational potential? 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
insane_alien Posted February 15, 2007 Posted February 15, 2007 For the falling object, first the potential enrgy would be turned into kinetic energy(and its mass would stay the same) but if it hit something to make it stop it would lose energy as heat (or something) and would decrease in mass according to m=E/c^2 however, there would still be the same number of massive particles, just in a lower state.
Farsight Posted February 16, 2007 Author Posted February 16, 2007 And where is that potential energy situated before the falling object starts falling?
swansont Posted February 16, 2007 Posted February 16, 2007 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 That doesn't answer the question. The mass of a deuteron is less than the mass of a proton + neutron. The mass of hydrogen is less than the mass of a proton + electron. You claim that his will not happen if the force is gravitational.
Farsight Posted February 16, 2007 Author Posted February 16, 2007 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.
Royston Posted February 16, 2007 Posted February 16, 2007 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. That's because gravity is a description of the geometry of space itself, as I'm sure you're aware. So an object follows the curvature of space due to a large mass (such as the earth) and gains kinetic energy...due to mass. You can't have one without the other, whatever scenario you care to pick. So the object falls to earth, it's energy is displaced through sound and heat, and is at rest (earths reference) then you pick the object up, it gains potential energy due to gravity, you drop the object, it gains kinetic energy and so on and so forth...I fail to see the problem here, and this is in simplistic terms. I've read your energy explained, a number of times...and you've stated nothing new, it's just a spiel on energy exchange, photosynthesis et.c why don't you just start with the rules of thermodynamics and be done with it. Then you get to this part... It all started at the beginning of the universe. Visualize yourself in a dark cylindrical room. The walls are banded and helical. You feel a tremble, and you realise with horror that the room is the biggest baddest spring you’ve ever seen. It’s the “prime mover”, and it is exerting an incredible pressure, but is bound by thick steel cables called “symmetry”. The cables are under impossible tension, and you can hear ping ping ping as individual cable wires snap. Symmetry is about to break, and you know your prime mover will disintegrate into a fireball of nuclear and electromagnetic springs that will go bouncing out to fill the night and make the world what it is. I'm sorry Farsight, but using an analogy to describe this 'spring' doesn't cut it...and why is the universe cylindrical, do you have any geometry to back this up. Nobody can comment on these ideas unless we have some maths to work with, and then compare your spring idea with accepted principles and geometry. How can anyone give you any meaningful input, if all you provide are rather wishy washy explanations. Give us some maths, and then some of us may take you more seriously, until then, all you seem to have, is a rather hokey interpretation of energy. That's all I can say on the matter...and I'm certainly not going to keep coming back, like poor Edtharan has. Give us something to chew on.
Farsight Posted February 16, 2007 Author Posted February 16, 2007 That's because gravity is a description of the geometry of space itself, as I'm sure you're aware. So an object follows the curvature of space due to a large mass (such as the earth) and gains kinetic energy...due to mass[/u']. You can't have one without the other, whatever scenario you care to pick. 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. So the object falls to earth, its energy is displaced through sound and heat, and is at rest (earths reference) then you pick the object up, it gains potential energy due to gravity, you drop the object, it gains kinetic energy and so on and so forth... I fail to see the problem here, and this is in simplistic terms. 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. I've read your energy explained, a number of times...and you've stated nothing new, it's just a spiel on energy exchange, photosynthesis et.c why don't you just start with the rules of thermodynamics and be done with it. Then you get to this part... This is the TIME EXPLAINED thread, and the link I posted for Swansont was to MASS EXPLAINED. I'm sorry Farsight, but using an analogy to describe this 'spring' doesn't cut it...and why is the universe cylindrical, do you have any geometry to back this up. Nobody can comment on these ideas unless we have some maths to work with, and then compare your spring idea with accepted principles and geometry. How can anyone give you any meaningful input, if all you provide are rather wishy washy explanations. Give us some maths, and then some of us may take you more seriously, until then, all you seem to have, is a rather hokey interpretation of energy. That's all I can say on the matter...and I'm certainly not going to keep coming back, like poor Edtharan has. Give us something to chew on. 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.
