[Deecart (OP)]

I dont think i really understand your explaination.
Not sure if it is right or wrong but at least you tried to answer the question.

Concerning the "now".
Is there a universal now ?

I think that yes,"everywherewhen" (a new word that should exist if we really understand relativity), there is a "now" that is unambiguous for every point of view.
The proof of that is that everytime someone that had some other point of view would approach the "local position" (in position and in time), he would agree with any other who had some other point of view, of the local reality (when he can understand the transformation from his point of view toward the local reality it would be more easy)

Saying this, the "now" we talk about in special realivity, is only "some illusion" (yes, an illusion has some real visual effect onto the far away observer)  of what happens localy.
But localy we have what we can tell "the now" : The full phenomenon.(not only the light related illusion).

It is not because light can travel the fatsest that it is representativ of the full local reality.

[Kryptid]

Is there a universal now ?

I think that yes,"everywherewhen" (a new word that should exist if we really understand relativity), there is a "now" that is unambiguous for every point of view.

There isn't: https://en.wikipedia.org/wiki/Relativity_of_simultaneity

Saying this, the "now" we talk about in special realivity, is only "some illusion" (yes, an illusion has some real visual effect onto the far away observer)  of what happens localy.

It's not an illusion. Events literally happen at different times for different observers. The train thought experiments outlined in the link above demonstrate that it is a direct consequence of a frame-invariant speed of light.

[Deecart (OP)]

There isn't: https://en.wikipedia.org/wiki/Relativity_of_simultaneity

You dident contradict what i said.

It's not an illusion. Events literally happen at different times for different observers. The train thought experiments outlined in the link above demonstrate that it is a direct consequence of a frame-invariant speed of light.

Since the events are placed along the axis of train movement, their time coordinates become projected to different time coordinates in the moving train's inertial frame. Events which occurred at space coordinates in the direction of train movement happen earlier than events at coordinates opposite to the direction of train movement. In the moving train's inertial frame, this means that lightning will strike the front of the train car before the two observers align (face each other).

It is still an illusion.
i dont understand why you (and many others) cant agree with this obvious thing.
The phenomenon appears localy, and yes when you start with the UNIQUE phenomenon you will have some different points of view of the phenomenon.
Why is it an "illusion" ?
I repeat : Because the full phenomenon is not available at distant observers. (so the mathematical proof can not be a physical proof).

Just to give you some insigth : Do you think the sound of the thunder is "nothing" ? And do you think you should think that "the reality" (local phenomenon) of this sound should be linked to the "cone of light" ? So linked to the same speed limit as the speed of light ?

 

[Origin]

It is still an illusion.
i dont understand why you (and many others) cant agree with this obvious thing.

First of all, it is important to note that "and many others" is actually all of the scientific community.
The reason we can't agree it is an illusion is because it isn't an illusion.

Why is it an "illusion" ?
I repeat : Because the full phenomenon is not available at distant observers.

Please explain what you mean by this statement.

So the mathematical proof can not be a physical proof.

What do you mean by this, AFAIK the mathematical explanation matches the physical observations

[Deecart (OP)]

The reason we can't agree it is an illusion is because it isn't an illusion.

Are you what whe could name a sophist ?
"I am great because i am great. kneel before the king !!"
Lol.

I am sorry, but your "demonstration" (lol) can not be accepted by any scientist.

Please explain what you mean by this statement.

If only one quanta of "change" stay localy, so the relativity theory (sorry, not "the theory", but "the interpretation" of the theory of many peoples) shut down.
Why cant you understand this obvious fact ?
Light is not the only thing involved in phenomenons, and many of the light never reach any distant observer
So what ?
And if you finaly understand that the gravitational effect not reach the light speed (i dont speak of gravitational waves that is some other phenomenon)... how can you accept the block univers ?

[Kryptid]

I repeat : Because the full phenomenon is not available at distant observers. (so the mathematical proof can not be a physical proof).

If you're trying to say that distant observers see the timing of events differently because it takes longer for light to reach them, that's not relativity of simultaneity. The train thought experiments take observational delay out of the picture. Relativity of simultaneity is a direct consequence of Lorentz invariance. Since Lorentz invariance has been demonstrated to extremely high precision experimentally, then we know by consequence that relativity of simultaneity is also a physically real phenomenon. It's not an illusion.

[Deecart (OP)]

An illusion is something that you think it is, but it isnt what it looks like.
Thats what an illusion is.

Here, you talk about some "event".
But the real event only exists localy : This is the physical event : The real event occuring only one time and having only one description when observed localty.
What you see of the event from some other point of view is not the local event.
It can not be the full event (the local event).
So if you say : Oh i can describe this event exactly how "it is"; doeing some translation and this is the same event far away... you are wrong.
The full event is where it happens, and what you can say of it, further away is only a fraction of the real local event.

The lorentz invariance has been prooved ?
Surely you can proove something when you only take in account what you can proove.
Here, you only assume the movement.
Sure this is not enough to define the reality of some event.
You dont agree ?

[Deecart (OP)]

I think it's commonly believed that if different momentarily-co-located observers come to different conclusions about the current age of the same distant person, then that IMPLIES that those results cannot be meaningful or real.  But I'm convinced that each of those different conclusions IS meaningful and real, TO THAT OBSERVER.

This is what i have already said.
Saying that it is an illusion is not saying it is "nothing"'.
If you see a mirage in the desert, this mirage is "real to the observer", we can do some photography etc of it.
But it is not real, so it is what we can tell an illusion, in the sense where it lacks of the full phenomenon that occur localy.
Localy, the mirage is not "so old", "so shaped" etc.and the best to know this is to travel to the place where the mirage happens.
Every distant observer will finally observe the same local phenomenon when they are at the same place.
At the same place they will experiment "the now".

