What proof do we have that TIME exists?

[petm1]

What? The distance the photon travels is used to measure the time, the photon is not time itself. I can't follow the rest of your post as it doesn't make any sense to me. My personal view is simply that time is a measurement just like distance is.

Does a photon stand outside of time? You do not think it is a part of time? After all a photon is the smallest part of my present as far as I can see.

 

[Drakkith]

Does a photon stand outside of time? You do not think it is a part of time? After all a photon is the smallest part of my present as far as I can see.

I have no idea what you are trying to say.

 

[TheTechNoir]

As I said, this speaks more about us than it does about the reality of time. We don't experience the real world raw and unfiltered. We experience the world through the lens of our senses and the processing that goes on in our brains.

I am inclined to agree with this.

As for what Chalnoth was saying about a finite number of instances, you should read about quantization and consider that concept.

 

[Homesick345]

I am inclined to agree with this.

As for what Chalnoth was saying about a finite number of instances, you should read about quantization and consider that concept.

Brilliant I would never have hoped to get such depth and insight from all the guys thanks people!

 

[TheTechNoir]

I found myself wondering the same thing long before I took an interest in reading about/learning about physics as well. The idea of length or time occurring in discreet packets never really crossed my mind as a solution but when I started learning about physics and learned of this concept it appealed to me because it put the pieces together in my head and resolved my puzzlement.

I later found out that the question was long ago posed (albeit in a more thought out and encompassing manner) as a paradox, or series of paradox' called Zeno's Paradox. You may find some of this article relates to what you were asking http://en.wikipedia.org/wiki/Zeno's_paradoxes (note: you may find some of the philosophical talk to be rubbish)EDIT: I should probably be careful here not to derail this into the realm of philosophy - that isn't my intention. The scientific answers are being/have been provided in this thread. I am just as an afterthought thinking/wondering if this concept is what you had in mind as what was puzzling you.

 

[Homesick345]

I found myself wondering the same thing long before I took an interest in reading about/learning about physics as well. The idea of length or time occurring in discreet packets never really crossed my mind as a solution but when I started learning about physics and learned of this concept it appealed to me because it put the pieces together in my head and resolved my puzzlement.

I later found out that the question was long ago posed (albeit in a more thought out and encompassing manner) as a paradox, or series of paradox' called Zeno's Paradox. You may find some of this article relates to what you were asking http://en.wikipedia.org/wiki/Zeno's_paradoxes (note: you may find some of the philosophical talk to be rubbish)

I was just looking the Zeno paradoxes yesterday! Of course it's the same line of thinking. ...in all humility, I see time a more complex and puzzling thing than matter. I know about the famous Einstein quote, time is what you measure with a clock...to a trained brilliant physicist, of course this would be easy to grasp , time as an experimental concept. All in all it is such an elusive and dizzying concept, this time thing...

 

[alt]

Not at all!

The main point here is that we don't trust our perceptions, or even our thought process. We check them against others. Others are unlikely to fall for the same errors in the same way, and even when they are due to various cognitive biases, there are generally many different ways to test a given scientific model, and those different ways of testing the same model are highly unlikely to be susceptible to our cognitive biases in the same way.

To say it another way, science is a way of answering the question, "How can we learn what's true without being able to trust ourselves?" Independent verification provides that.

I wasn't really arguing against this.

I don't go by personal experience. I go by evidence.

I was asking you for your personal view on what the present momnet is - it's duration, how you conceive it, etc. But if you have none, or care not to render one, that's OK

The evidence to date is that the best description we currently have for the description of time lies in General Relativity. And GR has a number of interesting features which upset our typical colloquial notions of time. One of the most critical is that there is no such thing as a global "now" in General Relativity. That is to say, different observers will generally disagree as to which far-away events occur simultaneously.

While it may seem weird or trivial, this is a truly profound insight. The lack of a global now means, necessarily, that the past and future have the exact same existence as the present. And that is profoundly strange, given our colloquial notions. We are not a set of beings traveling in time, for example: we exist at all times. If we were able to somehow step outside of our space-time and observe the whole of our space-time from the outside, we would see both our past and future selves.

