What really is time?

And what does time have to do with the speed of light?

A perception

Originally posted by EmLasker
And what does time have to do with the speed of light?

i've asked myself this many times and think it's a really interesting question! i hope more people get involved in the discussion, but will put in my two cents now to maybe get the ball rolling?...

i think time is merely a metric by which we measure "change." the most obvious type of change would be the change in relative position of massive bodies in space, and the rate at which their relative positions are changing. similarly, it's the "yard-stick" for measuring change in an organism's development (which is based around movement and action on a microscopic or even subatomic level). and as such, all of the units of time (microseconds, seconds, minutes, years, eons, etc.) are just an arbitrary system by which we relate amounts of change to one another. these arbitrary units are generally based around seemingly periodic changes - specifically those concerning earth's revolution around the sun (and thus the periodicity of the seasons), and earth's rotation on its axis (the periodicity of day/night). this is probably because these periodic changes that we all experience are the easiest to relate to other human beings. and over time, subdivisions of those changes have been arbitrarily agreed upon for easier synchronization of events, and for better/more efficient output of things like agriculture, business, war, reproduction, etc. (also to allow for the differences in when days/seasons occur at different locations on the planet, as global communication/trade became possible/necessary)

that being said -- and i think many disagree with this viewpoint of time, and believe it is an absolute construct removed from the idea of motion -- i think that light, as well as other non-massive particles, are simply the best-equipped things in the universe for traversing distance. thus we think of c as the limiting speed of the universe, and as such is irrevocably linked with time since it's rate of motion is the fastest reference frame with which to compare the motion of other things(?) this is where my ideas become rather unclear and it becomes more difficult to characterize what i think. in fact, i think the major implication of this view of time is the absence of a possibility for "backward time travel" since time is not external to the cause-and-effect motion of events. i.e. since time is just the way we measure continuous change, and not in itself a part of the causation of that change, the concept of "looping back" to events that have already happened is in itself contradictory?

what are your thoughts? cheers, and happy new year! 🙂

Time is a measure of how much entropy the universe has gained since the Bang.

Originally posted by Aetherael
i've asked myself this many times and think it's a really interesting question! i hope more people get involved in the discussion, but will put in my two cents now to maybe get the ball rolling?...

i think time is merely a metric by which we measure "change." the most obvious type of change would be the change in relative position of massive bodies in ...[text shortened]... itself contradictory?

what are your thoughts? cheers, and happy new year! 🙂

I too ( if I understood correctly ) think it is a man made system devised for measurment. It would seem most likley to me that time first posits itself in the human psyche in the heartbeat of a mother. So I guess I veiw time as a rhythm that can become as complex as desired. Are there distinctions between types of time? Maybe this is the communication breakdown. Time in nature seems to be cyclic (with seasons and rotations), while man made time could be the cycles of a clock creating a directionless continuum. Maybe time is memory, for without memory the notion of time would be useless. time is now shown to be intimatley woven into space? So many definitions so little time....Here are just some thoughts.

This thought just occurred to me:

Imagine a being which is not moving in time, but in one of the three cartesian dimensions. Let's call it up. He only has perception of two dimensions.

As he moves along one dimension, he sees how things in his two dimensional world changes. If we imagine that the world is a compact subspace, then he would see a continuous change.

This being would regard "up" as being time. Changes in his perception of other two dimensions would seem irrevocably "subordinated" to up/time.

I like that Palynka as it provides a construct for explaining our perception of time, but it doesn't explain the substance of it. How time affects matter is of interest to me, but I'm not a scientist so have to speak in lay terms. It interests me because as far as I understand it time is a product of mass, gravity and the movement of mass through the fabric of space. If this is the case then everything we see in the universe is of an unpredictable time origin as distances, speeds and masses have been changing over the vastness of "time" since the big bang. How do we know how old the universe is when we are using our 'perception' of time and potentially a flawed measure of it anyway?

Originally posted by divegeester
I like that Palynka as it provides a construct for explaining our perception of time, but it doesn't explain the substance of it. How time affects matter is of interest to me, but I'm not a scientist so have to speak in lay terms. It interests me because as far as I understand it time is a product of mass, gravity and the movement of mass through the ...[text shortened]... when we are using our 'perception' of time and potentially a flawed measure of it anyway?

I would say it doesn't matter that our perception of time is flawed, time is relative. we could just as easily apply the "perception argument" to anything in existance, this is why standard measurements are important.

Originally posted by divegeester
I like that Palynka as it provides a construct for explaining our perception of time, but it doesn't explain the substance of it. How time affects matter is of interest to me, but I'm not a scientist so have to speak in lay terms. It interests me because as far as I understand it time is a product of mass, gravity and the movement of mass through the ...[text shortened]... when we are using our 'perception' of time and potentially a flawed measure of it anyway?

I think it can also say something about the substance of it. According to some string theorists our universe could have 11 dimensions. In my example, the substance of up/time is identical to the other two cartesian dimensions. It's the 2 dimensional being's perception that subordinates the first 2D to up/time.

Originally posted by Palynka
This thought just occurred to me:

Imagine a being which is not moving in time, but in one of the three cartesian dimensions. Let's call it up. He only has perception of two dimensions.

As he moves along one dimension, he sees how things in his two dimensional world changes. If we imagine that the world is a compact subspace, then he would see a continu ...[text shortened]... in his perception of other two dimensions would seem irrevocably "subordinated" to up/time.

How can something move in space without moving in time? Movement in space is defined as distance/time.

Originally posted by divegeester
I like that Palynka as it provides a construct for explaining our perception of time, but it doesn't explain the substance of it. How time affects matter is of interest to me, but I'm not a scientist so have to speak in lay terms. It interests me because as far as I understand it time is a product of mass, gravity and the movement of mass through the ...[text shortened]... when we are using our 'perception' of time and potentially a flawed measure of it anyway?

We don't "know" how old the universe is strictly speaking. We reason, based on numberous axiomatic assumptions (general relativity is a correct model, Laws of Thermodynamics, etc). If the axioms are flawed then the conclusion is wrong.

Originally posted by AThousandYoung
How can something move in space without moving in time? Movement in space is defined as distance/time.

What is time?

Originally posted by Palynka
What is time?

Don't make me bust out Newton and his perfect clocks analogy...

Originally posted by Palynka
What is time?

As I already answered,

Time is a measure of how much entropy the universe has gained since the Bang.

Originally posted by AThousandYoung
As I already answered,

Time is a measure of how much entropy the universe has gained since the Bang.

If time is just a measure of entropy, then entropy would exist without time? Mmm... Something doesn't add up. I've heard that entropy implies a direction of time, but time cannot simply be a measure.