LTE
in [Relativity]
|
Prev: Properties of a preferred frame, an inertial frame in SR andan inertial frame in IRT
Next: About the maximal electrostatic potential energy U(r) of a pair electron-positron at rest with distance r
From: Sam Wormley on 19 Jul 2010 17:00 On 7/19/10 3:49 PM, glird wrote: > Metaphysics, which is the study of the things that exist and how > their mechanisms physically work, is not only "part of science" it was > and -- despite being ignored by today's physicists -- remains the most > important part! > > glird Try this: http://physics.suite101.com/article.cfm/physics_vs_metaphysics
From: harald on 20 Jul 2010 07:35 On Jul 19, 10:49 pm, glird <gl...(a)aol.com> wrote: > On Jul 18, 6:16 pm, harald <h...(a)swissonline.ch> wrote: > > > On Jul 17, 12:39 am, xxein <xxxx...(a)gmail.com> wrote: > > > > Geez! Doesn't anybody know how to think logically of the physic > > > beyond the archaic sceintific method? > > >< Yes of course - there are at least several people who contribute to this group and who understand this very well. For sure Lorentz and Poincare understood it! The later generation of "geometers" lost grip with reality but physical modeling [i.e. METAPHYSICS] is certainly part of science. > Glird, physical models are erroneously identified with "metaphysics" - except of course if one wishes to change the meaning of words. For example atom models have never been regarded as metaphysics, as far as I can tell; they were always part of *physics*. > Metaphysics, which is the study of the things that exist and how > their mechanisms physically work, is not only "part of science" it was > and -- despite being ignored by today's physicists -- remains the most > important part! Physical models are indeed an important part of physics that is currently being neglected. Newton's mechanics was based on physical modeling, although with strong mathematical modeling on top of it. SRT is mathematical modeling that was - as Einstein admitted - based on Maxwell's and Lorentz's physical theories. It is the combination of such two approaches that is most effective. Note: Sam Wormley provided a good link about physics vs metaphysics. Regards, Harald
From: xxein on 26 Jul 2010 22:57 On Jul 16, 9:48 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > xxein wrote: > > Does anyone out there know how velocity addition > > works to describe how we measure it besides a math? What is the > > physical reason? > > Consider a pointlike object moving with constant velocity v along the x axis, > and plot its x position vs time t. You'll get a straight line with a slope of v. > Now do the same for 2v, and get a straight line with slope 2v. In such a graph, > relative velocity is a rotation of the axes, and by considering the angle > related to the relative velocity, not its slope, it's clear that in Galilean > relativity when composing relative velocities the angles merely add (when > plotted on a Euclidean piece of paper). > > In relativity there is also an angle associated with relative velocity, called > rapidity. When composing relative velocities, their rapidities add. But this is > hyperbolic geometry, and when plotted on a Euclidean piece of paper the angles > corresponding to the rapidities do not simply add, they combine in such a way > that the sum of angles never exceeds 45 degrees (= the invariant speed of the > Lorentz transform = the speed of light). > > If you think this is far fetched, remember that v is the slope of the relative > velocity, not an angle. Look up the formula for composing two Euclidean > rotations in terms of the slopes of lines and you'll find a formula quite > similar to the Lorentz addition of velocities, differing only in a sign. > > You'll also find that composing two large-enough slopes can > flip the sign of the line's slope. That's highly unphysical > when applied to relative velocities.... > > As for "why" hyperbolic geometry applies rather than Euclidean geometry, that is > outside the realm of science. In the world we inhabit it just does. > > > I know what it is but I doubt that anyone else does. > > Such hubris! Such cowardice! > > Tom Roberts xxein: You don't understand the physic. All you understand is Einstein. I'm lightyears ahead of you. I can put Einstein's physical explanations of STR and GTR in the trash. His cumbersome math can somehow survive though. But NASA uses the simple form of Newton's and makes in-flight corrections. What is the orbit velocity of any small mass around any large mass at 3M (M = the mass in meters used as a radius)? It is always the same orbit velocity, right? You have a lot of math to go through to show this. How about: sqrt(c^2 - escape velocity^2) = orbit velocity? It gives the same velocity as Einstein, doesn't it? Light bends in gravity. It can only circularly orbit at 3M, right? Are you going to say that it's orbit velocity is c, or is light too special and doesn't have