ACG52 Posted April 22, 2014 Posted April 22, 2014 So now all that's left is to show with some equation that relates density to the distance between atoms and mass that forms a finite volume that the atoms will shrink as they approach the speed of light in such a way that length the cube is contracted by will be less than the proportion of the proportion of the relative distance between atoms and the new dimensional size of the atoms themselves that show their electro-magnetic fields will also contract in the direction of motion therefore inhibiting matter from reaching a degenerate state. Length contraction does not happen because atoms pack themselves more tightly. It happens because the geometry of space/time changes with relative motion. Nothing becomes denser in it's own frame of reference.
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) Length contraction does not happen because atoms pack themselves more tightly. It happens because the geometry of space/time changes with relative motion. Nothing becomes denser in it's own frame of reference. : Not only did I already state that the atomic structures contract according to relativity which makes your first point moot (even though they DO actually pack more tightly to increase density as well and relativistic mass increases even more), I already demonstrated a mathematical equation that accurately models that density varies from a wide variety of other frames. There's no reason to talk about what the near-light object sees from it's own frame if we're talking about what other frames see. You keep bringing that point up, but the basis even for proper time isn't what something measures from it's own frame, it's what something measures something else it as if that something else were in an inertial frame from the original something's frame. It doesn't matter if something isn't denser from it's own frame, I'm also not in a position I'm not, and x=x. But that doesn't matter from other frames, because as the equation points out, density of something will change in the frame of something that see's that object moving, and if it's inertial, it's still an outside view that's saying it's inertial, and all views will be simultaneously correct about their observations. Edited April 23, 2014 by SamBridge
md65536 Posted April 23, 2014 Posted April 23, 2014 (edited) Both I and ACG52 will agree that Delta1212 is mistaken as are you Sam. Density is frame INDEPENDANT. In other words, relativistic length contraction and mass increase DO NOT affect the density of an object as they do not change in their own frame. They are only RELATIVE ( to other frames ) effects. I don't think this is stated correctly (though I agree SamBridge is mistaken, but not Delta1212. I also agree that different frames "agree" only as in "are mutually consistent" but not as in "have the same measurements"). If an object's density is relative, then its measured density depends on the frame of reference in which it is measured. An object's density can be different in different frames, and that doesn't require that it changes in its own frame. Of course the object's density (or length etc) doesn't change due to relativistic effects in its rest frame. So for example this statement is perfectly sensible: 'Heavy ions that are spherical when at rest should assume the form of "pancakes" or flat disks when traveling nearly at the speed of light. And in fact, the results obtained from particle collisions can only be explained, when the increased nucleon density due to length contraction is considered.' http://en.wikipedia.org/wiki/Length_contraction Doesn't that mean that density is frame DEPENDENT? Its "rest density" would be frame independent (vacuously I guess, because it specifies the frame in which to measure). Edited April 23, 2014 by md65536
SamBridge Posted April 23, 2014 Posted April 23, 2014 I don't think this is stated correctly (though I agree SamBridge is mistaken. I also agree that different frames "agree" only as in "are mutually consistent" but not as in "have the same measurements"). If an object's density is relative, then its measured density depends on the frame of reference in which it is measured. An object's density can be different in different frames, and that doesn't require that it changes in its own frame. Of course the object's density (or length etc) doesn't change due to relativistic effects in its rest frame. So for example this statement is perfectly sensible: 'Heavy ions that are spherical when at rest should assume the form of "pancakes" or flat disks when traveling nearly at the speed of light. And in fact, the results obtained from particle collisions can only be explained, when the increased nucleon density due to length contraction is considered.' http://en.wikipedia.org/wiki/Length_contraction Doesn't that mean that density is frame DEPENDENT? Its "rest density" would be frame independent (vacuously I guess, because it specifies the frame in which to measure). I'm not really sure what you're suggesting, relative density can vary from other frames which we know with the relative mass equation and the relative length equation, but there's just something that we haven't completely identified that is kept constant during length contraction that isn't kept constant during compression due to force that accounts for the fact that contracted matter doesn't necessarily become degenerate matter. Anyway, there's already another thread with a similar topic so we should make plans to return to the original discussion and move this one to the other thread.
