B Relativity of simultaneity and the balance of the systems

[Sisoeff]

Hi everybody,
Glad to be with you, in the most popular physics forums on the Internet.
First of all, I'm not a physicist and the problem I hope to get the answer from you, is part of the work I'm writing in another field.
To cut it short, I don't quite understand how the relativity of simultaneity works without braking the laws of physics.
My understanding is that one system must be in balance in all frames of reference, meaning that the chain of cause and the effect cannot be broken in any of the reference frames.
Do I make sense

I'll give an example with the ladder paradox.
Mentioning the balance word, let us balance the garage on a triangle, and it will go out of balance in the ladder reference frame, which will make it impossible for the ladder to go through.

If you think, we can create many such cases (not only with balanced on triangle garages), where the cause and effect chain will brake in the frames of reference where the simultaneity is not seen. The funniest of all such cases would be the flight of a bird

Please help me with this.

 

[andrewkirk]

it will go out of balance in the ladder reference frame

Why do you think that will happen? Are you imagining the ladder contacting the floor of the garage as it slides through, and applying a downwards force? If so then the overbalancing is basic physics and doesn't have anything to do with relativity.

 

[PeterDonis]

Mentioning the balance word, let us balance the garage on a triangle, and it will go out of balance in the ladder reference frame

It will also go out of balance in the garage frame, because the ladder's center of mass is not directly over the balance point at all times.

 

[Dale]

the cause and effect chain will brake in the frames of reference where the simultaneity is not seen

The cause and effect chain is limited to c. So causes always preceed effects in all reference frames.

 

[Sisoeff]

Thank you for your answers, guys.
The garage will go out of balance in the ladder reference frame, because the doors are not moving simultaneously thus moving the center of gravity left and right.
Or if we imagine how the flight of a bird will be seen, it will be against laws of physics.
Or perhaps you could imagine that simultaneous events from one frame are sending signals to another in order to keep it in motion.
If that events are the simultaneously closing garage doors, the ladder shouldn't move, according to its own pint of reference.

 

[PeterDonis]

The garage will go out of balance in the ladder reference frame, because the doors are not moving simultaneously thus moving the center of gravity left and right.

Just to be clear: you are assuming that the ladder never actually touches the garage floor? So the ladder itself will not throw the garage out of balance in the garage frame?

Assuming that's the case, then a correct SR analysis would have to take into account that the garage is not moving inertially, so what we have been calling the "garage frame" is not an inertial frame. Neither is the "ladder frame". Non-inertial frames don't work the same as inertial frames, so your reasoning, which assumes that the "ladder frame" is an inertial frame and that the transformation between the "garage frame" and the "ladder frame" is a Lorentz transformation, is not correct.

 

[Sisoeff]

Yes, Peter,
I'm assuming that the ladder does not touch the garage, and will not throw it of of balance.
It is the doors that will do it, because they don't open simultaneously to keep the center of gravity in one point.
And with your answer you left me completely confused.
Are you saying that two moving airplanes are not inertial frames?
Would you explain, please, why the garage wouldn't be inertial frame if the ladder doesn't touch it?

 

[A.T.]

I'm assuming that the ladder does not touch the garage, and will not throw it of of balance.
It is the doors that will do it, because they don't open simultaneously to keep the center of gravity in one point.

Seems like the ladder is completely irrelevant to your question, and just makes it confusing. Can we boil down your scenario to the relevant bit:

An object is in a unstable balance under gravity, and extends symmetrically in both directions, simultaneously as measured in it's initial center of mass rest frame.

Would you explain, please, why the garage wouldn't be inertial frame if the ladder doesn't touch it?

The object is not in free fall, so it's not inertial in the relativistic sense. An neither is a frame moving horizontally relative to it. So you have to consider two non inertial-frames, and the mechanical signal propagation delays within the object.

 

[Sisoeff]

If I consider the garage and the ladder as two non inertial frames, how would the ladder go through the garage?
And if the garage-ladder does not make sense in connection to my question, I'll give another example. One can think of countless examples.
We have a train moving with fast speed on a track. It only moves on the tracks because on the side of the tracks simultaneously opening and closing doors are keeping the rails inline (or producing power for the train, or sending signals to keep the engine running .e.t.c.)
These simultaneity is not present in the train. Should it move?

 

[andrewkirk]

If the scenario has doors that open and close - which I note are not present in the drawing - then there are crucial details missing from the problem specification. When and how do the doors open?

