The Theory of RELATIVITY

[arian]

[center]Relativity - 101 Grade school - High school version I've been told, and that this has been known and taught for over a hundred years![/center]

Relativity
Physics - the dependence of various physical phenomena on relative motion of the observer and the observed objects, esp. regarding the nature and behavior of light, space, time, and gravity.

OK, .. so there seems to be a various physical phenomena on relative motion of the observer and the observed object, even I have noticed this phenomena, it is somewhat a different perspective going 150mph on a motorcycle vs standing still and watching someone pass me by doing 150 mph on a motorcycle.

This states that all motion is relative and that the velocity of light in a vacuum has a constant value that nothing can exceed.
E=MC^2 - where E is energy, m is mass, and c is the speed of light. Thus, Einstein stated that the universal proportionality factor between equivalent amounts of energy and mass is equal to the speed of light squared. The formula is dimensionally consistent and holds true irrespective of which system of measurement units is used.

All motion is relative, got it, but why ‘state’ that “the velocity of light in a vacuum has a constant value that nothing can exceed� .. and then go and square the speed of light in the equation E=MC^2?
OK, so this equation states that ‘C’ is Speed of Light which has a constant value of 186,282 miles / s.
Now squaring a speed that which nothing can exceed gives us a somewhat faster than ‘C’ speed of light, ... about 186,282 times faster because C squared is 34,700,983,524 miles / second.

Fine, let’s use that value of 34,700,983,524 miles / second to figure out the effects, or the relativity to T (time) on M (mass) when it is in motion at given V (velocity)?

- Among its consequences are the following: the mass of a body increases, and its length (in the direction of motion) shortens, as its speed increases;

OK, so the Mass of a body increases with speed, another word something with let’s say a mass of 50lb. becomes heavier and heavier as it goes faster and faster. So any mass reaching the assumed speed of light squared (34,700,983,524 miles / s) would become infinitely heavy, .. is this correct?

.. and ALSO, it’s length in the direction of the motion shortens, which I understand that at the speed of C^2 (34,700,983,524 miles / s) the Mass (any mass) would become the size of this universe (since they don’t consider anything outside the universe), meaning infinitely heavy and infinitely big .. is that correct?

- Holding true more generally, any body having mass has an equivalent amount of energy, and all forms of energy resist acceleration by a force and have gravitational attraction; the term matter has no universally-agreed definition under this modern view.

Continuing with the Energy=Mass C^2, what I’m understanding is (since ‘infinite’ is not imaginable for them in this universe, we’ll just stick with the size of the universe (whatever that may be?) .. so Mass at the speed of light squared, would become as ‘heavy’ as the entire universe, and as big as the universe since as stated; “the mass of a body increases, and its length (in the direction of motion) shortens as its speed increases� meaning that the leading end of the mass going at 34,700,983,524 miles / s would get shorter and shorter until it reached its trailing end, and since mass and energy is equal, it would all be one huge mass of energy (only this would happen at just past the speed of light, the effects of mass moving 186,282 times the speed of light would be much different effect) ... do I have this right?

But that is not all, they say that at the speed of light (especially at speeds C squared), Time would also slow down to a stop. Now if all the IFF’s are true, that would make sense since Mass and Weight would reach infinite, it would engulf the entire universe including time & space, thus everything would become an enormous gravitational Mass void of space, time or light ... am I close?

Is this what they call a ‘Gravitational Singularity’?

Question; to get to this point, don’t we need space and time where mass, any mass could have room to accelerate to reach the speed of light squared?

Let’s move on with relativity to how things 'might' appear by different observers at speed of light at 186,282 miles per second, or squared at 34,700,983,524 miles / second;

- the time interval between two events occurring in a moving body appears greater to a stationary observer; and mass and energy are equivalent and interconvertible.

As I understand and some of it based on - Among its consequences are the following: the mass of a body increases, and its length (in the direction of motion) shortens as its speed increases that if somebody was traveling near the speed of light for millions of years would have experienced only days, or just minutes vs the man standing would have been long gone and vanished millions of years ago,
also if a man traveling at the speed of light was able to look over at the watch of a man standing still, it would be flying by years not minutes, while his at the speed of light would be standing still, or stopped.

How close am I to understanding the Theory of Relativity as described by Einstein's equation of E=MC^2? And what parts am I misunderstanding?

