Time dilation flashlight problem

[JesseM]

You are pointing out that you only need to use Lengh contraction when you "know" an object is in motion. What if you don't "know" it is in motion but is compared to a separate (also unknown) object.

Huh? In the first sentence are you talking about absolute motion, rather than motion relative to some frame? If not I don't understand what the difference between motion relative to some frame and motion "compared to a separate object" is supposed to be. If the first sentence is talking about absolute motion, I've already told you before that no concepts in relativity have anything to do with absolute motion, so of course that applies to length contraction as well. Even if there was such a thing as absolute motion/absolute rest, it would be utterly irrelevant to relativistic length contraction: an object at rest in the absolute sense would appear shorter in the frame of an observer in absolute motion, and an object in absolute motion would appear shorter in the frame of an observer at absolute rest, all that matters is their relative velocity. (If you believe in absolute space, there would of course be an absolute truth about whose meter-stick was longer and whose was shorter, but the observer with the absolutely shorter meter-stick would still measure the other meter-stick to be shorter than his own, because he's making "simultaneous" measurements of either end with clocks that are out-of-sync in an absolute sense. The diagrams in this thread can be used to illustrate this, just imagine that one frame's perspective is the true "absolute" frame, you can see nevertheless that their measurements of one another are totally symmetrical...I can elaborate on this if you wish.)

Also, if you ever use the words "moving" to refer to absolute motion, please make this clear by specifically using a phrase involving "absolute" like "absolute motion" or "moving in an absolute sense", otherwise your posts get very confusing.

The fact that an object would actually change size/shape dependent of the "knowledge" of motion is kinda silly.

I don't know what you mean by "actually". In a frame where the object is moving, the coordinate distance between ends of the object at a particular moment in coordinate time is shorter than the coordinate distance between ends in the frame where the object is at rest. There is no notion of the "actual" length of any object independent of how it's described in any given coordinate system.

In relativity each frame defines length in terms of simultaneous measurements of either end of the object, but different frames define simultaneity differently, so you can partially understand the different lengths in different frames by realizing that different frames are taking different 3D "cross sections" of the same 4D world-tube. If you think of a 2D spacetime diagram where we just consider one space dimension, it's easier to visualize, see the diagram on http://www.anselm.edu/homepage/dbanach/st.htm:

Here the two long slanted lines represent the worldlines of the front and back of the rod. A is an event at the back end of the rod, and B and C are two events at the front end of the rod. In the frame of the observer X whose coordinates are being represented in this diagram, A and B are simultaneous (they are at the same vertical height in the diagram, and the vertical axis represents time), so the "length" of the rod in this frame is the distance from A to B. But in the rod's rest frame, A and B are not simultaneous, rather A is simultaneous with C, so the "length" in the rest frame is the distance from A to C. You can see that the distance AB is shorter than the distance AC, so the rod is contracted in the observer's frame (there is a subtlety in that if we actually drew "ticks" of some fixed distance like 1 meter on lines of constant time in both frames, the distance between ticks wouldn't appear the same in this diagram, but still the diagram gives a qualitative sense of why the length of the rod is different in the two frames).

In ordinary 3D Euclidean geometry, we could similarly create different Cartesian coordinate systems and use them to find cross-sections of constant z-coordinate of some solid object like a cylinder (intersections of the cylinder with the xy plane of each coordinate system). If two different coordinate systems had their axes at different angles, then each one's xy plane would intersect the cylinder at different angles, and thus the concept "area of a 2D cross-section of constant z-coordinate" for the cylinder would be different in the two coordinate systems. Do you think there must be an "actual" value for "area of a 2D cross-section of constant z-coordinate" that's independent of what coordinate system we choose? Probably not. So, I don't see why you should have a problem with the analogous notion that there is no "actual" value for "distance between ends of an object at a single t-coordinate", independent of what frame's definition of simultaneity we choose.

It does not seem right if you can pick and chose when to use something like Lenth contraction when you "always" take into account Time contraction/expantion (Dilation).

