what we know about Time

[owl]

_your post was quite negative. Instead of putting new information, you are destroying the few we have.

 

It is obvious that no one of us exacltly knows what he is talking about (a reason why so few members are engaged in the discussion).

 

Please do not automatically include me in your “know one exactly knows” assumption above.

 

I did not intend to be “negative”, and my information (and "knowing") about time is not “new.”

 

I am not “destroying” anything but only questioning your assumptions about time.

 

I didn't answer to your post for 2 reasons:

_I didn't want to disturb my duel with Iggy

_your post was quite negative. Instead of putting new information, you are destroying the few we have.[/Quote]

 

Sorry, i forgot the time/identity stamp.

[michel123456]

Let's drop something else about time.

 

If you stare at the sun raising at East and at the same time observe the sun at West, there are 3 solutions:

1. you are dreaming, dont worry youll wake up in a while.

2. you are getting mad, call the doctor.

3. there are 2 suns.

 

Hypothesis 3 arises logically from the fact that the same object (the sun) cannot be at 2 places at the same time.

So, in the East-West double suns example, what is bothering is not the position of the sun East or West, what is bothering is the time condition.

Second example: I have a black pen on my desk. I look at my feet and see another identical black pen on the floor. How do I know that it is not the same black pen that fall from the desk?

Simple: I look back on the desk. If there is a black pen there, I know for sure that it is not the same pen that is on the floor, because at the same time an object cannot be at 2 different places.

Another bizarre example:

Your car has been stolen. You chevrolet was found by the police. You go for identification. At the police station, you see 2 identical chevrolet side by side, same colour, same appearance. You have a look around because you remember a small scratch on the left wing. Surprinsingly, the 2 cars have the same scratch. You have a look inside and observe on both cars the same dirt on the back seat, the same papers in the glovebox, even the same sunglasses forgotten under the passenger seat. You open the front hood to verify the identification number on the chassis and you find the same number on the 2 cars. Something is going wrong. It's a nightmare.

Then you wake up.

It is not possible to have the same object at different places at the same time.

 

In other words, 2 objects are different from each other when they are observed at different places at the same time. The condition is sufficient, even if the 2 objects have the exactly same qualities/properties.

One could thus ask himself if ultimately time is not that thing that makes an object's uniqueness.

Edited March 26, 2012 by michel123456

[zapatos]

Let's drop something else about time.

 

If you stare at the sun raising at East and at the same time observe the sun at West, there are 3 solutions:

1. you are dreaming, dont worry youll wake up in a while.

2. you are getting mad, call the doctor.

3. there are 2 suns.

 

Hypothesis 3 arises logically from the fact that the same object (the sun) cannot be at 2 places at the same time.

So, in the East-West double suns example, what is bothering is not the position of the sun East or West, what is bothering is the time condition.

Second example: I have a black pen on my desk. I look at my feet and see another identical black pen on the floor. How do I know that it is not the same black pen that fall from the desk?

Simple: I look back on the desk. If there is a black pen there, I know for sure that it is not the same pen that is on the floor, because at the same time an object cannot be at 2 different places.

Another bizarre example:

Your car has been stolen. You chevrolet was found by the police. You go for identification. At the police station, you see 2 identical chevrolet side by side, same colour, same appearance. You have a look around because you remember a small scratch on the left wing. Surprinsingly, the 2 cars have the same scratch. You have a look inside and observe on both cars the same dirt on the back seat, the same papers in the glovebox, even the same sunglasses forgotten under the passenger seat. You open the front hood to verify the identification number on the chassis and you find the same number on the 2 cars. Something is going wrong. It's a nightmare.

Then you wake up.

It is not possible to have the same object at different places at the same time.

 

In other words, 2 objects are different from each other when they are observed at different places at the same time. The condition is sufficient, even if the 2 objects have the exactly same qualities/properties.

One could thus ask himself if ultimately time is not that thing that makes an object's uniqueness.

 

 

http://en.wikipedia.org/wiki/Gravitational_lens

Edited March 26, 2012 by zapatos

[michel123456]

What has gravitational lensing anything to do here?

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

 

So (continuing), the fact that 2 objects are different is guaranteed by the fact that an object cannot reach infinite velocity. Indeed, if infinite velocity was reachable, an object could be at 2 different places in zero time.