Here are some doubts about Einstein's (that is if it's truly Einstein's idea?) Theory of Relativity, so the question for the Original Post is: 'Am I wrong, and if so, where am I wrong?'

1. 'C'^2 is 186,282 times faster than the assumed speed of light in a vacuum. How can Mass move so fast, and where is it moving IN? (not the universe we know, because there is a 'speed-limit' in our universe as defined by Einstein, which is mutually agreed upon, .. right?)

2. it is claimed that; nothing is faster than the speed of light, yet they assume that on the outer-skirts of our expanding fabric-of-space lies entire galaxies that are expanding ten times the speed of light, AND still emitting light at the speed of light both in the direction of the expansion, and leaving a trail behind?

3. Why is it that at these speeds distance would be shorter, not the time it takes to get to these distances? Matter of fact, they claim 'time would stop' at 186,282 miles per second. This can only mean one thing; that once these expanding galaxies passed the speed of light, they are actually coming behind us, or as we see ourselves in the mirror, we behold our face from the back. That what we see out there is US passing through us?

But that can happen only UP-TO twice the speed of light, because three times the speed of light would pass through the 'twice the speed of light', and if Einstein is right about squaring 'C', we are actually seeing 186,282 TIMES the outskirts of our universe passing through us! That would be like taking a mirror and looking back INTO a mirror, ... our universe creating infinite universes... or am I missing something?

I could use any help on this,

Thanks.

[Bust Nak]

Everyone within this universe can use the "Universal Frame of Reference", it's not like anyone has a patten on it.

Perharps you should explain in detail what you mean by universal frame of reference.

And how did you figure this out?

From you description.

Was it standing still in 'A' brain dead? Or was it observing everything that is presented before you?

What is this "it" you are referring to? What is standing still in A?

Putting each frame of reference in perspective and viewing it within the "Universal Frame of Reference", .. like you just did above?

How is the world did I just "view it within the universal frame," when I were infact giving you 4 seperate frames of reference?

How can you say that? If we took a radar gun that measures the speed relative to the car and the road right below it, (not relative to the other cars) and used it to clock the man 'B' running, what would we get?
We would get a man running at 8 mph.

Not necessarily. It depends on which frame of reference you are talking about. We would clock man B at 8 mph ONLY from frame of reference no. 3.

Now we point it at man 'D' (who is walking head to head with running man 'B') what would we get?
We would get a man walking at 4 mph.

Again not necessarily. We would clock man D at 4 mph ONLY from frame of reference no. 1.

It is ONLY in the 'Universal Frame of Reference' where we can figure out and understand why these two men with two different speeds can be traveling head to head.

Incorrect, it would not make sense in ANY ONE frame of reference. You could only say they are moving at 8 and 4 mph respectively, if you measure their speed from TWO seperate frames of reference (1 and 3 as stated in my earlier post.)

The universal answer?
There are two reference frames, where in 'B' a man is running opposite a moving sidewalk clocked at 8 mph,
and in another reference frame a man is clocked walking at 4 mph the same direction as the man 'B' is running.

Sure. So far so good, man B and D are going at different speed only in different frames of reference.

The reason they are head to head is because IN OUR Universal Reference frame we see TWO shared reference frames.

Are you using the word "universal" interchangeable with "shared"? You do understand that if two people share the same taste, it doesn't make it universal.

You could not observe this in any ONE reference frame because things would seem very different than what it really IS.

Actually, you could observe them going head to head in EVERY frame of reference. And from EVERY frame of reference, they are going at the same speed.
From frame of reference 1. Both men are travelling at 4 mph.
From frame of reference 2. Both men are travelling at 0 mph.
From frame of reference 3. Both men are travelling at 8 mph.
From frame of reference 4. Both men are travelling at 0 mph.

Mix and matching is ONLY in Einstein's Relativity where they throw in time dilation and length contraction along with single frame reference views and what MAY SEEM like for one frame looking into the other, and they blend this all up and tell people; "Here drink this, it's from Einstein, trust us it will make you wise!"

We haven't got as far as time dilation or length contraction yet. This is still in the realm of classical Newtonian physics. Understand the basics first. I haven't said anything about time slowing down or distance getting shorter.

[arian]

Everyone within this universe can use the "Universal Frame of Reference", it's not like anyone has a patten on it.

Perharps you should explain in detail what you mean by universal frame of reference.

Please read my post #262 to 'help3434'.