Not sure what you mean, length contraction always applies to the coordinate distance between ends of an object moving inertially, just like time dilation always applies to the coordinate time between ticks of a clock moving inertially. If we have an object moving at velocity v in our frame, and we want to know the distance D an object travels in a time T in terms of our frame's coordinates, then no length contraction is figured into D and no time dilation is figured into T, the answer is just D=v*T. This is really true by definition, since we define velocity in a given frame by [change in position]/[change in time] in terms of the coordinates of that frame, no distances and times from other frames (or other rulers and clocks not at rest in that frame) are relevant to the definition of velocity.

Are you asking what the distances would be in B's frame if you assume each one comes to rest relative to B's frame when the light hits them (and likewise for C), or do you still want to assume they all come to rest relative to A's frame, but now you want to know the final distances between them in the inertial frame where B was at rest prior to changing velocities and coming to rest in A's frame? Or something else?

It has already been noted and assumed that an object "at rest" compared to another object is at rest. So if C is at rest to A and B is atrest to A then C is at rest to B and B is at rest to C. At rest = 0 relative motion to all parties involved (in this instance only 4 points (if you include the light source [also "at rest']).

No, because there is an objective difference between case #1 where B and C accelerate to come to rest relative to A while A continues to move inertially, and case #2 where A and C accelerate to come to rest relative to B while B continues to move inertially, and case #3 where A and B accelerate to come to rest relative to C while C continues to move inertially. Not all types of motion are "relative" in relativity, if the relative velocity between two objects changes there is an objective truth about which one accelerated (the one that accelerated will feel G-forces which can be measured with an accelerometer), this is crucial to defining the difference between "inertial frames" (where the usual equations of SR, like the time dilation equation, are intended to apply) and "non-inertial frames" (where these equations don't apply, and light generally doesn't even have a constant coordinate speed of c). The objective difference between inertial and accelerated motion is also crucial to understanding the twin paradox, since otherwise you could say that each twin viewed themselves at rest the whole time while the other moved away and back, and then you'd (falsely) conclude that each twin should predict the other will be younger when they reunite.

 

[Physicist1231]

If we followed NP and assumed that time and space are rigid strucures then the math is pretty easy. Since you did most of it I will not hog up the space in the forum.

with the Light source at rest at 0,0,0

the end results:

A
Location: 20,0,0
Time of impact: T=20s

B
Location: 30,0,0
Time of impact: T=40s

C
Location: 0,11.547,0
Time of impact: T=23.09401077

This still shows that since B and C were in motion they pervieved the same action at a different time and physically separate and calulateable positions that hold true even if you were to place Origin (0,0,0) in a separate location.

 

[Physicist1231]

I think we are getting confused as to wether or not there is such thing as absolute motion. Can an object be in motion if there is no other reference point other than itself. This object sees no other objects, no other mass or gravity. He is feeling no acceleration.

Personally I say yes but i have noted where you say there is not such. I wanted to get that cleared up so we are on the same page.

 

[JesseM]

In order to solve this problem (the example provided) you need to have some sort of rigid structure of space time.

By "rigid" do you just mean absolute? Each frame's coordinates can be defined in terms of readings on a rigid grid of rulers with clocks placed at each grid intersection, but I don't think that's what you mean. Again, please use the word "absolute" in your posts when you're referring to absolute notions of motion, rest, etc. so they'll be more clear.

For instance the assumption that the light was emitted "at the same time" as body B and C were moving is on a rigid strucure. Otherwise you can just comeback with the question "at the same time" to who's frame?

Except you didn't say originally that the light was emitted "at the same time" in an absolute sense as A,B,C being at the same position, instead you said that the light was emitted at T=0 in the same frame where A remained at position 0,0,0 while B and C moved at 0.5c:

Time:
T=0

Positions: Units in light seconds
A light source at 0,0,0
Body A, B and C are at coord 20ls,0,0

Velocities:
Body A remains at 20ls,0,0
Body B has a speed of .5c,0,0
Body C has a speed of 0,.5c,0

Light is emitted from the source at T=0 and at this time Body B and C start their motion.

