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Author Topic: Are there three dimensions of time?  (Read 12039 times)

Offline allan marsh

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Are there three dimensions of time?
« on: 17/07/2014 19:27:48 »
There are quite clearly three dimensions of space.
My question why do we not consider the three dimensions of time, as past, present, and future?

[mod edit- please phrase subjects as questions in line with AUP]
« Last Edit: 21/07/2014 09:47:02 by Georgia »


 

Offline CliffordK

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Re: Time
« Reply #1 on: 17/07/2014 20:13:30 »
It is easiest to look at time as one dimensional, from past to present to future.  I.E.  a timeline.

"Present" is essentially a single point, although it could be defined as tightly or as broadly as one's needs at the time.

This millisecond.
This second
This minute
This hour
Today.
This week
This month
This year
This decade
This century
This millennium.
etc.

But, still, present occupies a single point on your timeline.

Now, the question is what you would gain from taking a single dimensional entity of time, and making it into a 2 or 3 dimensional entity.  Especially since there is so much uncertainty in the future.  Would you truly get some kind of a space-filling structure, or would it still regress back to the single dimensional timeline?
 

Offline JP

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Re: Time
« Reply #2 on: 17/07/2014 21:00:19 »
A loose description of the number of dimensions is the shortest set of instructions you have to give someone to go from an arbitrary start point to an arbitrary end point, assuming they aren't blocked by anything.  In space, you need three items in your instructions.  For example, you can say to move forward by X units, move left by Y units and up by Z units.  Or you can tell someone to rotate about two axes so they're facing the proper direction, then to move forward by a certain distance. 

In time, we don't have the freedom to move backwards, but we only need to know a single number to move forward in time (how long to wait), and if we had a time machine, we'd need to know how far back to go.  To specify a point in space-time, you need four numbers (hence why we say space-time is 4 dimensional in relativity): three numbers for how to go to a point in space and one number for the time of arrival.
 

Offline jccc

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Re: Time
« Reply #3 on: 18/07/2014 04:32:41 »
Space is everywhere, time is always now.

Past and future are concepts in our minds, not physically exist.

Time will not slow down, the meter will if the force runs the meter decreased.

 

Offline jccc

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Re: Time
« Reply #4 on: 19/07/2014 04:35:10 »
Maybe time is the clock itself

The wave front carries the universe moving

When the wine in the glass is gone

Fill up another one my friend

I miss those good old time

 

Offline PmbPhy

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Re: Time
« Reply #5 on: 19/07/2014 07:02:44 »
Quote from: JP
In time, we don't have the freedom to move backwards, but we only need to know a single number to move forward in time (how long to wait), and if we had a time machine, we'd need to know how far back to go.
Great explanation as always. To be a bit more precise, the number dimensions of a set is how many numbers it takes to uniquely determine an element in the set. In order to specify a point in time one needs only one single number. To uniquely determine a point in spacetime one needs four numbers.

Quote from: jccc
Space is everywhere, time is always now.
That's incorrect. The present is always now. Saying like you did is like saying space is always where
I am, which certainly isn't true.

Quote from: jccc
Time will not slow down, the meter will if the force runs the meter decreased.
That's not quite right either. Time does slow down depending on what one means by that. We know that the rate at which time passes in one frame relative to another depends on the relative speeds of the two frames. Also, as reckoned observers outside a gravitational field, time runs slower for those in a gravitational field.
 

Offline petm1

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Re: Are there three dimensions of time?
« Reply #6 on: 24/07/2014 22:47:42 »
If you think of a clock only counting its own existence as a clock then the deeper you take one into a gravity well the longer its exists in the present.  It is the duration of the clock, or age, that is getting longer just as if you move the clock faster through space it is a longer amount of time occupied that changes the clock's count. Keeping in mind that space is time.
 

Offline Ethos_

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Re: Are there three dimensions of time?
« Reply #7 on: 24/07/2014 22:59:59 »
Einstein concluded that the past, present, and future were all occurring  simultaneously.

http://everythingforever.com/einstein.htm
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #8 on: 25/07/2014 03:54:43 »
Quote from: petm1
Keeping in mind that space is time.
Nope. That's very wrong. Relativity does not say that space is time.
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #9 on: 25/07/2014 03:56:16 »
Einstein concluded that the past, present, and future were all occurring  simultaneously.

http://everythingforever.com/einstein.htm
Einstein never said that nor has any relativist ever suggested such a thing. Where in that page do you claim that it says Einstein said that?
 

Offline jccc

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Re: Are there three dimensions of time?
« Reply #10 on: 25/07/2014 06:29:04 »
You travel from a to b takes time t. You travel back from b to a takes time t1. you spent t + t1 time total.

