Universal now hijack split from Universal Concept of Time (Is the Big Bang wrong?)

[michel123456]

1 minute ago, Strange said:

Obviously. 

By the time you hear the thunder a few seconds after seeing the lightning, the storm may have moved a bit closer or a bit further away.

Do you think that this is a novel insight that no one has thought of before? Or do you just like stating the obvious for no reason?

Well, that also mean that there are objects out there that have coordinates that we cannot observe. And that is not obvious.

[Strange]

Just now, michel123456 said:

Well, that also mean that there are objects out there that have coordinates that we cannot observe. And that is not obvious.

I don't know what that means. There are things we can't observer? Well obviously. There are things we can observe but we don't know how they are moving? Well, it can be harder to know speeds orthogonal to the line of sight if the objects are moving slowly. This is all pretty obvious.

Another example:

Quote

Voyager 2 is about 18.5 billion kilometers (11.5 billion miles) away, so communicating takes a long time. It’s a 34 hour round trip for mission engineers to send a signal to the spacecraft and for the spacecraft to respond. 

https://www.universetoday.com/144812/voyager-2-went-into-fault-protection-mode-but-engineers-brought-it-back-online/

That means that between sending a message to Voyager and getting a reply, it has moved about 1,970,000 km further away. Why is that problematic for you?

[MigL]

7 minutes ago, michel123456 said:

Well, that also mean that there are objects out there that have coordinates that we cannot observe.

The fact that we can't observe them yet, is due to the fact that light travels at the maximum speed of information in this universe.
Which means that if we can't observe them at that speed, no other information can reach us any faster.
IOW we can't be affected in any way.

[michel123456]

12 minutes ago, Strange said:

I don't know what that means. There are things we can't observer? Well obviously. There are things we can observe but we don't know how they are moving? Well, it can be harder to know speeds orthogonal to the line of sight if the objects are moving slowly. This is all pretty obvious.

I don't think it is obvious that there are "things that we can't observe". When you look around you, or look at the night sky, it is not at all obvious that there are "things that we can't observe" there in front of your eyes.

The next step is to realize that the "things that we can't observe" are hidden in time. The reason why we cannot observe them is that the t coordinate does not correspond to the distance. In fact, the ONLY things that we can observe are those that have the correct time coordinate that correspond to the distance from the observer. The things that we cannot observe have a different t coordinate.

5 minutes ago, MigL said:

The fact that we can't observe them yet, is due to the fact that light travels at the maximum speed of information in this universe.
Which means that if we can't observe them at that speed, no other information can reach us any faster.
IOW we can't be affected in any way.

Yes.

But the rest of the Universe can be affected, or at least some part of it.

If you wrap your mind around the concept, welcome to my universe.

Edited February 1, 2020 by michel123456

[MigL]

Only within a radius of causality.
Which is defined by the distance and c .

[Strange]

13 minutes ago, michel123456 said:

I don't think it is obvious that there are "things that we can't observe". When you look around you, or look at the night sky, it is not at all obvious that there are "things that we can't observe" there in front of your eyes.

That there are things that are too dark or too small to see s pretty obvious. I don't know if that is what you were referring to.

Perhaps what is less obvious is that there are things we cannot see because the light from them hasn't reached us yet.

And there are things that we will never be able to see because the expansion of the universe means the light from them will never reach us.

15 minutes ago, michel123456 said:

The next step is to realize that the "things that we can't observe" are hidden in time.

"Hidden in time" is poetic, but not very meaningful.

16 minutes ago, michel123456 said:

The reason why we cannot observe them is that the t coordinate does not correspond to the distance.

What "t coordinate" are you talking about? And why wouldn't it correspond to distance?

So what exactly is the reason we can't observe them? Please provide a proper (mathematical) answer, not one based on incomprehensible hints or metaphor.

17 minutes ago, michel123456 said:

In fact, the ONLY things that we can observe are those that have the correct time coordinate that correspond to the distance from the observer.

What does "the correct time coordinate" mean? Again, a precise mathematical answer would be helpful.

How can some things have the "right" time coordinate and others have the "wrong" time coordinate? What causes them to be different?

19 minutes ago, michel123456 said:

welcome to my universe.

I prefer reality.

[dimreepr]

15 hours ago, michel123456 said:

In your analogy, the "thunder" is the message, the wave. In cosmology, the signal we are receiving is the wave: light.

In Strange's example, the lighting flash ( light) moves faster than the thunder ( sound ), ie two different nows.

 

15 hours ago, michel123456 said:

I don't think it is obvious that there are "things that we can't observe". When you look around you, or look at the night sky, it is not at all obvious that there are "things that we can't observe" there in front of your eyes.