This is a well-defined problem which doesn't require that we believe that the light was emitted "at the same time" in an absolute sense as the event of the positions of A,B,C coinciding. Even if you believe in absolute space and absolute simultaneity, the answer would be the same even if this frame was moving in an absolute sense and its definition of simultaneity was incorrect in an absolute sense.

If you were to stick with RP and ask the question "at the same time relative to whos frame"? That would be difficult to define but we could say at the referece point of A. If we did that though A would not percieve the light (thus knowing when teh light was emitted) to compare it to the time B and C left A. The same holds true for the view points of B and C since they were with A at the time of interception.

The coordinates that an event happens in a given frame are not based on when an observer in that frame perceives the event. For example, if in t=2011 I see the light from an event, and I can see that in my frame the event happened at a distance of 10 light-years in my frame, I will retroactively say this event occurred at a time coordinate of t=2001 in my frame. In most textbooks (and in Einstein's original paper) the coordinates of the frame are defined using a hypothetical grid of rulers and clocks at rest in that frame, with the clocks "synchronized" in that frame using the Einstein clock synchronization convention. Once you have such a grid, the coordinates of each event can be assigned in a local way, by looking at the marking on the ruler that was right next to the event when it happened, and looking at the reading on the clock that was attached to that marking at the moment it happened. So in the above example, even though I didn't see the event until t=2011, sitting at the x=0 light year mark on my ruler, when I look through my telescope I can see that the event happened right next to the x=10 light year mark on my ruler, and that the clock at that mark showed a reading of t=2001 at the moment the event happened next to it.

If you were to put the frame at the light source

A frame is not "at" a particular position, it's a coordinate grid that fills all of space. I suspect your comment here has something to do with the incorrect notion that the time an event occurs is determined by when an observer at the origin sees it, in which case it would matter where you placed the origin, but as I said above it doesn't work that way.

SO. If the proper RP question was asked in the beginning the math would be a little different as you would wind up with different answers depending on your perception.

My math was correct for the problem as stated, if you disagree you are misunderstanding basic aspects of relativity, please show a little intellectual humility and consider the possibility that you might actually learn something from my answers as opposed to lecturing me based on your own misconceptions about a subject you obviously haven't studied in any detail.

 

[JesseM]

I think we are getting confused as to wether or not there is such thing as absolute motion.

My point is that absolute motion is irrelevant to relativity, even if there is some absolute truth about the matter. It is possible to have an "interpretation" of relativity which does assume an absolute truth about motion, distances and times, for historical reasons this is called a type of "Lorentz ether theory", but here the absolute truths are purely metaphysical and undetectable by any conceivable experiment, since the laws of physics still work the same way in different relativistic inertial frames.

Can an object be in motion if there is no other reference point other than itself.

What does "in motion" mean? Are you talking about absolute motion, or a frame-dependent idea of motion? In either case it seems to me the answer would be yes, if there is such a thing as absolute space we can imagine a single object moving relative to it, and in relativity inertial frames are just coordinate systems, you don't need for there to be any real physical object at rest in frame X in order to use the coordinates of frame X for the purposes of a calculation.

 

[Physicist1231]

By "rigid" do you just mean absolute? Each frame's coordinates can be defined in terms of readings on a rigid grid of rulers with clocks placed at each grid intersection, but I don't think that's what you mean. Again, please use the word "absolute" in your posts when you're referring to absolute notions of motion, rest, etc. so they'll be more clear.

I guess we can use the term absolute in this sense. I am trying to express a non flexiblity of time and space where the distance between two coords (and the time it takes to get there at a certian velocity) is the same regardless of where the origin (0,0,0) is located. These measurements are not bent or altered by perception.

Except you didn't say originally that the light was emitted "at the same time" in an absolute sense as A,B,C being at the same position, instead you said that the light was emitted at T=0 in the same frame where A remained at position 0,0,0 while B and C moved at 0.5c:.

