How do you define Time?

it's a brand new 'co-ordinate'tion challenge!

I had not read Flatland (ref post 793757). I have now read some of it.
One thing that came to mind (excuse me if this is included in the text and I have not read it yet) is that the square in flat land may well have better perceived the sphere from spaceland if he had used time.
As Sphere passed through flatland he appeared as a point that became a circle and grew in size then shrank back down to a point that disappeared. Squares inability to see the hole sphere would make it impossible for him to compered the sphere. The only way square can comprehend the whole sphere in one go is to remember the apparent change in shape of sphere over time. Square would call the 3rd dimension time but sphere would see it as a spatial dimension.

Asherman, You apear to have ignored the possibility that the universe is shaped as I described it to be, and therefore is finite without boundaries. Dose this simple not fit into the way you see the universe to be?


To me if there are boundaries then something exists outside of them, therefore making the universe or its container infinite. The only way to remove infinity is to have a universe which is finite and without boundaries, like the shapes I have described above.
If time is a string of events then what caused time to start? This doesn't make sense to me. But if time is viewed as a dimension with shape as described then to ask what happened before time stared is as irrelevant as asking what is north of the north pole. The big bang is nothing more than a point in space where part of all items in the universe are located.
In a 2 dimensional universe shaped like the surface of the earth a being may well not be capable of viewing the lines of longitude in there entirety. The only way this being may be capable of seeing these lines would be to view them one part at a time and create the lines as a passing of time in his mind. Over time these lines would appear to move apart as time got closer to the equator. We can see that the lines are always there and run from north/past to south/future and in fact are not moving apart at all

If there is a beginning, an ending, and boundaries, you are describing a finite model. Models based on infinity have no beginning, no end, and no boundaries. Within infinity there may be a number of finite elements, but no finite system can ever encompass infinity. I'll go back and re-read your posting, as you say perhaps I missed or misread something.

A one dimensional universe would be a point, not a circle. A two dimensional universe would be a single static plane defined by at least two points. A third point on the 2D plane defines the Y axis. The fourth point, or element, if spatial adds the Z axis to form a three dimensional space. So long as nothing changes, and the universe is infinite there is no time. If any of the points changes location, then time comes into being. In a finite universe, there is a change from nothing to something, and in that change time is born. Before and after.

The topographical shape of the universe is certainly of interest. The classical shape which we humans seem to prefer is the sphere. A sphere has infinite direction, but has finite boundaries. The surface of the sphere is one thing, and the space around it something else. If the sphere had a beginning, it is occupying both time and space. Perhaps some other shape better describes the perceptual universe anyway.

A physicist (Robert Johnstone) I knew back in the 70s before his death spent a lot of time trying to establish that the best descriptor would be the tovaroid (doughnut shaped). I never quite got his reasoning. The expanding universe might be following curbed space, though Einstein seemed to reject the notion of space curvature apart from the distortions caused by mass. Space is defined by the expansion of those elements we call stars and matter. It is certainly possible that the expansion might be rather like a cosmic Klein bottle, or is "shaped" to fit the N-dimensional foundations of the universe found down on the Planck level.

Don't ask me to explain it, but I believe the whole universe is a sphere, and that's the reason most planets are round.

C.I., that's a beautifully round thought. A good example of the conceptual power of metaphor.

Asherman regards your post 800098. Your correct in what you say, but you can also have a model that is without beginnings endings or boundaries and be finite at the same time. We will have to agree to disagree on this one.

Asherman, regards your post 800127, I think you slipped up with your description of a one dimensional universe, and you have probably realised it yourself. A point is dimensionless a line is one dimensional. So a one dimensional universe could be described as a line if you describe a 2 dimensional universe as a plane.

I can't resist having one last go at describing my finite boundaryless universe.
If you extend your line in a one dimensional universe and eventually the end meets the beginning you would have what looked like a circle to us multi dimensional beings (which is why I described it as that) but it would be a straight line without beginning end or boundaries in the one dimensional universe. Hence you have a one dimensional finite universe without beginning, end or boundaries.

limbodog said



This is the way I sense it also. "Time and boundaries, etc." exist in the minds of men. They are representative of our limits.

With whom do we communicate? Other mankind of course.
I like the promise written by Paul in the New Testament Bible:
'we see as through a glass darkly, but then face to face'.

