Intriguing question about Time, Physics and SRT in general

Quantum Quack

Quantum Quack

Life's a tease...
Valued Senior Member
I am not making a claim..
The math itself is..
The light cone diagram [see below ] often used as a part of understanding Minkowski/Einstein space time [therefore Special Relativity Theory as generally accepted], is.

I am simply asking a question about what I observe that poses an intriguing question about the nature of time and how science, in particular Mathematics deals with it.

lightcones.png

image courtesy of wiki :
http://en.wikipedia.org/wiki/Special_relativity

Observation:

When studying the above diagram one can see that we have a future and past light cone with a Hyper Surface of the Present in between, can we conclude that the time duration of the Hyper surface (HSP) for any observer is zero?
Given that absolute Rest is "forbidden" the answer can only be yes... [please correct me if I am wrong]


The question:

If the time duration between past and future, light cones, is zero then what mathematics can be used to describe the reality of the universe [ or any relevant observer frame of reference ] at that point in time?
Or
How does mathematics and physics accommodate the issue of an apparent zero duration existence?
 
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I'm having a hard time understanding your question. The hypersurface marked as "present" is by definition a set of points at a specific given time as measured by the observer. There's no such thing as a "time duration" for the hypersurface, because there's a different hypersurface corresponding to each value of time. Not a good idea to try deducing anything profound and new about physics from a layman diagram illustrating a 100 year-old theory, so I hope that's not what you're aiming for.
 
CptBork said:
I'm having a hard time understanding your question. The hypersurface marked as "present" is by definition a set of points at a specific given time as measured by the observer. There's no such thing as a "time duration" for the hypersurface, because there's a different hypersurface corresponding to each value of time. Not a good idea to try deducing anything profound and new about physics from a layman diagram illustrating a 100 year-old theory, so I hope that's not what you're aiming for.
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hmmm.. the image you refer to is taken originally from:
http://en.wikipedia.org/wiki/Special_relativity
and I am not sure whether it is a layman's image or not...
but either way the point in time between past and future for all observers would have to be zero in duration, would you agree?

/Edit: I have amended the OP to show Image credits. Thanks for the heads up. :)



Maybe a simple text description would suffice...

hspzeroduration.jpg
 
The separation between immediate past and immediate future for a given observer is always of zero duration, that's something which holds in Newtonian mechanics too, it follows directly from the definition of time. I don't see why this would cause a problem in physics, since nothing physical stays stuck on a timeless hypersurface, so you need to please elaborate.
 
CptBork said:
The separation between immediate past and immediate future for a given observer is always of zero duration, that's something which holds in Newtonian mechanics too, it follows directly from the definition of time. I don't see why this would cause a problem in physics, since nothing physical stays stuck on a timeless hypersurface, so you need to please elaborate.
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ok so we agree...that the point in time is zero duration.
Re: the OP:
If the time duration between past and future, light cones, is zero then what mathematics can be used to describe the reality of the universe [ or any relevant observer frame of reference ] at that point in time?
Or
How does mathematics and physics accommodate the issue of an apparent zero duration existence?
Click to expand...
or to be more blunt, how does Physics and Mathematics justify distance dimensions manifesting at this point in time?
 
Quantum Quack said:
ok so we agree...that the point in time is zero duration.
Re: the OP:

or to be more blunt, how does Physics and Mathematics justify distance dimensions manifesting at this point in time?
Click to expand...

Because events that occur at those other points on the hypersurface can affect the observer at some time in the future when those spatial points are later contained inside the observer's past light cone, and the observer can then use those effects to triangulate on the positions at which those events would have had to occur as viewed from their reference frame.

Edit: Made a couple of corrections, see above.
 
CptBork said:
Because events that occur at those other points on the hypersurface can affect the observer at some time in the future when those spatial points are later contained inside the observer's past light cone, and the observer can then use those effects to triangulate on the positions at which those events would have had to occur as viewed from their reference frame.

Edit: Made a couple of corrections, see above.
Click to expand...
Thanks Cpt :)
Yes I understand the above to be correct if one accepts that the hyper surface has a positive dimension if t=0 duration... however it appears to fail in addressing the fundamental question posed by the OP.

The question could be rephrased as:

How big is the hyper surface of the present, if time duration of that surface is zero?

The observation of the light cones suggests that it must be zero also.. if t= 0 duration then d= 0.

So I am curious how physics and math can generate a hyper surface that has dimension when time is of zero duration. And that's the intriguing bit...IMO
 
From what I see the observer doesn't exist to observe if t= 0 duration.
So there must be math/physics to accommodate this issue ...
 
It's not an issue. At t=0, no other point on the hypersurface can affect the observer at that same given moment, because the effect would have to carry information infinitely fast, that's why the light cone shrinks to zero in size. I think you're just misunderstanding what light cones actually represent.
 
CptBork said:
It's not an issue. At t=0, no other point on the hypersurface can affect the observer at that same given moment, because the effect would have to carry information infinitely fast, that's why the light cone shrinks to zero in size. I think you're just misunderstanding what light cones actually represent.
Click to expand...
Does the observer exist at t=0 duration?
If so how is this possible according to the Math and Physics?
 
Quantum Quack said:
Does the observer exist at t=0 duration?
If so how is this possible according to the Math and Physics?
Click to expand...
t=0 is a coordinate, not a duration. And yes, of course he exists.