And how did you figure this out?

From you description.

OK, .. that's funny I guess, .. so what?

Was it standing still in 'A' brain dead? Or was it observing everything that is presented before you?

What is this "it" you are referring to? What is standing still in A?

Quote myself -
What if you were at (A) the airport and seen (B) a man running at 8 mph opposite direction of (C) a moving-sidewalk that was going 4 mph, and was head and head with (D) another man walking 4 mph next to the moving-sidewalk? That is not nonsense my friend, it is fact and ONLY makes sense when viewing it within a universal frame of reference.

Putting each frame of reference in perspective and viewing it within the "Universal Frame of Reference", .. like you just did above?

How in the world did I just "view it within the universal frame," when I were infact giving you 4 seperate frames of reference?

Come on Bust Nak, look again, you are describing 4 different reference points from which reference point?:

1) From the reference frame of A. A is stationary, B is running at 4 mph, C is moving at -4 mph, D is walking at 4 mph.
2) From the reference frame of B. A is moving at -4 mph, B is stationary, C is moving at -8 mph, D is stationary.
3) From the reference frame of C. A is moving at 4 mph, B is running at 8 mph, C is stationary, D is walking at 8 mph.
4) From the reference frame of D. A is moving at -4 mph, B is stationary, C is moving at -8 mph, D is stationary.

You can't be describing all this from a single reference point because if you were quoting from reference frame of A, you would only notice that; A is stationary, B is running at 4 mph, C is moving at -4 mph, D is walking at 4 mph and thats it. You'd be stuck in reference point A.
But no, you jumped to reference point B, then C and D because you are NOT stuck in reference point A, but exercise your freedom in a Universal Reference Frame where you can see EVERYTHING that is pertinent to our experiment.

How can you say that? If we took a radar gun that measures the speed relative to the car and the road right below it, (not relative to the other cars) and used it to clock the man 'B' running, what would we get?
We would get a man running at 8 mph.

Not necessarily. It depends on which frame of reference you are talking about. We would clock man B at 8 mph ONLY from frame of reference no. 3.

Oh come on now, .. even if superman flew at 0.7 C across all the reference frames mentioned, and millions we did not yet take into consideration, .. he could radar clock the man running in 'B' at 8 mph. No matter what frame of reference you clock the man in 'B', he will always be clocked at 8 mph because that is his speed relative to the sidewalk he is running on.

Put that moving sidewalk on another moving sidewalk going parallel, with another speed, and he would still be clocked running at 8 mph, .. only then we would have more reference frames to consider within our Universal Frame of Reference.

Now we point it at man 'D' (who is walking head to head with running man 'B') what would we get?
We would get a man walking at 4 mph.

Again not necessarily. We would clock man D at 4 mph ONLY from frame of reference no. 1.

Really? But he would be walking 4 mph in reference frame 1 no matter what reference frame we radar clocked him from. Aren't you being confused by Einstein's rules on relativity?

It is ONLY in the 'Universal Frame of Reference' where we can figure out and understand why these two men with two different speeds can be traveling head to head.

Incorrect, it would not make sense in ANY ONE frame of reference. You could only say they are moving at 8 and 4 mph respectively, if you measure their speed from TWO seperate frames of reference (1 and 3 as stated in my earlier post.)

I understand what you're saying Bust Nak, you have all this vast knowledge so what I believe you're doing is adding what seems-like from different perspectives to what it IS because that is what you said before to me that "remember what seems like is what it is" isn't that just a relativistic theory and not to be considered as real, or part of a mathematical equasion?

Another word I could have two telephone poles in a straight line 20 feet apart lined up in front of me. If I walk perpendicular to them, they will 'seem' to move away from each other, and if I move back, or away from them both, the farther-one will SEEM to get smaller than the other.
So Are they really moving away from each other, or is one getting smaller than the other? No. They just 'seem like' from different perspectives, that's all. No Time Dilation, no length contraction but are what they are and we can figure this out in our universal frame of reference.

Within this universal frame I can walk across any and all frames of individual references, walk right up to each telephone pole and measure their heights. If they are all the same, then what it is and what seems like can be very different, and not to be mixed up because some theory says so.

Now about these two guys traveling head to head at different speeds, yes I agree that the only time I could see them moving head to head is if I lined them up with each other and run with him at either 8 mph on the moving sidewalk, or walk 4 mph on the carpet in the hall with the other. But soon as I stopped, one would 'seem' to go faster than the other.

