Wonderful!
in [Physics]
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From: PD on 21 Dec 2009 15:59 On Dec 21, 1:48 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Dec 21, 12:15 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Dec 17, 12:21 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Dec 17, 1:05 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Dec 17, 1:03 pm, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > > On 17 dic, 14:59, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > On Dec 17, 12:54 pm, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > > > The water is at rest relative to the embankment. There is a single > > > > > > LIGHTNING STRIKE in the water at A/A' and a single LIGHTNING STRIKE in > > > > > > the water at B/B'. Where does the Observer at M' measure to in order > > > > > > to determine how far the LIGHT travels? Does the Observer at M' > > > > > > measure to A' and B', or does the Observer at M' measure to A and B in > > > > > > order to determine how far the LIGHT travels to M'? > > > > > > Observer M' is passing by the location of observer M, at time t0. M' > > > > > is moving at a speed v, relative to observer M, on the direction of x. > > > > > All this is happening in deep space, without an gravitational mass > > > > > (including water). Later, at time t1, observer M sees TWO simultaneous > > > > > light signals A and B arriving from opposite directions along x. > > > > > > Question: a) Since observer M', in the interval of time (t1-t0) has > > > > > already moved towards the source of the light signal B, did he observe > > > > > the light signal coming from B before observer M, or did he not? > > > > > b) Since at time t1, the ligth signal coming from point A is at the > > > > > location of observer M, is it true that the light signal coming from > > > > > point A has some travel to do to arrive to the location of observer > > > > > M', or is it not true? > > > > > c) From (a) and (b) is it true that observer M' will declare that he > > > > > received two non simultaneous light signals (first the ligt signal > > > > > from point B, later the light signal from point A), or is it not true? > > > > > > Miguel Rios > > > > > The water is at rest relative to the embankment. There is a single > > > > LIGHTNING STRIKE in the water at A/A' and a single LIGHTNING STRIKE in > > > > the water at B/B'. Where does the Observer at M' measure to in order > > > > to determine how far the LIGHT travels? Does the Observer at M' > > > > measure to A' and B', or does the Observer at M' measure to A and B in > > > > order to determine how far the LIGHT travels to M'? > > > > Since no one is able to answer this question, I will have to answer > > > it. > > > > Since the light waves associated with the lightning strikes are > > > traveling relative to the water which is at rest relative to the > > > embankment, the Observer at M' measures to A and B in order to > > > determine how far the light traveled to M'. > > > This doesn't have anything to do with Einstein's gedanken, then. > > > > With the water being at rest relative to the embankment, measuring to > > > A' and B' is meaningless. > > > Why is it meaningless? > > Because light propagates outward at the same speed in all directions > with respect to the water. In the Einstein gedanken there is no water. And what is a MEASURED OBSERVABLE fact is the following: Light propagates toward M from either direction at the same speed c. Light propagates toward M' from either direction at the same speed c. Both these statements are confirmed by isotropy experiments. > > http://evans-experientialism.freewebspace.com/einstein_relativity03.htm > > "In accordance with the principle of relativity we shall certainly > have to take for granted that the propagation of light always takes > place with the same velocity w with respect to the liquid, whether the > latter is in motion with reference to other bodies or not." - Albert > Einstein
From: Inertial on 21 Dec 2009 16:32 > On Dec 20, 4:38 pm, mpc755 <mpc...(a)gmail.com> wrote: > Do the light waves travel from A' and B' to M' or from A and B to M'? Yes. Both. A and A' were the same location when the strike hit. That defines a fixed event in space and time .. the light travels from that fixed event to all observers. Same for B/B'
From: Michael Moroney on 21 Dec 2009 17:13 mpc755 <mpc755(a)gmail.com> writes: >The problem with Einstein's train gedanken is it is assumed the state >of the aether does not matter, but even Einstein punted on this one: >'Ether and the Theory of Relativity by Albert Einstein' >http://www-groups.dcs.st-and.ac.uk/~history/Extras/Einstein_ether.html >"If we assume the ether to be at rest relatively to K, but in motion >relatively to K', the physical equivalence of K and K' seems to me >from the logical standpoint, not indeed downright incorrect, but >nevertheless unacceptable." I think you need to read his next two sentences: "The next position which it was possible to take up in face of this state of things appeared to be the following. The ether does not exist at all." There are too many contradictions when trying to involve an aether. Physicists wrestled with it many decades ago and generally came to the conclusion that there is no need for an aether, and it likely simply does not exist. This would be a "particle" artifact of the photon that all "particles" in physics have with the wave/particle duality. A "particle" has no need for a medium, just like a bullet doesn't need air (or anything else) to shoot through.