[Origin]

Are you what whe could name a sophist ?
"I am great because i am great. kneel before the king !!"
Lol.

No nothing like that.  I am saying I agree with the scientific community.  You on the other hand have something you made up on your own, that does not agree with observation.

[Deecart (OP)]

No nothing like that.  I am saying I agree with the scientific community.  You on the other hand have something you made up on your own, that does not agree with observation.

Dont call mommy.
Why do you no want to use your own brain ?
You. What do you think about all that ?

Explain with your own words. What did you understand ? What is wrong with the things i say ?
If not, it is useless to do some some discussion. I already have read wikipedia.

[Origin]

Dont call mommy.
Why do you no want to use your own brain ?
You. What do you think about all that ?

No need to be a jerk.

What is wrong with the things i say ?

This.
"Saying this, the "now" we talk about in special realivity, is only "some illusion" (yes, an illusion has some real visual effect onto the far away observer)  of what happens localy"

[Bored chemist]

I already have read wikipedia.

Read it again.

[Kryptid]

An illusion is something that you think it is, but it isnt what it looks like.
Thats what an illusion is.

And relativity of simultaneity isn't an illusion.

Here, you talk about some "event".
But the real event only exists localy : This is the physical event : The real event occuring only one time and having only one description when observed localty.
What you see of the event from some other point of view is not the local event.
It can not be the full event (the local event).
So if you say : Oh i can describe this event exactly how "it is"; doeing some translation and this is the same event far away... you are wrong.
The full event is where it happens, and what you can say of it, further away is only a fraction of the real local event.

I don't know what you're talking about. A supernova is just as real whether it is happening next door or 1,000 light-years away.

The lorentz invariance has been prooved ?

There generally isn't proof in science, but there is very great evidence for Lorentz invariance.

Here, you only assume the movement.

No, it isn't assumed. It is demonstrable that the Earth rotates on its axis and accelerates around the Sun. If Lorentz invariance was incorrect, then the experiment would have measured a varying local speed of light due to those factors.

[Deecart (OP)]

If you cant disproof with some example (calling mommy is not an example) that SR is not based on illusions, then i must conclude that you do not  understand how SR work.

You could (and i could, because i know at least how to prove it, and this is what we atttend of some physicists) and you dident.

But this "illusion thing" (very complicated to understand if you really try) is not what permit to think that the "now" reality is true.
I claim that, within all the "realities", we can state that we can find some invariant that can be understand as the "ground state" of every point of view.
Noether theorem.

[Origin]

If you cant disproof with some example (calling mommy is not an example) that SR is not based on illusions, then i must conclude that you do not  understand how SR work.

Please give an example of one of these illusions.

[Bored chemist]

Noether theorem.

What about it?

[Deecart (OP)]

Please give an example of one of these illusions.

Please be more specific.
Starting with the assertion of your post, nobody will ever understand what you are talking about.

What about it?

i can help you :

Noether's Theorem

*In 1915, the German mathematician Emmy Noether formulated her famous theorem.  It states that every symmetry transformation of a system leads to the conservation of some quantity that is a property of the system

A symmetry transformation is any transformation that preserves the equation(s) of motion for the system.

https://go.owu.edu/~physics/StudentResearch/2005/LauraBecker/SymmetrytoConservation.html

This leads to the fact that there should be some conservation of some quantity that is a property of the system, so the now.
Why dont you agree that some "now" consideration could exists within all the points of views ?

[Bored chemist]

Please give an example of one of these illusions.

Please be more specific.
Starting with the assertion of your post, nobody will ever understand what you are talking about.

What about it?

i can help you :

Noether's Theorem

*In 1915, the German mathematician Emmy Noether formulated her famous theorem.  It states that every symmetry transformation of a system leads to the conservation of some quantity that is a property of the system

A symmetry transformation is any transformation that preserves the equation(s) of motion for the system.

https://go.owu.edu/~physics/StudentResearch/2005/LauraBecker/SymmetrytoConservation.html

This leads to the fact that there should be some conservation of some quantity that is a property of the system, so the now.
Why dont you agree that some "now" consideration could exists within all the points of views ?

I'm aware of Noether's theorem.
It tells us that conservation laws form  a 1 to 1 correspondence with symmetries.
So, for example, the fact that the universe is symmetrical in time (the laws of physics are the same tomorrow as they were yesterday) tells us that mass/energy is conserved.
The fact that  the universe is isotropic tells us that momentum is conserved and the fact that there is no preferred rotation tells us that angular momentum is conserved.

What symmetry are you putting forward as the counterpoint to your idea that ""now" is conserved?

[Deecart (OP)]

What symmetry are you putting forward as the counterpoint to your idea that ""now" is conserved?

I dont say anything like that.
I only say that if you dont agree that Noether theorem states that there is some "now" within the block universe, then you are stupid.
You can say : Oh no ! i dont believe ! Or whatever you can say.
This will not change the fact (and i am totaly sure some non stupid guys will understand that; soon they read it).

[Bored chemist]

What symmetry are you putting forward as the counterpoint to your idea that ""now" is conserved?

I dont say anything like that.
I only say that if you dont agree that Noether theorem states that there is some "now" within the block universe, then you are stupid.
You can say : Oh no ! i dont believe ! Or whatever you can say.
This will not change the fact (and i am totaly sure some non stupid guys will understand that; soon they read it).

I believe the usual meme here is "Tell me you don't understand Noether's theorem without saying you don't understand Noether's theorem".