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

[michel123456]

1 hour ago, Strange said:

It is either current or in the future (or in the past).

So you say that there is only one "present", the one we are living in, a kind of universal "Now" in which everything exists.

 

[Strange]

6 minutes ago, michel123456 said:

So you say that there is only one "present", the one we are living in, a kind of universal "Now" in which everything exists.

No. 

I don't see how an alien can be living "currently" and "in the future" (well, I suppose "the future" includes the rest of their lifetime). That has nothing to do with "universal now" or "one present".

An alien living now, some distance away, could be watching us as we were in the past. 

And an alien living in the future could see us as we are now.

But nether of those seem to fit what you said.

Also, this is completely off topic. So start a new thread if you want to discuss light propagation delay.

 

[swansont]

43 minutes ago, michel123456 said:

So you say that there is only one "present", the one we are living in, a kind of universal "Now" in which everything exists.

These are not terms generally used in physics analyses. 

[studiot]

45 minutes ago, michel123456 said:

So you say that there is only one "present", the one we are living in, a kind of universal "Now" in which everything exists.

 

39 minutes ago, Strange said:

I don't see how an alien can be living "currently" and "in the future" (well, I suppose "the future" includes the rest of their lifetime). That has nothing to do with "universal now" or "one present".

 

1 hour ago, michel123456 said:

2. If you look in your telescope and you observe an alien on another planet, this alien will be delayed, you will see him as it was a few minutes ago. The alien, from his point of view, will also see you a few minutes ago, the same delay goes for both sides. Now the question is: Is there currently an alien living in the future, looking at us? And we will receive his message in few minutes? Or are we all on the surface of the same "time-sphere", in an universal "now" situated ~13 BY from the BB? (I hope the question is clear)

Surely the proposed scenario demonstrates exactly why there is no universal 'now'.

Now of course equates to 'the present', whatever that may be.

My (or that of any observer) 'now' is made up of an enclosing or envelopeing 'bubble' around me containing signals from an enormous number of sources. Depending upon how long it took each signal to reach me all those signals are of different ages.

[michel123456]

6 hours ago, Strange said:

And an alien living in the future could see us as we are now.

You said it better. Smile, he is there looking at you.

[michel123456]

Is it physically possible that this future alien belongs to any planet we are currently observing around us (in the past)?

 

[Strange]

27 minutes ago, michel123456 said:

Is it physically possible that this future alien belongs to any planet we are currently observing around us (in the past)?

Absolutely. The average distance to planets found so far is about 2000 light years. 

(Still off topic, though.)

[michel123456]

5 hours ago, Strange said:

Absolutely. The average distance to planets found so far is about 2000 light years. 

(Still off topic, though.)

Please explain. We are observing a planet 2000 LY away. How possibly can it be in our future with an alien looking at us?

[Strange]

5 minutes ago, michel123456 said:

Please explain. We are observing a planet 2000 LY away. How possibly can it be in our future with an alien looking at us?

Please start another thread to discuss the finite speed of light.

So we observe a planet 2000 light year away. So we are seeing it as it was 2,000 years ago. The alien civilization may just be getting started (or maybe is already well developed) at that point.

4,000 years after that, a future alien of that civilization is observing Earth. They see it as it was 2,000 years before that; ie. as it is now. *waves*

What is the problem with that (apart from language not really making it easy to describe events happing in the past in the future - we need the future historic tense).

[swansont]

Quote

What is the problem with that (apart from language not really making it easy to describe events happing in the past in the future - we need the future historic tense).

This is one of the reasons that physics doesn't tend to rely on the terms future/present/past. Language is sloppy and imprecise, and relativity makes a further muddle of relative timing.

[michel123456]

13 hours ago, Strange said:

Please start another thread to discuss the finite speed of light.

So we observe a planet 2000 light year away. So we are seeing it as it was 2,000 years ago. The alien civilization may just be getting started (or maybe is already well developed) at that point.

4,000 years after that, a future alien of that civilization is observing Earth. They see it as it was 2,000 years before that; ie. as it is now. *waves*

What is the problem with that (apart from language not really making it easy to describe events happing in the past in the future - we need the future historic tense).