Or I cold make them hold hands here all opposing concepts from all reference frames would be eliminated! Isn't that right? Since the two events are happening at the same time and same place, no one could say it otherwise. (see, .. I did watch that Professors lecture on relativity) So we would have hands joined from people of two different speeds one double that of the other, occupying the same time and same space as they travel head and head at these different speeds.

Am I correct, or am I missing something?

The universal answer?
There are two reference frames, where in 'B' a man is running opposite a moving sidewalk clocked at 8 mph,
and in another reference frame a man is clocked walking at 4 mph the same direction as the man 'B' is running.

Sure. So far so good, man B and D are going at different speed only in different frames of reference.

But now they're holding hands too!?! So how would you explain that? The professor at Yale (I believe) said that the only time all frames of reference must agree on something (and he clapped his hand) is when two events happen at the same time and same place, .. isn't that right?

The reason they are head to head is because IN OUR Universal Reference frame we see TWO shared reference frames.

Are you using the word "universal" interchangeable with "shared"? You do understand that if two people share the same taste, it doesn't make it universal.

Yes, I understand.
Universal: of, affecting, or done by all people or things in the world or in a particular group; applicable to all cases

That is why I say that it is in our universal frame of reference that we see the two different events shared, .. no? It is here in the Universal Frame of Reference that everything is to make sense no matter what velocity or direction each separate event took place.
Unless Einstein seen another universal effect like time dilation and length contraction that is outside of our universal frame of reference? But what sense would that make within our universe? Even going forward in time would have to be within our universe, no?

You could not observe this in any ONE reference frame because things would seem very different than what it really IS.

Actually, you could observe them going head to head in EVERY frame of reference. And from EVERY frame of reference, they are going at the same speed.
From frame of reference 1. Both men are travelling at 4 mph.
From frame of reference 2. Both men are travelling at 0 mph.
From frame of reference 3. Both men are travelling at 8 mph.
From frame of reference 4. Both men are travelling at 0 mph.

Again, and I really don't want to sound like a smart-ass, and if I do, blame yourself because without you guys I would not be debating this at this level on this subject. So all credit goes to you guys, .. that is if I'm correct? If not, that'll be all mine.

What I believe you are describing above again is what seems like from those 4 different perspectives, NOT what it is. Example; From frame of reference 1. Both men are NOT travelling at 4 mph but two different speeds respectively. They only SEEM to be going 4, or 0, or 8 mph.

But from our Universal Perspective, two people are traveling head and head holding hands which share the same space and same time, yet are traveling at two different verified and measured speeds in their own respective frames of references.
Did I say that right?

Mix and matching is ONLY in Einstein's Relativity where they throw in time dilation and length contraction along with single frame reference views and what MAY SEEM like for one frame looking into the other, and they blend this all up and tell people; "Here drink this, it's from Einstein, trust us it will make you wise!"

We haven't got as far as time dilation or length contraction yet. This is still in the realm of classical Newtonian physics. Understand the basics first. I haven't said anything about time slowing down or distance getting shorter.

I can only dream of debating with you on those higher levels and I would be truly grateful Bust Nak, thanks, .. really!

PS
But you do have to admit that the above scenario could create some pretty good paradoxes in Einstein's Relativity theory, no? Especially if we put them in space and sped those guys up to more relativistic speeds!?

Thanks again.

[Bust Nak]

Please read my post #262 to 'help3434'.

That didn't make any sense. One cannot move at 8 mph and be head to head with another person moving at 4 mph in one reference frame. But I do have a better idea what you are talking about.

Quote myself -
What if you were at (A) the airport and seen (B) a man running at 8 mph opposite direction of (C) a moving-sidewalk that was going 4 mph, and was head and head with (D) another man walking 4 mph next to the moving-sidewalk? That is not nonsense my friend, it is fact and ONLY makes sense when viewing it within a universal frame of reference.

That still doesn't tell me what this "it" is? A, B C or D? How does it make any sense to say that this "it" is standing still in A? The airport is standing still in the airport maybe?

Come on Bust Nak, look again, you are describing 4 different reference points from which reference point?

Try this. Jack like vanilla ice-cream over chocolate, Jill likes chocolate ice-cream over vanilla. Clearly:

From Jack's point of view "vanilla is better."
From Jill's point of view "chocolate is better."