There is nothing terribly new in these concepts though. Many ancient texts have considered them. Even Augustine, in his 'Confesssions' struggled very deeply with them. And may I add, said 'Confessions' (absent of all the "If it please thee Lord", etc), is as as excellent a treatise of the concept of time, as I have come across.

The only thing that gives the illusion of the flow of time is our cognitive processes. Specifically, our brains process information about our surroundings in a time-ordered fashion, and store memories in a time-ordered fashion. So that when we perceive the world, everything appears strongly time-ordered, when in reality this ordering is simply a feature of our cognitive processes, which in turn have a strict time ordering due to the nature of entropy (which tends to increase with time).

So if this ordering is simply a feature of our cognitive processes, is it suggested that the reality is that of one, eternal now ? In truth, I'm not sure what you are saying .. what your conclusion is, in this above paragraph.

 

[Chalnoth]

I later found out that the question was long ago posed (albeit in a more thought out and encompassing manner) as a paradox, or series of paradox' called Zeno's Paradox. You may find some of this article relates to what you were asking http://en.wikipedia.org/wiki/Zeno's_paradoxes (note: you may find some of the philosophical talk to be rubbish)

Zeno's paradox doesn't really have anything to do with the nature of time. It has to do with the fact that when you use the wrong coordinate system for a given application, you get strange results. The problem arises in Zeno's paradox because you've created an artificial infinity at distance=1 (or time=0, depending on the paradox). The infinity has nothing to do with reality, it's just due to the numbers we are using to describe reality.

These sorts of situations are very common in General Relativity. In fact, for most space-times, it is impossible to describe the entire space-time with only one coordinate system and still have things well-behaved everywhere. A simple example is the surface of a sphere, like the Earth. With the Earth, we usually like to use a simple coordinate system containing longitude and latitude. But the longitude/latitude coordinates have a problem: at the north and south poles, many different longitudes correspond to the exact same point (the pole). The fact that many points in our coordinate system map onto just one point on in the real world causes infinities for some calculations, leading to nonsensical results (you might conclude, for example, that the gravitational attraction at the poles was infinite!).

So Zeno's paradox is an artificial paradox: it only exists because we've used a particular set of numbers to describe the real world, and then tried to use those numbers beyond infinity. That is a nonsensical thing to do.

 

[sahmgeek]

The only thing that gives the illusion of the flow of time is our cognitive processes. Specifically, our brains process information about our surroundings in a time-ordered fashion, and store memories in a time-ordered fashion. So that when we perceive the world, everything appears strongly time-ordered, when in reality this ordering is simply a feature of our cognitive processes, which in turn have a strict time ordering due to the nature of entropy (which tends to increase with time).

I would also be interested in hearing further clarification on this perspective.

Let me change your language a bit and see what happens:
Specifically, our brains process information about our surroundings at input (i.e. when observation takes place) and that input occurs at EVERY present moment. Is that time-ordered processing?

Also, are you suggesting that the "perceived world" is not orderly independent of observation?

What I'm hinting at here is the combined use of "time" and "ordered" could be misleading. For instance, the world may be orderly independent of observation, but "flow of time" could still just be a function of cognitive processes. does that make sense? it is not my intention to confuse or complicate, but just to get at the heart of the matter.

sidenote: whether or not memories are stored in a time-ordered fashion is debatable, i think. i would have to dig, but recall research suggesting that memory can be unreliable b/c, with time, they can become "entangled", shall we say ;).

 

[sahmgeek]

Also, are you suggesting that the "perceived world" is not orderly independent of observation?

If I understand QM correctly (which i may not!), this is kind of what it says, right? I was just wondering if that was your contention as well?

 

[Chalnoth]

I would also be interested in hearing further clarification on this perspective.

Let me change your language a bit and see what happens:
Specifically, our brains process information about our surroundings at input (i.e. when observation takes place) and that input occurs at EVERY present moment. Is that time-ordered processing?

Well, the time ordering comes in due to the nature of entropy. Entropy fixes a set arrow of time, makes it so that things in the future depend upon things in the past. The appearance of time ordering that we interpret is a feature of this effect occurring within our brains, of this inexorable rise of entropy. It isn't the only thing that does this, however.