Edgard Neuman Posted April 23, 2014 Author Posted April 23, 2014 (edited) I think the main probleme is the way you define the "volume" to calculate your density. A volume is a limit in space at a given moment, and density is define by the quantity of mass/energy in it. But when the frame change, the limit of the volume are contracted, but the moment is also shifted through time along the direction, and also slowed. So if you define a volume in a frame, it won't be valid to mesure density in other frames. I think the right way to mesure density is to use a spacetime volume (extended in time).. this way, when the frame change, time slowing increase the size of the box in time (and also rotate it so the front get to be at another time that the back). the new density wouldn't be frame dependant. Edited April 23, 2014 by Edgard Neuman
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) I think the main probleme is the way you define the "volume" to calculate your density. A volume is a limit in space at a given moment, and density is define by the quantity of mass/energy in it. But when the frame change, the limit of the volume are contracted, but the moment is also shifted through time along the direction, and also slowed. So if you define a volume in a frame, it won't be valid to mesure density in other frames. I think the right way to mesure density is to use a spacetime volume (extended in time).. this way, when the frame change, time slowing increase the size of the box in time (and also rotate it so the front get to be at another time that the back). the new density wouldn't be frame dependant. But what your saying doesn't make any sense at all because the back of the object is moving at the same speed as the front. There's already an equation that models relative density, and according to that model, you get a higher mass in a smaller volume, even if it doesn't happen the same way as force compression. Edited April 23, 2014 by SamBridge
ACG52 Posted April 23, 2014 Posted April 23, 2014 Not only did I already state that the atomic structures contract according to relativity which makes your first point moot (even though they DO actually pack more tightly to increase density as well and relativistic mass increases even more), Atomic structures do not contract. Density does not increase and there is no relativistic mass. You're simply wrong.
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) Atomic structures do not contract. Density does not increase and there is no relativistic mass. You're simply wrong. Look for yourself, there's a relativistic density equation in this thread. If atomic structures didn't contract then matter would become degenerate from length contraction, there's no force stopping them from contracting, I don't think you understand how length contraction works, look at the equations yourself, pretend you have a sphere that's 10 nanometers across and apply the length contraction formula at 99% the speed of light and see what happens. If I take a ruler and send it off near the speed of light, it appears shorter. If I take an atomic ruler that's the size of a hydrogen atom and send it off near the speed of light, it shrinks too, the fact that atoms are really small doesn't matter. "There is no relativistic mass"? What do you call Mo/(1-v^2/c^2)^(1/2) http://www.phy.olemiss.edu/HEP/QuarkNet/mass.html You're simply wrong. Edited April 23, 2014 by SamBridge
Edgard Neuman Posted April 23, 2014 Author Posted April 23, 2014 (edited) But what your saying doesn't make any sense at all because the back of the object is moving at the same speed as the front. There's already an equation that models relative density, and according to that model, you get a higher mass in a smaller volume, even if it doesn't happen the same way as force compression. It's moving at the same speed but it's late in time. The front border of the initial volume (you used to mesure density) is now at a different moment for you that the back. The video explain it very well : It's the same problem that the train in the tunnel, because the question of density can be seen like "would the mass of the train fit in the volume of the tunnel" Edited April 23, 2014 by Edgard Neuman
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) But as the video explains, the train does in fact fit into the tunnel when it's contracted from an outside frame that sees it moving, the outside frames are just as correct as frames from the inside of the train which he also says. And as the video also explains, time dilation isn't the only factor, something physically looks shorter when it's appears to be traveling near the speed of light in addition to the time dilation because time isn't the only component of space, there's also 3 other dimensions of space that change relativistic-ally that the axis of time is orthogonal to. Time dilation can't account for the entire phenomena of a hyperbolic approach to the speed of light, so If the spacial dimension also didn't change, it would imply the near-light object's spacial metric didn't contract from our frame or with the environment from near-light object's frame and therefore measure that it traveling a greater distance in one measured second than light could have traveled in one second. Didn't he say at the end the math was simple? If you want to see relative density, take m/v, then plug in the relativistic equations for relativistic mass and relativistic volume. Edited April 23, 2014 by SamBridge