 

[Sisoeff]

Hi Andrew,

The scenario is presented in Wikipedia, and I gave the link to it in the OP.
Here it is again. You can find there graphics of the way the doors open.
It's well known problem of a long ladder going through short garage which is solved with relativity of simultaneity.
And my question is how that relativity of simultaneity works, if the system is going out of balance in one of the reference frames.

 

[A.T.]

It's well known problem of a long ladder going through short garage which is solved with relativity of simultaneity.

Yes, but usually the frames are assumed to be free falling and thus inertial. You are introducing gravity or non-inertiality, but also the dynamics of an extended deforming object.

 

[andrewkirk]

This problem is similar to the 'Gravity on Einstein's Train' thread from a few months back, for which Peter did lots of interesting calculations. The key point is that both reference frames are non-inertial, so none of the usual SR expectations are valid.

The frame that matters for the question of whether the garage is balanced is the garage's own frame - as we would expect. If the doors open simultaneously in that frame then it remains balanced and doesn't topple. The garage is analogous to the rocket in the older thread.

In the frame of the ladder (which is analogous to the train) the doors may or may not open simultaneously. The calculations are complex so we can't easily assume either as we would in SR. However another effect of the gravity/speed combo is that, in the ladder's frame, the garage is tilted (not horizontal). That may offset issues involving the garage doors, as regards balance.

 

[jartsa]

I am sure the garage does not tilt.

Why does it not tilt? I guess the doors weigh different amounts during the opening process, in that frame where the doors do not open simultaneously.

 

[Sisoeff]

The key point is that both reference frames are non-inertial, so none of the usual SR expectations are valid.

Guys, as I already mentioned I'm not a physicist and my knowledge in that field is limited.
The "ladder paradox" in Wikipedia starts with the statement: "The ladder paradox (or barn-pole paradox) is a thought experiment in special relativity."
If the ladder paradox is explained with special relativity, why do you say that "none of the usual SR expectations are valid".
My question concerns the simultaneity which gives the solution of the ladder paradox.
I already gave another example. Here it is again. Does it make any difference to the ladder example?

We have a train moving with fast speed on a track. It only moves on the tracks because on the side of the tracks simultaneously opening and closing doors are keeping the rails inline (or producing power for the train, or sending signals to keep the engine running .e.t.c.)
These simultaneity is not present in the train. Should it move?

Please help me understand it, as I need the right understanding for my work.

 

[andrewkirk]

Guys, as I already mentioned I'm not a physicist and my knowledge in that field is limited.
The "ladder paradox" in Wikipedia starts with the statement: "The ladder paradox (or barn-pole paradox) is a thought experiment in special relativity."
If the ladder paradox is explained with special relativity, why do you say that "none of the usual SR expectations are valid".

Because in the situation that you are describing, the garage is stationary in a gravitational field. In the ladder paradox scenario, as described in the page you linked, there is no gravitational field. The situation you are envisaging is completely different from the ladder paradox.
Your other example is insufficiently specified to allow any analysis. We don't know what shape the track is, what the velocity of the train is, what's happening to the sides of the tracks etc etc. Thought experiments need to be very simple in order to be amenable to analysis. That one does not sound simple at all.

 

[Sisoeff]

Because in the situation that you are describing, the garage is stationary in a gravitational field. In the ladder paradox scenario, as described in the page you linked, there is no gravitational field.

Thank you Andrew.
Now I understand
I didn't know that the gravity defines a frame as non inertial.
If we put back the garage in an inertial frame and set the simultaneously closing and opening doors to send signals to the ladder/rocket in order to keep it moving, should I also provide all the information about the speed of the ladder, the speed of the doors and so on. Or the information in the initial thought experiment should be sufficient for your answer?

 

[A.T.]

send signals to the ladder/rocket in order to keep it moving

If the ladder doesn't always move at constant speed it's non-inertial as well. And different parts of the ladder will be moving at different speeds in some frames.

 

[jartsa]

How about this version of the thought experiment:

There are two counter rotating flywheels at opposite ends of a space station. The flywheels are stopped simultaneously in the space station frame, this operation does not tilt the space station in the space station frame. Does the space station tilt in a frame where the stopping of the flywheels was not simultaneous?

 

[A.T.]

How about this version of the thought experiment:

There are two counter rotating flywheels at opposite ends of a space station.

I don't think bringing in rotation makes it easier to analyze.