Also, are you suggesting that the "perceived world" is not orderly independent of observation?

No, not at all. What I am saying is that by virtue of how our brains work, we observe the world from a fixed perspective. That perspective is not, however, the only way to describe the behavior of the universe that surrounds us. We are starting to obtain inklings of just how different the universe can appear from different perspectives with our studies of General Relativity and Quantum Mechanics.

Holography in particular is a fascinating subject, where the physical behavior of one system in, for example, two dimensions is mathematically identical to the physical behavior of a different system in three dimensions. This means that for this system, whether we think of it as a two-dimensional system or a three-dimensional system depends entirely upon our perspective. And that is mindbogglingly weird.

sidenote: whether or not memories are stored in a time-ordered fashion is debatable, i think. i would have to dig, but recall research suggesting that memory can be unreliable b/c, with time, they can become "entangled", shall we say ;).

What I mean is that the order in which they are stored is ordered by time. Memories are, of course, distributed all across the brain, are not accessed in anything remotely related to time ordering, and are modified every time they are accessed. I was merely referring to the way in which they are originally stored.

 

[Mark M]

Think of Planck's time, we use a photon to measure it but is time the photon? Is time the length of the photons motion in one dimension? I liken time to the duration of the photon's motion not as one dimensional like the photon but as a dilating three dimensional sphere with the photon used as the radius, making time the dilating area that gives the photon's its direction in space.

It really isn't that trivial - time can be defined as T=\frac{D}{S}. At times less than the Planck Time, no distance is traveled by anything. Hence, T=0. No time has passed. So, we can quantize time into units of Planck Time.

 

[sahmgeek]

Holography in particular is a fascinating subject, where the physical behavior of one system in, for example, two dimensions is mathematically identical to the physical behavior of a different system in three dimensions. This means that for this system, whether we think of it as a two-dimensional system or a three-dimensional system depends entirely upon our perspective. And that is mindbogglingly weird.

Indeed, it is all fascinating and mindbogglingly weird! I suppose that is why I find myself here discussing it (in an orderly fashion, at ever present moments...)

 

[sahmgeek]

btw Homesick, if you don't already have it, Scientific American's "A Matter of Time" special edition had some really thought-provoking articles. http://www.scientificamerican.com/special/toc.cfm?issueid=40&sc=singletopic

 

[Tanelorn]

Is time not a physical characteristic of our Universe and our reality?
Time is also a relative measurement separating two events.

 

[petm1]

It really isn't that trivial - time can be defined as T=DS. At times less than the Planck Time, no distance is traveled by anything. Hence, T=0. No time has passed. So, we can quantize time into units of Planck Time.

Time is how we count existence; a clock can only count its own existence as a clock. A photon may not change in time as it moves in space, other than red shift, but its duration of existence always matches the length in space that it has traveled. Motion may not be measured at Planck's time but we should still have existence at that scale. Time is the smallest and largest common denominator of existence, everything that exists does so as its own part of our temporal universe, otherwise we would not be able to describe the anything as a four dimensional object.

 

[sahmgeek]

Is time not a physical characteristic of our Universe and our reality?

Can you flesh that out a little more?

 

[SHISHKABOB]

The above and your further comments in a later post about time having infinite speed.

I'm not sure what you're getting at. I just walked past my desk - it has an infinite number of points on it, yet I walked past them in about one second - not t infinite speed.

I've only taken a class called contemporary physics that touched on quantum mechanics for just a portion of the quarter, but my understanding of it drew me to the conclusion that space was quantized. Or at least that's what I got out of the class. The idea that space is not infinitely divisible.

Therefore, unless this conception is erroneous, then walking past your desk *in reality* is not a matter of walking past something with an infinite set of points on it, but rather walking past something with a finite number of points.

If you take a line, and consider each and every single one of the infinite points on it as you move along it, wouldn't you never get anywhere?

 

[Drakkith]

I've only taken a class called contemporary physics that touched on quantum mechanics for just a portion of the quarter, but my understanding of it drew me to the conclusion that space was quantized. Or at least that's what I got out of the class. The idea that space is not infinitely divisible.

Therefore, unless this conception is erroneous, then walking past your desk *in reality* is not a matter of walking past something with an infinite set of points on it, but rather walking past something with a finite number of points.

