# Philosophical view of time

1. Oct 29, 2003

### orgmark

I suppose this would be a philosophical view
of time...

Time is a dimension of matter as opposed to a
changing or flowing entity. Nothing can exist
outside of the present in real terms, which
encompasses the immediate sum of existence and
is always now. As time does not flow or change,
however, concepts such as past and future
events do not exist. In abstract logic only,
the past has had an effect on the present which
in turn creates future probabilities. What the
observer sees as the flow of time is really
only a change in position relative to some
other change in position.

As a dimension, however, the present by
definition can be represented as a range of
possible values. The apparent contradiction of
an existence with no past or future is the fact
that an object moving near the speed of light
ages at a slower rate when compared to a
stationary object. Another rationalization of
this effect is that the time dimensional value
of each object can be influenced by their
respective velocities. Take an example of two
stationary objects in close proximity. At this
point, each may have an equivalent time
dimensional value equal to some arbitrary number.
Apply the argument above and the faster object
will begin to age at a slower rate. As the
present has no single value, however, what is
occurring is not time travel as described above
but rather the divergence of each object’s time
dimensional value. As the two objects return
to close proximity, each again appears to
an observer to be in the present although
with noticeable differences, proof of a range
of possible time dimensional values. This
concept is analogous to altering the length of a
steel rod by changing its temperature.

The connectivity of matter is revealed in this
dimensional view of time. There is little
difference between establishing a standard of
length which can be applied anywhere in the
universe and an object's time dimensional
value. In other words, events occurring at
separate locations are inexorably linked by the
immediate present, just as the length of two
rods may be certainly equivalent. An explanation
of why matter can neither exceed the speed of
light nor cease all movement could be this aspect
of matter.

Accelerating an object past the speed of light,
however, may be no different than heating the
steel rod past its melting point. Time travel
may in fact be no more than a change in state
much like this example.

2. Nov 3, 2003

### Philosophysics

Interesting points, like the style.

I personally belive that there are six dimentions of time but that's another story...

I just wanted to say something that might get your head in gear coz you obviously have similar thought patterns to me.

Time in a sense is timeless- one structure is measured time. But consider this... if time is a perpetual moment that space travels through then time changes as we age. IE we could look to the sky as a 7 year old child for ten seconds then when we were 49 we would have to look up for 70 seconds to gain the same intensity of experience because the moment we live in becomes less of a percentage of our lives as we age. Full moons come round quicker then birthdays then one day you're old. Time does not speed up but the moment becomes shorter for us.
What do you think? Thought this notion of mine struck a chord with your light speed idea...

3. Nov 4, 2003

### orgmark

I agree. As our perception of time is
governed by how our brains process
information it must follow that this
sense is affected by a person's age.

4. Nov 9, 2003

### Mike2

The future is filled with many possible outcomes, an open samples space, if you like. But the past is completely determined. We know exactly what events lead to other events in the past. But we do not know what the future will hold, only what it may hold. Therefore, time seems to be the process of selecting which samples to include in events. In quantum mechanical terms, time is what collapses the wave function into a particular choice of all the possibilities.

-----------------------
Logical consistency is the ultimate thought experiment.

5. Nov 15, 2003

### drag

Greetings !

Hmm... A past, a present and a future ?
Sorry to dissapoint you folks, but there are no such
things. The same way an electron is nothing but a cloud
of probabilities in space it is that same cloud in time.
While our brains may percieve it differently there is
no actual order of this kind in the Universe.

An intresting example is Steven Weinberg's (if I'm not
mistaken 'cause I read it a while back in SciAm, I think)
discription of a theoretical experiment: A photon leaves
a distant galaxy billions of light-years away. Due
to gravitational lensing the WF of the photon that "reaches"
the Earth is split in two. Now, by trying to detect the photon
in even just one of these directions we will collapse the
WF and decide about the path it travelled for billions
of years. However, if we repeat the double slit experiment
we'll recieve the "good old" diffraction pattern.

Yeah, I know, the world never makes sense...

Live long and prosper.

6. Dec 23, 2003

### Yahweh

Past, present, and future dont exist?

Althought I have a very strong Philosophical muscle, what you said, I'm not sure if I understand it properly.

I think you mean "past, present, and future" dont exist concretely in reality, instead they are just words to reference the passing of one event to another in relation to their chronology.

It what I just said was an actual coherent sentence, then I would tend to agree. However, I'm still a little fuzzy to what you actually mean. Did I describe what you were implying correctly, if not could you detail what you mean futher?