IOW, the Speed Of Light is that feature of the universe that makes possible to 2 different objects to exist separately from each other, in space. Without a barrier like SOL, 2 different objects in space could eventually be the one and same object.

Or:

a single hypothetical object that is not influenced by the time dimension, and thus is not restrained by the above condition, can eventually be positionned in 2 different points of space.

Edited March 27, 2012 by michel123456

[zapatos]

What has gravitational lensing anything to do here?

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

Sorry, I thought it was rather obvious.

 

Your entire post was dedicated to the proposition that:

...2 objects are different from each other when they are observed at different places at the same time.

 

I then showed a picture of four objects that are not different from each other, even though they are observed at different places at the same time.

 

Thus disputing your claim.

[khaled]

"We know that higher gravity fields make clocks oscillate ("tick") more slowly."

 

1. What if we can make the clock, calculate the gravitational force, to normalize its timing ?

 

2. Can't we create a clock that has an oscillator that is, by some mechanism, not affected by gravity fields ?

 

3. There are variants, you know things that change with time and things that remain constant

 

4. "An object can have two positions in space, at the same moment" this is wrong,

but is "An object is observed in two positions at the same moment" wrong ?

Edited March 27, 2012 by khaled

[Iggy]

I'll try to find another analogy:

What you say is that when you progress in time, you leave an indelebile imprint on each spacetime coordinates that you have occupied.

I'm not sure what "progress in time" means, but I never said it.

 

Like the skateboarder below

This image shows a skateboarder occupying three different spatial locations at the same time. Objects (point particles specifically) don't occupy different spatial locations simultaneously, and I certainly never said or implied that they do.

 

Your POV is also to imagine that if you are standing still sitting on your chair, time flows over you, like a strong wind extracting an imprint from your presence in spacetime. As if you were inside an extruding machine.

I never said or implied anything close to that.

 

An object in spacetime cannot exist at 2 time coordinates at the same space coordinate: it exist either then, either after, but not duplicately then and after.*

If you are willing to believe that the sun didn't exist in the same spot yesterday at noon and the day before at noon then nothing anybody could say would convince you that you are misunderstanding. If you can disregard the existence of the sun then you can disregard arguments against your view. There simply is no point of evidence that would mean you have to change your mind... so I'm not sure the point in conversing.

[owl]

Michel,

You nailed it saying:

We gave a name to "something" we call "time" without knowing if it is "something.

But then you go on to say:

 

It may be a property, it may be an illusion, it may be nothing, we don't know yet. But I think that with a little cleverness, we can catch devil's tail.

Philosophy doesn't help.

 

How can we even speak intelligently about time if we rule out the ontological (philosophical) question, “what is it?”

 

As things move (and everything moves) we say “time elapses” as an object moves through space from point A to point B. Anything beyond that is “making something of it.” That includes “weaving it together with space” and calling spacetime “something” more than just a coordinate system designating “at that place at that time” or “moving from here to there during this period of time” (in conventional ‘time units’)

 

Your quote of Etienne Kline also demonstrates “making something of it” as in:

 

What does it mean when, for example, we are repeating that time "flows", "passes through...

 

Likewise the common reference to the “arrow of time” as if it were an entity with a directional component.

 

Of course we can speak metaphorically of the future “passing through” the present and becoming the past.... or time “flowing” from future to past... as long as we don’t take the metaphor too literally.

 

Likewise with the “block universe” theory in which everything that has ever existed or will ever exist, in some sense exists now. That is where the famous light cone *model* takes us.

Here is Wiki on Eternalism (my bold):

Eternalism is a philosophical approach to the ontological nature of time, which takes the view that all points in time are equally "real", as opposed to the presentist idea that only the present is real.[1] Modern advocates often take inspiration from the way time is modeled as a dimension in the theory of relativity, giving time a similar ontology to that of space (although the basic idea dates back at least to McTaggart's B-Theory of time, first published in The Unreality of Time in 1908, only three years after the first paper on relativity). This would mean that time is just another dimension, that future events are "already there", and that there is no objective flow of time. It is sometimes referred to as the "block time" or "block universe" theory due to its description of space-time as an unchanging four-dimensional "block",[2] as opposed to the view of the world as a three-dimensional space modulated by the passage of time.

 

Of course I always advocate the latter view. The "existence" of future *whatever* is nonsense. Future events no not obviously already exist, nor do past events still "exist."