The next step is to realize that the "things that we can't observe" are hidden in time. The reason why we cannot observe them is that the t coordinate does not correspond to the distance. In fact, the ONLY things that we can observe are those that have the correct time coordinate that correspond to the distance from the observer. The things that we cannot observe have a different t coordinate.

Yes.

But the rest of the Universe can be affected, or at least some part of it.

If you wrap your mind around the concept, welcome to my universe.

In my analogy, everywhere in the Universe is the center of the Universe, even yours.

[michel123456]

6 hours ago, dimreepr said:

In Strange's example, the lighting flash ( light) moves faster than the thunder ( sound ), ie two different nows.

Sorry for the confusion. I treated Strange's example as an analogy because it doesn't fit the real situation (since Strange likes reality) I wanted to describe.

When you look at distant stars, the ONLY information you get is from the wave. There is no 2nd hint, there is no "flash" that indicates simultaneity. There is not one thing that goes slow and another thing that goes fast. There is only one information and that is light.

At cosmological scale, light is terribly slow. The delay gets huge.

I cannot find another analogy (or example) to describe the situation. In all that I think there are 2 elements (like in the "flash-thunder" example)

 

Edited February 2, 2020 by michel123456

[swansont]

5 minutes ago, michel123456 said:

Sorry for the confusion. I treated Strange's example as an analogy because it doesn't fit the real situation (since Strange likes reality) I wanted to describe.

When you look at distant stars, the ONLY information you get is from the wave. There is no 2nd hint, there is no "flash" that indicates simultaneity. There is not one thing that goes slow and another thing that goes fast. There is only one information and that is light.

At cosmological scale, light is terribly slow. The delay gets huge.

I cannot find another analogy (or example) to describe the situation. In all that I think there are 2 elements (like in the "flash-thunder" example)

 

In a supernova you can get a signal from neutrinos. They move a little slower than c, though they arrive first because the light is also slowed by having to travel through a medium where n>1 

[Strange]

8 hours ago, dimreepr said:

In Strange's example, the lighting flash ( light) moves faster than the thunder ( sound ), ie two different nows.

Exactly. (Emphasis added.)

1 hour ago, michel123456 said:

Sorry for the confusion. I treated Strange's example as an analogy because it doesn't fit the real situation (since Strange likes reality) I wanted to describe.

When you look at distant stars, the ONLY information you get is from the wave. There is no 2nd hint, there is no "flash" that indicates simultaneity. There is not one thing that goes slow and another thing that goes fast. There is only one information and that is light.

The point was to show that even in mundane, everyday situations the concept of "now" or "at the same time" is not necessarily well defined.

1 hour ago, michel123456 said:

At cosmological scale, light is terribly slow. The delay gets huge.

Irrelevant. We experience exactly the same thing with signals that take a few picoseconds to cross from one part of a microprocessor to another. (The cosmological case may be complicated by the fact that light travel time is not always proportional to distance because of expansion. But that doesn't seem relevant to your confusion.)

1 hour ago, michel123456 said:

In all that I think there are 2 elements (like in the "flash-thunder" example)

You just said that there were not two elements (signals or, in astronomer speak, messengers).

How about explaining what you are talking about instead of being so evasive:

23 hours ago, michel123456 said:

The reason why we cannot observe them is that the t coordinate does not correspond to the distance.

What "t coordinate" are you talking about? And why wouldn't it correspond to distance?

So what exactly is the reason we can't observe them? Please provide a proper (mathematical) answer, not one based on incomprehensible hints or metaphor.

23 hours ago, michel123456 said:

In fact, the ONLY things that we can observe are those that have the correct time coordinate that correspond to the distance from the observer.

What does "the correct time coordinate" mean? Again, a precise mathematical answer would be helpful.

How can some things have the "right" time coordinate and others have the "wrong" time coordinate? What causes them to be different?

 

If you still refuse to answer these questions, I will request this thread is closed.

1 hour ago, swansont said:

In a supernova you can get a signal from neutrinos. They move a little slower than c, though they arrive first because the light is also slowed by having to travel through a medium where n>1 

The delay is mainly due to the time (a few hours!) it takes the light to escape from the star itself, which is not due to refractive index. Further discussion of this fascinating subject would be off topic... But excellent summary here for anyone interested: https://www.forbes.com/sites/startswithabang/2020/01/23/this-is-what-well-see-when-betelgeuse-really-does-go-supernova/#673e896743a2

[michel123456]

12 minutes ago, Strange said:

What "t coordinate" are you talking about? And why wouldn't it correspond to distance?

So what exactly is the reason we can't observe them? Please provide a proper (mathematical) answer, not one based on incomprehensible hints or metaphor.

In spacetime there is a set of 4 coordinates that determine the position of an event. coords x,y,z,t where x,y,z are spatial & t is time.

Around us we are observing that the distance from the observer to the event determines the time gap.