The flywheels are stopped simultaneously in the space station frame, this operation does not tilt the space station in the space station frame.

But it will twist the space station. The propagation of that twist through the structure will be different for different frames. The final orientation will be the same.

 

[jartsa]

A new version of my previous thought experiment:

There are two robotic arms at opposite ends of a space station. The arms are extended simultaneously in the space station frame, this operation does not displace the space station in the space station frame. Is the space station displaced in a frame where the extending of the arms is not simultaneous?

"Displaced" means displaced relative to another space station that is parked next to the space station.

 

[jartsa]

Hey now I think I have a nice thought experiment, not too different to OP's original one:

There are two folded solar panels at opposite ends of a space station. The panels are unfolded simultaneously in the space station frame, this operation does not cause sun light to apply any net torque on the space station in the space station frame.

Does sun light exert net torque on the space station in a frame where the unfolding of the panels is not simultaneous?

 

[Sisoeff]

Hey now I think I have a nice thought experiment, not too different to OP's original one:

There are two folded solar panels at opposite ends of a space station. The panels are unfolded simultaneously in the space station frame, this operation does not cause sun light to apply any net torque on the space station in the space station frame.

Does sun light exert net torque on the space station in a frame where the unfolding of the panels is not simultaneous?

Haha
I enjoy your enthusiasm and hope that your ideas help to solve the problem.
As I already said, there are countless examples (at leas to my understanding of the problem) that can be used.
Let's focus on only one
I'm sure that the masters in physics can think of all the inconsistencies and correct the experiment to the extent of explaining it or not having an answer.
I doubt it would be the late. We cannot be genius enough to refute Einstein ideas

 

[Sisoeff]

I'm writing a work about how we observe and how we perceive our surrounding, and I wanted to include some of the Special and General Relativity beauty in that regard. I have very basic knowledge about it, but I'm still amazed by Einstein's beautiful mind.
So, I had to do some reading to be able to include it in my work.
When I came to the relativity of simultaneity, I was confused by the fact, that Special Relativity allows the events to be missing, not accounting for the output.
It is my understanding that an event cannot go missing in another frame of reference. It could exist in later time, in another way, but falling tree must fall in all reference frames. Since simultaneity is an event, it should be existent in all reference frames.
Am I correct?

 

[PeterDonis]

simultaneity is an event

No, it isn't. "Simultaneity" means that two different events happen at the same time in a particular frame.

 

[Sisoeff]

No, it isn't. "Simultaneity" means that two different events happen at the same time in a particular frame.

Well this is more of a semantics than physics, but paying attention to semantics helps even in physics.
It depends how you look at it. It is true that we say "simultaneous events" but again, it is a way of expression.
All events correlate with the surrounding and have their effect on it.
A group of people jumping at the same time is one event, not thousands of events, because the output of group of people jumping at once is different from the output of all this people jumping separately. Think about the energy produced and the way it is distributed.
Therefore it is my understanding that simultaneous events should be treated as one event.
Well, this is how I see it, but I'm here to learn, not to teach

 

[Ibix]

The resolution to this one is fairly simple, I think. The barn cannot be perfectly rigid because if it were it would have an infinite speed of sound. What happens when the door closes is that the barn starts to sag from that end. A mechanical wave starts to propagate along the barn, with the bits behind the wave starting to sag and the bits ahead of the wave not yet sagging.

Of course, the same thing happens from the other end when that door closes. The two waves meet at the fulcrum. This is true in any frame.

One way of looking at this is that the barn starts to tip in every frame. It's just that it doesn't do it as a rigid body, and it starts to tip in opposite directions from opposite ends. If one of the doors fails to operate there will be no opposite mechanical wave and the whole shebang will be genuinely tipping from the moment the wave passes the fulcrum.

The same applies to jartsa's other examples - there is always mechanical distortion of the station propagating at finite speed (there is no way round this even in theory), and the distortion waves will always meet in the middle. Parts of the station recoil, but the whole thing never does.

 

[Ibix]

A group of people jumping at the same time is one event, not thousands of events, because the output of group of people jumping at once is different from the output of all this people jumping separately. Think about the energy produced and the way it is distributed.
Therefore it is my understanding that simultaneous events should be treated as on event.

No. Because those thousands of people are only jumping simultaneously in one frame. In any other it's like the barn doors - they jump at different times. Coloquially something like a crowd doing something is an event, but that is not correct physics terminology and you will get horribly confused if you try to use casual language in relativity.