Royston Posted February 16, 2007 Posted February 16, 2007 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. Well enjoy your holiday, but when you come back (if you must)...why does there need to be a change in C to explain curvature, that makes little or no sense...local gradient, with respect to what exactly. 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. Mass and energy are interchangeable, you have a load of mass, it will create energy for any objects in the vicinity <shrug> This is the TIME EXPLAINED thread, and the link I posted for Swansont was to MASS EXPLAINED. and... 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. Well that says it all quite frankly...you've failed to come up with anything convincing whatsoever, and you've resorted to 'just wait and see'...why does anyone have to wait, if you had anything substantial you'd be able to explain it now, and you've failed. PS: I'm on holiday for a week from tomorrow and will probably be incommunicado. I'm on the edge of my seat...
swansont Posted February 17, 2007 Posted February 17, 2007 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. It takes energy to pull the electron from the earth. But g being so small, we're talking about a part in 10^16 per meter. 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. Propping this up with pseudoscientific stuff about electromagnetic loops being electrons isn't going to fly. You'd need to defend that, too, and do it first. You state without proof that the mass is invariant in a gravitational system — you haven't demonstrated it. Gravity isn't a force in GR, and as such energy need not be conserved. The mass is a Lorentz invariant, but that only works in certain metrics. You can't assume it works in a gravity field. But that's about as far as my understanding of GR takes me. But the non-GR argument is basically this: gravitational redshift is real, as the Pound-Rebka experiment demonstrates. A photon emitted from an excited nucleus at the top of a gravity well has a different energy than one emitted at the bottom. That frequency difference would violate conservation of energy if the mass were the same. It's explained in the Feynman lectures on gravity, here, about halfway down: http://www.qedcorp.com/pcr/pcr/feynman/feyngrav.html
Royston Posted February 17, 2007 Posted February 17, 2007 Mass and energy are interchangeable, you have a load of mass, it will create energy for any objects in the vicinity <shrug> Der, I messed this sentence up in the heat of the moment...there should be an 'also, if' thrown in there. Obviously the amount of energy in a planet is not equivalent to it's attraction, that would be ridiculous, however mass does curve space towards its position (obviously)...which Farsight appears to ignore.
Edtharan Posted February 19, 2007 Posted February 19, 2007 No it doesn't. Where did that come from? Did you even read my previous post? I always measure c to be 300,000km/s, and so do you. I got that from what you said. Specifically that one would measure a different value of C in a different frame of reference. That was what I was using. If you are going to change your claims halfway through your argument, then how can we possibly argue against you. Come on now, pay attention, when an object falls to earth where does the kinetic energy come from? Here's a clue: E=MC2 and M didn't change. The kinetic energy came from the potential energy. No change in C needed. SO what are you talking about here? For an object to fall to Earth, it must have been move to a higher position. The energy to do so must have come form somewhere else. If it is a rocket, then it came form chemical energy, If we are talking about an asteroid, then the energy came form the Big Bang, if it is a rock I threw, then it came form the kinetic energy from my arm as I threw it (and that energy came from the chemical energy in my muscles which came from the chemical energy from the food I ate, which came form the energy from the photons from the sun which came from the energy released from the fusion of hydrogen into helium...). So all energy is accounted for, and we know where it came from. No need to invoke a change in C to account for a discrepancy in energy as there is no discrepancy. You've taken a conclusion and turned it into a measurement So, I have made a prediction as to what would happen if your theory is correct. What is wrong with that? then back into a conveniently "mutually exclusive" conclusion. As I said, if a prediction, using your theory, is different to what happens in reality, then there is something wrong with the theory... Why do you do this? Because that is science... Why duck and dive with all this dishonesty that can't explain anything and doesn't want to see anything explained? I am not trying to explain anything. Just disprove your claims. As is good science. I don't have the burden of proof. I have the burden of disproof. Come on, show me I'm wrong. The fact that you repeatedly don't include a full account of the physics that are involved, the fact that conclusions drawn from your theory disagree with reality, the fact that you have contradicted your own claims... None of that is enough? What do I need to do to prove you wrong then? Explain to me what gives if c=s/t and the t is dilated. Space. This has been observed. Space is distorted in a gravitational field, just as it is when you are accelerating or moving. So C does not have to change and observations indicate that it is Space that changes. One such observation is the motion of the planet Mercury around the sun. They once thought that another planet had to be inside the orbit of Mercury because the position it was observed at did not match it's calculated position. When they use the spatial distortions due to gravity (as specified by relativity) the calculated position of Mercury matched observations. If it was C that changed and not Space, then Mercury 's position would not have been mismatched between the non-relativity calculations and observations. So this means that gravity bends and distorts space. Another observed effect of distorted space by gravity is gravitational lensing. This is a well studied phenomena used in astronomy. The gravitational mass of a galaxy can distort space to the extent that light from behind the galaxy is "lensed" and bent so that it world in a similar way (but not the same) as a normal glass lens. If it was C that changed, there would be no gravitational lensing effect as it is the distorted space that causes it, not distorted time or variable