Galilean transformation equations
in [Relativity]
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From: rbwinn on 29 Jun 2010 00:05 On Jun 26, 12:14 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Jun 26, 1:26 pm, rbwinn <rbwi...(a)gmail.com> wrote: > > > > > > > On 26 June, 07:29, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jun 25, 7:00 pm, rbwinn <rbwi...(a)gmail.com> wrote: > > > > > On 25 June, 08:50, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Jun 24, 10:59 pm, rbwinn <rbwi...(a)gmail.com> wrote: > > > > > > > On 24 June, 07:24, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > They agree within the precision of the measurements you make. That's > > > > > > > because theGalileantransformation are an excellent *approximation* > > > > > > > to the real thing, especially at the low speeds that welders like to > > > > > > > work with. As I told you before, Robert, feel free to use theGalilean > > > > > > > transforms if they work for you and your needs. Physicists, on the > > > > > > > other hand, sometimes work in domains where theGalileantransforms > > > > > > > don't work well at all, because they don't always agree with > > > > > > > measurments. It's in those cases that they're more careful, where > > > > > > > you're happy to be simple and sloppy. > > > > > > > > PD > > > > > > > Well, I have noticed that with regard to people who subscribe to > > > > > > disciplines. In any event, you may have noticed that I only apply the > > > > > >Galileantransformation equations to two frames of reference at a > > > > > > time. > > > > > > And depending on the precision of your measurements of x, y, z, t, x', > > > > > y', z', t', and how big v is, those transformations will provide you > > > > > sufficient accuracy to work well enough. After all, 1.002 inches +/- > > > > > 0.003 inches and 1.004 inches +/- 0.002 inches are EQUAL to the > > > > > precision of those numbers. > > > > > > But in other cases, you will find that those transformations do not > > > > > work well at all, and there is no way the equality can be believed. > > > > > > > When I say t'=t, I am not talking about all clocks in the > > > > > > universe, just to the two references to time that are measuring these > > > > > > equations: > > > > > > > x'=x-vt > > > > > > y'=y > > > > > > z'=z > > > > > > t'=t > > > > > > > Consequently, if I say that t' is time on a clock in S, the equations > > > > > > are satisfied, regardless of what a clock running at a different rate > > > > > > may say. > > > > > > Well, you can say that all you want, Bobby, but then you aren't using > > > > > theGalileantransformations, because theGalileantransformations are > > > > > more than algebraic equations. In theGalileantransformations, the > > > > > variables actually have a specific meaning, otherwise they are no > > > > > longer theGalileantransformations. (This is what marks the > > > > > difference between physics and algebra. In algebra, you can say the > > > > > variables stand for anything you want them to stand for. In physics, > > > > > you cannot.) > > > > > > > As a scientist, you may not like this, but if so, prove it > > > > > > wrong. Just complaining about an equation does not prove anything. > > > > > > I'm not complaining about anything, Bobby. I'm just making a simple > > > > > statement that the variables in the transformation mean something > > > > > specific in physics, and that those transformations turn out not to > > > > > work so well in a variety of circumstances, and so I'm not inclined to > > > > > use something that does not work well. I would not use a hammer to > > > > > drive a deck screw, either, even if there were nothing wrong with the > > > > > hammer. > > > > > > PD > > > > > I know a psychologist who was trying to drill through a board with an > > > > electric drill, and he was having great difficulty. He said to > > > > himself, This drill bit is obviously very dull, so he applied more > > > > pressure, and after a long difficult time he was able to get the hole > > > > drilled completely through the board, although it was more burned than > > > > drilled. > > > > Then he discovered that he had drilled completely through a > > > > board with the drill running in reverse. > > > > College graduates are certainly interesting people. > > > > So are welders attempting to useGalileantransformations where they > > > do not work at all well. > > > > So you see, some welders seem to have the same foibles and goofball > > > tactics that you've sometimes observed with college graduates. This > > > should caution you about being prejudicial about classes of people, > > > no? > > > > PD > > > TheGalileantransformation equations seem to me to work just fine. > > What problem were you having with them? > > I've already told you, Robert. They may work just fine with the > measurements you wish to do, at the precision with which you measure > them. > Physicists often use them too as a handy approximation. But they also > have to deal with many situations where they do not work at all well. > > On the other hand, you seem to be ok just as long as they appear to be > legitimate algebraic equations and just as long as they fit your > preconceived notions about the world. You don't seem to worry much at > all about whether measurements play a role in their usage or not. This > is where what you do with them becomes barely discernible from > whittling a stick with a pocket knife. > > PD So if my equations show the same time on a clock as the Lorentz equations to six digits at 30 miles /sec, the measurements show the Lorentz equations to be correct but my equations wrong. Well, so go ahead and show why, PD.
From: Inertial on 29 Jun 2010 01:25 It sounds like perhaps you are proposing something similar to LET In LET, reality is Galilean. Space doesn't contract and time doesn't slow down. The Galilean transforms apply. However, in that simple 3D galillean universe, what happens is clocks (and all processes) run slower and rulers (and all matter and fields) contract due to absolute motion. They do so in such a way that the MEASUREMENTS made with such clocks and rulers are no longer related by Galilean transforms, but by Lorentz transforms. It seems you are proposing the instead, we just have clock running slow so that the relation ship between what we MEASURE clocks (and processes) to do is related by x'=x-vt y'=y z'=z t'=t(1-v/c) Only you are using n for the measured time, there is no need for that. If you are talking about what is measured, you can just use x,y,z,t.
From: eric gisse on 29 Jun 2010 02:46 Inertial wrote: [...] Bobby does not understand the meaning of the variables he is discussing. There is no point of a higher level discussion than that.
From: eric gisse on 29 Jun 2010 02:47 rbwinn wrote: > On Jun 27, 5:08 pm, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: >> rbwinn wrote: >> > On 26 June, 22:48, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: >> >> rbwinn wrote: >> >> >> [...] >> >> >> > Well, I know there is not a length contraction, if that is what you >> >> > are talking about. >> >> >> Since you 'know' about as much about length contraction as you do >> >> quantum tunneling, do you also 'know' that does not exist as well? >> >> > I have no idea what you call quantum tunneling. The Europeans dug a >> > tunnel under the English channel. Is it something like that? >> >> You have no idea what length contraction is either, yet you retain a >> strong opinion on it. Why is that? > > I know what length contraction is. It is shown in the equations that > you are using. Why do you feel you understand the equations that lead to length contraction better than the equations that lead to quantum tunneling?
From: YBM on 29 Jun 2010 08:00
rbwinn a �crit : > On Jun 27, 5:08 pm, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: >> rbwinn wrote: >>> On 26 June, 22:48, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: >>>> rbwinn wrote: >>>> [...] >>>>> Well, I know there is not a length contraction, if that is what you >>>>> are talking about. >>>> Since you 'know' about as much about length contraction as you do quantum >>>> tunneling, do you also 'know' that does not exist as well? >>> I have no idea what you call quantum tunneling. The Europeans dug a >>> tunnel under the English channel. Is it something like that? >> You have no idea what length contraction is either, yet you retain a strong >> opinion on it. Why is that? > > I know what length contraction is. It is shown in the equations that > you are using. You know nothing at all : two years ago I asked you to show how Lorentz Transformations lead to length contraction, and you failed. |