to follow the rules of the physic? This is where both Newton and Einstein made a wrong assumption. Newton was correct with the amount of curvature of light around mass. Einstein came up with twice the curvature to make the path length greater. Experiments verified this. Or did they? No! They only verified the time that light took because of a bent path. It was affixed to speed c and so the curvature had to be doubled. Here's an interesting math playground for you that will perplex you. Take your spaceship to any M radius and hover there. You are not moving wrt the central mass but you have a gravitational time dilation, right? Incidentally, it is the same time dilation you would compute if you were traveling at the value of your escape velocity. Compute it. Everything you see and measure is with a slow clock. You are on the shell wrt a sphere. Here comes some light that will graze the tangent point of where you are. You are in gravity and expect that the light was bent. Do you measure it as c? Of course. But how with a slow clock? There's only one physical answer. Light is not traveling at c. Just as it is not orbiting 3M at c. This tangent light is subject to the same vector velocities as anything else. Sqrt(c^2 - escape velocity^2) = it's path velocity at that point. It is only the square of the sums that equals c. So how did you measure it at c? You computed your timerate on that shell, right? What is the vector velocity of light as it grazes you? The same numeric value. This means that if light came to you at a speed (x) (not it's velocity), you would see and meaure it as c. x/x=1=c to you. But the important physic to be derived from this is that c is a constant in the measure of it only. Be a good old boy and I might just explain how velocity addition works in the physic - not just a math. So simple, really. Who knows? I might even tell you what gravity is. All this will keep you decades to explore. Cowardice? Examine yourself for being a follower and not an explorer of the physic. Hubris? I earned mine. I didn't take it by copy and paste. But you are very good at that.
From: Androcles on 26 Jul 2010 23:14 "xxein" <xxxxein(a)gmail.com> wrote in message news:7668fbfa-d655-4b55-b298-be75f04a2a04(a)f8g2000vbl.googlegroups.com... On Jul 16, 9:48 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > xxein wrote: > > Does anyone out there know how velocity addition > > works to describe how we measure it besides a math? What is the > > physical reason? > > Consider a pointlike object moving with constant velocity v along the x > axis, > and plot its x position vs time t. You'll get a straight line with a slope > of v. > Now do the same for 2v, and get a straight line with slope 2v. In such a > graph, > relative velocity is a rotation of the axes, and by considering the angle > related to the relative velocity, not its slope, it's clear that in > Galilean > relativity when composing relative velocities the angles merely add (when > plotted on a Euclidean piece of paper). > > In relativity there is also an angle associated with relative velocity, > called > rapidity. When composing relative velocities, their rapidities add. But > this is > hyperbolic geometry, and when plotted on a Euclidean piece of paper the > angles > corresponding to the rapidities do not simply add, they combine in such a > way > that the sum of angles never exceeds 45 degrees (= the invariant speed of > the > Lorentz transform = the speed of light). > > If you think this is far fetched, remember that v is the slope of the > relative > velocity, not an angle. Look up the formula for composing two Euclidean > rotations in terms of the slopes of lines and you'll find a formula quite > similar to the Lorentz addition of velocities, differing only in a sign. > > You'll also find that composing two large-enough slopes can > flip the sign of the line's slope. That's highly unphysical > when applied to relative velocities.... > > As for "why" hyperbolic geometry applies rather than Euclidean geometry, > that is > outside the realm of science. In the world we inhabit it just does. > > > I know what it is but I doubt that anyone else does. > > Such hubris! Such cowardice! > > Tom Roberts xxein: You don't understand the physic. All you understand is Einstein. I'm lightyears ahead of you. I can put Einstein's physical explanations of STR and GTR in the trash. His cumbersome math can somehow survive though. But NASA uses the simple form of Newton's and makes in-flight corrections. What is the orbit velocity of any small mass around any large mass at 3M (M = the mass in meters used as a radius)? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. It is always the same orbit velocity, right? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. You have a lot of math to go through to show this. How about: sqrt(c^2 - escape velocity^2) = orbit velocity? