Register to reply 
Relativity, a theory of information? 
Share this thread: 
#1
Apr812, 11:53 AM

P: 140

I know that the relativistic effects really do happen, such as time dilation and length contraction. However both frames of references predict these effects in the other frame of reference. It is said that these effects really happen in both of them, due to relativity of simultaneity. The thing is that I don't really believe in relativity of simultaneity. Isn't it possible that only one or none of the frames of references make the right prediction. The other frames prediction is then wrong? The measurements between each frames are different events from the ones being measured.
Consider this example. There is observer A on the ground and observer B on a train. Observer A sees two lightening bolts strike the train at both sides simultaneously. Observer A sees that observer B observes the light from the front lightening bolt first, because he travels towards it. Observer B sees that the front lightening bolt strikes at first and then the one behind. He predicts that observer A sees them simultaneously because the lightening bolt at the back strikes when the light from the front bolt is at the same position. So the question is, why aren't just one or none of these predictions the right one according to more absolute properties of time and space? In the end when two observers arrive at an equal frame of reference, it is only one of them who shows relativistic effects. 


#2
Apr812, 12:12 PM

Mentor
P: 16,978




#3
Apr812, 04:53 PM

P: 5,632

Simultaneity is a tricky 'dude' when time and distance are not agreed upon by different observers, yet the speed of light is agreed upon by different observers....that still seems 'impossible' to me, but it's what we observe, so that's 'reality'.....consistently inconsistent!!!! It simply refuses to conform to everyday 'logic'... 


#4
Apr812, 11:48 PM

P: 533

Relativity, a theory of information?
To the degree that the data one receives (magnitude and sequence) is dependent on one's frame of reference, relativity might very well be characterized as a theory of information, not an existential theory of reality.
An existential theory would require absolute positions, magnitudes, and sequences that would ultimately be comprehensive, complete, and consistent for any measures from each frame of reference, and across all possible frames of reference. From an existential perspective, it does seem peculiar that each observer views his local measures as normal but requires relativistic transforms to interpret measures from a distance or at high speed. The "firm fundamental foundation" aspect of an existential concept of physical reality is just not present in relativity measures. The sense that ultimate reality must be at least logically existential is what I think has motivated analysis of mathematical structures where comprehensive, complete, and consistent entities can be found that display invariant attributes. 


#5
Apr912, 12:37 AM

PF Gold
P: 4,686




#6
Apr912, 12:40 AM

PF Gold
P: 4,686




#7
Apr912, 05:28 AM

P: 140

Also, it seems as though they have different conclusions as well. In the given example, both of them believe that it is the other person who moves and have relativistic effects, leading to different predictions of sequences of events. The reason I don't believe in relativity of simultaneity is because I think it can be a bit ignorant to only consider what measurements tells us, without taking into account that what we see is actually based on an objective existence. Measurements are nothing but a seperate prediction of a true event. What about entanglement? This tells us how particles relate to each other simultaneously regardless of speed. 


#8
Apr912, 07:24 AM

Mentor
P: 16,978




#9
Apr912, 10:23 AM

P: 1,097

for the part in bold; "Relate" to each other in the same sense I "relate" to my brother. And that relation exists no matter the spacial seperation. Also regardless of speed. What does "entanglement" mean to you faen? 


#10
Apr912, 04:54 PM

P: 533




#11
Apr912, 05:55 PM

PF Gold
P: 4,686




#12
Apr912, 07:29 PM

P: 1,162

Originally Posted by ghwellsjr View Post
Simultaneous light flashes are set off on a train [inertial of course and by train clocks] In that frame the sequence is simultaneous and the magnitudes of the light spheres are isotropically uniform only varying equally with distance from the sources. No Doppler shift. In the ground frame they are sequential. The observed magnitude is location dependent and does not vary consistently with distance from the source . There is position dependent Doppler shift. Perhaps this isn't what you are talking about at all, so maybe you could give an example of what you mean. 


#13
Apr1012, 12:16 AM

PF Gold
P: 4,686




#14
Apr1012, 01:14 AM

P: 1,162

So a midpoint train observer would see the flashes as simultaneous and equal in magnitude/brightness and without Doppler shift , other train observers would measure the magnitude as a consistent function of their distance from the sources. No Doppler A midpoint ground observer would see the rear flash first ,measure it as of lesser magnitude than the front flash even though equidistant and would see the rear blue shifted and the front red shifted. Another ground observer behind the train but at an equal distance from the rear flash as the mid observer would measure it as having a lesser magnitude and being red shifted . No consistency of the ratio of distance to measured magnitude.Etc,etc........ But maybe I am missing something here and this is still not what you are talking about??? BTW I thought what bahamagreen was talking about was exactly this and thought his view was lucid and to the point. 


#15
Apr1012, 01:31 AM

PF Gold
P: 4,686

For instance, take your first observer, if you analyzed what he sees using the ground frame (or any other frame), would you conclude that he sees the flashes at different times or with different magnitudes or with a Doppler shift? Or any of the other observers analyzed from any other frame? 


#16
Apr1012, 02:24 AM

PF Gold
P: 4,686




#17
Apr1012, 04:08 AM

P: 1,162




#18
Apr1012, 03:27 PM

P: 140




Register to reply 
Related Discussions  
What is the conflict between General theory of relativity and Quantum theory?  Cosmology  38  
Is Quantum Field Theory and General Relativity Theory mutually exclusive?  Beyond the Standard Model  0  
General relativity Theory, spacetime and string theory question.. Please Help  Introductory Physics Homework  2  
Information theory+relativity  Special & General Relativity  0 