 

[Sisoeff]

And because in my previous comment I mentioned "energy", I think that the easiest way to present the idea is:
Simultaneous events in one inertial frame are producing energy.
The simultaneity is not present in another inertial frame.
Where does the energy go?

 

[Ibix]

If they "produce energy" in one frame they produce energy in all. Unless you have a detailed countexample in mind...?

 

[PeterDonis]

this is more of a semantics than physics

If you think that, you need to really take a step back and review your physics.

A group of people jumping at the same time is one event

No, it isn't. An "event" is a point in spacetime. Each individual person's jump takes place at a different point in spacetime. Therefore they are different events.

This is not just "semantics" because the separation in spacetime between different events has physical implications: it means that there cannot be any direct "connection" between them. Any "connection" between different points in spacetime can only propagate causally, i.e., at the speed of light. That means that two events that are spacelike separated--which any pair of events which are simultaneous in any frame must be--cannot be causally connected.

Your entire analysis ignores this critical limitation. Ibix's responses are valid and you should really take some time to read and understand them.

Think about the energy produced and the way it is distributed.

Exactly: think about how the energy produced at one event (one individual person jumping) will propagate through spacetime. It must do so no faster than the speed of light. Again, take some time to read and understand Ibix's analysis; he is doing exactly what you describe, but he is doing it correctly, taking into account the separation in spacetime between different events.

 

[Nugatory]

Therefore it is my understanding that simultaneous events should be treated as one event.
Well, this is how I see it, but I'm here to learn, not to teach

An event is defined as a single point in spacetime. Thus, if two things happen at the same place and time that counts as one event. However, if they happen in different places that's always going to be two events; if the two events happen at different places but have the same time coordinate in some frame then we say that they are simultaneous in that frame.

 

[Sisoeff]

Thanks for the time taken to answer, Peter.
I'm not going to argue whether simultaneity is one or more events.
I just gave my understanding about it, and I apologize if my comment appeared like I was trying to teach you or enforce my opinion on you.
Lets focus on my question, and if you can help me, I'll be gone for the next few years

Would you tell me what do you think about this:
Simultaneous events in one inertial frame are producing energy.
The simultaneity is not present in another inertial frame.
Where does the energy go?

Ibix answer was:

If they "produce energy" in one frame they produce energy in all. Unless you have a detailed countexample in mind...?

It is a bit vague answer, but if understand it correct, then simultaneity is present in all frames. It is just seen differently. Which makes the relativity of simultaneity false.
Is that what are you guys saying?

 

[PeterDonis]

Would you tell me what do you think about this:

I think just what I said before: you are misunderstanding the physics because you are not taking into account the spacetime separation between events.

if understand it correct, then simultaneity is present in all frames. It is just seen differently. Which makes the relativity of simultaneity false.
Is that what are you guys saying?

No. We are saying that there is not one "energy" being produced by all the different people jumping at different events. If there are N people jumping, then there are N "packets" of energy being produced, each one at a different event in spacetime. Those N packets of energy are separate and you can't think of them as one thing; they aren't. The fact that the jumps are all simultaneous in one particular frame is irrelevant; they are still N separate things.

 

[Sisoeff]

Well, let me put it in a simple way, as I understand it, and then you tell me where am I wrong.
I see energy as information.
Different amount of energy transferred in certain time holds different information.
If in inertial frame A two simultaneous events release 2 joules of energy, and they are transferred to another inertial frame B in 1 second, that information would reveal part of the properties of frame A. That property would be: Inertial frame A releases 2 joules of energy per second.
Note that if frame B receives 1 joule per second because simultaneity does not exist in this frame, that information would be different and won't be part of the property of frame A.
If the simultaneous events in frame A do not exist in frame B, but frame B still gets the same information (2 joules per second), that would mean, that simultaneity exist, but is not seen in as such.
Hope that this make sense, and you'll have an easy way to guide me to better understanding.

 

[PeterDonis]

If in inertial frame A two simultaneous events release 2 joules of energy, and they are transferred to another inertial frame B in 1 second

Energy doesn't get transferred between frames; that makes no sense. Frames are not physical things; they're abstract tools we use to analyze the behavior of physical things. Energy gets transferred between events. Those events can be described in frame A or frame B.

that information would reveal part of the properties of frame A

Energy is not a property of a frame; frames don't have "properties" in this sense. Energy is a property of an object. If an event releases energy, that energy gets carried by something: a moving billiard ball, a pulse of radiation, etc. The "transfer" of energy is just the motion of whatever is carrying the energy.