So if I understand correctly this planet is traveling in time together with us and is somewhere on the time-line Now. I cannot conceive that it is alltogether yesterday now and tomorrow, spread over the time-line (the "tomorrow" is especially uncomfortable to me)

Edited January 31, 2020 by michel123456

[Strange]

3 hours ago, michel123456 said:

I cannot conceive that it is alltogether yesterday now and tomorrow, spread over the time-line (the "tomorrow" is especially uncomfortable to me)

That's a shame. *shrug*

If you see a lightning flash and then a few seconds later here the thunder, do you worry that they didn't happen at the same time.

It doesn't sound like there is any science here, just your confusion about the finite speed of light. We have had this conversation before and it doesn't seem that anyone can help you get your head around it.

[michel123456]

3 hours ago, Strange said:

That's a shame. *shrug*

If you see a lightning flash and then a few seconds later here the thunder, do you worry that they didn't happen at the same time.

It doesn't sound like there is any science here, just your confusion about the finite speed of light. We have had this conversation before and it doesn't seem that anyone can help you get your head around it.

 I worry that the only signal we get is the thunder (in your analogy). The flash is missing. We are receiving a message (a wave). This message is delayed. On one hand it is perfectly sensible. OTOH that is where the problem begins.

If I suppose that on some planet an alien will one day in the future get my image, he will observe me as I am today. This instant will be in my future. The image he will get will be an image of the past (as seen by him, maybe until then I am dead). That will happen in the future as seen by me. Maybe this alien is not born yet.

But when I say "maybe this alien is not born yet" I  think that I am implying that his planet is actually in a sort of Now together with the Earth. In such a way that his planet & my planet travel through time in a parallel way.

 

[Strange]

2 hours ago, michel123456 said:

 I worry that the only signal we get is the thunder (in your analogy). The flash is missing. We are receiving a message (a wave). This message is delayed. On one hand it is perfectly sensible. OTOH that is where the problem begins.

If I suppose that on some planet an alien will one day in the future get my image, he will observe me as I am today. This instant will be in my future. The image he will get will be an image of the past (as seen by him, maybe until then I am dead). That will happen in the future as seen by me. Maybe this alien is not born yet.

I'm really not sure what you are trying to say.

It seems perfectly reasonable to say that the flash of lightning happens "now" (even though it was actually microseconds ago) and the thunder happens later. Even though both happened at the same time at the origin (which you would call "now" if you were located there). I can't see what is confusing about that. And maybe sometimes we can't see the lightning but I don't know how that is relevant.

I also can't see what the problem is with the relative time difference between two planets separated by a significant light-travel delay.

This is the same thing we saw when astronauts were on the moon. There was a 2 or 3 second delay before the signal got there then another delay before their reply got back. So conversations were filled with 5 second pauses. Nothing odd about that.

Quote

But when I say "maybe this alien is not born yet" I  think that I am implying that his planet is actually in a sort of Now together with the Earth. In such a way that his planet & my planet travel through time in a parallel way.

Well, that's true. We are all travelling in parallel to the future. But we will see other's time at a slightly different rate.

So when we experience 2,000 years pass on Earth, we may see that 1,999 years have passed on that distant planet because of relative difference in speed.

[michel123456]

21 hours ago, Strange said:

Well, that's true. We are all travelling in parallel to the future. But we will see other's time at a slightly different rate.

If indeed we are traveling in parallel to the future, it means that the aliens right now are calculating that the Universe is ~13 BY old. Right now they have the same age than we have. We cannot communicate real-time with them, all our signals will be delayed but we can be sure that Now they are somewhere at coordinates x,y,z,t, where the t coordinate is the same than ours (counting from the BB event)

The same thing counts for any planet anywhere in the Universe. Studiot wrote:

On 1/29/2020 at 4:39 PM, studiot said:

My (or that of any observer) 'now' is made up of an enclosing or envelopeing 'bubble' around me containing signals from an enormous number of sources. Depending upon how long it took each signal to reach me all those signals are of different ages.