(Sorry, I actually registered for these boards to get a better handle on Physics. While I do have a very knowledgable understanding of Physics, it isnt comparable to my take on Philosophy... what I'm trying to get at is: I have no idea what you are talking about when you detailed Steven Weinberg's theoretical experiment... )

7. Dec 28, 2003

### Sikz

"Past", "present", and "future" don't exist. Isn't it interesting that "exist" is a word in the "present" tense? Of course "past" and "future" can't presently exist! That would defeat the entire notion of "past" and "future".

Of course, the present CAN'T exist. If the present was any larger than a geometric point it would have finite size and thus objects would take TIME to traverse it. But since it is the present, with no elements of past or future, there can be no traversing, no movement- and thus there would be no time. The present must be a geometric point. A geometric point does not exist, it is like the border between two countries- the countries actually touch directly, there is no line between them.

So if the present doesn't exist, that leaves us with past and future. Hmmm but wait, "exist" is a word in the present-tense. Normally this wouldn't matter, since in most contexts "present" is only an approximation. However, we are discussing the nature of time itself, so it is VERY important. How can we question whether things "exist" when the entire concept of "existance" is built upon a faulty foundation, namely the present?

Another interesting question... What actually is the present? We say "What we percieve as the present is actually slightly in the past, since light and sound and all other forms of sensory input take slight amounts of time to reach us and be processed by our brains.". So we can't use our perception as the present. So now I ask the obvious next question: what is the present?! Any sensory information takes a different amount of time to reach us and be processed with a different distance from us, so there is no concrete "present" we can refer to as when all of these inputs occur.

Einstein already said this (although he came to the conclusion through a slightly differnet method than I did...). He said that time is relative, there is no absolute time. So our perception of the present is as valid as any.

In any case, just some interesting ideas. Any comments?

8. Dec 28, 2003

### Jimmy

My thoughts about time are influenced by science. I don't see time as something that flows. I see it as a direction in which we are always moving. In special relativity, an inertial frame is defined as a frame with a constant velocity. No matter how fast you are moving with respect to something else, you can always consider yourself and objects moving with you to be at rest. You still have a motion in time, however. Some one moving with a different velocity will measure your motion in time differently but you will notice no difference. You will see your clock running at the same rate.

I'm am also of the belief, I am not certain of this, that past and future do not exist physically. We have memory of the past and expectations of the future based on past experience.

That's a very good point.

When I think of time, I compare it with riding in the back seat of a car looking out the rear window. We don't see what's ahead, only what's behind us. The farther we look out, the farther we see into the past. The present must be centered on you. However, as you point out, processes in the brain happen during a finite interval of time so the present may not be something that we can actually experience.

I stated before that I do not believe the past or future exist. That leaves only the present which I believe exists somewhere within us.

I struggle with the idea of physical time. Does physical time exist in the form a dimension like space or is it purely abstract?

For me, Special Relativity doesn't prove the existence of physical time, but the experimental tests of it's predictions are suggestive. When studying SR, I can't help but visualize time as part of the geometry of the universe.

Anyone who is interested in SR, Relativity Visualized by Lewis Carroll Epstein is an excellent book for the lay person.

In special relativity, one second of time is equivalent to the distance that light travels in that one second. That is 300,000 km/s. In fact, the invariant interval equation which is used to determine the space-time distance between two events converts time into equivalent units of distance. This is done my multiplying time by the speed of light.

$$i = \sqrt{dt^2c^2-dx^2-dy^2-dz^2}$$

This equation will yield the interval between two events. It is invariant because it does not matter how the observer is moving with respect to those events. Different observers may measure different distances and times but the interval will always be the same when both separation in time and space are taken together.

When I think of the possible geometry of time, I do not see it as an absolute direction within space-time. Consider a space-time diagram of an object's motion. Let time be the vertical axis and space the horizontal. An object(A) at rest will just move up the time axis. Another object(b) which is moving with respect to the rest frame will be moving at an angle. It will have motion along both the time and space axes. It will seem to move faster in space and slower in time. Now from the point of view of object B, object A is in motion and B considers himself at rest. They are moving in different directions but each considers their motion as purely temporal. This suggests that there is no physical difference between time and space. Space-time is a four dimensional continuum with no absolute direction of time. The only thing that differentiates time from space is our orientation within space-time. I consider time a property of matter. It's analogous to the direction forward. We can both walk together in the forward direction. I can decide, however, to walk in a different direction but still be walking forward. Our forward directions are different.

As I stated above, within the context of relativity, 1 second of time is equivalent to 300,000 m/s. It seems that we have a constant speed in time much like light has a constant speed in space. Lewis Carroll Epstein mentions in his book that all matter moves in time at C. We can move in different directions in space-time which will be observed as different speeds and/or directions in space, but is constant from a four dimensional perspective.