If the simultaneous events in frame A do not exist in frame B

Events always "exist" in every frame; they just aren't simultaneous in every frame.

Hope that this make sense

Not really. See above.

you'll have an easy way to guide me to better understanding

The best advice I can give you is to stop thinking in terms of "frames" and start thinking in terms of objects and events and how they are related in spacetime. If we have two events that each release a pulse of energy, what carries that energy? Where does it go? What other objects will receive it? And how are all these things connected in spacetime? (Hint: two events being simultaneous in some particular frame is not a "connection" in this sense; it has no physical meaning.) If you analyze things in these terms, you will see that energy never appears from nowhere or disappears into nowhere; all it does is change form.

 

[andrewkirk]

If we put back the garage in an inertial frame

I think a tractable, reasonably similar, experiment can be constructed using only inertial frames.

Consider the garage sitting in free fall in empty space, far from any gravitational field. Call the inertial frame in which the garage is initially stationary F. Then at at time t1 in frame F, both garage doors open. Let's assume they slide up (in positive y direction), rather than rotating, to make the motion as simple as possible. Then the garage will start moving downwards (in negative y direction) in F and come to a rest (in F) at time t2 in F when the doors come to rest fully open. The centre of mass of the garage will not have moved in F, and its orientation will not have changed at any point - it will always be parallel to the x axis. But after the door-opening the garage floor will have a lower y coordinate than it originally had.

Now consider the inertial co-moving frame F' of a body (a ladder, if you like) that is flying past the garage (no need to go through it - it makes no difference) in the positive x direction. In that frame the two doors do not start opening simultaneously, but instead start opening at times $t'_{front}$ and $t'_{back}$ where $t'_{back}>t'_{front}$. The door that has a larger x coordinate is 'front'. The doors finish opening at times $t'_{front}+\gamma(t2-t1)$ and $t'_{back}+\gamma(t2-t1)$ respectively.

My initial expectation from that would be that, in frame F', the garage appears to tilt, with the front end first tilting down, then it starts tilting back when the other door starts opening, and ends up with no y-direction velocity in F' and parallel to the x-axis in F'.

That is, it ends up with the same configuration in F' as it would have if the two doors opened simultaneously in F'. But its velocity, angular velocity and location is different between when the first door starts opening and second door finishes opening.

That sounds a bit weird. I expect I've got something wrong, because things like tilting seem less likely when both frames are inertial.

But I've got to run now, so I'll have to leave it to later to think more about what would really be going on.

 

[Sisoeff]

Peter, there is a better way to answer such a simply put explanation, which if not else, it gives you the idea.
Diving in details to show how much I am far from the scientific terms, after I already said that I'm not a physicist, brings the feeling of trolling (no offense, just saying)
Thank you for giving me some understanding, which helps me to correct the way for presenting the idea.

I know that frame are not physical things :) By saying "transfer to another frame" I refer to whatever is that moving object. I thought that this is acceptable way of expression and if not correct it is at least easy to understand.
I'll change that.
You don't agree with "simultaneous events do not exist", but then you say that the events exist but not as simultaneously. Isn't that the same thing?
OK, then I'll use "simultaneity" instead.
You say that the energy is not a property of a frame, but I did not say that.
I said that the property is "releases energy". Or perhaps I should use another word instead of "property"? Perhaps you could help me with that, please.
Furthermore, I'd like to thank you for your advise, and to mention that I know about energy transformation and energy preservation.
I don't understand why must I stop thinking in terms of frames if the core of the problem (which I see as such for now) is in the simultaneity in different reference frames.

So, let me clean up my presentation:

I see energy as information.
Different amount of energy released in certain time holds different information.
If in inertial frame A two simultaneous events release 2 joules of energy per second, this is an information which reveals part of the properties of frame A. That property would be: Inertial frame A releases 2 joules of energy per second. That information must be present for inertial frame B.
Note that if frame B receives/has information for 1 joule per second because simultaneity does not exist in this frame, that information would be different and won't be part of the property of frame A.
If the simultaneity in frame A do not exist in frame B, but frame B still gets the same information (2 joules per second), that would mean, that simultaneity exist, but is not seen as such.