By saying universe reference, are you are saying "Jack thinks vanilla is better, while Jill thinks chocolate is better" is the universal point of view?

By saying there is no universe reference, we are saying nether "vanilla is better" or "chocolate is better" make any sense by themselves; they only make sense in conjuction with someone tasting ice-cream. Which is better depends on who is stating their preference.

You can't be describing all this from a single reference point because if you were quoting from reference frame of A, you would only notice that; A is stationary, B is running at 4 mph, C is moving at -4 mph, D is walking at 4 mph and thats it. You'd be stuck in reference point A.
But no, you jumped to reference point B, then C and D because you are NOT stuck in reference point A, but exercise your freedom in a Universal Reference Frame where you can see EVERYTHING that is pertinent to our experiment.

I am describing 4 individual Frames of Reference, because "B is moving at 4 mph" does not make any sense by itself; it only make sense in conjuction with "in frame of Reference no. 1.

A minor point, A, B, C and D are objects. A is the airport, C is the moving sidewalk, B and D are people. The Frame of References are numbered 1-4. Try sticking to the same terms to avoid confusing the issue.

Oh come on now, .. even if superman flew at 0.7 C across all the reference frames mentioned..., and millions we did not yet take into consideration, .. he could radar clock the man running in 'B' at 8 mph.

No, he cannot. He cannot fly at 0.7 C accross all reference frames, he can only fly at 0.7 C accross ONE reference frame at a time. He would also get a different result depending on which out of these millions of reference point he is measuring from.

No matter what frame of reference you clock the man in 'B', he will always be clocked at 8 mph because that is his speed relative to the sidewalk he is running on.

Read what you wrote very carefully. You are doing the measuring in ONE reference point - "relative to the sidewalk" IS Frame of Reference no. 3.

Put that moving sidewalk on another moving sidewalk going parallel, with another speed, and he would still be clocked running at 8 mph, .. only then we would have more reference frames to consider within our Universal Frame of Reference.

Incorrect. He could ONLY be clocked running at 8 mph from Frame of Reference no. 3. Just like "chocolate is better" is only true according to Jill, but not Jack.

Really? But he would be walking 4 mph in reference frame 1 no matter what reference frame we radar clocked him from.

No, ONLY from reference frame 1. From any other reference frame, you would get a different speed.

Aren't you being confused by Einstein's rules on relativity?

No, we are still talking about classical Newtonian physics at this point.

I understand what you're saying Bust Nak, you have all this vast knowledge so what I believe you're doing is adding what seems-like from different perspectives to what it IS because that is what you said before to me that "remember what seems like is what it is" isn't that just a relativistic theory and not to be considered as real, or part of a mathematical equasion?

Exactly, what it seems like, IS what is IS. And it is still true in classical Newtonian physics. You get a radar gun and measure it, it is what it IS. The revalition in Einstein's relativity, is that time dilate and length contract depends on the speed. So far, we have not mentioned time dilation and length contraction yet.

Another word I could have two telephone poles in a straight line 20 feet apart lined up in front of me. If I walk perpendicular to them, they will 'seem' to move away from each other, and if I move back, or away from them both, the farther-one will SEEM to get smaller than the other. So Are they really moving away from each other, or is one getting smaller than the other? No. They just 'seem like' from different perspectives, that's all. No Time Dilation, no length contraction but are what they are and we can figure this out in our universal frame of reference.

Within this universal frame I can walk across any and all frames of individual references, walk right up to each telephone pole and measure their heights. If they are all the same, then what it is and what seems like can be very different, and not to be mixed up because some theory says so.

No, that is not the "seem to" I am talking about. I am talking about actual measurment. Using radar guns and rulers. I use "seem to" because the actual measurment would be different depending on who is doing the measuring. You get different results using the same radar guns and rulers due to time dilation. But to reiterate, we haven't got that far yet.

Now about these two guys traveling head to head at different speeds, yes I agree that the only time I could see them moving head to head is if I lined them up with each other and run with him at either 8 mph on the moving sidewalk, or walk 4 mph on the carpet in the hall with the other.

Right, from any frame of reference, either both at 4 mph or both at 8 mph, but never one at 4 mph and the other at 8 mph from.

But soon as I stopped, one would 'seem' to go faster than the other.