 

And "what exists" (in the present) does not depend on when we know about it, i.e., travel time for light/info to travel through space.

 

Finally, you say, ...”the entire reality passes through, and not time itself.”

 

“Passes through?” Reality happens (*is happening.*) Things move. It “takes time.”

Seems like much ado about nothing to me, ever since we conceptually merged time and space and then mistook this very useful coordinate system for Reality.

Edited March 27, 2012 by owl

[MigL]

Owl, I don't mean to be rude by ignoring your post, but I'm done banging my head against the philosophical wall.

 

Michel123456, you keep separating space-time coordinates with your arguments about different locations/same time and alternatively different times/same location. This makes the coordinates nonsensical, the event in space-time is defined by ALL 4 coordinates, not just the three spatial or just the time coordinate. You could make the same arguments about a straight vertical or horizontal line on an x-y graph ( multiple x values for a specific y value or alternatively multiple y values for a specific x value ). Unless you use ALL coordinates, you are not specifying a particular event, but just as in the x-y graph, a multitude ( infinite number ) of events.

[khaled]

"We know that higher gravity fields make clocks oscillate ("tick") more slowly."

 

1. What if we can make the clock, calculate the gravitational force, to normalize its timing ?

 

2. Can't we create a clock that has an oscillator that is, by some mechanism, not affected by gravity fields ?

 

3. There are variants, you know things that change with time and things that remain constant

 

4. "An object can have two positions in space, at the same moment" this is wrong,

but is "An object is observed in two positions at the same moment" wrong ?

[hypervalent_iodine]

!

Moderator Note

owl, consider this your warning. Stop hijacking this thread with your ontological nonsense, or you're looking at suspension.

[owl]

!

Moderator Note

owl, consider this your warning. Stop hijacking this thread with your ontological nonsense, or you're looking at suspension.

 

Will do. Didn't intend to "hijack"...

Thought I was on topic.

Not sure whether your judgment ,"ontological nonsense" is scientifically valid (re: 'what do we know about time' and 'what is time?',) or just your personal judgment, but I'm outta this thread. Got the warning.

[michel123456]

(...)

This image shows a skateboarder occupying three different spatial locations at the same time. Objects (point particles specifically) don't occupy different spatial locations simultaneously, and I certainly never said or implied that they do.

That is a much better statement than mine. At least we agree on something: "Objects (point particles specifically) don't occupy different spatial locations simultaneously" (...)

 

If you are willing to believe that the sun didn't exist in the same spot yesterday at noon and the day before at noon then nothing anybody could say would convince you that you are misunderstanding. If you can disregard the existence of the sun then you can disregard arguments against your view. There simply is no point of evidence that would mean you have to change your mind... so I'm not sure the point in conversing.

 

I am not expressing myself clearly and as a result you are misunderstanding my statements.

I didn't ment to say that the sun didn't exist yesterday. What I say is that the sun changed coordinates between yesterday and today. You cannot add the mass of the sun yesterday with the mass of the sun today, there is only one mass. And this lonely mass is at each instant of time somewhere on the graph, at the place where the object is. Mass is not multiplicating itself as time passes by. The sun is sliding into the graph, changing coordinates in spacetime.

[Iggy]

That is a much better statement than mine. At least we agree on something: "Objects (point particles specifically) don't occupy different spatial locations simultaneously" (...)

We agree

 

Who's got the champagne!

I am not expressing myself clearly and as a result you are misunderstanding my statements.

You are expressing yourself fine. I understand very well.

 

I didn't ment to say that the sun didn't exist yesterday. What I say is that the sun changed coordinates between yesterday and today... The sun is sliding into the graph, changing coordinates in spacetime.

Let me accept your premise, and make the assumption about moving through time with you and ask...

 

When you are at the spacetime coordinate x=0, y=0, z=0, t=12:00:10 (twelve o'clock, zero minutes, 10 seconds), what is at x=0, y=0, z=0, t=12:00:09?

 

In other words, what is one second behind you in the time dimension?

[michel123456]

We agree

 

Who's got the champagne!

I always keep a bottle in my fridge. You're welcome.

 

Let me accept your premise, and make the assumption about moving through time with you and ask...

 

When you are at the spacetime coordinate x=0, y=0, z=0, t=12:00:10 (twelve o'clock, zero minutes, 10 seconds), what is at x=0, y=0, z=0, t=12:00:09?