Tried to correct all mentioned flaws in the scientific terms used for this explanation.
And I really, really appreciate Peter's notes and help.
Thanks, Peter.

 

[Ibix]

Would you tell me what do you think about this:
Simultaneous events in one inertial frame are producing energy.
The simultaneity is not present in another inertial frame.
Where does the energy go?

Ibix answer was:

If they "produce energy" in one frame they produce energy in all. Unless you have a detailed countexample in mind...?

It is a bit vague answer, but if understand it correct, then simultaneity is present in all frames. It is just seen differently. Which makes the relativity of simultaneity false.
Is that what are you guys saying?

I meant that your definition of simultaneity is bizarre, and at odds with the basic physics: if two things produce energy they produce energy, no matter how you are moving when you look at them (which is one way of looking at a choice of frame).

"Simultaneous" just means that two events happen at the same time. Special relativity makes this more complex because not everyone agrees on what "the same time" means. That's all. It's absurd to ask "where does the energy go" because either the two events are producing energy (whether you see them as simultaneous or not) or they are not (whether you see them as simultaneous or not).

 

[Ibix]

If in inertial frame A two simultaneous events release 2 joules of energy per second, this is an information which reveals part of the properties of frame A. That property would be: Inertial frame A releases 2 joules of energy per second. That information must be present for inertial frame B.
Note that if frame B receives/has information for 1 joule per second because simultaneity does not exist in this frame, that information would be different and won't be part of the property of frame A.

It isn't at all clear where you are getting these numbers from, or what process you think you are modelling. Energy measurements can be different between frames, but this is not a consequence of simultaneity or lack thereof, but the frame does not release energy or do anything with energy. A frame is just a choice of coordinates. A choice of coordinates can can't release energy.

 

[PeterDonis]

Diving in details to show how much I am far from the scientific terms, after I already said that I'm not a physicist, brings the feeling of trolling (no offense, just saying)

Whether or not you're a physicist is irrelevant; we're discussing physics here, so we use physics to evaluate people's proposed thought experiments. That's what I'm doing. The issue isn't with your terminology; the issue is with your understanding of the physics.

By saying "transfer to another frame" I refer to whatever is that moving object.

What moving object? You haven't included any actual moving object in your description of the scenario. All you've included are two "frames" and a bunch of events at which some energy is "released".

I don't understand why must I stop thinking in terms of frames if the core of the problem (which I see as such for now) is in the simultaneity in different reference frames.

Simultaneity is not a physical thing. Focusing on it is only confusing you. You should stop thinking about simultaneity and start thinking about events and objects and how they are connected in spacetime.

Tried to correct all mentioned flaws in the scientific terms used for this explanation.

You didn't; I see no substantive difference between your "cleaned up" version and your previous version. It still has all of the same problems.

 

[PeterDonis]

in inertial frame A two simultaneous events release 2 joules of energy per second

Where does this energy come from? Does it get created out of nothing? Or is it just that some energy that already existed changes form? (Hint: the correct answer is the latter.) And if energy didn't get created out of nothing, but just changed form, what does that say about what energy is "present" at a given instant of time in any inertial frame?

 

[Sisoeff]

@Ibix sorry I didn't answer your comments until now, but I have the feeling that you don't want to look at the idea, and instead you are enlightening the unimportant details.
Any way, let's give you the idea.

There is output from every event.
Should I say, every event as cause, produces an effect.
You got the idea, right?
Two simultaneous events can produce one output (simultaneously touching two sides of a metal plate acts like switch and puts on the lights)
If the events are not simultaneous, no light.
So, in frame A, two simultaneous events, put on the lights.
Lights are part of the properties of frame A.
They also serve as information about the identity of frame A.
The lights also tell you that there are simultaneous events on frame A, which are the cause for the light being present.
If you see the lights, you know that this is frame A. The lights are kind of its signature.
If they are seen in B, then simultaneity is present in frame B, but not seen as such.
If the lights are not seen in B, then B does not see frame A, but C, D... or any other frame.
Why? Simply because in frame A the lights are on.

Please let me know if you understand the idea.
If you understand the idea, but don't like the way I put it together, please help me put it together in more understandable from scientific point of view way.
If you don't understand it, I'll try again, but I don't have too much time

 

[Ibix]

If the lights are on they are on. Your choice of frame does not and cannot change this. This is a fairly straightforward concept.

Two observers might have different reasons for explaining why the light is turned on or they might not - it depends on details of the experiment that you have not given. However, that the lights turn on or not is a frame-independent fact.