C, it is distorted space. So, if space can be distorted, you don't need to invoke a variable C to balance the equation. C can remain constant. So, we have examples where Space can be distorted, and Time can be distorted. We have no reason to invoke a variable C (under Occam's razor) with the examples you have given. Every single one has been shot down as being incomplete or having another, simpler explanation (which fits with what is currently accepted). So, I will repeat: What reason have you got that requires a variable value of C. Not an example that could be explained by a variable Space, or a variable Time, but only by a variable C. So far none of your examples has given this requirement. Yes, if you assume an absolute Space, or an Absolute time, then we have to have a variable C. But, as we have evidence that we have variable Time and variable Space, we don't need a variable C (so far). We observe colour, heat, sound, et cetera, but we do not conclude that these things are fundamental properties of the world. But, as you have stated, these are not even an analogy of what you mean. So how then are they relevant? If they are an analogy, then it still is not a good argument. We also observe Motion (and as this is a major point of your essay) does this mean that it is not a fundamental property of the World (which means you just disproved your own essay if it does). No. You are pushing those analogies too far, to the point that they have no relevance to the topic of discussion. But, even so, how do they even address the point I was making. That is: If your theory makes predictions about the outcome of an experiment, and those predictions do not match up with the results of that experiment. Then the theory must be wrong. This is at the core of Science. If you are not following this concept then you are not doing science, therefore your essay is not science and can not be used to disprove current scientific theories. It might be in the "speculations" sub forum, but this is a science forum.
swansont Posted February 19, 2007 Posted February 19, 2007 I am not trying to explain anything. Just disprove your claims. As is good science. I don't have the burden of proof. I have the burden of disproof. Exactly. And Farsight has the burden of making predictions, and hasn't been doing very much of that. It's fortuitous that there is a discussion on what makes a good theory (Theory evaluation) going on right now The summary is that explaining is not enough, since more than one model can explain a phenomenon, especially if you limit the scope of what you're looking at. Explanations are not theories.
Farsight Posted February 26, 2007 Author Posted February 26, 2007 Well enjoy your holiday, but when you come back (if you must)...why does there need to be a change in C to explain curvature, that makes little or no sense...local gradient, with respect to what exactly. 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.
Farsight Posted February 26, 2007 Author Posted February 26, 2007 It takes energy to pull the electron from the earth. But g being so small, we're talking about a part in 10^16 per meter.Propping this up with pseudoscientific stuff about electromagnetic loops being electrons isn't going to fly. You'd need to defend that, too, and do it first. I'll defend it in the Mass Explained thread. Don't dismiss it as psuedoscientific until you've actually looked at it. You state without proof that the mass is invariant in a gravitational system — you haven't demonstrated it. Gravity isn't a force in GR, and as such energy need not be conserved. The mass is a Lorentz invariant, but that only works in certain metrics. You can't assume it works in a gravity field. But that's about as far as my understanding of GR takes me. 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. But the non-GR argument is basically this: gravitational redshift is real, as the Pound-Rebka experiment demonstrates. A photon emitted from an excited nucleus at the top of a gravity well has a different energy than one emitted at the bottom. That frequency difference would violate conservation of energy if the mass were the same. 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. It's explained in the Feynman lectures on gravity, here, about halfway down: http://www.qedcorp.com/pcr/pcr/feynman/feyngrav.html 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.
swansont Posted February 26, 2007 Posted February 26, 2007 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. OK, I'll go with this. "Your view employs the wrong concepts" Are you willing to be dismissed this trivially?
mr d Posted February 26, 2007 Posted February 26, 2007 Hello Gone so missed the first part of this, but seem to remember and old idea that time is merely changes in the state of energy/matter(speed, location, orientation...). Combined with a organisms means of percieving those changes. The past is a former state, the present the current state and the furture a prediction of a state yet unrealised. As to the perception part, time exists differently dependant on the organism. How a plant or house fly interprets time might be totally different than how a human experiences time, and individual humans would show some variation in their ability to interpret time due to physical differences between individuals. Also for items or organisms that can not detect changes no time exists. Any name or numeric value assigned to represent time would be the invention of the organism or species as a means to represent their interpretation for their preceptive range of state change. It would mean that in speaking of time you have to factor into an equaltion who's/what's vantage point you are speaking from. For no time to exist would tend to mean under such an idea that 1) no change in the state of energy/matter occurs 2) all states of energy/matter exist at the same time (human reference word), but organisms only percieve range limited to their species/individual 3)organism's are falsely percieving changes or misinterpreting changes to produce their conception of time. So if a beam of light, photons, are traveling in a wave pattern, if no concept such as time exist why would a wave pattern be produced. Since the perception of peaks and valleys denotes some interval has occurred between to different states? Should light then not be but a single line. Mr D Enjoying the optical illusions included, but doesn't that have more to do with optical formations and processing limitations in the human species. Still find them fun none the less.