That is not possible. If they are holding hands, as you suggested below, they don't suddenly get pulled apart when you stop. The would still be head to head, regardless of how fast you are going.

Or I cold make them hold hands here all opposing concepts from all reference frames would be eliminated! Isn't that right?

No, nothing would change.

From frame of reference 1. Both men are travelling at 4 mph.
From frame of reference 2. Both men are travelling at 0 mph.
From frame of reference 3. Both men are travelling at 8 mph.
From frame of reference 4. Both men are travelling at 0 mph.

Since the two events are happening at the same time and same place, no one could say it otherwise. (see, .. I did watch that Professors lecture on relativity)...

That much is true.

So we would have hands joined from people of two different speeds one double that of the other, occupying the same time and same space as they travel head and head at these different speeds.

The only reason they can hold hands IS because they are going at the SAME speed in any one frame of reference.

But now they're holding hands too!?! So how would you explain that?

As I said, quite simply because they are going at the same speed.

The professor at Yale (I believe) said that the only time all frames of reference must agree on something (and he clapped his hand) is when two events happen at the same time and same place, .. isn't that right?

Yes.

Yes, I understand.
Universal: of, affecting, or done by all people or things in the world or in a particular group; applicable to all cases

That is why I say that it is in our universal frame of reference that we see the two different events shared, .. no? It is here in the Universal Frame of Reference that everything is to make sense no matter what velocity or direction each separate event took place.

Does my ice-cream scenario explain what we meant?

Unless Einstein seen another universal effect like time dilation and length contraction that is outside of our universal frame of reference? But what sense would that make within our universe? Even going forward in time would have to be within our universe, no?

Forget about Einstein. We need to sort out this Frame of Reference business first.

Again, and I really don't want to sound like a smart-ass, and if I do, blame yourself because without you guys I would not be debating this at this level on this subject. So all credit goes to you guys, .. that is if I'm correct? If not, that'll be all mine.

What I believe you are describing above again is what seems like from those 4 different perspectives, NOT what it is. Example; From frame of reference 1. Both men are NOT travelling at 4 mph but two different speeds respectively. They only SEEM to be going 4, or 0, or 8 mph.

No, what seems to be, IS what it is. With radar guns and rulers. They ARE both travelling at 4, or 0, or 8 mph respectively.

Man B is not running at 8 mph fullstop; he is running at 8 mph relative to the sidewalk, I could only measure that he is going at 8 mph, if I am using the radar gun while standing on that moving sidewalk.

Man D is not walking at 4 mph fullstop; he is walking at 4 mph relative to the airport, I could only measure that he is going at 4 mph while standing still relative to the airport.

But from our Universal Perspective, two people are traveling head and head holding hands which share the same space and same time, yet are traveling at two different verified and measured speeds in their own respective frames of references.
Did I say that right?

It certainly made more sense than before.

But you do have to admit that the above scenario could create some pretty good paradoxes in Einstein's Relativity theory, no? Especially if we put them in space and sped those guys up to more relativistic speeds!?

Sure.

[arian]

Please read my post #262 to 'help3434'.

That didn't make any sense. One cannot move at 8 mph and be head to head with another person moving at 4 mph in one reference frame. But I do have a better idea what you are talking about.

Thanks again my friend for your kind response to my long post. In some of my statements I agree I stated wrong, in some you misunderstood me, and in others I don't agree. But instead of addressing and re-addressing these same things, why don't I re-set the stage again so my little mind would not wonder off and confuse things? As I set the stage, I will wait for your response if my stage and each reference frame is correct or not, .. I hope this will eliminate me making you repeat yourself, .. agreed?

The STAGE:

* We are standing in the hall IN the airport and we'll name this Reference frame A Now whatever happens in this hall remains in our reference frame A, .. is this correct?

* To our right here, we notice a moving sidewalk traveling away from us at 4 mph relative to the floor of the hall that we are observing this from. This moving sidewalk is still in Reference Frame A .. correct?

* Then we notice, and radar a man walking towards us in the hall at 4 mph, which is still in our Reference Frame A, .. correct? (To avoid confusion, let's leave the mans reference frame out of this for now, or what he sees, and concentrate what is happening in OUR reference frame A, which is the entire hall and what WE see) fair enough?
From OUR point of view, in our Frame of Reference A, .. do we assign another Frame of Reference to the walking man? If so, why, .. since he is coming towards us?

