what we know about Time

[Spyman]

???? there is no duplicate.

Then what is the black dot in your diagram representing? Because it is clearly not comoving in the red dots past light cone.

[michel123456]

Then what is the black dot in your diagram representing? Because it is clearly not comoving in the red dots past light cone.

 

You are confused because there is only one yellow dot in the diagram. You must imagine what happens when the red dot emits continuously rays of light. That's a bit complicated to draw.

 

Another way to represent the same phenomena consists in considering the diagonal as the simultaneity line.

The good thing is then that the black dot is continuously upon the PLC, comoving with the red dot. The bad thing it that the path of the yellow dot is confusing: it is not the way light goes from the source to the observer but it is the way the observer observes things happening.

(edit) It shows the line of sight, as if the observer was sending the information instead of receiving it. I am not sure it helps.

I'll do that (maybe).

 

-----------------------

That's bad, sorry. The blue dot represents the point where the observer looks at, it does not represent a ray of light. It is more a point of expansion of his observable universe.

Edited April 2, 2012 by michel123456

[Iggy]

You can put as many observers as you want in space-time using relativity. It is not constrained by inconsistencies the way yours is.

But their observation will be different. By definition.

Their observations will be different, but will be consistent. In your previous interpretation the observations were not consistent.

 

But, that no longer matters because you have now completely changed your approach to diagramming spacetime in order to avoid this inconsistency. All I can do now is appreciate that you changed your mind and repeat Spyman in an effort to get you to admit it. You previously said that the surface of the past light cone is populated with objects that move through spacetime. This leads to some inconsistencies one of which I've been harping at.

 

In your new interpretation:

 

 

The past light cone does not move through time with the observer.

 

In an effort to fix this you've created the same problem you previously had...

 

That's bad, sorry. The blue dot represents the point where the observer looks at, it does not represent a ray of light. It is more a point of expansion of his observable universe.

But, according to your first diagram in this post light moves like so:

 

 

The blue dot is therefore not the "point where the observer looks at".

 

 

The problem is that the universe has one dimension of time and you are trying to show that one dimension as both a t axis and an animation. In other words, this is true in our universe:

 

• Objects move through space over time
  

 

You are trying to make both of these things true:

 

• Objects move through space over time
  
• Objects move through time over time
  

 

It isn't a position that is consistent with physics.

[Spyman]

You are confused because there is only one yellow dot in the diagram.

No, I am not, you are wriggling around again...

[michel123456]

(...)

 

But, according to your first diagram in this post light moves like so:

 

 

The blue dot is therefore not the "point where the observer looks at".

(...)

 

This above diagram is wrong, you are mixing 2 different things. The yellow dot is light, the blue dot is not. You are making a recipe for chili with chocolate: the ingredients are wrong.

 

 

----------------------------------------

Here below a screenshot from my diagram of post #167

 

 

 

At this time frame, where do observer A sees the light coming from?

From point B or point C ?

 

(...)

You are trying to make both of these things true:

 

• Objects move through space over time
  
• Objects move through time over time
  

 

It isn't a position that is consistent with physics.

 

It is difficult to explain the concept of motion without time.

If you superpose all the time frames of my gif in post#167, you will obtain a regular static diagram with multiple red & black dots.

My interpretation of that static diagram is that there is only one red & one black dot "moving" in the time dimension. Mass is where the dot is at the chosen time frame. You cannot choose more than one time frame "at a time" because it equals to add a time dimension which, as you said, is not consistent with physics.

I thought it was easier to figure that out.

Edited April 3, 2012 by michel123456

[Iggy]

You aren't explaining the very obvious contradiction. You are talking around it.

 

For me the surface of the Past Light Cone is occupied by our companions traveling with us in time.

In your latest diagrams the past light cone is not "traveling with us in time". The triangle in this diagram is not the past light cone:

 

 

In the following diagram the positive dx/dt section of the black line is a past light cone, but it is not "traveling with us in time".

 

 

Have you changed your mind about your previous statement (please indicate), or would you like to change the present diagram?

Edited April 4, 2012 by Iggy

[michel123456]

I don't see any "obvious" contadiction. I am not changing my mind, I maintain what I said and wrote down because I don't understand your arguments.