Every event happens at a single point in space and time, at the origin of the coordinate system in the diagram. Mathematically, a point has no dimensions: no size or duration. Why you think that means the observer doesn't exist, I can't imagine. It seems axiomatic to me. Like a "you are here" sign on a map. You can't be here if you don't exist!
 
Russ_Watters said:
Mathematically, a point has no dimensions: no size or duration. Why you think that means the observer doesn't exist, I can't imagine.
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well to answer you, as far as I can tell the observer is that point!
Where else could he be on the time line except between his past and future? [axiomatically?]
How he exists or is existent in Physics and Math when he is zero dimensional is what this thread is about...
 
Math is math. Physics is physics. You haven't defined what you mean by "exist" and how that relates to the topic you raise. You haven't make an argument from generally accepted premises or even unconventional but explicitly stated premises. Therefore no one has a rational basis to say that they understand why you assert your claim, let alone endorse it for the same reasons you do.

Pure mathematics has no problems saying zero-dimensional points exist within geometry. For instance the Euclidean axiom that two distinct straight lines intersect in at most one point. The same is true in algebra where polynomials of finite order have zero-dimensional solution sets. And of course there's algebraic geometry.
 
rpenner said:
Math is math. Physics is physics. You haven't defined what you mean by "exist" and how that relates to the topic you raise. You haven't make an argument from generally accepted premises or even unconventional but explicitly stated premises. Therefore no one has a rational basis to say that they understand why you assert your claim, let alone endorse it for the same reasons you do.

Pure mathematics has no problems saying zero-dimensional points exist within geometry. For instance the Euclidean axiom that two distinct straight lines intersect in at most one point. The same is true in algebra where polynomials of finite order have zero-dimensional solution sets. And of course there's algebraic geometry.
Click to expand...

What claim are you referring to?
 
Quantum Quack said:
well to answer you, as far as I can tell the observer is that point!
Where else could he be on the time line except between his past and future? [axiomatically?]
How he exists or is existent in Physics and Math when he is zero dimensional is what this thread is about...
Click to expand...
Wherever you go, there you are.

Since you don't have zero dimensions and a light cone starts at a zero dimensional point, if the situation calls for it you can describe your body as a collection of points, each with its own separate light cone.
Quantum Quack said:
What claim are you referring to?
Click to expand...
You have claimed that the observer doesn't exist -- even though you are trying hard to argue by question-talking instead of stating your argument clearly so it can be understood. You slipped-up and agreed with me in your post above that that is indeed your point here.

This is a very annoying argument style you are using that is not conducive to a productive discussion and you should really stop it. If you explain clearly and concisely why you think what you are suggesting is true, we will then understand your position better and be able to explain exactly where your error in understanding is. Absent that, you force us to simply guess what your error is.
 
You have claimed that the observer doesn't exist -- even though you are trying hard to argue by question-talking instead of stating your argument clearly so it can be understood. You slipped-up and agreed with me in your post above that that is indeed your point here.
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I haven't claimed any such thing.
It is claimed by SRT and other, not me.. All I am doing is asking about the math that supports it.

The observer as displayed in the light cones diagrams "exists" in a zero dimensional point between past and future? True of false?
Am I reading the diagram correctly? Yes or No?

lightcones.png


If the observer exists as the diagram seems to suggest it does, how is that so if he exists in a zero duration dimensional point?
What Math is there to support his existence?
 
This is a very annoying argument style you are using that is not conducive to a productive discussion and you should really stop it. If you explain clearly and concisely why you think what you are suggesting is true, we will then understand your position better and be able to explain exactly where your error in understanding is. Absent that, you force us to simply guess what your error is.
Click to expand...
it is NOT an argument...there is nothing to argue...just attempting to understand the issue of an observer existing at a zero dimensional point between past and future..
It is the claim of Physics that the observer exists at the zero point between past and future. If you are unhappy about it take it up with physics not me...
 
Quantum Quack said:
I haven't claimed any such thing.
Click to expand...
I said: "Why you tink that means the observer doesn't exist, I can't imagine." and you responded with: "well to answer you, as far as I can tell the observer is a point!"

Since you answered my query* as it was, that means you accept/agree with my premise: that you do think that means the observer doesn't exist.

*I flipped the tables on your argument: You are arguing by question-talking and I asked you a question by statement-asking.
It is claimed by SRT and other, not me.. All I am doing is asking about the math that supports it.
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No, what you've also done is claim that it is wrong.
The observer as displayed in the light cones diagrams "exists" in a zero dimensional point between past and future? True of false?
Am I reading the diagram correctly? Yes or No?
Click to expand...
True.
If the observer exists as the diagram seems to suggest it does, how is that so if he exists in a zero duration dimensional point?
Click to expand...
There is nothing about the light cone's center being a zero dimensional point that implies he doesn't exist. "How" is a meaningless question here: the light cone is describing his existence. You can't make a light cone about something unless it exists! To put it another way: the light cone diagram says he exists.

Your "question" is a wrong question. It is based on the faulty premise that the center of the light cone being a point is a strike against the observer's existence.
What Math is there to support his existence?
Click to expand...
There is no math in this thread or in the question/your claim. There is only the geometry of the diagram you posted.
 
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