None of this is "unimportant details". It's requiring that your scenarios have basic self-consistency. If it doesn't bother you that your scenarios make no sense then that's fine - but it's not science you are talking about.

 

[PeterDonis]

Two simultaneous events can produce one output

No, they can't. They produce two causal "signals", which both propagate to some other location where the output is produced. In your example, the two events would be two ends of a switch touching the two metal plates to close a circuit. But closing the circuit doesn't magically turn on the lights; all it does is allow energy to flow through the circuit from the power source to the lights. That takes time, and the switch has to stay closed while it's happening. So your analysis of this scenario is very incomplete; you haven't taken into account the flow of energy in the circuit that actually turns the lights on.

 

[Sisoeff]

Well, it is logic, and science requires logic.
You didn't tell me whether you understand the idea.
Saying that "If the lights are on they are on." does not gives me any understanding.
What do you mean by that?
What is missing in the scenario.
The fact that the observer does not know why the lights are on, or that they should be on, doesn't change the given scenario.
I already set it for you, and you know that lights goes on as a result of two simultaneous events.
I started from the ladder paradox, which explains relativity of simultaneity, and I'm explaining why I see problem in that explanation.
For better understanding we changed the scenario few time, not in great details, but I thought that it is enough for you guys to understand it.
Non of you even told me what you don't understand, and I don't feel like you have the intention to help me.
Sorry!

 

[Sisoeff]

No, they can't. They produce two causal "signals", which both propagate to some other location where the output is produced. In your example, the two events would be two ends of a switch touching the two metal plates to close a circuit. But closing the circuit doesn't magically turn on the lights; all it does is allow energy to flow through the circuit from the power source to the lights. That takes time, and the switch has to stay closed while it's happening. So your analysis of this scenario is very incomplete; you haven't taken into account the flow of energy in the circuit that actually turns the lights on.

Are you serious?
Wow!

 

[russ_watters]

Well, let me put it in a simple way, as I understand it, and then you tell me where am I wrong.
I see energy as information.
Different amount of energy transferred in certain time holds different information.
If in inertial frame A two simultaneous events release 2 joules of energy, and they are transferred to another inertial frame B in 1 second, that information would reveal part of the properties of frame A. That property would be: Inertial frame A releases 2 joules of energy per second.
Note that if frame B receives 1 joule per second because simultaneity does not exist in this frame, that information would be different and won't be part of the property of frame A.
If the simultaneous events in frame A do not exist in frame B, but frame B still gets the same information (2 joules per second), that would mean, that simultaneity exist, but is not seen in as such.
Hope that this make sense, and you'll have an easy way to guide me to better understanding.

I think what you are missing is that the observation that two events are simultaneous can be agreed upon by all if everyone understands how relativity works. If an observer at A detects two simultaneous events and releases some energy, an observer at B will be able to use his/er understanding of relativity to calculate that two events which B did not observe simultaneously A did observe simultaneously.

Your way of thinking is a bit like standing at a train station confused about how a train can get there at 10:00 if it is somewhere else at 11:00 -- as long as you know how to read the schedule, it shouldn't confuse you!

 

[PeterDonis]

Are you serious?

Yes, I'm quite serious. If you are going to really try to think about how "energy" is accounted for in different frames, you have to actually account for all of it, where it is and how it flows. Anything less will lead you to erroneous conclusions--as you have illustrated multiple times now in this thread.

The correct conclusion is that energy is locally conserved, i.e., it can never be created or destroyed at any point in spacetime. That means that in any frame, the "total energy", meaning the energy at each spatial point added up at a given instant of time in that frame, is conserved. But you have to actually look at where each piece of energy is and how it moves, in spacetime, to arrive at this correct conclusion.

 

[PeterDonis]

I don't feel like you have the intention to help me.

We would like to help, but you need to pay attention to what we are actually saying. What we are actually saying is that the way you are looking at things is fundamentally wrong. (The fact that you had to ask me whether I was "serious" about my description of the light switch scenario, when my description was a simple and obvious consequence of relativity, is an indication of this.) I realize this is not what you wanted to hear, but unfortunately that's what we are saying.

A few small tweaks to your conceptualization of your scenario won't help. You need to forget everything you think you know about "frames" and "simultaneity" and so forth, and start fresh, focusing on the actual physics: actual, physical objects that contain and transport energy, and where they are and how they move in spacetime.