Edgard Neuman Posted April 23, 2014 Author Posted April 23, 2014 (edited) What I tried to explain is that when you mesure density, you basicly use a volume at a moment and count the mass in it. But when the frame change, the "physcial" limits of your volume are shifted in space time. So you can't use these same limits to mesure density in the new frame because it's not at a unique moment for you. Of course, if you define a new box from the outside, you will see more density (the train is indeed compressed) but it wouldn't have any effects because time is now slown for the object. For instance : a star wouldn't heat more, because temperature is given by the average speed of particule : once slown, temperature (mesured from outside) is also divided. etc.. All particule interactions, seen from the outside and mesured like the density was, would be lessen by the time slown factor. So what I sayed is that density mesured the "regular way" is frame dependant, but density mesured in a spacetime box (with time extension) is frame independant (because time is slown so the "hypervolume" of the box is bigger). This give me a idea to solve the shape of particule paradox : - shape of particules can be frame independant, if they are not only considere as a sphere, but as a spacetime hypersphere. The particule would have a certain extension in space time, that explain that when the frame is changed, time extension replace space extension (as the rotation in space time leave the hyper sphere unchanged). Time extension would be like a persistence : it's possible if we considere that particule are quantic and so extended in time. Interaction probabilities are not only depending on size of particules also on how long a particule is along its trajectory (it's wavelength) So in a compressed object travelling near light speed, particule wouldn't be compressed, because what is "time extension" in the moving frame is now seen as space extension in observator's frame and vice versa. I don't know if it's true, but it blows my mind. Edited April 23, 2014 by Edgard Neuman
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) What I tried to explain is that when you mesure density, you basicly use a volume at a moment and count the mass in it. Simultaneousity isn't relative, that's fine, but the fact of the matter remains that you cannot put all of space into terms of only what happens in time, they are different dimensions, there is a physical contraction that you see beyond a relative simultaneity of measuring the ends of the object that is caused by the different phenomena of spacial length contraction and that's why there's two different operators for lorent'z transformations that describe this phenomena. Only considering the time dilation of the matter cannot account for the special metric differences that one would measure with something like density or the distance one says is one point and the next. Edited April 23, 2014 by SamBridge
ACG52 Posted April 23, 2014 Posted April 23, 2014 What do you call Mo/(1-v^2/c^2)^(1/2) http://www.phy.olemi...rkNet/mass.html I call it energy, not mass. Relativistic mass is an outdated concept.
Edgard Neuman Posted April 23, 2014 Author Posted April 23, 2014 Simultaneousity isn't relative, that's fine, but the fact of the matter remains that you cannot put all of space into terms of only what happens in time, they are different dimensions, there is a physical contraction that you see beyond a relative simultaneity of measuring the ends of the object that is caused by the different phenomena of spacial length contraction and that's why there's two different operators for lorent'z transformations that describe this phenomena. Only considering the time dilation of the matter cannot account for the special metric differences that one would measure with something like density or the distance one says is one point and the next. I agreed with that : mesured in a classic way, density is frame dependant (the object is indeed compressed for the observer). But, because time (dt<1) is slown, it has no effect on the object : from the outside point of view, all its physic is slown in time (so it doesn't heat or collapse). Slown physics is very different from observer physics : all mesurement depending on time (temperature, and pressure for instance) are also multiplied by dt (it become less).
MigL Posted April 23, 2014 Posted April 23, 2014 If what you stated about density increase for a near light-speed particle being due to length contraction were true md65536, then there would be nothing to keep a particle from becoming a black hole in one frame and not in its own frame. An irreconcilable difference. Edgard Neuman is right that you cannot consider space only for near light speed objects, you must consider space-time. ACG52 is right about you being wrong, Sam.