Note: We haven't moved any, but are standing still in our Frame of Reference A with our radar gun observing all this in the hall.

* We then notice a man running towards us on the moving sidewalk, we take our radar gun and clock him at 8 mph relative to the sidewalk, and 4 mph relative to the floor of the hall we are standing on, which is our reference frame A (now lets leave what the running-man sees out of this also, .. for now, and concentrate only on what we observe)

Now please correct and explain if and where I described this scene in error, and why? Then re-set the stage intelligently, as you believe it should be stated.


Thanks again.

[Bust Nak]

Thanks again my friend for your kind response to my long post. In some of my statements I agree I stated wrong, in some you misunderstood me, and in others I don't agree. But instead of addressing and re-addressing these same things, why don't I re-set the stage again so my little mind would not wonder off and confuse things? As I set the stage, I will wait for your response if my stage and each reference frame is correct or not, .. I hope this will eliminate me making you repeat yourself, .. agreed?

Sure.

The STAGE:

* We are standing in the hall IN the airport and we'll name this Reference frame A Now whatever happens in this hall remains in our reference frame A, .. is this correct?

Reference fame A is what I called Frame of Reference no. 1 in my post. I'll use your terminology from this point onwards. Objection one, there are other frames of references inside the airport, such as the moving sidewalk. So no, there are things that happens in this hall that are not in reference frame A.

* To our right here, we notice a moving sidewalk traveling away from us at 4 mph relative to the floor of the hall that we are observing this from. This moving sidewalk is still in Reference Frame A .. correct?

Yes. The sidewalk is moving at -4 mph if we take moving to our right as negative.

* Then we notice, and radar a man walking towards us in the hall at 4 mph, which is still in our Reference Frame A, .. correct? (To avoid confusion, let's leave the mans reference frame out of this for now, or what he sees, and concentrate what is happening in OUR reference frame A, which is the entire hall and what WE see) fair enough?

Yes, let call him the walker to differentiate him from the guy on the moving side walk.

From OUR point of view, in our Frame of Reference A, .. do we assign another Frame of Reference to the walking man? If so, why, .. since he is coming towards us?

Note: We haven't moved any, but are standing still in our Frame of Reference A with our radar gun observing all this in the hall.

We can assign another frame if we like, we can assign as many as we like, but I see no reason to just yet.

* We then notice a man running towards us on the moving sidewalk, we take our radar gun and clock him at 8 mph relative to the sidewalk, and 4 mph relative to the floor of the hall we are standing on, which is our reference frame A (now lets leave what the running-man sees out of this also, .. for now, and concentrate only on what we observe)

Lets call this second man the runner from now on.
Objection two. When you use your radar gun, you'll clock him at 4 mph only, because your radar gun is in reference frame A. Only by working out the maths could you figure out that he is moving at 8 mph (4 - -4 = 8) relative to the sidewalk.
Objection three. When you said relative to the sidewalk, you have introduced a second Frame of Reference (shall we call this reference frame B?) As mentioned above, he is not moving at 8 mph in reference frame A, only in rf B.

[arian]

Thanks again my friend for your kind response to my long post. In some of my statements I agree I stated wrong, in some you misunderstood me, and in others I don't agree. But instead of addressing and re-addressing these same things, why don't I re-set the stage again so my little mind would not wonder off and confuse things? As I set the stage, I will wait for your response if my stage and each reference frame is correct or not, .. I hope this will eliminate me making you repeat yourself, .. agreed?

Sure.

The STAGE:

* We are standing in the hall IN the airport and we'll name this Reference frame A Now whatever happens in this hall remains in our reference frame A, .. is this correct?

Reference fame A is what I called Frame of Reference no. 1 in my post. I'll use your terminology from this point onwards. Objection one, there are other frames of references inside the airport, such as the moving sidewalk. So no, there are things that happens in this hall that are not in reference frame A.

* To our right here, we notice a moving sidewalk traveling away from us at 4 mph relative to the floor of the hall that we are observing this from. This moving sidewalk is still in Reference Frame A .. correct?

Yes. The sidewalk is moving at -4 mph if we take moving to our right as negative.

* Then we notice, and radar a man walking towards us in the hall at 4 mph, which is still in our Reference Frame A, .. correct? (To avoid confusion, let's leave the mans reference frame out of this for now, or what he sees, and concentrate what is happening in OUR reference frame A, which is the entire hall and what WE see) fair enough?