Why isn't it the PLC in the 1st diagram? Why do you say that it is not "traveling with us in time"?

and what do you call "dx/dt section of the black line" ? the black line is dx=0, the red dot is at rest.

dx/dt is a ratio (represented by the angle of on the grey line), by convention 45 degrees.

Edited April 4, 2012 by michel123456

[Iggy]

I don't see any "obvious" contadiction. I am not changing my mind, I maintain what I said and wrote down because I don't understand your arguments.

If you maintain what you said then we need to change your current diagrams.

 

Why isn't it the PLC in the 1st diagram?

A past light cone consists of all the things you see at one moment in time. The things on this line:

 

 

are *not* all seen at once. It is not a past light cone. It is, in fact, called a particle horizon.

 

Why do you say that it is not "traveling with us in time"?

It is traveling through time, it is not a past light cone.

 

and what do you call "dx/dt section of the black line" ?

I said the *positive* dx/dt section. That is the upper half of the thin black line on this diagram:

 

 

The line that traces out the path of the light ray. The top section of that line has a positive slope, dx/dt. The lower half has a negative slope -dx/dt. Calling that section of line the "positive dx/dt section" was an easy way to identify the section that makes a past light cone for the red object.

 

the black line is dx=0, the red dot is at rest.

The black line has a slope that changes from -1/1 on the lower half to 1/1 on the top half. On a typical spacetime diagram the slope of a line is the speed of the particle in space over time. For example, light is sloped at 45 degrees because the line rises one unit of time for every one unit of space. Its speed is dx/dt or (1/1) or one. One lightyear per year for example.

 

Slower objects make lines that are closer to 90 degrees. 90 degrees is at rest.

 

The slope in the case of this line on this diagram changes from -1/1 (or, -1) to 1/1 (or, 1) between the bottom half and the top half

Edited April 4, 2012 by Iggy

[michel123456]

(...)

 

A past light cone consists of all the things you see at one moment in time.

 

yes.

 

The things on this line:

 

 

are *not* all seen at once. It is not a past light cone. It is, in fact, called a particle horizon. It is traveling through time, it is not a past light cone.

Imagine more blue dots. You have the same problem with Spyman. The only one blue dot is for simplification, in fact there are a lot of blue dots that make up the whole diagonal.

 

I said the *positive* dx/dt section. That is the upper half of the thin black line on this diagram:

 

The line that traces out the path of the light ray. The top section of that line has a positive slope, dx/dt. The lower half has a negative slope -dx/dt. Calling that section of line the "positive dx/dt section" was an easy way to identify the section that makes a past light cone for the red object.

O.K.

 

 

 

The black line has a slope that changes from -1/1 on the lower half to 1/1 on the top half. On a typical spacetime diagram the slope of a line is the speed of the particle in space over time. For example, light is sloped at 45 degrees because the line rises one unit of time for every one unit of space. Its speed is dx/dt or (1/1) or one. One lightyear per year for example.

O.K.

 

Slower objects make lines that are closer to 90 degrees. 90 degrees is at rest.

Yes.

 

The slope in the case of this line on this diagram changes from -1/1 (or, -1) to 1/1 (or, 1) between the bottom half and the top half

That describes the effect of a mirror at the black dot. Your objection is like saying that light cannot be reflected by a mirror because it must have stopped in the meanwhile. The changing of slope is a result of direction in space. Direction in time is unchanged.

[Spyman]

You have the same problem with Spyman.

Since both Iggy and I seem to understand each other perfectly well the odds are in favor of you being confused and not us.

 

I thought I asked a very simple question:

 

Then what is the black dot in your diagram representing? Because it is clearly not comoving in the red dots past light cone.

 

But you didn't seem to be able to explain it, so I ask again: What is the Black dot at point B representing?

 

Here below a screenshot from my diagram of post #167

 

 

 

At this time frame, where do observer A sees the light coming from?

From point B or point C ?

[michel123456]

Since both Iggy and I seem to understand each other perfectly well the odds are in favor of you being confused and not us.

I know that. I play one against 2 for a while now.

 

I thought I asked a very simple question:

 

 

 

But you didn't seem to be able to explain it, so I ask again: What is the Black dot at point B representing?

The black dot is the actual position of Paul in spacetime. It is never observed by anyone in his actual position, except by himself.

 

Maybe the following diagram make things clearer:

I added another ray of light (orange dot) to show that the red dot (Marion) constantly observes the black dot (Paul) in her past.