The distance between 2 points P1 and P2 is given by the generalization of Pythagora

And we are observing that the time gap  t(P1,P2) is equal to d(P1,P2) with a change of units (from meters to seconds), simplifying by avoiding the expansion & other elements.

This is an observable object.

When t ≠ d the object is not observable. Not directly observable.

 

[Strange]

2 minutes ago, michel123456 said:

The distance between 2 points P1 and P2 is given by the generalization of Pythagora

Important to note that the distance is observer dependent. The only thing that is invariant is the "four-distance" between two events: (x₁, y₁, z₁, t₁) and (x₁, y₂, z₂, t₂).

Quote

And we are observing that the time gap  t(P1,P2) is equal to d(P1,P2) with a change of units (from meters to seconds), simplifying by avoiding the expansion & other elements.

This is an observable object.

When t ≠ d the object is not observable. Not directly observable.

So there are two cases to be considered, (t<d) and (t>d).

1. An object cannot be seen if the light has not reached us yet (t < d). That is basically the case of Betelgeuse mentioned earlier: it  may already have gone supernova but we have not seen that yet.

2. An object cannot be seen if the light has passed us (t>d) and the object no longer exists. This describes, for example, supernovae that happened in the past. They were visible at the time but the light has now passed us and there is no more coming (because the event is over).

In other words, we can't see a lightning flash before it happens (or, more exactly, before the light reaches us). And we can't see the lightning flash after it has finished (or, more exactly, after the last of the light has passed us). Well, duh.

Both of these are pretty obvious. And neither are very relevant to almost everything we see, which exists for a significant period of time (billions of years in the case of stars and galaxies.

So I still don't know what point you are trying to make. It doesn't seem to be anything very insightful or interesting.

 

[michel123456]

That seemed to me an affirmative answer. Thank you.

What I want to say is this:

1. If you take the Spacetime continuum and fill it with random events, the only events we can directly observe are the ones described as above. The great majority of events are not observable.

2. Number two is speculation (auto censured)

 

[Strange]

6 minutes ago, michel123456 said:

1. If you take the Spacetime continuum and fill it with random events, the only events we can directly observe are the ones described as above. The great majority of events are not observable.

This is well understood (by some people, at least) https://en.wikipedia.org/wiki/Light_cone

Note that an "event" is a single point [x,y,z,t] and has no duration. That is the only way your description above makes sense. 

9 minutes ago, michel123456 said:

2. Number two is speculation (auto censured)

Feel free to start a thread in Speculations to explain what you are thinking.

[dimreepr]

22 hours ago, michel123456 said:

I cannot find another analogy (or example) to describe the situation. In all that I think there are 2 elements (like in the "flash-thunder" example)

look at the stars, the now we feel is not the now we see (or hear).

so, really there are three nows. 

And thats before it gets complicated. 

[michel123456]

16 hours ago, dimreepr said:

look at the stars, the now we feel is not the now we see (or hear).

so, really there are three nows. 

And thats before it gets complicated. 

On the same stance:

If around you everything is in the past, if the present is what you feel on your skin, it follows logically that the future is inside you.

[Strange]

1 minute ago, michel123456 said:

On the same stance:

If around you everything is in the past, if the present is what you feel on your skin, it follows logically that the future is inside you.

I think you need to look up the word "logically" in a dictionary. And remember that this is a science forum.

[michel123456]

?? What is wrong?

Look at your light cone, the observer is exactly at the junction of the past & the future.

The past light cone is observable. In Reality it is the sum of things we can get information from.

The Observer is our skin, our eyes our brain, .

Where is the future? Logically?https://dictionary.cambridge.org/dictionary/english/logically

I mean where is the future scientifically? (not emotionally)

 

 

 

On 2/2/2020 at 11:59 PM, Strange said:

1. An object cannot be seen if the light has not reached us yet (t < d). That is basically the case of Betelgeuse mentioned earlier: it  may already have gone supernova but we have not seen that yet.

2. An object cannot be seen if the light has passed us (t>d) and the object no longer exists. This describes, for example, supernovae that happened in the past. They were visible at the time but the light has now passed us and there is no more coming (because the event is over).

In other words, we can't see a lightning flash before it happens (or, more exactly, before the light reaches us). And we can't see the lightning flash after it has finished (or, more exactly, after the last of the light has passed us). Well, duh.

On a side note, I was refuted when I put this on a spacetime diagram some years ago. please do this for me: draw on a spacetime diagram the areas that are not observable.

[dimreepr]

8 minutes ago, michel123456 said:

Look at your light cone, the observer is exactly at the junction of the past & the future.

the observer is, the observed isnt.

ie. now is not universal.

even my feet runs a different time to my head.

[Strange]

40 minutes ago, michel123456 said:

Where is the future?