Royston Posted February 27, 2007 Posted February 27, 2007 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. Farfromright, Einstein used the Riemann curvature tensor which is non-euclidean . Could you cite where Einstein did not agree that GR equates to curvature of space, post GR. I also didn't say that mass 'creates' energy (that can be mis-interpreted) for objects in the vicinity, but obviously the closer a body gets, it's acceleration increases in this context...have you heard of Unruh's law, well temperature is proportional to acceleration... [math]T = a \left( \frac{h}{2\pi c}\right) [/math] Now...actually forget it, if you don't think gravity means curvature, then I'm wasting my time, good luck with whatever you're trying to prove.
Royston Posted February 27, 2007 Posted February 27, 2007 Ok, I had a very, very long day yestarday, so please ignore the above (wasn't thinking straight)...apart from the comment on curvature tensor.
Farsight Posted February 27, 2007 Author Posted February 27, 2007 Einstein used the Riemann curvature tensor which is non-euclidean . Could you cite where Einstein did not agree that GR equates to curvature of space, post GR. 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. Are you willing to be dismissed this trivially? 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.
swansont Posted February 27, 2007 Posted February 27, 2007 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. Dismissing and not addressing are not the same thing. I have no stake in your metaphysical arguments, and have repeatedly pointed out that I have no desire to discuss them. But when you make a physics statement, and it's wrong, I will comment. If you will not be satisfied with "the argument uses the wrong concepts" then you'd better not use it to dismiss a counter-argument using accepted physics. Rest mass is a Lorentz invariant, and that's useful where you can assume flat spacetime. But two masses comprise a composite system, just like with a nuclear or electromagnetic attraction, and the rest mass of that composite system is smaller. I can measure it fairly easily with these two forces because they are large enough. I can't with gravity, because gh/c^2 is about a part in 10^16 per meter. If you can't do a measurement that shows the effect, because it's too small, then there's no need to worry about including in your calculations. As an example, in nuclear binding energy calculations the mass of H-1 is used for the proton and electron, even though that ignores the 13.6 eV of binding energy of the electron, and atomic masses are used for the product, even though they include a different amount of net binding for their electrons. It doesn't matter, because that's at least five or six orders of magnitude smaller than nuclear binding energies. If it were big enough, then people would worry about the term, just like they would note the rest mass having a gravitational potential term. They Feynman example shows that the mass terms have to be different by gh/c^2 to conserve energy.
Royston Posted February 27, 2007 Posted February 27, 2007 Pete Brown is pmb, I'm sure he'd be perfectly happy if you emailed him for more details. That was an illuminating read, thanks for the link...but I think you've misinterpreted the point of the paper. The article is stating that curvature is a product of gravity, and 'not' vice versa...that's the confusion, and why it wouldn't agree with the equivalence principle if gravity was a result of curvature. Very interesting all the same.
swansont Posted February 27, 2007 Posted February 27, 2007 Einstein may have disagreed that constant gravity was curvature, but to that I say, "So what?" It doesn't matter how Einstein interpreted it. That's either argument from authority (Einstein also said "God does not play dice" and he was wrong) or equivocation, because it depends on whose definitions you use. What matters is the actual theory, which has progressed from the time Einstein introduced it. That paper states that gravity equating to curvature of spacetime is the current interpretation (p.15). It seems to depend on how you define your terms. Even considering all that, "There is no curvature" is wrong. "There need not be curvature, according to Einstein's definitions" would be correct, with constant gravity being one example, according to the paper cited.
Farsight Posted February 28, 2007 Author Posted February 28, 2007 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.
swansont Posted February 28, 2007 Posted February 28, 2007 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] "So what" is appropriate when you use logical fallacies. Did you not read beyond that? When you proceed from a false premise, or use invalid logic, any conclusion at all may be reached, so the conclusion is worthless. Hence the "so what." There is no scientific value in it. I've explained the science in some detail. What, specifically, don't you understand? The energy comes from the mass of the composite system.
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