The different ages are caused by the time needed for the signal to reach me. We know that the sources have long traveled to other coordinates. But right at this moment they all have in common the T coordinate. All the sources (the entire observable universe) are today ~13 BY old, distributed in random points over space.

And when you put this into a diagram, with the entire universe at equal T coordinates, it gets weird. It is as if the entire universe belonged to a surface-like limit 13 BY old.

And that makes no sense (to me).

 

[dimreepr]

now is the same for the entire universe, its just that now is different for everyone, just like we are the center of the observable universe.

Edited February 1, 2020 by dimreepr

[Strange]

1 hour ago, michel123456 said:

If indeed we are traveling in parallel to the future, it means that the aliens right now are calculating that the Universe is ~13 BY old. Right now they have the same age than we have. We cannot communicate real-time with them, all our signals will be delayed but we can be sure that Now they are somewhere at coordinates x,y,z,t, where the t coordinate is the same than ours (counting from the BB event)

No. Everyone will (possibly) measure a different value for t. (As was explained in the thread this was split from.)

 

 

[michel123456]

38 minutes ago, Strange said:

No. Everyone will (possibly) measure a different value for t. (As was explained in the thread this was split from.)

 

 

I guess you misunderstood something. Yes every observer from the planets of our Observable Universe will observe a different T.

But that is not the meaning of Now.  Now means in present time. At the edge of the arrow of time. Today (how to say it otherwise?)

I cannot conceive that today February 2020 there are galaxies only 8 BY from the BB, for example. Yes we may possibly observe them, but Now there are somewhere else, in a place where we cannot observe them.

[dimreepr]

4 minutes ago, michel123456 said:

in a place where we cannot observe them.

why

[Strange]

1 hour ago, michel123456 said:

But that is not the meaning of Now.  Now means in present time. At the edge of the arrow of time. Today (how to say it otherwise?)

And everybody will say that (their) now is "now".

But even if you could synchronise all those different perceptions of "now", then the next "now" would not be synchronised.

[MigL]

On ‎1‎/‎31‎/‎2020 at 6:23 AM, Strange said:

If you see a lightning flash and then a few seconds later here the thunder, do you worry that they didn't happen at the same time.

 

On ‎1‎/‎31‎/‎2020 at 10:19 AM, michel123456 said:

I worry that the only signal we get is the thunder (in your analogy). The flash is missing. We are receiving a message (a wave). This message is delayed. On one hand it is perfectly sensible. OTOH that is where the problem begins.

In Strange's example, the lighting flash ( light) moves faster than the thunder ( sound ).
You worry that no information gets to us faster than the visual image of distant galaxies.
You seem like an intelligent guy...
Exactly what do you think will move faster than the light from these far-away galaxies ?
And if any information could, would that not break causality ?

[michel123456]

1 minute ago, MigL said:

 

In Strange's example, the lighting flash ( light) moves faster than the thunder ( sound ).
You worry that no information gets to us faster than the visual image of distant galaxies.
You seem like an intelligent guy...
Exactly what do you think will move faster than the light from these far-away galaxies ?
And if any information could, would that not break causality ?

There is no reason to suppose a faster than light motion. You only need to put enough time.

[Strange]

4 minutes ago, michel123456 said:

There is no reason to suppose a faster than light motion. You only need to put enough time.

So what was your "we only hear the thunder" comment supposed to mean?

[michel123456]

For example we are accepting that we are observing distant stars as they were (in the past). We also accept that they may have evolved in-between. So we should accept that the distant star has simply changed position: it has moved to another point of space and we are not able (yet) to observe it. We will observe the change of position in the time of the delay (in a few years or BY)

 

Just now, Strange said:

So what was your "we only hear the thunder" comment supposed to mean?

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

[Strange]

Just now, michel123456 said:

For example we are accepting that we are observing distant stars as they were (in the past). We also accept that they may have evolved in-between. So we should accept that the distant star has simply changed position: it has moved to another point of space and we are not able (yet) to observe it. We will observe the change of position in the time of the delay (in a few years or BY)

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?

3 minutes ago, michel123456 said:

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

No, in my statement of fact (it wasn't an analogy) the light is a wave called "light" and the thunder is a wave called "sound".