Actually what I said was "Light is emitted from the source at T=0 and at this time Body B and C start their motion."

So I did say that they were at the same time. You either assumed that it was an absolute time (which is why I did not specify according to whom). For the correct relative math to be done you needed to know that it was the simultanious to a certian reference point. You did not take that into account. Personally I agree with the ability of having an Absolute Time and Space usage and know that these can be calcuated without being skewed by perception.

This is a well-defined problem which doesn't require that we believe that the light was emitted "at the same time" in an absolute sense as the event of the positions of A,B,C coinciding. Even if you believe in absolute space and absolute simultaneity, the answer would be the same even if this frame was moving in an absolute sense and its definition of simultaneity was incorrect in an absolute sense.

You are not correct on that notion. If you have this whole setup in motion (though the measurements are not moving relative to each other, IE Light source and A remain 20ls distance apart). By simply adding a new reference point and declaring THAT point as motionless you then need to alter your formulas to account for this new speed percieved. Thus a difference in formulas all because someone else said the objects were in motion. Now if you believed in Absolute Space and Time then it would not matter the reference point. So long as you know the velocities of all parties and the distance between them you can calculate all perceptions with the same formula.

A frame is not "at" a particular position, it's a coordinate grid that fills all of space. I suspect your comment here has something to do with the incorrect notion that the time an event occurs is determined by when an observer at the origin sees it, in which case it would matter where you placed the origin, but as I said above it doesn't work that way.

You are partly correct. The actual time the event occurred is NOT the time it was percieved. However, one would need to calculate the time delay it takes from the event to start to when the reference point begins to percieve. To do this you need to know the velocities and distances on a rigid and stationary coordinate system. Should you chose to calculate the end of an event (say a second wave of light sent out 6 minutes later) you can then compare the perceived start time and perceived end time to come up with how long a perciever perceived the event.

My math was correct for the problem as stated, if you disagree you are misunderstanding basic aspects of relativity, please show a little intellectual humility and consider the possibility that you might actually learn something from my answers as opposed to lecturing me based on your own misconceptions about a subject you obviously haven't studied in any detail.

Not really saying that your math was off, however. It had a faulty setup (which was intentional) to see if the correct questions would be asked to get the correct relativisic answers. Given what you know about relativity your math was correct. No arguments there.

 

[JesseM]

I guess we can use the term absolute in this sense. I am trying to express a non flexiblity of time and space where the distance between two coords (and the time it takes to get there at a certian velocity) is the same regardless of where the origin (0,0,0) is located.

Well that's true if you are just talking about inertial coordinate systems which are at rest relative to each other but have the origin at different locations. On the other hand, if you're talking about different inertial coordinate systems in motion relative to each other, then of they can disagree about the distance and time between two events, although they agree on the proper time experienced by an object which travels from one event to the other (assuming the events have a time-like separation so it is possible to travel from one to the other moving slower-than-light)

Actually what I said was "Light is emitted from the source at T=0 and at this time Body B and C start their motion."

So I did say that they were at the same time. You either assumed that it was an absolute time (which is why I did not specify according to whom).

No, I assumed it was not absolute time, I assumed "at this time" still meant the coordinate time T=0. That's why I said the problem was solvable in relativity, because your statement of the problem only involved coordinate times and velocities.

This is a well-defined problem which doesn't require that we believe that the light was emitted "at the same time" in an absolute sense as the event of the positions of A,B,C coinciding. Even if you believe in absolute space and absolute simultaneity, the answer would be the same even if this frame was moving in an absolute sense and its definition of simultaneity was incorrect in an absolute sense.

You are not correct on that notion.

Yes, I am, since the "answer" I was talking about was just about what coordinates would be assigned to events in A's frame, and what times various clocks would read when light hit them. I wasn't talking about answers to any questions involving the Absolute distance or Absolute time between different events.