 

BTW you didn't answer my question:

At this time frame, where do observer A sees the light coming from?

From point B or point C ?

[Iggy]

(...)

 

A past light cone consists of all the things you see at one moment in time.

yes.

 

The things on this line:

 

 

are *not* all seen at once. It is not a past light cone.

Imagine more blue dots. You have the same problem with Spyman.

Excuse me? Are you saying that the blue dots *are* seen by the red dot? Are you saying that the black dot is seen by the red dot? Please answer directly.

[Superfusion]

Interesting arguement please update me on the brush over basics so i can take a side

[HuMoDz]

What is wrong with that?<br style="font-size: 13px; line-height: 16px; background-color: rgb(248, 250, 252); ">We know that an object far away is observed now as it was in the past.<br style="font-size: 13px; line-height: 16px; background-color: rgb(248, 250, 252); ">When you propulse an object far away, the same happens.<br style="font-size: 13px; line-height: 16px; background-color: rgb(248, 250, 252); ">Why is that incorrect?

There's me, my letter-writing friend and a personal courier I hired. The farther my friend is, the more time the courier takes to bring his letters to me, and so I get older and older letters. If he is too far away, those letters would be from a distant past, and so my friend would be on the past too.

Me: Observer

Friend: object that travels aways from the observer

Courier: Photons

You're receiving light that interacted with the moving object far ago, but this doesn't mean the object is going "paster". Just like the stars we see at night, most of them already collapsed, but their light is still coming to us. Just because we see them, doesn't mean they are still there

[michel123456]

Excuse me? Are you saying that the blue dots *are* seen by the red dot? Are you saying that the black dot is seen by the red dot? Please answer directly.

Yes.

[Iggy]

Yes.

If the black dot in this diagram is seen by the red dot,

 

 

then the green dot in this diagram is seen by the red dot,

 

 

But, that is clearly not what you said before and it clearly isn't what happens.

 

You keep saying very contradictory things. It is nobody's fault that we are unable to square the contradictions you are telling us. You say that the black dot in the first diagram above is seen by the red dot... that is absolutely wrong according to the second diagram and everything you've said about it.

 

You don't realize this, but the problem is that you have two different variables of time represented in these diagrams... one represented with the t axis and the other represented by the diagram's animation. This leads to contradictions because some aspects of time are being attributed to a change in vertical position on the t axis and others as changes between frames in the animation. I'm trying to explain why you are saying contradictions. That your views are contradictory is indisputable. We need to focus on why that is or how to fix it.

Edited April 5, 2012 by Iggy

[michel123456]

If the black dot in this diagram is seen by the red dot,

 

 

then the green dot in this diagram is seen by the red dot,

 

 

But, that is clearly not what you said before and it clearly isn't what happens.

 

You keep saying very contradictory things. It is nobody's fault that we are unable to square the contradictions you are telling us. You say that the black dot in the first diagram above is seen by the red dot... that is absolutely wrong according to the second diagram and everything you've said about it.

 

You don't realize this, but the problem is that you have two different variables of time represented in these diagrams... one represented with the t axis and the other represented by the diagram's animation. This leads to contradictions because some aspects of time are being attributed to a change in vertical position on the t axis and others as changes between frames in the animation. I'm trying to explain why you are saying contradictions. That your views are contradictory is indisputable. We need to focus on why that is or how to fix it.

 

As I stated before:

You have mixed the 2 diagrams: you made chili sauce with chocolate. It is wrong. Draw a ray of light from the green dot and you will see what happens.

(edit) the diagram with the blue dot describes what we see, the diagram with the yellow dot describes the path of a ray of light: these are 2 different concepts, you cannot mix the one with the other.

 

For the 3rd time, can anyone here answer my question:

 

At this time frame, where do observer A sees the light coming from?

From point B or point C ?

Edited April 5, 2012 by michel123456

[Iggy]

As I stated before:

You have mixed the 2 diagrams: you made chili sauce with chocolate. It is wrong. Draw a ray of light from the green dot and you will see what happens.

I have mixed? I have mixed? They are your diagrams. You drew them both and made contradictory claims about them! If I draw light from the green dot it doesn't reach the red dot:

 

 

I think you could have figured that out without me drawing it. It is the same as your diagram:

 

 

In YOUR diagram the red dot doesn't see the green dot. A moving line between the green dot and the red dot *does not* make a light cone according to this diagram. Can you admit this please?