If you take a line, and consider each and every single one of the infinite points on it as you move along it, wouldn't you never get anywhere?

Sure you would, as each point would be visited for an infinitely short amount of time. Or something like that.

 

[SHISHKABOB]

Sure you would, as each point would be visited for an infinitely short amount of time. Or something like that.

but... if it's infinite... then, each one gets an infinitely short amount of time but then what is 1/∞ times infinity and... ouch there goes my brain

I don't think 1/∞ makes sense anyways

 

[Chalnoth]

Being able to infinitely divide space merely means that dividing space is the wrong way to describe motion.

 

[alt]

I've only taken a class called contemporary physics that touched on quantum mechanics for just a portion of the quarter, but my understanding of it drew me to the conclusion that space was quantized. Or at least that's what I got out of the class. The idea that space is not infinitely divisible.

Therefore, unless this conception is erroneous, then walking past your desk *in reality* is not a matter of walking past something with an infinite set of points on it, but rather walking past something with a finite number of points.

If you take a line, and consider each and every single one of the infinite points on it as you move along it, wouldn't you never get anywhere?

I don't know whether space (or time for that matter) is quantized.

In post #18, a contributor said;
Super weird indeed. Moreover, if time exists, & it passes linearly, it should have an infinite speed, since it passes continuously..Time is weirder than existence itself

My comments which you addressed in the above, were simply to respond to that. But in any event, I'd always thought that a point is dimensionless - and that there are an infinite number of points in a line, as there are an infinite number of lines in a plane, as there are infinite planes in a solid. That's what I was getting at when I used my 'desk' example.

Regarding your last paragraph, this seems to me, a rephrasing of Zeno's Achilles and the tortoise paradox, which has been discussed here earlier.

Zeno's flying arrow paradox - now that's another thing. That one's really got me stumped, because imo, it goes to the heart of what is the present moment / instant in time. And that's a point I've been trying to explore for some time, but haven't gotten far.

 

[Homesick345]

I don't know whether space (or time for that matter) is quantized.

In post #18, a contributor said;
Super weird indeed. Moreover, if time exists, & it passes linearly, it should have an infinite speed, since it passes continuously..Time is weirder than existence itself

My comments which you addressed in the aove, were simply to respond to that. But in any event, I'd always thought that a point is dimensionless - and that there are an infinite number of points, in a line, as there are an infinite number of lines in a plane, as there are infinite planes in a solid. That's what I was getting at when I used my 'desk' example.

Regarding your last paragraph, this seems to me, a rephrasing of Zeno's Achilles and the tortoise paradox, which has been discussed here earlier.

Zeno's flying arrow paradox - now that's another thing. That one's really got me stumped, because imo, it goes to the heart of what the present moment, or an instant in time is. And that's a point I've been trying to explore for some time, but haven't gotten far.

MAYBE our existence, material universe, is finite & quantized, discrete, etc... And MAYBE our intellect or thinking is infinite, or at the very least - & this is even weirder - has a grasp of infinity, for some weird reason.

 

[petm1]

Super weird indeed. Moreover, if time exists, & it passes linearly, it should have an infinite speed, since it passes continuously..Time is weirder than existence itself

Time as measured with a photon has the speed of light tied to it thereby leaving no gaps in our view of reality.

 

[Drakkith]

MAYBE our existence, material universe, is finite & quantized, discrete, etc... And MAYBE our intellect or thinking is infinite, or at the very least - & this is even weirder - has a grasp of infinity, for some weird reason.

Or maybe a clock is just like a ruler but for time, and time is as finite or infinite as space is.

Time as measured with a photon has the speed of light tied to it thereby leaving no gaps in our view of reality.

Are you suggesting that time measured by something other than a photon has gaps in it?

 

[Chalnoth]

Zeno's flying arrow paradox - now that's another thing. That one's really got me stumped, because imo, it goes to the heart of what is the present moment / instant in time. And that's a point I've been trying to explore for some time, but haven't gotten far.

This so-called paradox is trivially shown to not apply to reality based upon one simple fact:
We can measure how fast something is going by observing it at one instant in time.