If you have this whole setup in motion (though the measurements are not moving relative to each other, IE Light source and A remain 20ls distance apart). By simply adding a new reference point and declaring THAT point as motionless you then need to alter your formulas to account for this new speed percieved.

In relativity it's irrelevant whether A's frame is moving or at rest relative to some other "reference point" (even if we assume the "reference point" is at rest in an absolute sense while A is moving in an absolute sense), all that is needed to solve the problem is the coordinates of events in A's frame. As long as it's still true in A's frame that the flash is emitted at T=0 at spatial coordinates -20,0,0 and that at T=0 A,B,C are all located at spatial coordinate 0,0,0, and that A has a velocity of 0 in this frame while B has a velocity of 0.5c along the x-axis in this frame, and C has a velocity of 0.5c along the y-axis in this frame, then this is sufficient to solve the problem of how much proper time A,B,C would experience between departing from one another and receiving the light, and it would also be sufficient to figure out the coordinate position and coordinate time that each receives the light in A's frame.

Thus a difference in formulas all because someone else said the objects were in motion.

Are you talking about calculating things from the perspective of the rest frame of this "someone else"? In this case of course the coordinates of various events would be different in this "someone else's" frame, but the physical question of how much time would elapse on each clock between the time A,B,C departed and the time they received the light would have exactly the same answer. Also if we found the coordinates of events in this frame, and applied the Lorentz transformation to them using the relative velocity between this frame and A's frame, we would get back the coordinates of the events in A's frame. So considering the perspective of this "someone else" makes no difference to questions about what coordinates are assigned to events in A's own frame, or questions about local frame-independent facts like what a clock reads when light first reaches it.

Now if you believed in Absolute Space and Time then it would not matter the reference point. So long as you know the velocities of all parties and the distance between them you can calculate all perceptions with the same formula.

I don't know what you mean by "perceptions". Are you talking about local facts which are the same in each frame, like what a particular physical clock reads at the moment some light first strikes it? Or are you talking about the values of coordinate-dependent quantities like coordinate speed and coordinate time in some particular choice of frame? Or something else? If it's either of the first two, then the values of both these things can be calculated without knowing anything about Absolute Space and Time, and the answers could be calculated in some frame without it being remotely relevant whether that frame was itself moving relative to some other "reference point".

A frame is not "at" a particular position, it's a coordinate grid that fills all of space. I suspect your comment here has something to do with the incorrect notion that the time an event occurs is determined by when an observer at the origin sees it, in which case it would matter where you placed the origin, but as I said above it doesn't work that way.

You are partly correct. The actual time the event occurred is NOT the time it was percieved.

Don't know what you mean by "actual time". I was referring to the coordinate time of that the event occurred in a particular frame, my point was that this coordinate time of the event itself is not the same as the coordinate time when some observer at rest in the frame sees the light from the event.

However, one would need to calculate the time delay it takes from the event to start to when the reference point begins to percieve. To do this you need to know the velocities and distances on a rigid and stationary coordinate system.

I still don't know what you mean by "rigid and stationary". Do you mean "stationary" in an absolute sense, or just stationary relative to the reference point? If you mean it in an absolute sense, please keep in mind the request I made in an earlier post:

Also, if you ever use the words "moving" to refer to absolute motion, please make this clear by specifically using a phrase involving "absolute" like "absolute motion" or "moving in an absolute sense", otherwise your posts get very confusing.

Please extend this request to any concept that you mean in an absolute sense, like "stationary", "at the same time", "time delay" etc.

Anyway, if we just want to calculate the "time delay" between the event and the observer seeing the event in the observer's own rest frame, not in any absolute sense, then the answer doesn't depend on the observer's velocity in an absolute sense. In relativity it is true in all frames that light has a coordinate velocity of c, so the coordinate time between two events (in this case, between the light being emitted and the observer receiving the light) is always equal to the coordinate distance divided by c. So, if we have a ruler at rest relative to the observer, and the observer is standing at the x=0 mark and can see through his telescope that an explosion happened right next to the x=10 light-years mark, then he knows that the time delay in his frame between the explosion itself and his seeing the light from the explosion must have been 10 years. This may not be the "time delay" in Absolute Time, but that's irrelevant if all we want to know is the time delay in the coordinates of the observer's own frame.