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. It gives the same velocity as Einstein, doesn't it? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. Light bends in gravity. It can only circularly orbit at 3M, right? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. Are you going to say that it's orbit velocity is c, or is light too special and doesn't have to follow the rules of the physic? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. This is where both Newton and Einstein made a wrong assumption. Newton was correct with the amount of curvature of light around mass. Einstein came up with twice the curvature to make the path length greater. Experiments verified this. Or did they? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. No! ============================================ It's not an artefactual/superficially imposed yin-yang of sorts. They only verified the time that light took because of a bent path. It was affixed to speed c and so the curvature had to be doubled. Here's an interesting math playground for you that will perplex you. Take your spaceship to any M radius and hover there. You are not moving wrt the central mass but you have a gravitational time dilation, right? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. Incidentally, it is the same time dilation you would compute if you were traveling at the value of your escape velocity. Compute it. Everything you see and measure is with a slow clock. You are on the shell wrt a sphere. Here comes some light that will graze the tangent point of where you are. You are in gravity and expect that the light was bent. Do you measure it as c? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. Of course. But how with a slow clock? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. There's only one physical answer. Light is not traveling at c. Just as it is not orbiting 3M at c. This tangent light is subject to the same vector velocities as anything else. Sqrt(c^2 - escape velocity^2) = it's path velocity at that point. It is only the square of the sums that equals c. So how did you measure it at c? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. You computed your timerate on that shell, right? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. What is the vector velocity of light as it grazes you? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. The same numeric value. This means that if light came to you at a speed (x) (not it's velocity), you would see and meaure it as c. x/x=1=c to you. But the important physic to be derived from this is that c is a constant in the measure of it only. Be a good old boy and I might just explain how velocity addition works in the physic - not just a math. So simple, really. Who knows? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. I might even tell you what gravity is. All this will keep you decades to explore. Cowardice? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. Examine yourself for being a follower and not an explorer of the physic. Hubris? ============================================ It's an artefactual/superficially imposed yin-yang of sorts. I earned mine. I didn't take it by copy and paste. But you are very good at that.
From: Helmut Wabnig hwabnig on 27 Jul 2010 02:56
On Tue, 27 Jul 2010 04:14:10 +0100, "Androcles" <Headmaster(a)Hogwarts.physics_z> wrote: > >"xxein" <xxxxein(a)gmail.com> wrote in message >news:7668fbfa-d655-4b55-b298-be75f04a2a04(a)f8g2000vbl.googlegroups.com... >On Jul 16, 9:48 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >> xxein wrote: >> > Does anyone out there know how velocity addition >> > works to describe how we measure it besides a math? What is the >> > physical reason? >> >> Consider a pointlike object moving with constant velocity v along the x >> axis, >> and plot its x position vs time t. You'll get a straight line with a slope >> of v. >> Now do the same for 2v, and get a straight line with slope 2v. In such a >> graph, >> relative velocity is a rotation of the axes, and by considering the angle >> related to the relative velocity, not its slope, it's clear that in >> Galilean >> relativity when composing relative velocities the angles merely add (when >> plotted on a Euclidean piece of paper). >> >> In relativity there is also an angle associated with relative velocity, >> called >> rapidity. When composing relative velocities, their rapidities add. But >> this is >> hyperbolic geometry, and when plotted on a Euclidean piece of paper the >> angles >> corresponding to the rapidities do not simply add, they combine in such a >> way >> that the sum of angles never exceeds 45 degrees (= the invariant speed of >> the >> Lorentz transform = the speed of light). >> >> If you think this is far fetched, remember that v is the slope of the >> relative >> velocity, not an angle. Look up the formula for composing two Euclidean >> rotations in terms of the slopes of lines and you'll find