Why Do Theories Rely on the Concept of Time If It's a Human Construct?

[littlebanger]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

 

[Drakkith]

Time is integral to science.

 

[Dale]

there is nothing natural about time at all didnt we just make it up for are own use ?

Do you really believe that we just made up time and that before we came around days and years didn't exist?

 

[Pengwuino]

I think he doesn't understand relativity. Back in the day, "time" was just a parameter that apparently just flowed and it always flowed at the same rate anywhere and everywhere. Well, for over a hundred years we have found out that this is certainly NOT the case. That's why people talk about time so much. If you treat time as something that just flows and nothing effects the flow of time, your theory will fail immediately.

 

[Idoubt]

Time is a very real dimension. I'd recommend reading up on the special theory of relativity.

Actual effects of this are noticeable. For example clocks on satellites run a tad slower than those on Earth and engineers have to compensate for that or our gps wouldn't work.

(This is because time is slower and not because the clocks have a problem working by the way.)

P.S

This effect can only be explained with general relativity but I think this example gives you a sense of how time isn't just a figment of our imagination and is a real physical quantity

 

[littlebanger]

Do you really believe that we just made up time and that before we came around days and years didn't exist?

ofcourse days and years exsist because they are a cycle which we put a name too )
but to say that's its a acutal thing because equipment slows or stops leaves me thoughtless does anything acutaly change when these clocks slow down ? il go read up a lot on this .

thanks for all the answers i do respect them its just a very hard thing to get my head around

 

[Idoubt]

As I emphasised when I posted, the clocks are not slowing down, If you are sitting inside a satellite 1 hour still feels like 1 hour for you, but when seen from the Earth the one hour on the satellite is ( faster I think ) different than the 1 hour here on earth. So time really is flowing at different rates for the two observers ie time is relative.

 

[Dale]

ofcourse days and years exsist because they are a cycle which we put a name too

What does us naming something have to do with anything? Are you suggesting that a rock is "nothing natural at all" and "we just make it up for are own use" simply because we decided to call it by the name "rock"? If you are not trying to say that anything with a name is unnatural, then in your opinion what is the existential difference between a year and a rock?

 

[HallsofIvy]

ofcourse days and years exsist because they are a cycle which we put a name too )
but to say that's its a acutal thing because equipment slows or stops leaves me thoughtless does anything acutaly change when these clocks slow down ? il go read up a lot on this .

thanks for all the answers i do respect them its just a very hard thing to get my head around

I suppose one could argue that "time" is not real in the same way that "x", "y", and "z" are not real, but depend on the coordinate system used. That is, when we say that "this event happened on at coordinates (1, 3, -6) at t= 10", the "10" is no more "real" than the "1", "3", or "-6". Those values all depend upon the choice of "origin", orientation of the coordinate system, and choice of units.

But in physics "time" is not used into mean the value of that coordinate, any more than "distance" or "position" is used to me coordinates of a point in a given coordinate system. That which we measure when we talk about the "time" being a particular number exists in the same way that "position" does.

An event occurs at a specific time, even if there is no coordinate system or anyone around to see it occur, as surely as it occurs at a specific position. You may be confusing the physical concept being measured with the number used to measure it.

 

[Darryl]

"there is a time and a place for everything". Seems to sum it up, everything exists in its own unique time and place, they exist together, in space time, but you cannot be in the same time, or space as anything else. Gravity is everywhere, at infinately different levels, at each level of gravity, therefore at each point in space, will have its very own unique time (or rate of time flow) if observed from outside the system.

When you look at an object you are seeing it in your time, but what you see happened some other time in the past, so in your space you have your very own time, and you have to wait a period of time to observe events that occur in someone elses time.

the only real thing that appears constant in time is that it moves in one direction only, or is zero. And everyone and everything has a unique place in space and time.

That makes me think that if we observe massive objects in space that appear to rotate very fast like pulsars at 600 Revs per second, it that because time is going slower at the pulsar than it is for us, so we observe high rotation speed in our time frame, but if you were on the pulsar with would be very slow rotation.

And on a black hole if time stops, that would imply an infinite rotation speed, in our time, but very slow rotation on the actual black hole, because time is going so slowly, and if not at all, it would have infinite rotation, and on the surface you would see frozen space, and you would have to wait an infinite time to see any movement at all !..

 

[Darryl]

"TIME ! is not real is it ?"

When you think about it that question makes more and more sense, its only as real as we are able to measure and label it within a range or error in our local space/time conditions.

so it depends on how much gravity you have, where you are and how fast you are going is what determines how you can label durations of time. But those labels are only valid within a range of errors like complex gravitation and speeds.

So if we were anywhere else, or any other speed or density we would observe the universe unfolding at a different rate.

I guess if you were thrown out of the big bang, in a ship, at 0.99% speed of light, your personal time would be very slow if observed from the outside (on Earth say), you would experience 'normal' local time, and you could have a watch that ticks off one tick a second, but millions of years on Earth may go by between two ticks of your watch.

So if you measured the age of the universe, it would be like 3 weeks old. we'll something less than 13.8b years.

 

[uros]

No it doesn't. What we perceive as time I conceive as organized changes in perception archived by our brains. Physically it doesn't exist, its simply always present.

 

[russ_watters]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

No. Some of what you are saying is philosophical and endlessly debateable but the simplest way to answer is to simply say this:

Time is as real as length.

 

[SinghRP]

Thank you. I have been saying about the same thing: time is real, but ...

"The genesis of a time lies in an interaction." -- Singh

The brain and the mind: the former is the physical self, the latter is the
"result" of the interactions in the former. That's why personal time is very
personal and subjective. Medical science is finding out that different human
bodies work on different time runs. I have extended this concept of time to
systems (animate or inanimate).