No mater which way you travel, time adds up, how can you travel back in time? How can you spend spent money?

Why don't we have a time conservation law? t>=0.
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #11 on: 25/07/2014 06:38:23 »
Quote from: jccc
Why don't we have a time conservation law? t>=0.
A conservation law only means that the sum of something remains constant. I.e. the numerical value does not change in time. That's not what you're talking about.
 

Offline JSS

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Re: Are there three dimensions of time?
« Reply #12 on: 25/07/2014 11:01:06 »
Time is the measure of relative change.

You can say that the relative changing in one direction is different than another direction and thus claim different "times" for each orthogonal direction. That would give you "3 dimensional time". But of what use is it?

In practical physics, there is almost never a case of concern for the measure of changing in one direction being different than another and also affecting the overall time dilation enough to measure or be concerned about. The differences, although capable of being calculated are minuscule. Even the effort to measure how much changing took place in one direction verses another would be pretty tough.

So as a convention, time is accepted as merely the measure of the overall relative changing, thus a single dimension of measure.
 

Online evan_au

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Re: Are there three dimensions of time?
« Reply #13 on: 25/07/2014 11:17:08 »
Why don't we have a time conservation law? t>=0.
Causality is used as a constraint on feasible solutions, for example by assuming that nothing (not even information) can travel faster than the speed of light, nor can it travel backwards in time.

Many equations in physics can be written with the sign of time reversed - in fact a positron can be regarded mathematically as an electron traveling backwards in time.

So causality is more an assumption than a proof - but some strange things could occur if someone did manage to travel backwards in time.

The laws of thermodynamics only work when time is going "forwards", and human lives are inherently bounded by thermodynamics.

See: http://en.wikipedia.org/wiki/Causality#Physics
 

Offline Ethos_

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Re: Are there three dimensions of time?
« Reply #14 on: 25/07/2014 13:01:27 »
Einstein concluded that the past, present, and future were all occurring  simultaneously.

http://everythingforever.com/einstein.htm
Einstein never said that nor has any relativist ever suggested such a thing. Where in that page do you claim that it says Einstein said that?
In the very first sentence Pete: "Albert Einstein concluded in his later years that the past, present, and future all exist simultaneously."

How could you have missed it if you had indeed read it?
« Last Edit: 25/07/2014 14:10:45 by Ethos_ »
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #15 on: 25/07/2014 18:13:05 »
Quote from: Ethos_
In the very first sentence Pete: "Albert Einstein concluded in his later years that the past, present, and future all exist simultaneously."

How could you have missed it if you had indeed read it?
I didn't read it. I don't have the time to read everything people tell me to read. I only read the stack of  textbooks sitting on my side table in order to prepare myself for graduate school. I looked at it somewhat and I am quite surprised that I missed that. Se la vie! :)

I don't buy that interpretation though. Nothing exists in relativity that could lead to such a conclusion. I e-mailed a friend of mine. He used to be the editor of the Einstein papers project and as such as an extremely good knowledge of Einstein's writings. I'll let you know what he has to say about it.
 

Offline Ethos_

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Re: Are there three dimensions of time?
« Reply #16 on: 25/07/2014 19:28:17 »
Quote from: Ethos_
In the very first sentence Pete: "Albert Einstein concluded in his later years that the past, present, and future all exist simultaneously."

How could you have missed it if you had indeed read it?
I didn't read it. I don't have the time to read everything people tell me to read. I only read the stack of  textbooks sitting on my side table in order to prepare myself for graduate school. I looked at it somewhat and I am quite surprised that I missed that. Se la vie! :)

I don't buy that interpretation though. Nothing exists in relativity that could lead to such a conclusion. I e-mailed a friend of mine. He used to be the editor of the Einstein papers project and as such as an extremely good knowledge of Einstein's writings. I'll let you know what he has to say about it.
Thanks for the feedback Pete, I will also be interested to hear what your friend has to say about this..................regards.......Ethos
 

Offline jccc

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Re: Are there three dimensions of time?
« Reply #17 on: 25/07/2014 19:36:04 »
Seems Einstein is God for scientists.

I heard that he doesn't know how to play his sail boat.
 

Offline JSS

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Re: Are there three dimensions of time?
« Reply #18 on: 25/07/2014 19:51:12 »
Causality and the existence of the past and future are issues of ontology and beyond the scope of physics. Einstein might have made some comment about it or anything else (such as God). That doesn't mean it is a declaration of physical law.

