Doc Al said:
Hardly a challenge there. Whereas Einstein starts with two events simultaneous in one frame and then
shows that they cannot be simultaneous as viewed from a moving frame, how does
your version of the gedanken experiment begin? Let's see:
"Just as a moving observer arrives at the midpoint of two light sources each emit a pulse of light, later verified by a stationary observer to have arrived at the midpoint at the same time. Assigning the time base for this event, at the instant the pulses were emitted the stationary and moving platform are collocated at the midpoint of the pulses at a common base time t0 = 0."
All your first sentence can mean is: Observers in the stationary frame observe the moving observer to pass the midpoint at the exact time that the two pulses are emitted--
as viewed in the stationary frame. Your second sentence just repeats the illusion that everyone agrees that the pulses were emitted simultaneously and that a unique time can be assigned to those two emissions valid in all frames. Not off to a good start!
http://frontiernet.net/~geistkiesel/index_files/
If you read "Relativity" page 25-27 does not Einstein makes the point that just because the lights are detected at different instances that this is suffiicient to invoke the 'loss of simultaneity consequences" upon humanity? Cannot the moving ovservers test to see if they are moving, which would offer one explantion for the difference in the way the pulses are detected? DUH!
Actually nobody observed the event of the simultaneous pulses. Rather than confining our thinking to Einstein's retricitions let us look at this universally. The pulses came on simultaneously. You, sir, are talking about clocks and observers as if they are able to modify the reality of the simultaneous emitted pulses. The illusion is the appication of RT to rational thought that corrupts physical laws. The events occurred at the same instant, Thee is no dt to measure, even if clocks were relevant.
DocAl said:
What you can do is have the moving observer synchronize his clock with the clock of a stationary observer at the midpoint. Is that what you are trying to do?
No, I would have said so had that been my intention. Evrybody just starts counting at zero. But since you ask, there is a common base time of t = 0 when everybody starts counting, or do you want to corrupt this fact also? Please advise.
Doc Al said:
Then you go on:
"Later, at t1, the moving observer detects the pulse from B at a position collocated with a stationary detector that also records the B pulse (See the blue figure above). Later, at t2 the A pulse from behind is detected simultaneously by the moving observer and a collocated stationary observer."
Ah... but you neglect to mention who is measuring t1 and t2. Or do you just
assume that the moving observer (using his own clock) and the stationary observers measure the same times t1 and t2? Things are getting murkier!
Lets say both are measuring t1 and t2.
AH, I see you are getting there though reluctantly as you struggle to avoid the anticipated end. Who said anything about clocks? The measureing devices on the stationary platform are collocated with the detectors on the moving platform as it passes. Each observer notices the other's observation that occurred at the same instant. Was this a corruption of the hypothetical? No, just string a series of small mirrors along the path and when the light strikes one it will strike both. Maybe some electronics gear and light sensitve receptors, OK? You may righteously call this cheating, but it is still good physics.
It seems you are trying to negate the collocated measurements because you anticipate this will crumble RT? I sppose if you made everybody as ignorant as possible you could invoke any wildy scheming theory that has no physical meaning, implication or reality. This is clear isn't it? Did you mean that if we remove the collocated measuring devices you get to keep RT? Wow, what a concept?
Doc Al said:
But you go on:
"Assigning the events as the emission of the pulses, the detection of the B and A pulse, and the simultaneous arrival of the light pulses at the midpoint at 2t1, each of the events are physically simultaneous in all frames."
Now things are really clouding up. Somehow all observers detected the coincidence of light pulse B and the moving observer at time t1 (whose time? who cares at this point?) but now that light pulse arrives at the midpoint at time 2t1. Huh?
Whose time did the light reach the point it was collected? It occurred at the same time to both moving and stationary detectors. Whatever timing method used each observer knows the measurements were simultaneous with the other observer. The clocks don't matter at this point, do they? Ok, I'll give a little as a show of congeniality. The moving t1 and the stationary t1 are both recorded at the measuring point and each instantly transfers his time reading to the other, let's say in a time system using x-ray size wavelengths for message resolution purposes.
If you read where I asssumed the pulses would meet at the midpoint for both observers, there is the test intrinsic to the analysis that alllows this as a valid conclusion.
Doc Ai said:
And then, careening out of control now, you claim that the pulses are not only emitted simultaneously (in all frames, mind you), but are also detected by both the moving and stationary observers simultaneously.
And round and round you go, merely assuming what you presumably are trying to prove. Need I go on?
Yes, everybody has their detectors placed such that both will record the A and B light simultaneously.
Tho not quite. I recognize that the moving observer does not have a detector at the midpoint of the statioanry frame, well unless the train is long enough and the observer has detectors on the train to measure the simultaneous arrival of the pulses in both frames. If this were the case how do you wiggle out? It really isn't all that difficult to grasp, unless of course, one's mental faculties have been corrupted by the acceptance of the insanity of RT.
What is wrong? We put measuring devices along the path of the moving platform and made measuremnts when the pulses arrived. If nothing else each measurment is simultaneous with the other frame's measurement. Cannot we hypothecize extremely small mirrored reflectors a few wave lengths in area placed within a few wavelengths of each other? If you are going round and round, get a hold of yourself man. The original experimental conditions have not been altered, mthe expeiment is as pure and virignal as when Ak conjured it .up, smoking who knows what. The stationary measurement does not affect thje moving measurements and vice versa. Likewise the mesurement by any entity, consious or inert, does not alter the physical reality that the pulses were turned on simultaneously in the same universe. This ain't quntum mechanics. Does that narrow it down sufficiently for you? Ah, I get it. If they use RT the observers get to perceive a universe of their very own and this is your promise toi them, isn't it? Why didn't I see that?
Your problem is your edginess in wanting to jump right in with RT and start poluting the physical reality of the pulses emitting at the same instant.
Here is the insanity of RT: The simultaneous emission, that physical realty, no a mathematical construct, of the pulses cannot be altered by any theory, which is a simply mental construct some times offered by the most brillaint of men, some times offered by the most stupid. In the case of RT, well there are just too many of you to be other than a bit cynical, though positive in my outlook as I am, by nature, I predict that the darkness you find yourself immersed will be flooded with a bursting brilliant gleaming light which is but just simple, but firm and quick, jerk away.
So calculate, impose RT constraints, the light pulses were simulataneous in the universe and that you cannot alter. I apologize for having to say this to you, an adult, I mean.
So, appaently you got lost, took a wrong turn and discovered yourself in the theory development forum or are you just 'down here' slumming, checking on us exiled mortals? Hmmm, I get bumped from answering your inane posts earlier, but you get to scout around at leisure: trenurial privileges?. This is Amerca in the 3rd Millenium isn't it? Why do not you just crawl back . . .
If it did work, the moving astronauts wouldn't even need a clock, they could use the average value as a clock. I thought it would work and I laid my argument. That was then. Now, I changed my mind. So what else do you want. 