I am sure you know that time periods of interactions change under the fundamental interactions.

 

[JDługosz]

Well, it's billable anyway.

 

[mrspeedybob]

Well, it's billable anyway.

And the fact that 10-15 hours or more can be billed during an 8 hour work day demonstrated that time is indeed a very flexible concept ;-)

 

[Pythagorean]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

If you have that opinion, than you should share it with space, too.

Things change, events do not occur at the same time, just like material does not occur in the same place (assuming classical particles). Space is the measurement of the distance between objects, time is the measurement of the elapse between events.

What you really mean to ask, I think, is "isn't time relative?" to which the answer is yes (Einstein) and so is space. The relativity community has a fundamental understanding of how it relates to motion.

 

[JAlderman_FL]

Protons and neutrons are nearly eternal, therefore, time is irrelevant to existence, though perhaps not to life.

 

[JDługosz]

A free neutron has a mean lifetime of 885.7 seconds or so.

 

[JAlderman_FL]

I'll be sure enough of mine stay dedicated to their job :)

 

[Lost Again]

Can there be a description of time without the inclusion of motion?

Lost Again

 

[Maui]

Can there be a description of time without the inclusion of motion?

No. But how does motion occur? Can there be motion of physical bodies in spacetime without reference to superpositions and subsequent measurements?

 

[Lost Again]

If you accept the concept that 2 things cannot be in the same place at the same time. How do you describe motion without the inclusion of time? There might be a connection?

lost Again

 

[dacruick]

No. But how does motion occur? Can there be motion of physical bodies in spacetime without reference to superpositions and subsequent measurements?

A measurement in nature is a comparison to something else. You can't measure anything without a reference point.

 

[Maui]

A measurement in nature is a comparison to something else. You can't measure anything without a reference point.

Yes, but how is this related to what i said? What is 'measurement in nature'?

 

[Maui]

If you accept the concept that 2 things cannot be in the same place at the same time. How do you describe motion without the inclusion of time? There might be a connection?

Every equation in physics that has a variable labelled time T is related to motion(via speed, distance, position or momentum). What would make you doubt their relationship?

 

[Dremmer]

If you have that opinion, than you should share it with space, too.

If time really relates to space, why does it behave so differently? Why does it only ever go in one direction?

 

[dacruick]

If time really relates to space, why does it behave so differently? Why does it only ever go in one direction?

isn't the universe always expanding in every direction? sounds like space moves the same way too...

 

[Maui]

If time really relates to space, why does it behave so differently? Why does it only ever go in one direction?

I take it the BB and the law of entropy isn't a satisfactory answer to you. If so, you are left with 2 options:

Because if it didn't, you wouldn't be here asking this question. Or altrnatively, you are free to believe it's part of some kind of scheme(design) in nature.

 

[Noja888]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

Space is Time demonstrated.
Time is Space demonstrated.

Action in space takes time. Action in time requires space.

How we choose to chop up time or space is a matter of metrics. I would guess Einstein understood this at a very deep level and was able to propagate the mathematics from it. I still wonder is space/time digital (segmented) or is it analog?

If you could get outside the confinement of space and time perhaps you could 'see' all moments and all space at once.

 

[ThomasT]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

Time is real. That's why it's so important "in theories and stuff".

How do you think about time? What do you think the word, time, refers to?

 

[qsa]

i was wondering why time gets mentioned so much in theories and stuff when there is nothing natural about time at all didnt we just make it up for are own use ? ( again sorry for the lame question and thanks for any comments )

http://arxiv.org/PS_cache/arxiv/pdf/1011/1011.0746v1.pdf


The formulation of quantum mechanics within the framework of entropic
dynamics includes several new elements. In this paper we concentrate
on one of them: the implications for the theory of time. Entropic
time is introduced as a book-keeping device to keep track of the accumulation
of changes. One new feature is that, unlike other concepts of
time appearing in the so-called fundamental laws of physics, entropic time
incorporates a natural distinction between past and future.


also julian barbour +time (google)

 

[qsa]

also my own idea

post #4, last sentence in #8

https://www.physicsforums.com/showthread.php?p=2694423#post2694423


Time is my next problem, as far as I could see, it looks easy. I shall derive it as a consequense of interactions.

 

[JAlderman_FL]

A measurement in nature is a comparison to something else. You can't measure anything without a reference point.

This. Energy = Time & Temperature. Matter is temperature's decorations on energy vacuums (see Dirac Sea). Time requires a reference point to be relevant for discussion.

 

[JDługosz]

This. Energy = Time & Temperature.

Or is it Time = Money ?

Matter is temperature's decorations on energy vacuums (see Dirac Sea). Time requires a reference point to be relevant for discussion.

Or maybe Time is just nature's way of preventing everything from occurring at once?

 

[Rasalhague]

Or maybe Time is just nature's way of preventing everything from occurring at once?

There's a fun passage in The Cloud of Unknowing a mystical tract from 14th century England where the author argues exactly that (with God in place of nature, of course):

https://www.physicsforums.com/showpost.php?p=2778899&postcount=16

 

[petm1]

How can you even discuss time when most of the people, each of which make up our common present, in the world think of it as not real. Time is a how we count intrinsic motion and it is a measure of duration the inverse of space in any direction. I must be crazy for thinking it is fundamental to our common reality because for most of the population it is a illusion and not real.

 

[JAlderman_FL]

Or maybe Time is just nature's way of preventing everything from occurring at once?

This is more in the arena of Consciousness. Depending on how succinct your discussion of time is, everything could quite literally be occurring at once. Your perception tells the tale, therefore occurrence seems more an issue of Consciousness.

 

[D N Wright]

Time does not exist - only the present configuration of the universe has ever and will ever exist. All else are human "records" that create the "emotion" of time.

 

[Evo]

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