Not really saying that your math was off, however. It had a faulty setup

In what way was it "faulty"? You gave the initial coordinate times, coordinate positions and coordinate velocities in terms of the frame where A was at rest, this was sufficient to calculate the coordinate positions and times of later events in A's frame, and also sufficient to calculate the frame-independent truth about what each clock would read at the moment the light struck it. In relativity none of these answers would change if we were told A was moving relative to Absolute Space, or if we were told A was at rest in Absolute Space.

 

[Physicist1231]

JesseM,

You assumed that T=0 then according to the light source (according what my ambiguity). If that is the case how did you come to the determination that T=0 when the bodies A, B and C split up unless you were using an absolute time (or absolute distance) to go by?

 

[JesseM]

JesseM,

You assumed that T=0 then according to the light source (according what my ambiguity).

I don't understand this sentence, "according to the light source" what?

If that is the case how did you come to the determination that T=0 when the bodies A, B and C split up unless you were using an absolute time (or absolute distance) to go by?

You're not really making sense, if I had assumed that they all split up simultaneously with the light emission in terms of absolute time, then I would have no reason to believe they split up at T=0! After all there is no reason to believe that the definition of simultaneity in A's rest frame (the one that uses the time coordinate T) matches up with absolute simultaneity, if such a thing exists. It's only because I assumed you weren't talking about absolute simultaneity, but just meant "at the same time" in the same coordinate system that all your other statements were using, that I concluded it was a well-defined problem.

Anyway, the language of your statement did seem to suggest you meant that they split up at T=0 in A's frame:

Light is emitted from the source at T=0 and at this time Body B and C start their motion.

This would be an extremely weird sentence if right in the middle you switched from talking about coordinate time to absolute time! I assumed that since you were giving me the coordinate time of light being emitted, then when you said "at this time" you still meant a coordinate time of T=0. There was nothing to suggest that you were claiming that "Body B and C start their motion" at the same absolute time as the light being emitted, which might be at a completely different T-coordinate if this frame's definition of simultaneity doesn't match with absolute time.

 

[Physicist1231]

I don't understand this sentence, "according to the light source" what?

You're not really making sense, if I assumed it they all split up simultaneously with the light emission in terms of absolute time, then I would have no reason to believe they split up at T=0! After all there is no reason to believe that the definition of simultaneity in A's rest frame (the one that uses the time coordinate T) matches up with absolute simultaneity, if such a thing exists. It's only because I assumed you weren't talking about absolute simultaneity, but just meant "at the same time" in the same coordinate system that all your other statements were using, that I concluded it was a well-defined problem.

Anyway, the language of your statement did seem to suggest you meant that they split up at T=0 in A's frame:

This would be an extremely weird sentence if right in the middle you switched from talking about coordinate time to absolute time! I assumed that since you were giving me the coordinate time of light being emitted, then when you said "at this time" you still meant a coordinate time of T=0. There was nothing to suggest that you were claiming that "Body B and C start their motion" at the same absolute time as the light being emitted, which might be at a completely different T-coordinate if this frame's definition of simultaneity doesn't match with absolute time.

T=0 was honestly supposed to be Absolute Time but you took it as a coord time for reference A. Where according to my original setup it was T=0 and all was in relation to the light source. (hence why the light source in the original setup was 0,0,0) It does seem there was confusion as to where T=0 at.

I left this ambiguous to come to one of two conclusions about T=0.

1. T=0 in the absolute sense and for all parties

or

2. T=0 in the frame of the light source.

It was not my intent to make it T=0 (in a coord sense) for the frame A. Instead the setup was changed (by you [not making an accusation just pointing out]) to make A be at 0,0,0 and T=0 according to A.

So two things happened. First the origin (0,0,0) was changed by you, and it seems I left the interpretation for T=0 too open.