a formula quite >> similar to the Lorentz addition of velocities, differing only in a sign. >> >> You'll also find that composing two large-enough slopes can >> flip the sign of the line's slope. That's highly unphysical >> when applied to relative velocities.... >> >> As for "why" hyperbolic geometry applies rather than Euclidean geometry, >> that is >> outside the realm of science. In the world we inhabit it just does. >> >> > I know what it is but I doubt that anyone else does. >> >> Such hubris! Such cowardice! >> >> Tom Roberts > >xxein: You don't understand the physic. All you understand is >Einstein. I'm lightyears ahead of you. I can put Einstein's physical >explanations of STR and GTR in the trash. His cumbersome math can >somehow survive though. But NASA uses the simple form of Newton's and >makes in-flight corrections. > ######################################################### hans hanson said: Engineers don't need relativity. Androcles says: Engineers don't need theories, they do it all by trial-and-error. (emphasis on the latter) http://www.youtube.com/watch?v=j-zczJXSxnw http://www.youtube.com/watch?v=_10T4UYpzV8 http://www.youtube.com/watch?v=Qid2s89OfZU w. ######################################################### >What is the orbit velocity of any small mass around any large mass at >3M (M = the mass in meters used as a radius)? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > It is always the same >orbit velocity, right? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >You have a lot of math to go through to show >this. How about: sqrt(c^2 - escape velocity^2) = orbit velocity? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >It >gives the same velocity as Einstein, doesn't it? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >Light bends in >gravity. It can only circularly orbit at 3M, right? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > Are you going to >say that it's orbit velocity is c, or is light too special and doesn't >have to follow the rules of the physic? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >This is where both Newton and Einstein made a wrong assumption. >Newton was correct with the amount of curvature of light around mass. >Einstein came up with twice the curvature to make the path length >greater. Experiments verified this. Or did they? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >No! >============================================ > It's not an artefactual/superficially imposed yin-yang of sorts. > >They only verified the time that light took because of a bent >path. It was affixed to speed c and so the curvature had to be >doubled. > >Here's an interesting math playground for you that will perplex you. >Take your spaceship to any M radius and hover there. You are not >moving wrt the central mass but you have a gravitational time >dilation, right? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >Incidentally, it is the same time dilation you would >compute if you were traveling at the value of your escape velocity. >Compute it. Everything you see and measure is with a slow clock. > >You are on the shell wrt a sphere. Here comes some light that will >graze the tangent point of where you are. You are in gravity and >expect that the light was bent. Do you measure it as c? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > > Of course. >But how with a slow clock? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > >There's only one physical answer. Light is not traveling at c. Just >as it is not orbiting 3M at c. > >This tangent light is subject to the same vector velocities as >anything else. Sqrt(c^2 - escape velocity^2) = it's path velocity at >that point. It is only the square of the sums that equals c. > >So how did you measure it at c? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >You computed your timerate on that >shell, right? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >What is the vector velocity of light as it grazes you? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > >The same numeric value. > >This means that if light came to you at a speed (x) (not it's >velocity), you would see and meaure it as c. x/x=1=c to you. But the >important physic to be derived from this is that c is a constant in >the measure of it only. > >Be a good old boy and I might just explain how velocity addition works >in the physic - not just a math. So simple, really. Who knows? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > I >might even tell you what gravity is. All this will keep you decades >to explore. > >Cowardice? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > Examine yourself for being a follower and not an explorer >of the physic. Hubris? >============================================ > It's an artefactual/superficially imposed yin-yang of sorts. > > I earned mine. I didn't take it by copy and >paste. But you are very good at that. |