Wonderful!
in [Physics]
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From: glird on 22 Dec 2009 14:06 On Dec 22, 12:08 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > mpc755 <mpc...(a)gmail.com> writes: > >Dear glird, > >I understand STR better than anyone. > >mpc755 > > Thanks for the laugh! ;-} glird
From: mpc755 on 22 Dec 2009 14:07 On Dec 22, 1:06 pm, glird <gl...(a)aol.com> wrote: > On Dec 22, 9:38 am, PD wrote:> mpc755 <mpc...(a)gmail.com> wrote: > > ><< 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 DO NOT travel from A' and B' to M', the light from > the lightning strikes travels from A and B to M'. > Is this your response, or is this my response? If this is your response, great! > >< 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. >> > > >< That's true for water. > > What's true for light is this experimental observation: > The speed of light approaching M from either direction is the same: > c. > The speed of light approaching M' from either direction is the same: > c. > The fact that what you say about water is true does not mean that the > experimental facts about light I just listed are disputable. They > aren't. >> > > What PD listed aren't experimental FACTS; they are interpretations -- > by physicists -- of experimental data. > The data is indisputable, but the interpretations are off the wall. > Even the smartest physicist of them all, Einstein, knew that it is > impossible for anything to move at a given velocity relative to two > differently moving objects. > That's why he invented a novel method of setting clocks of a given > system. (As Einstein showed, at least one of PD's two indisputable > facts would be experimentally false without it.) > > glird
From: PD on 22 Dec 2009 14:11 On Dec 22, 1:02 pm, glird <gl...(a)aol.com> wrote: > On Dec 22, 11:44 am, "papar...(a)gmail.com wrote: > > > On Dec 22, 9:38 am, PD wrote: > > > << What is disputable is where the light travels from to M and M'. Without knowing the state of the aether the light propagates through, simultaneity cannot be determined. >> > > >< Of course it can!!!!. Just ask the two guys what they saw. One of them (M) will tell you "I saw two simultaneous strikes", the other (M') will assure you "I saw two non simultaneous strikes"....case closed. > > > The defense lawyer objects: "The two guys are wrong. M saw two > lights that reached him simultaneously and M' saw two that reached him > non-simultaneously. That doesn't prove anything at all about whether > or not the lightning bolts struck two remote places > simultaneously." ... case closed in favor of the defense. Not so. They have additional information. M' measures the distance from himself to the two scorch marks and notes that those two distances are the same. M does the same and gets the same result. M' measures the speed of light in both directions and observes that it is the same. M does the same and gets the same result. Now here is an INDISPUTABLE train of thought: 1. If you know that the distance two signals travel is the same, and 2. If you know that the speed of two signals is the same, and 3. If the signals arrive at the observer at the same time, 4. Then the original source of the signals occurred at the same time. Likewise: 1'. If you know that the distance two signals travel is the same, and 2'. If you know that the speed of two signals is the same, and 3'. If the signals arrive at the observer at not the same time, 4'. Then the original source of the signals occurred at not the same time. So here are the facts: M observes facts 1, 2, 3, and rightfully makes INDISPUTABLE conclusion 4. M' observes facts 1', 2', 3' and rightfully makes INDISPUTABLE conclusion 4'. > > > << If the water is at rest with respect to the embankment, the light waves travel through the water from A and B to BOTH M and M'. If the Observer at M and M' know the state of the water, which is at rest with respect to the embankment and if the light from the lighting strikes reaches M simultaneously, BOTH Observers will conclude the lightning strikes were simultaneous, in nature. If the Observers do not know the state of the water, determining the simultaneity of the lightning strikes is impossible. >> > > >< What is the point of that?. For sure we all know that. In fact it is a given in Einstein gedanken!!!! > > We know both strikes were simultaneous.. No, we don't know that. We only know that if conditions 1, 2, and 3 above hold. And if conditions 1', 2', and 3' hold then we know they were not simultaneous. >.there is no question as to > that. > What it is relevant if that observations agree about that, and the > result is that they do not agree....case closed.> > > The defense lawyer replies, "How do you know that both strikes were > simultaneous? Indeed," he continued, "how do you KNOW whether Mr. M > or Mr. M' is stationary?" > The offensive lawyer would probably answer, "Because Einstein said > so!" ... case remains open. > > > << If the aether is at rest with respect to the embankment, the light waves travel through the aether from A and B to BOTH M and M'. If the Observer at M and M' know the state of the aether, which is at rest with respect to the embankment and if the light from the lightning strikes reaches M simultaneously, BOTH Observers will conclude the > > lightning strikes were simultaneous, in nature. If the Observers do > not know the state of the aether, determining the simultaneity of > lightning strikes is impossible. >> > > > > > Again nonsense. That is not relevant to the relativity of simultaneity gedanken. And in practical terms, I doubt you would be able to travel to points A and B to check what happened there!!! > > > A and B are not "points". They are places on the ground where > lightning bolts hit. Even a bug could go to them and check what > happened there -- which was that a lightning bolt hit and scorched > each place. > > glird
From: paparios on 22 Dec 2009 14:39 On 22 dic, 16:00, mpc755 <mpc...(a)gmail.com> wrote: > On Dec 22, 11:44 am, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > > > On 22 dic, 12:57, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Dec 22, 9:38 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > Correct. What is disputable is where the light travels from to M and > > > M'. Without knowing the state of the aether the light propagates > > > through, simultaneity cannot be determined. > > > Of course it can!!!!. Just ask the two guys what they saw. One of them > > (M) will tell you "I saw two simultaneous strikes", the other (M') > > will assure you "I saw two non simultaneous strikes"....case closed. > > A lightning strike occurs one light year away from the Observer on the > embankment. A second before the light from the lightning strike > reaches the Observer on the embankment, a lighting strike occurs one > second away from the Observer on the embankment. The light from both > lightning strikes reach the Observer simultaneously. Were the > lightning strike simultaneous? For the observer location YES!!!!. He did observe TWO simultaneous flashes at his location. There are an infinity number of ways in which this simultaneous observation can be obtained. Do you have a problem with this? Miguel Rios
From: mpc755 on 22 Dec 2009 14:39
On Dec 22, 1:48 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Dec 22, 9:57 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Dec 22, 9:38 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Dec 21, 6:40 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > 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. > > > > That's true for water. > > > It is true for light waves in water. > > > > What's true for light is this experimental observation: > > > The speed of light approaching M from either direction is the same: c.. > > > The speed of light approaching M' from either direction is the same: > > > c. > > > Correct. > > > > The fact that what you say about water is true does not mean that the > > > experimental facts about light I just listed are disputable. They > > > aren't. > > > Correct. What is disputable is where the light travels from to M and > > M'. Without knowing the state of the aether the light propagates > > through, simultaneity cannot be determined. > > Of course it can be determined. The location of the source of the > light is determined by the scorch mark left at the end of the train by > the lightning strike at A'. There can be no other source of light. > Measuring the distance between the scorch mark at the end of the train > and the little black mark at M' can be done with a tape measure. I > don't know why you think this is complicated. It's not. > Without knowing the relative motion of an object with respect to the aether simultaneity cannot be determined. If light reaches M simultaneously from A and B and it is assumed the aether is at rest with respect to the embankment, then the lightning strikes at A/A' and B/B' were simultaneous. If however, the aether is at rest with respect to the embankment and the Observer on the train is aware of this information, when the Observer on the train measures to A' and B' and factors in when the light from the lightning strike reached M' and factors in the trains speed relative to the embankment (which gives the speed of the train relative to the aether), the Observer on the train concludes the lightning strikes at A/A' and B/B' were simultaneous. |