You can't expect a doctor to explicate the meaning of life.
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #19 on: 25/07/2014 19:57:02 »
Quote from: Ethos_
Thanks for the feedback Pete, I will also be interested to hear what your friend has to say about this..................regards.......Ethos
He wrote back just now and said
Quote
If you look at the quotes from Einstein in the article you cite:
Quote
In 1952, in his book Relativity, in discussing Minkowski's Space World interpretation of his theory of relativity, Einstein writes:

Since there exists in this four dimensional structure [space-time] no longer any sections which represent "now" objectively, the concepts of happening and becoming are indeed not completely suspended, but yet complicated. It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence.
Einstein wrote a letter to Besso's family, saying that although Besso had preceded him in death it was of no consequence, "...for us physicists believe the separation between past, present, and future is only an illusion, although a convincing one."

you will see that neither uses the word "simultaneously."

What the first quote says is that one should conceive of processes as primary, rather than reducing them to the evolution in time of sets of spatially simultaneous events.

The second says that "the separation between past, present, and future is only an illusion," which is a consequence that can be drawn from the first: the primacy of process.
Which is exactly correct as I see it too.

Another expert on the subject I wrote to said Well, it's an obvious misuse of the word "simultaneous". which also agrees with what I said.

I wish people would simply take my word for these things. I can't tell you how many thousands of times I've consulted with my expert friends in instances like this only for them to tell me in all cases that I'm right. They're getting the idea that because I ask them these questions whose answers are obvious to us that I should know the answer myself and may be getting tired of me asking things I already know the answer to.
« Last Edit: 25/07/2014 20:00:58 by PmbPhy »
 

Offline Ethos_

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Re: Are there three dimensions of time?
« Reply #20 on: 27/07/2014 03:17:57 »

Another expert on the subject I wrote to said Well, it's an obvious misuse of the word "simultaneous". which also agrees with what I said.
Thanks for the clarification Pete, it appears that misquotes are abundant on the internet.

Quote from: PmbPhy

I wish people would simply take my word for these things.

But this is how most of us fall into error, by just taking someone's word for these things. Case in point, me trusting a quote from what I thought was a reputable source. And that's not to say that I mistrust you Pete, we are all responsible to research our source material and my mistake was not doing that.

Peace my friend..........................Ethos_
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #21 on: 27/07/2014 03:32:16 »
Quote from: Ethos_
But this is how most of us fall into error, by just taking someone's word for these things. Case in point, me trusting a quote from what I thought was a reputable source. And that's not to say that I mistrust you Pete, we are all responsible to research our source material and my mistake was not doing that.

Peace my friend..........................Ethos_
I said I wish. I didn't say it'd be best. :)  I know how people feel about these things and I know people certainly don't take me as an authority on any of these fields. I might be thought of as an expert in SR but certainly not an authority. So I really don't expect that people should just take my word for it. It'd just make my life easier by not appearing ignorant to my friends.
 

Offline Ethos_

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Re: Are there three dimensions of time?
« Reply #22 on: 27/07/2014 03:39:20 »
Quote from: Ethos_
But this is how most of us fall into error, by just taking someone's word for these things. Case in point, me trusting a quote from what I thought was a reputable source. And that's not to say that I mistrust you Pete, we are all responsible to research our source material and my mistake was not doing that.

Peace my friend..........................Ethos_
I said I wish. I didn't say it'd be best. :)  I know how people feel about these things and I know people certainly don't take me as an authority on any of these fields. I might be thought of as an expert in SR but certainly not an authority. So I really don't expect that people should just take my word for it. It'd just make my life easier by not appearing ignorant to my friends.
I'm confident that no one here thinks that you're ignorant Pete, I certainly don't. In fact, I appreciate the knowledge you share with us but as I said, we are all ultimately responsible to seek out the truth where ever we find it. And proving our source material is a personal and  individual responsibility.
 

Offline PmbPhy

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Re: Are there three dimensions of time?
« Reply #23 on: 27/07/2014 05:45:46 »
Quote from: Ethos_
I'm confident that no one here thinks that you're ignorant Pete, ....
Thanks buddy. That's awfully kind of you to say. You're one of the brighter posters yourself if you don't mind me saying.  :)
« Last Edit: 27/07/2014 08:51:29 by PmbPhy »
 

Offline allan marsh

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Re: Are there three dimensions of time?
« Reply #24 on: 30/07/2014 09:38:08 »
thanks folks for all your thoughts and interactions.
Einstein's world of thought was based on imagineering in lifts and acceleration bodies. his ability like you and me is to use one aspect of human consciousness..... that of imagination in forms and time.
I can imagine the past as well as the future, deciding points in time to review.
if we did not have this ability to imagine,   our evolution would depend on random accidents or just luck!

is not our ability to imagine points in time, a form of dimensions
 

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Re: Are there three dimensions of time?
« Reply #24 on: 30/07/2014 09:38:08 »

 

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