From: Michael Moroney on 21 Dec 2009 17:36 mpc755 <mpc755(a)gmail.com> writes: >On Dec 21, 12:06=A0pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> Can't you read? It is no longer Einstein's train gedanken. There is >> no longer anything moving at c. Your water changes it to an exercise of >> adding relativistic velocities [W = (v + w)/(1+vw/c^2), namely one with >> w = 0.75 c (due to the index of refraction of water) and v = 0.25 c (the >> train). >Why are you afraid to answer the modified Einstein train gedanken? You >do realize when I say 'modified' I know it is a different gedanken >than the Einstein gedanken. What is it about the modified gedanken >that has you so scared you won't answer it? You have "modified" Einstein's train gedanken to the point where your gedanken experiment is no longer applicable to Einstein's. Einstein's train gedanken was designed to show how the constant speed of light, time and space dilation interact to show the effect on what is seen as "simultaneous". With your stupid water, we no longer have light moving at c. It moves at 0.75 c, ("w" in the Einstein reference you refer to, it's significant he does NOT use "c") so any conclusion about what happens at c is meaningless. Something moving at c moves at c in any reference frame, but something moving at w (0.75 c) can move at other speeds in other reference frames. Also, I notice you *still* haven't addressed the fact that Einstein concluded that W was *not* the simple sum of w and v. Your experiment mistakenly assumes it does. > Does the light travel from A' and B' to M' or from A and B > to M'? Asked and answered.
From: mpc755 on 21 Dec 2009 19:40
On Dec 21, 3:58 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Dec 21, 1:44 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Dec 21, 12:14 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Dec 17, 12:05 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Dec 17, 1:03 pm, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > > On 17 dic, 14:59, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > On Dec 17, 12:54 pm, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > > > > > The water is at rest relative to the embankment. There is a single > > > > > > LIGHTNING STRIKE in the water at A/A' and a single LIGHTNING STRIKE in > > > > > > the water at B/B'. Where does the Observer at M' measure to in order > > > > > > to determine how far the LIGHT travels? Does the Observer at M' > > > > > > measure to A' and B', or does the Observer at M' measure to A and B in > > > > > > order to determine how far the LIGHT travels to M'? > > > > > > Observer M' is passing by the location of observer M, at time t0. M' > > > > > is moving at a speed v, relative to observer M, on the direction of x. > > > > > All this is happening in deep space, without an gravitational mass > > > > > (including water). Later, at time t1, observer M sees TWO simultaneous > > > > > light signals A and B arriving from opposite directions along x. > > > > > > Question: a) Since observer M', in the interval of time (t1-t0) has > > > > > already moved towards the source of the light signal B, did he observe > > > > > the light signal coming from B before observer M, or did he not? > > > > > b) Since at time t1, the ligth signal coming from point A is at the > > > > > location of observer M, is it true that the light signal coming from > > > > > point A has some travel to do to arrive to the location of observer > > > > > M', or is it not true? > > > > > c) From (a) and (b) is it true that observer M' will declare that he > > > > > received two non simultaneous light signals (first the ligt signal > > > > > from point B, later the light signal from point A), or is it not true? > > > > > > Miguel Rios > > > > > The water is at rest relative to the embankment. There is a single > > > > LIGHTNING STRIKE in the water at A/A' and a single LIGHTNING STRIKE in > > > > the water at B/B'. > > > > I'm glad you're at least talking about two strikes, not four. That's > > > at least somewhat close to Einstein's gedanken. > > > > > Where does the Observer at M' measure to in order > > > > to determine how far the LIGHT travels? Does the Observer at M' > > > > measure to A' and B', or does the Observer at M' measure to A and B in > > > > order to determine how far the LIGHT travels to M'? > > > > M' measures to A' (because that's where the lightning struck) and to > > > B' (because that's where the lightning struck). > > > And the Observer at M' would be incorrect. The light from the > > lightning strike at A/A' and B/B' travels with respect to the water > > which is at rest with respect to the embankment. The light from the > > lightning strikes DOES NOT travel from A' and B' to M', the light from > > the lightning strikes travels from A and B to M'. > > At the time of the lightning strike, A and A' are at the same > location. Then the light leaves that common spot before A and A' > separate. Therefore to say that the light comes from A and not A', > when A and A' were at the SAME PLACE at the moment of the strike, is > not just stupid, it is spectacularly stupid. > The water is at rest with respect to the embankment. A pebble is dropped into the water when A and A' are at the same location. The wave the pebble creates propagates outward in all directions at the same speed WITH RESPECT TO THE WATER. The wave the pebble creates propagates outward in all directions at the same speed WITH RESPECT TO A. When the wave the ripple makes in the water reaches the Observer at M', has the wave traveled from A' to M' or from A to M'? The ripple the pebble makes in the water travels from A to M'. A' is meaningless when discussing the distance the wave travels to M'. The water is at rest with respect to the embankment. A flash of light occurs when A and A' are at the same location. The light wave the flash creates propagates outward in all directions at the same speed WITH RESPECT TO THE WATER. The light wave the flash creates propagates outward in all directions at the same speed WITH RESPECT TO A. When the light wave the flash makes in the water reaches the Observer at M', has the wave traveled from A' to M' or from A to M'? |