One way to do this, for example, is if there is a mirror on the object. If we bounce a single photon off of this mirror, that photon will be redshifted/blueshifted based upon how fast that mirror is moving away/towards us.

In a world where objects have both momentum and position, Zeno's flying arrow paradox makes no sense. It is clearly just the wrong way to think of the way the world works.

 

[Tanelorn]

Can you flesh that out a little more?

I was just suggesting that what we call time, and the continuous passage or flow of time, seems very much to be a physical property and characteristic of the way our Universe and our reality works. Without time, cause and effect would not work, because everything would happen at the same moment.

The passage of time acts relentlessly on matter and moves continously onward on matter through out all of space.
Accelerating to the speed of light slows down the passage of time to stationary observers.

I am mainly saying that time is not just an abstract measurement made with a timepiece.

 

[sahmgeek]

Actually, Zeno's flying arrow paradox makes perfect sense IF time and space are one and the same (i.e. if the true nature of time is another way of measuring things in space). I personally think this is a great candidate for the essence of "time".

 

[Chalnoth]

Actually, Zeno's flying arrow paradox makes perfect sense IF time and space are one and the same (i.e. if the true nature of time is another way of measuring things in space). I personally think this is a great candidate for the essence of "time".

Except they aren't the same. They are similar, but not the same.

Regardless, I don't see why you think this makes a difference.

 

[sahmgeek]

Except they aren't the same. They are similar, but not the same.

true. maybe i should have said:

time = a measurement of different locations in quantized space, where the 2nd law of thermodynamics is fundamental, as experienced by a single observer.

 

[Drakkith]

true. maybe i should have said:

time = a measurement of different locations in quantized space, where the 2nd law of thermodynamics is fundamental, as experienced by a single observer.

What? Time is not a measurement of space. We can use the distance that something travels, such as light, as a tool to measure time, but time itself is not a measurement of space.

 

[Chalnoth]

true. maybe i should have said:

time = a measurement of different locations in quantized space, where the 2nd law of thermodynamics is fundamental, as experienced by a single observer.

I do not see how this helps. Time, though very similar, does not behave like space.

 

[Tanelorn]

One way in which time and distance in space are somewhat related is that due to the way the Universe works, with a finite speed of light, the more distant an object is, the further back in time we also are looking.
It is very useful for understanding how the Universe evolved, because we believe the Universe to be similar everywhere, but it prevents us from seeing the Universe everywhere as it is today.

 

[petm1]

Are you suggesting that time measured by something other than a photon has gaps in it?

No, I think that the sea of photons we see as space fills the gaps in time very well.

 

[Drakkith]

No, I think that the sea of photons we see as space fills the gaps in time very well.

I'm sorry this doesn't make sense to me. What "sea of photons" are you referring to, how are they space, and how does this involve time?

 

[junjunjun233]

Maybe time don't exist at all. Its a perception of movements/change/transformation and so on (Point A-B-C-D-E etc). Since at quantum level, particle vibrate and eventually moves unless absolute zero movement is achieved, yet or never.

Actually in a sense we don't experience time. We experience changes and movements that we perceived as time and exist as observation.

 

[Drakkith]

Maybe time don't exist at all. Its a perception of movements/change/transformation and so on (Point A-B-C-D-E etc). Since at quantum level, particle vibrate and eventually moves unless absolute zero movement is achieved, yet or never.

Except that the movements/changes/transformations don't all occur at once. They take time.

Actually in a sense we don't experience time. We experience changes and movements that we perceived as time and exist as observation.

We measure time through change and movement but this does not mean we do not experience it.

 

[sahmgeek]

Except that the movements/changes/transformations don't all occur at once. They take time.

We measure time through change and movement but this does not mean we do not experience it.

What would that be like, to experience everything all at once? Wouldn't you experience something static? Would you actually experience anything at all? It's interesting to think about.

It seems to me that time is very deeply embedded in the experience of changes through space, from micro to macro.

 

[sahmgeek]

think about when you're watching a movie and they "stop time". what happens? all of the movement and change stops. almost as if they are one and the same. i certainly don't know if they are, but gosh...

 

[Homesick345]

Time as our psychological interpretation of events, whether they occur sequentially or all at once. Could time be our mind's way to arrange things, regardless of how they exist or occur really?