Yes, let call him the walker to differentiate him from the guy on the moving side walk.

From OUR point of view, in our Frame of Reference A, .. do we assign another Frame of Reference to the walking man? If so, why, .. since he is coming towards us?

Note: We haven't moved any, but are standing still in our Frame of Reference A with our radar gun observing all this in the hall.

We can assign another frame if we like, we can assign as many as we like, but I see no reason to just yet.

* We then notice a man running towards us on the moving sidewalk, we take our radar gun and clock him at 8 mph relative to the sidewalk, and 4 mph relative to the floor of the hall we are standing on, which is our reference frame A (now lets leave what the running-man sees out of this also, .. for now, and concentrate only on what we observe)

Lets call this second man the runner from now on.
Objection two. When you use your radar gun, you'll clock him at 4 mph only, because your radar gun is in reference frame A. Only by working out the maths could you figure out that he is moving at 8 mph (4 - -4 = 8) relative to the sidewalk.
Objection three. When you said relative to the sidewalk, you have introduced a second Frame of Reference (shall we call this reference frame B?) As mentioned above, he is not moving at 8 mph in reference frame A, only in rf B.

Hi, I hope you have some time tonight, I got kind of busy. Please correct as you see fit.

* OK, so far we have Reference frame A the hall

* IN Reference frame A the hall we see and observe Walking man coming towards us. We take our radar gun, (which clocks any moving object relative to what it/he is moving on) and clock Walking man at 4mph relative to the same hall carpet we are standing on. (is this good so far?)

* Also IN Reference frame A the hall we see a moving sidewalk moving 'away from us' at a preset speed of 4 mph.

-On this moving sidewalk we see a man running towards us at 8 mph, which of course is against the direction of the moving sidewalk.
- We radar Running man and the radar indicates he is running 8 mph relative to what he is running on, in this case the moving sidewalk

I would like us to agree on this so far, so please clarify first, and correct as you see fit.

[Bust Nak]

* OK, so far we have Reference frame A the hall

Yep.

* IN Reference frame A the hall we see and observe Walking man coming towards us. We take our radar gun, (which clocks any moving object relative to what it/he is moving on) and clock Walking man at 4mph relative to the same hall carpet we are standing on. (is this good so far?)

No, radar gun clocks object relative to the gun itself (i.e. Reference frame A,) not relative to what he is moving on.

* Also IN Reference frame A the hall we see a moving sidewalk moving 'away from us' at a preset speed of 4 mph.

Yep.

-On this moving sidewalk we see a man running towards us at 8 mph, which of course is against the direction of the moving sidewalk.
- We radar Running man and the radar indicates he is running 8 mph relative to what he is running on, in this case the moving sidewalk

Again, the radar would indicates he is running 4 mph relative to us, because the radar clocks object relative to the gun itself, not relative to what he is moving on. Only by knowing how fast the sidewalk is moving, can we work out how fast he is moving relative to the sidewalk.

[keithprosser3]

Let's have two walkways, one on Bill's left and one on Bill's right, both moving towards Bill at 4 mph. Abel is standing on one walkway, Chas is on the other. Abel and Chas are therefore both approaching towards Bill at 4 mph and towards each other at 8mph.

Now let the walkways be cranked up to their top speed of 0.6c (they are of course very long walkways). Now Abel and Chas approach Bill at 0.6c, and each other at... er, 1.2c?

Faster than the speed of light? What's going on here?

[sfs]

Let's have two walkways, one on Bill's left and one on Bill's right, both moving towards Bill at 4 mph. Abel is standing on one walkway, Chas is on the other. Abel and Chas are therefore both approaching towards Bill at 4 mph and towards each other at 8mph.

More precisely, Abel sees Chas approaching him at 8 mph and Chas sees Abel approaching him at 8 mph. Even more precisely, each sees the other approaching at very slightly less than 8 mph, since in the real world velocities add according to the rules of Special Relativity. (In this case, the speed will be one part in 10^17 lower, so don't look to be detecting this on a radar gun.)

Now let the walkways be cranked up to their top speed of 0.6c (they are of course very long walkways). Now Abel and Chas approach Bill at 0.6c, and each other at... er, 1.2c?

Faster than the speed of light? What's going on here?

No, they each see the other approaching at 0.88c.

[keithprosser3]

0.88c

Lucky guess.