md65536 Posted April 23, 2014 Posted April 23, 2014 If what you stated about density increase for a near light-speed particle being due to length contraction were true md65536, then there would be nothing to keep a particle from becoming a black hole in one frame and not in its own frame. An irreconcilable difference.Why? Does density alone determine whether something becomes a black hole or not? Are you basing this on the Schwarzschild solution, and does that solution work for moving bodies? DaleSpam and snoopies622 explain this better than I can, here: http://www.physicsforums.com/showthread.php?t=247484
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) What do you call Mo/(1-v^2/c^2)^(1/2) http://www.phy.olemi...rkNet/mass.html I call it energy, not mass. Relativistic mass is an outdated concept. But energy and mass are somewhat similar, even photons bend the fabric of space, and there's models of relativistic higg's fields that show a similar effect of mass increase via acceleration. Doesn't matter if its a little outdated, there's experimental evidence like in particle accelerators verifying that you don't measure mass as being constant when observing something that gains velocity to near the speed of light. Assuming that Einstein was crack pot and mass isn't relative in any way shape or form, if wasn't an accurate model in a lot of scenarios it can still approximate many others, just as it doesn't even matter that Newtonian mechanics is outdated, it won't change the fact that u+v is still mathematically a good approximation for speeds that total less than 1% the speed of light. But, because time (dt<1) is slown, it has no effect on the object : from the outside point of view, all its physic is slown in time (so it doesn't heat or collapse). That could be an additional component as well, objects that travel near the speed of light take more time such that an exchange rate of heat from kinetic motion may decrease, but the time slowing down doesn't discount the fact that an object still physically contracts. Edited April 23, 2014 by SamBridge
ACG52 Posted April 23, 2014 Posted April 23, 2014 But energy and mass are somewhat similar, even photons bend the fabric of space, and there's models of relativistic higg's fields that show a similar effect of mass increase via acceleration. Doesn't matter if its a little outdated, there's experimental evidence like in particle accelerators verifying that you don't measure mass as being constant when observing something that gains velocity to near the speed of light. Assuming that Einstein was crack pot and mass isn't relative in any way shape or form, if wasn't an accurate model in a lot of scenarios it can still approximate many others, just as it doesn't even matter that Newtonian mechanics is outdated, it won't change the fact that u+v is still mathematically a good approximation for speeds that total less than 1% the speed of light. You seem to be saying that you aren't really right, but you're close.
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) You seem to be saying that you aren't really right, but you're close. You seem to be saying relativity is wrong, but you're not close. Edited April 23, 2014 by SamBridge
ACG52 Posted April 23, 2014 Posted April 23, 2014 You seem to be saying relativity is wrong, but you're not close. The fact that you can get that from my posts shows that you don't understand relativity. Or that your reading comprehension needs work.
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) The fact that you can get that from my posts shows that you don't understand relativity. Or that your reading comprehension needs work. The fact that you think relativistic mass can't accurately describe this situation shows that you didn't even know of the basic concepts of special relativity. Is 2008 not modern enough for you? Or is the entire physics course of Stanford outdated, and no one cares about special relativity to model near-light objects anymore? Edited April 23, 2014 by SamBridge
ACG52 Posted April 23, 2014 Posted April 23, 2014 Relativistic mass is an obsolete concept. Most of what you post is simply erroneous, showing a shallow, partial at best understanding of relativity.
SamBridge Posted April 23, 2014 Posted April 23, 2014 (edited) Relativistic mass is an obsolete concept. Most of what you post is simply erroneous, showing a shallow, partial at best understanding of relativity. It's obviously not "obsolete" if it can accurately model the apparent change in mass for a wide variety of modern circumstances like its uses in a particle collider. You don't seem to realize the new age of particle physics is trying to reconcile the gaps between quantum mechanics and special relativity, not throw special relativity away, it's trying to show how a relative mass interaction with a higgs field is equal to Mo/(1-v^2/c^2)^(1/2) to further explain why something appears to increase in mass through acceleration via the higg's field. The relativistic equations are like pieces of the skeleton, patterns that we see and have confirmed but don't know exactly what body they come from, until we add the skin and muscle and discover a few other bones. You can go to a particle collider right now and experimentally confirm the "old" special relativity theories are very very accurate models, which even to this day are being tested and shown to still be accurate. Modern quantum physics merely tries to put those confirmed results into a different context as a way to more precisely explain how/why they appear. Edited April 23, 2014 by SamBridge -1
SamBridge Posted April 24, 2014 Posted April 24, 2014 (edited) Nonsense. Go to a particle accelerator right now and see for yourself. You will find muons decay more slowly when accelerated to near light speed by the amount predicted by SR, and they appear gain mass by the exact amount predicted by SR, and they appear to asymptotically approach light with a constantly applied force by the amount predicted by SR. It's standard SR and used in modern particle physics, you should look it up some time before saying its nonsense, the models of SR are some of the most accurately tested models to this date. Edited April 24, 2014 by SamBridge
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