 

(edit) the diagram with the blue dot describes what we see, the diagram with the yellow dot describes the path of a ray of light: these are 2 different concepts, you cannot mix the one with the other.

The light ray hitting you in your eye can't be mixed with what you see? You say the light from an object hitting you in the eye has nothing to do with what you see. Are you serious with this?

 

For the 3rd time, can anyone here answer my question:

 

At this time frame, where do observer A sees the light coming from?

From point B or point C ?

Point C, frame unknown. I can't give x and t values because you haven't labeled them and don't know at which frame it is because we've lost that information.

 

You could never see an object comoving at point C. A triangle that looks like a past light cone fixed to point A (as in your other diagram) is not a past light cone.

Edited April 5, 2012 by Iggy

[Lala]

i think the 1st thing to be known about time

is that time is a lot like snow

it may look alike but its not always the same

no two are 100% alike

 

 

By Olala ^.^)/

Edited April 5, 2012 by Lala

[michel123456]

I have mixed? I have mixed? They are your diagrams. You drew them both and made contradictory claims about them! If I draw light from the green dot it doesn't reach the red dot:

 

 

I think you could have figured that out without me drawing it. It is the same as your diagram:

 

 

In YOUR diagram the red dot doesn't see the green dot. A moving line between the green dot and the red dot *does not* make a light cone according to this diagram. Can you admit this please?

 

Welcome.

YES the red dot cannot see the green dot: welcome to my universe.

The red dot sees the information carried by the yellow dot above collated to him. The red dot "observes" the black dot at C although the black dot is not at C anymore (as described by our friend HuMoDz)

 

 

The light ray hitting you in your eye can't be mixed with what you see? You say the light from an object hitting you in the eye has nothing to do with what you see. Are you serious with this?

I say that what you see is not what it is. You see the black dot at point C when the black dot is at B. The information reaching my eye is different from what is (and it is also the difference between the 2 kind of diagrams).

 

Point C, frame unknown. I can't give x and t values because you haven't labeled them and don't know at which frame it is because we've lost that information.

Here you are. YES, point C of course.

 

You could never see an object comoving at point C. A triangle that looks like a past light cone fixed to point A (as in your other diagram) is not a past light cone.

Yes, the green dot is not observable from the red dot, is that what you are saying?

 

The model works.

Edited April 5, 2012 by michel123456

[Iggy]

Welcome.

YES the red dot cannot see the green dot...

 

Yes, the green dot is not observable from the red dot, is that what you are saying?

Yes!!! That's what I'm saying. You are saying the exact opposite:

 

Excuse me? Are you saying that the blue dots *are* seen by the red dot? Are you saying that the black dot is seen by the red dot? Please answer directly.

 

Yes.

 

Have you changed your mind now? Or, do "yes, the black dot is seen by the red dot" and "Yes, the green dot is not observable from the red dot" make perfectly consistent sense, but I'm mixing and matching sentences talking about two different things like chili sauce with chocolate.

 

Honestly?

[michel123456]

Yes!!! That's what I'm saying. You are saying the exact opposite:

 

 

 

Have you changed your mind now? Or, do "yes, the black dot is seen by the red dot" and "Yes, the green dot is not observable from the red dot" make perfectly consistent sense, but I'm mixing and matching sentences talking about two different things like chili sauce with chocolate.

 

Honestly?

 

Honestly I think you understand nothing.

[Iggy]

Honestly I think you understand nothing.

You have said these two things:

 

• "yes, the black dot is seen by the red dot"
   
  
• "Yes, the green dot is not observable from the red dot"
  

 

Do you know what a contradiction is? You have to do something to fix these contradictions. They are your diagrams and your statements about them.

 

Right now, the best that can be said is that you have an inconsistent interpretation of spacetime.

[michel123456]

The 1st statement

•"yes, the black dot is seen by the red dot"

was about the blue-dot-diagram, which shows what we see.

 

The 2nd statement

•"Yes, the green dot is not observable from the red dot"

was about the yellow-dot-diagram, which shows the path of a ray of light.

 

I can't help you more. If you don't grasp the difference between the 2 diagrams, it is useless to continue.

[Iggy]

The 1st statement

 

was about the blue-dot-diagram, which shows what we see.

If we see it then its light reaches us, yes?