Now I've heard it stated many times that from the perspective of a photon, space is contracted to 0 distance in the direction it is traveling. I can assume there is really no evidence for this but lets consider it. A photon is also considered to be timeless. It has a purely spatial motion. Matter, on the other hand, has a purely time-like motion. Maybe the distance in time is contracted to 0 like space is to a photon. Perhaps this is why the past and future does not exist.

Lewis Carroll Epstein also suggest that maybe the reason we can't go faster than c is because we can't go slower than c. Some will think that moving at c violates relativity but that restriction is on an object's spatial velocity. I'm talking about motion in space-time.

I'm not stating that any of this is necessarily true. I don't know if time is physical. Just offering up ideas for discussion.

Last edited: Dec 28, 2003
9. Dec 28, 2003

### Yahweh

What is the present? Its just a word which means "between the past the future".

Something to keep in mind, time is a relative concept (WOW!). Just like there is no absolute North but instead a "North of...", there is no absolute Past but instead an "Earlier than..." (or "Simultaneous with", etc.).

10. Jan 9, 2004

### albrock06

I don't exactly agree with the 'There is no "past" "future" or "present"' thing.

However, I do believe that there is no 'tomorrow.' There is no 'yesterday.' Yesterday was called 'today.' And tomorrow will be called 'today.'
When we get there.

But how to we get there? It won't be now. But in a few seconds, it will be 'now' again. So I see how there can be no 'past' or 'future.' Then wouldn't everything be present?
If yesterday WAS called 'today,' we named it such in the past. If we WILL call tomorrow 'today,' we will name it such in the future. But of course, those times were once called 'now' and 'present' as well.

I think of time like I think of distance. The speed at which you GET TO tomorrow isn't the same as your neighbor. And the attitude which you think about it won't be the same either.

No matter how many people post to this, you'll get a different answer every time. You can never really expect what's coming from another human brain. We're all different. Just like time. What if you're living now ... but in a few minutes someone else is living that same now?

Alright. So maybe none of that makes sense. I'm no science professor. I'm no phiosophy major. I'm just your average teen-aged girl trying to use my voice once in a while.

11. Jan 9, 2004

### Dezepar

Without quoting your entire post.... Absolutely fascinating Jimmy. A statement like this
is liable to sell a book. I assume I can get it at any bookstore? Also, the idea that 'humans' experience a sensory input and processing 'lag time' makes sense of the notion of not quite existing in the present. No doubt that judging the present from a quantum reality, we're more than likely way out of sync with it.

12. Jan 9, 2004

### Jimmy

13. Jan 10, 2004

### marcus

compliments to orgmark for starting this thread which is one of the more interesting I've seen in a while.
Rovelli says it doesnt look like people will be be able to merge General Relativity with quantum physics without re-thinking at a fundamental level about time and space.
He says his new book "Quantum Gravity" is as much about time as it is about gravity. (This is a quote from page 267 in the "Conclusions" section at the end----in a part called "Space, time and unitarity".)

There is a section near the beginning called "Meanings of Time"
where he points out that even in different areas of physics people use different notions of time---what time means depends on the context and he distinguishes about ten different ideas of time. Maybe there's no one right idea of time.
For example in some branches of physics time has no preferred direction and in others it does---and in some versions of time there is an idea of the present moment and others not. That is around page 58.

The book will be published by Cambridge U. P., but there is a draft PDF version you can download at Rovelli's homepage. (just google with the name rovelli, get his homepage, and scroll down to the link).
I dont necessarily recommend the book to everyone or promise you will like it. But I do believe that it is the first real book on quantizing General Relativity that has ever been written and that quantizing GR is a necessary major historical step that will inevitably cause us to change how we understand space and time.

Rovelli doesnt try to make it hard. He uses lots of concrete examples and tries to make the exposition as clear and conceptual as he can. But it is a difficult subject with some fundamentally new ideas one has to stretch to accomodate.

Last edited: Jan 10, 2004
14. Mar 3, 2004

### shevechron

after I read your ideas I get the feeling it all ends in understanding what the present is.Physics gives no credit to the present and as a human I think the present is the only thing we have. What I think of is that the present can't only be considered as a point. This idea stems from the paper of " H. A. C. Dobbs, "The Relation between the Time of Psychology and the Time of Physics,British J. for the Philosophy of Science, 2, August 1951: 137-41" In this paper another time dimension is put forward denoting the specious present(a term of psychology). Could it be that the present is more than just a point?