 

In other words, what is one second behind you in the time dimension?

 

That's an interesting question. Can I look around and see myself 1 sec. ago?

As a matter of fact when I look around, the things I can see that were 1 second ago are 300.000 km away from me. I cannot observe myself here where I am 1 sec. ago. So I have no physical observational clue of what is behind me in the time dimension.

One thing I could do is rely to your "common sense" belief that says that I am "still" frozen in time 1 sec. ago, here at the same position in space where I am now. Or not.

[Spyman]

That's an interesting question. Can I look around and see myself 1 sec. ago?

As a matter of fact when I look around, the things I can see that were 1 second ago are 300.000 km away from me. I cannot observe myself here where I am 1 sec. ago. So I have no physical observational clue of what is behind me in the time dimension.

One thing I could do is rely to your "common sense" belief that says that I am "still" frozen in time 1 sec. ago, here at the same position in space where I am now. Or not.

It might not be practically possible, but in theory you could place a mirror on the Moon and with a good telescope you could then see the reflection of yourself 3 seconds back in the past.

 

Edited to insert Michel's quote since my post ended up on a new page.

 

Edit 2: Corrected the time for light signals between the Moon and Earth.

Edited March 28, 2012 by Spyman

[michel123456]

It might not be practically possible, but in theory you could place a mirror on the Moon and with a good telescope you could then see the reflection of yourself 3 seconds back in the past.

 

Edited to insert Michel's quote since my post ended up on a new page.

 

Edit 2: Corrected the time for light signals between the Moon and Earth.

 

You could do that, but that would be an image not very different from the image on a video camera. Unless you could build a gravitational mirror.

 

In any case, from me on Earth or from the image on the mirror, only one would be real. There is not another "me" in the past waving at me in the future.

[Spyman]

In any case, from me on Earth or from the image on the mirror, only one would be real. There is not another "me" in the past waving at me in the future.

But the thing is that there is another you in the past waving at you in the future and it is in theory possible for you to observe it.

 

You need to reconsider the reality of observation and its impact on your view of time beacuse you make contradictory claims.

 

 

You could do that, but that would be an image not very different from the image on a video camera.

You need to to bear in mind that this is not a recording, it is real photons emitted live directly from yourself, they are equally real and valid as the photons coming from the astronaut standing beside the mirror on the Moon. The history that both these two live streams of photons show you are equally real and both the astronaut and you who were emitting these photons were also equally real, there is no fake or altered images trying to fool you.

 

 

Unless you could build a gravitational mirror.

When you are standing here on Earth and looking up at the Moon it is not orbiting around the Earth gravity you feel under your feet, according to Relativity gravity also travel at the speed of light, so the Moon you see is subjected to and orbiting around old Earth gravity from the past.

 

In fact if you would draw this on a spacetime diagram, you will notice that the Moon you see in the skye is orbiting the exact same old Earth gravity that you would see in the mirror, which is holding the reflection of the past you down on the surface of the old Earth.

[Iggy]

That's an interesting question. Can I look around and see myself 1 sec. ago?

As a matter of fact when I look around, the things I can see that were 1 second ago are 300.000 km away from me. I cannot observe myself here where I am 1 sec. ago. So I have no physical observational clue of what is behind me in the time dimension.

One thing I could do is rely to your "common sense" belief that says that I am "still" frozen in time 1 sec. ago, here at the same position in space where I am now. Or not.

Remember, I am accepting your premise that we are dots moving through spacetime. If you have to rely on a straw man about being frozen in time 1 second ago, you are making a straw man of your own model.

 

It sounds like you aren't sure what to put on the spacetime diagram one second lower in the time dimension.

 

If I may make a suggestion (based entirely on your model) -- if a person (let's say Marion) is a dot moving through spacetime then there is one thing for sure which cannot be one second in the -t direction from Marion, and that is Marion herself. Do you agree?

 

If I am represented by a dot moving through spacetime then I can't be at both 12:00:10 and 12:00:09. If I were at both then I wouldn't be a dot. Is that a correct interpretation of your model?

 

If not then could you please tell me where I've gone wrong.

Edited March 29, 2012 by Iggy

[michel123456]

But the thing is that there is another you in the past waving at you in the future and it is in theory possible for you to observe it.