As you said, earlier: "When t ≠ d the object is not observable. Not directly observable."

So the future consists of events for which t < d; i.e. the light (or other signal) has not reached us yet. 

[MigL]

32 minutes ago, dimreepr said:

even my feet runs a different time to my head.

I know quite a few people whose mouths are faster than their brain...
( not implying that about anyone here )

[michel123456]

24 minutes ago, Strange said:

As you said, earlier: "When t ≠ d the object is not observable. Not directly observable."

Here below put in diagram.

Zone 1 (black) corresponds to "1. An object cannot be seen if the light has not reached us yet (t < d). That is basically the case of Betelgeuse mentioned earlier: it  may already have gone supernova but we have not seen that yet." Zone 1 is not directly observable.

Zone 2 (orange, the volume inside the past light cone) corresponds to "2. An object cannot be seen if the light has passed us (t>d) and the object no longer exists. This describes, for example, supernovae that happened in the past. They were visible at the time but the light has now passed us and there is no more coming (because the event is over)." Zone 2 is not directly observable.

Zone 3 (Red, the surface of the Light Cone) corresponds to what is directly observable. The entire Observable Universe is there. The thickness of the surface corresponds to the time we have consumed getting information about the universe. At cosmological scale this thickness is negligible.

Line 4 is the time line of the observer. I cannot directly observe my own past, line 4 belongs to volume 2 which is not directly observable.

 

[dimreepr]

16 minutes ago, michel123456 said:

Here below put in diagram.

Zone 1 (black) corresponds to "1. An object cannot be seen if the light has not reached us yet (t < d). That is basically the case of Betelgeuse mentioned earlier: it  may already have gone supernova but we have not seen that yet." Zone 1 is not directly observable.

Zone 2 (orange, the volume inside the past light cone) corresponds to "2. An object cannot be seen if the light has passed us (t>d) and the object no longer exists. This describes, for example, supernovae that happened in the past. They were visible at the time but the light has now passed us and there is no more coming (because the event is over)." Zone 2 is not directly observable.

Zone 3 (Red, the surface of the Light Cone) corresponds to what is directly observable. The entire Observable Universe is there. The thickness of the surface corresponds to the time we have consumed getting information about the universe. At cosmological scale this thickness is negligible.

Line 4 is the time line of the observer. I cannot directly observe my own past, line 4 belongs to volume 2 which is not directly observable.

 

you know what the topic is, right?

[MigL]

Keep in mind that your light cone diagram is translating upward towards the future at 1 sec per sec.
Also you cannot directly observe past events, as your 'now' would have to move back down to the time of the event.
So it is not so much that the light signal has passed you by, as you can see the remnants of the past event, or the space where it used to be; Time has moved forward for the event also.

[michel123456]

16 hours ago, MigL said:

Keep in mind that your light cone diagram is translating upward towards the future at 1 sec per sec.
Also you cannot directly observe past events, as your 'now' would have to move back down to the time of the event.
So it is not so much that the light signal has passed you by, as you can see the remnants of the past event, or the space where it used to be; Time has moved forward for the event also.

Yes.  Except that in my understanding the observer has moved. Time has not moved because time is a kind of receptacle like space is. Anyway, in one or the other interpretation the effect is the same.

Begin of Disgression

The important thing is the word "move". Because (in my understanding) the translation in time is not different than the translation in space i.e. if you are at coords x,y,z,t and then move to coords x1,y1,z1,t1, you are not at x,y,z,t anymore.

That looks like a tautology but one must realize that in the current common understanding of time, when you are at x1,y1,z1,t1 you are still occupying coords x,y,z,t ! Because once you have occupied a t coordinate, this coordinate is ever occupied by you. All objects are 4 dimensionals, in the diagram an 4D object is represented by a line, you cannot change the past, etc. IOW common understanding states that "motion" in time has absolutely nothing to do with motion in space. In space an object changes coordinates, in time the object remains at the t coordinate and is being extruded through some new neighbouring coordinate.

End of disgression

23 hours ago, dimreepr said:

you know what the topic is, right?

The topic is Universal now hijack split from Universal Concept of Time (Is the Big Bang wrong?).

Today at t0 the observer sees galaxy g1 on the side the past light cone.

The observer knows that galaxy g1 he sees today is in fact the image of the ancient galaxy g when it was at g1.

Today, galaxy g is at g1'.

And the observer can say the same for another galaxy, and another.

Finally, asking where are the galaxies today, the observer has to suppose that the entire universe is upon the hypersurface of the present.

The problem is that no known physical force spreads over this hypersurface. This hypersurface has no known binding elements because all the bindings (gravity for example) are acting at max. Speed Of Light.

So the concept of universal now, where the universe has ~13 BY of age, does not make full sense.