 

[SHISHKABOB]

Time as our psychological interpretation of events, whether they occur sequentially or all at once. Could time be our mind's way to arrange things, regardless of how they exist or occur really?

are you suggesting that things that are observed to happen in one order could "really" happen in some other order? What would "really" be "reality" in that case?

 

[junjunjun233]

Except that the movements/changes/transformations don't all occur at once. They take time.

We measure time through change and movement but this does not mean we do not experience it.

Take away the concept of time and all we have are observations that are stored in our memory projected as experiences. We still don't have the technology to reached an absolute based starting point for time on a micro level. Well, we do have quantum clock (aluminum ion) near to a zero point precision but unless we can narrow it down to zero vibration state. And it is unlikely to find zero resistant particle.

A bit fuzzy. but i don't consider the existence of time because it is always relative to the movement, mass and state we are in. We can only measure that state and called it time.

Experience is how the brain perceived of the leaps from one state to another and eventually stored as information in the brain as memory.

 

[Homesick345]

are you suggesting that things that are observed to happen in one order could "really" happen in some other order? What would "really" be "reality" in that case?

Excellent point.

 

[Drakkith]

Take away the concept of time and all we have are observations that are stored in our memory projected as experiences. We still don't have the technology to reached an absolute based starting point for time on a micro level. Well, we do have quantum clock (aluminum ion) near to a zero point precision but unless we can narrow it down to zero vibration state. And it is unlikely to find zero resistant particle.

Define an "absolute based starting point for time" and "zero resistant particle".

A bit fuzzy. but i don't consider the existence of time because it is always relative to the movement, mass and state we are in. We can only measure that state and called it time.

The existence of time is the only way two objects can occupy the same points in space. They do it at different times.

Experience is how the brain perceived of the leaps from one state to another and eventually stored as information in the brain as memory.

I don't see how this is related to time in any way. Whether we are here to experience it or not the universe has time.

 

[junjunjun233]

Define an "absolute based starting point for time" and "zero resistant particle".


The existence of time is the only way two objects can occupy the same points in space. They do it at different times.



I don't see how this is related to time in any way. Whether we are here to experience it or not the universe has time.

Zero point energy in a vacuum. And maybe it has to do with the uncertainty principle of quantum mechanics that particles can't be stop completely. However, some behavior of specific particles interactions came close such as bosons given even number of electrons,protons and neutrons. When subjected to low temperature, bosons become a Bose-einstein condensate, in which a ground state occurs and the closest you can get to stopping their motion. However, there is always a fermion in each quantum state and obeys pauli excl principle that instead of going through a ground state, they fill all the lowest states in the system. Perhaps "Time" doesn't exist as objective but subjective. I might be wrong. Ill remain agnostic about it.

 

[tanzanos]

Without time matter cannot exist. Time is movement and not what you observe on the dials of a watch. After all was not time born with the big bang?

 

[Drakkith]

Zero point energy in a vacuum. And maybe it has to do with the uncertainty principle of quantum mechanics that particles can't be stop completely. However, some behavior of specific particles interactions came close such as bosons given even number of electrons,protons and neutrons. When subjected to low temperature, bosons become a Bose-einstein condensate, in which a ground state occurs and the closest you can get to stopping their motion. However, there is always a fermion in each quantum state and obeys pauli excl principle that instead of going through a ground state, they fill all the lowest states in the system. Perhaps "Time" doesn't exist as objective but subjective. I might be wrong. Ill remain agnostic about it.

I have no idea what you are trying to say here.

 

[junjunjun233]

I have no idea what you are trying to say here.

It simply means that time might not exist, just entropy. Or Time is the cause for entropy.

Motion replaces time and time no longer exist. We live in motion not time.

 

[Drakkith]

It simply means that time might not exist, just entropy. Or Time is the cause for entropy.

Motion replaces time and time no longer exist. We live in motion not time.

How do you have motion without time?

 

[Chalnoth]

It simply means that time might not exist, just entropy. Or Time is the cause for entropy.

Motion replaces time and time no longer exist. We live in motion not time.

This doesn't make any sense at all to me.