That seems to be our issue.

 

[JesseM]

Well, hopefully you understand that moving the spatial origin is completely irrelevant if we are trying to find the spatial distances or time intervals between events (in coordinate terms or absolute terms), so that change is totally trivial. But if T=0 was meant to be absolute time, in that case there is no way to solve your problem with the information given, because then we don't know the coordinate time interval between the light emission and the separation of A,B,C, nor do we know the absolute distance between them or the absolute velocities of A,B,C.

 

[Physicist1231]

Well, hopefully you understand that moving the spatial origin is completely irrelevant if we are trying to find the spatial distances or time intervals between events (in coordinate terms or absolute terms), so that change is totally trivial. But if T=0 was meant to be absolute time, in that case there is no way to solve your problem with the information given, because then we don't know the coordinate time interval between the light emission and the separation of A,B,C, nor do we know the absolute distance between them or the absolute velocities of A,B,C.

Absolutly we could. Let's assume (just assume) that there is Absolute time and Absolute space (thus absolute velocities as well)

If the light source was at absolute rest at 0,0,0 and all three bodies are at 20ls,0,0 at the absolute T=0.

At T=0 absolute time the light is emitted and the bodies assume their respective velocities. we will find that light hits

A at T=20s and 20ls,0,0

B at T=40s and 40ls,0,0

C at T=T=23.09401077s and 20ls,11.547ls,0

This would be in the absolute time and space coords. Now still using Newtonian physics you can determine the absolute time that A perceives that B and C see the light.

According to A, B saw the light at the absolute T=60s (the time it took from the light source to hit B and back to A) at coord 20ls,0,0 (relative to A)

According to A, C saw the light at the absolute T=34.6***ls. and at the point 0,11.547ls,0 (relative to A)


B would have a different view on when in absolute time the events happened as well. So would C.

If anything using Absolute time and Spacial assumptions makes the math not only easier to comprehend but still explain why bodies in motion see things at different times and possibly different orders.

 

[JesseM]

Absolutly we could. Let's assume (just assume) that there is Absolute time and Absolute space (thus absolute velocities as well)

If the light source was at absolute rest at 0,0,0

Now you're changing the conditions! Of course if you specify that the frame in which A is at rest (the one where A's position coordinates don't change with time) is the absolute frame, then the problem is solveable. But there was nothing to indicate that in your original explanation.

At T=0 absolute time the light is emitted and the bodies assume their respective velocities. we will find that light hits

A at T=20s and 20ls,0,0

B at T=40s and 40ls,0,0

C at T=T=23.09401077s and 20ls,11.547ls,0

This would be in the absolute time and space coords. Now still using Newtonian physics you can determine the absolute time that A perceives that B and C see the light.

According to A, B saw the light at the absolute T=60s (the time it took from the light source to hit B and back to A) at coord 20ls,0,0 (relative to A)

Your use of the phrase "according to A" is a little confusing--normally that phrase means "the coordinate time in A's rest frame when the event happened", not the time that A saw the light from the event. But yes, A will see the light from the event of B receiving the light (perhaps B signals this by waving a flag) at T=60s.

B would have a different view on when in absolute time the events happened as well. So would C.

How can B have a different view on when in absolute time events happened? Absolute time is independent of the observer, by definition. Do you just mean the time that B sees the light from different events will be different? i.e. B agrees that the light reached C at an absolute time of T=23.09401077s, but the time that B sees the light from this event is different from the time that A sees the light from this event?

If anything using Absolute time and Spacial assumptions makes the math not only easier to comprehend but still explain why bodies in motion see things at different times and possibly different orders.

I don't think that's true, the math is exactly the same if you just assume we're calculating things in A's frame without worrying about absolute space and time. The problem with the notion of absolute space and time is that it obscures the complete physical symmetry between the way the laws of physics work in different frames, and the fact that even if absolutes space & time existed it would be totally impossible to determine which frame was the absolute one by any physical experiment.