Oldgal, I agree. Time is a function of our nature. It reflects both our capacity and our limitations. We function better as a society because of our clocks, as it were, but spiritually we suffer because we think of time as something objectively given.

Charon. I thought that a dot is one dimensional and a line is two dimensional, but that only applies to the idea of dots and lines. Actual dots and lines drawn on paper with a pencil are three dimensional, as one can see when viewing them under a microscope; they are piles of lead.

Hello everyone,

This has been wildly interesting and most of this went above the top of my head. I'd like to ask though that, if time is a 4th dimension, and we are constitutionally incapable of seeing it, how come the one defining principle in life is that when we are born we will eventually die? How is this explained then?

To me it seems time is a construct of intelligent beings, namely us, in order to bring more coherence in the continually fluctuating state of objects around us. Without time, there is no proper way (I think... but please enlighten me if I'm wrong) of defining the principle of causality, and this is one of the cornerstones (I think) of the rational thinking human mind.

Yet perhaps if we become more aware of the intrincaties of our world/universe(is this proper spelling?), our definition of time may change, because I do think that there is more for us to know.
Someone here said the past is rigid. I disagree.

The past is as uncertain as the future, in some ways. While it is entirely true that the future hasn;t happened yet, and the past has, neither exist anymore in our current time frame. All we have left of the past is memory, and perhaps objects used or made in said past. With the help of new findings, we are continually (re)defining the shape of our past.
The concept of our unperfect memory also continually changes our own direct past, since we can at best reconstruct this from memory, which can be(come) faulty.

Naj

naj, I been reading through this thread as well. Hey! It's supposed to be over our heads. It's called philosophy, ain't it? <smile> I suppose that we could say that time is a legacy--a tome upon whose pages are written lots of lovely words with plenty of space left to write more.

Time is a real tricky one, for us we are bound up by our perception of time and its passing - which might be quite different from the actual thing.

Scientists still do not know if time is quantised into Planck moments - 10^-43 of a second (personally hold against this because of my interpretation of relativity).

In M-Theory Time predates the big bang - even if we call it virtual time (relative to our universe) for moments prior to the Big Bang and real time afterwards.

F-Theory allows for 10 -to 12 dimensional Universes with at least 2 time dimensions.

So time is a real toughie.

My honest answer is we don't know - our understanding of time is to biased by our cognitive perception of the flow of time in one direction at a constant rate only. In reality time might be very different than this.

Good post, G_day. It IS a toughie. I see "time" as two things: "time-1" refers to the fundamental fact of impermanence. Everything is in movement, becoming something else. "time-2" refers to our persistent attempt to give this constant movement some kind of order, to somehow tame this indeterminacy. To that end we create static conceptual units such as "now and then", past, present, and future, and 10 am and 9 pm, eons, horizons, epochs, etc. etc.

There is only a past, present and future if you are assuming that time exists. How do we know the past really exists? Have we ever traveled to the past? We can store many things in our memory. Things that we have never witnessed. Things we don't have any proof of happening except maybe word of mouth. We store ideas in our memory, so maybe the past and our memories are just ideas. It is basically as simple as this, things just happen, and things just are.

It seems to me that time is a constantly changing present. But, of course, the very IDEA of "present" (or now) entails the ideas of past and future. We can only point to "this" on-going X.

(I tried to edit one word and lost a number of sentences)

Distance
Distance between two points is space, distance between two events is time. Time is the product of this distance and duality. When the distance ends, like in love, the time too ends. For mommy and her baby, the time stops.

When the intellect kicks in, it discerns and creates the distance, and brings the time right back in.

I'll leave the definition of time to the scientists and philosophers. I'll just accept that my day consists of 24 hours, and it's up to me to make the most of it.

Time is measured as the convenient interval between one meal and the next...

Naj

I purposefully refrain from using "...convenient interval between one drink and the next", since I seem to suffer from a time disfucntionality problem there... Between one drink and the next, I seem to lose all sense of time...

Definition of Time
To me the reason people have so much trouble trying to define "Time" is because there is no such thing as "Time" in the sense that people try to think of it. "Time" is an illusion. It is merely the perception and remembrance of successive arrangements and rearrangements of matter in motion. If matter was not in motion there would be no "Time". "Time" was created when matter, energy and space were created and set in motion. Before the creation of matter, energy and space there was no "Time".