(...)

No. Utter nonsense. edit -too strong comment- utter nonsense IMHO, that is what we are discussing right now.

 

Remember, I am accepting your premise that we are dots moving through spacetime. If you have to rely on a straw man about being frozen in time 1 second ago, you are making a straw man of your own model.

Where is the strawman? I say there is not anything frozen anywhere, I simply stated that the frozen concept is the "common sense".

 

It sounds like you aren't sure what to put on the spacetime diagram one second lower in the time dimension.

it is like a chess game: you have only one King. If the king is in the present, it cannot be in the past. If it is in the past, it cannot be in the present. The only thing you can (theoretically) do is change the position of the King.

 

If I may make a suggestion (based entirely on your model) -- if a person (let's say Marion) is a dot moving through spacetime then there is one thing for sure which cannot be one second in the -t direction from Marion, and that is Marion herself. Do you agree?

Yes. Agree.

 

If I am represented by a dot moving through spacetime then I can't be at both 12:00:10 and 12:00:09. If I were at both then I wouldn't be a dot. Is that a correct interpretation of your model?

Yes.

 

If not then could you please tell me where I've gone wrong.

You are understanding very well. Edited March 29, 2012 by michel123456

[Spyman]

No.

Ok Michel, have it your way. There is no point in trying to discuss with you if you stubbornly refuse to acknowledge raised issues.

[michel123456]

Ok Michel, have it your way. There is no point in trying to discuss with you if you stubbornly refuse to acknowledge raised issues.

 

So you really believe there is another Spyman frozen corresponding for each passed instant? That you are multiplicating as time passes by? That the Spyman you see in the mirror is another Spyman?

[Iggy]

If I may make a suggestion (based entirely on your model) -- if a person (let's say Marion) is a dot moving through spacetime then there is one thing for sure which cannot be one second in the -t direction from Marion, and that is Marion herself. Do you agree?

Yes. Agree.

 

If I am represented by a dot moving through spacetime then I can't be at both 12:00:10 and 12:00:09. If I were at both then I wouldn't be a dot. Is that a correct interpretation of your model?

Yes.

 

You are understanding very well.

Good to hear.

 

Is this diagram correct?

 

 

 

Marion is the dot at t=12:00:10. The triangle is her light cone so she can't see the red dot (one second behind her in the -t direction). Is this correct or should I change it?

[Spyman]

So you really believe there is another Spyman frozen corresponding for each passed instant? That you are multiplicating as time passes by? That the Spyman you see in the mirror is another Spyman?

See - You are doing it again Michel, you don't even seem to be trying to understand what I said and engage in my arguments. I never claimed anything of what you seem to think I did. So I am done repeating my points and trying to explain where you are clearly wrong and why.

 

When I look in a mirror I belive I see myself in the past, the real me, not another Spyman that is not me or something else.

 

What do you think you see in the mirror, since it can't be the real Michel and not another Michel either, is it a fake Michel?

[michel123456]

See - You are doing it again Michel, you don't even seem to be trying to understand what I said and engage in my arguments. I never claimed anything of what you seem to think I did. (...)

 

You wrote: (bolded mine)

But the thing is that there is another you in the past waving at you in the future and it is in theory possible for you to observe it.

 

Contradicted by this statement:

 

When I look in a mirror I belive I see myself in the past, the real me, not another Spyman that is not me or something else.

 

(...)

Is this diagram correct?

 

 

 

Marion is the dot at t=12:00:10. The triangle is her light cone so she can't see the red dot (one second behind her in the -t direction). Is this correct or should I change it?

If Marion is the observer, Marion is at the origin.

 

But I will retain your statement "The triangle is her light cone so she can't see the red dot (one second behind her in the -t direction)." This only was worth the thread. That is because 2 years now I struggle maintaining that the interior part of the PLC is not observable. It was then dumped into the Forum waste basket.

 

(...)

What do you think you see in the mirror, since it can't be the real Michel and not another Michel either, is it a fake Michel?

 

It is Michel's image travelling at c.

 

@Iggy

I suppose you realize that each single bar on the horizontal line represents a distance of 300000 km. Number 2 on the horizontal represents 3 million kilometers (about 7 times the Earth-Moon distance). At this scale Marion is a tiny little dot (not visible on the screen) and not a big black/red dot.

Edited March 29, 2012 by michel123456