How do you perceive time?

[Epona]

Time, interesting subject Yorick.

There are many different ways to view the subject.

Einstein's Theory of General Relativity states that time does not move at a constant rate. A moving clock will tick slower than a stationary one (works with digital too, so not just motion acting on the gears of a clockwork device - and I've seen it demonstrated by means of a pushed trolley and groups of people with digital stop-watches). This is called time dilation. Spacetime is curved, imagine a rubber sheet suspended at the corners with a bowling ball in the middle. Rolling a marble onto the sheet demonstrates the effects of gravity not just on matter, but also on time. Hans von Baeyer described spacetime as 'an invisible stream flowing ever onward, bending in response to objects in its path, carrying everything in the univers along its twists and turns'.

Of course the effect of gravity on time is miniscule at low velocity - it is when you approach the speed of light that its effect is greatest (gravity being equivalent to motion - the gravitational pull of the earth is the same as no gravity but instead travelling upward in a lift at the rate of 32 feet per second.) Travel at the speed of light would distort time as would a black hole - from which the escape velocity is greater than the speed of light, which is why it is 'black'. Spacetime is curved by both events.

An observer far from a black hole would observe time passing extremely slowly for an astronaut falling through the hole's boundary (event horizon). The observer would never see the victim fall in, time would appear to stand still from the observers viewpoint. The same can be said of travel at the speed of light - the traveller would not age relative to stationary observers. This is true of travel at *any speed* but of course at low velocity the difference in the flow of time is unnoticeable.

Then there is the measurement and perception of time. To the hunter-gatherer time was largely unimportant, other than the passage of summer into winter for which he or she must stockpile food to some extent. Agriculture increased the importance of seasonal variation, with attention being paid to sowing time, harvest time, ploughing time. Although measuring the passage of time was an interesting study for pre-industrial societies, its function was mostly one of philosophical ponderance rather than a need to know what the time was. It is with early industrialisation and the Enclosures Act (in England) that the need to know time becomes most important - people moving away from agriculture and being forced into industrial labour - where the industry owner is dependent upon a workforce turning up at the same time and working for a certain number of hours. Since then the measurement of time has become more and more accurate, with people more fixated upon minutes and seconds, and will I be late for my meeting.

Hope that's the sort of comment you wanted Yorick! Sorry it's so long, I find the subject utterly fascinating.

[Yorick]

Originally posted by Moiraine: If one could travel faster than light to the end of the universe and come back to Earth, what he would then see from above would be not the actual Earth but the image of the Earth as it was in the past ... [img]smile.gif[/img]

Yes that is fascinating isn't it. [img]smile.gif[/img]

[Yorick]

Originally posted by Epona: Time, interesting subject Yorick. There are many different ways to view the subject. Einstein's Theory of General Relativity states that time does not move at a constant rate. A moving clock will tick slower than a stationary one (works with digital too, so not just motion acting on the gears of a clockwork device - and I've seen it demonstrated by means of a pushed trolley and groups of people with digital stop-watches). This is called time dilation. Spacetime is curved, imagine a rubber sheet suspended at the corners with a bowling ball in the middle. Rolling a marble onto the sheet demonstrates the effects of gravity not just on matter, but also on time. Hans von Baeyer described spacetime as 'an invisible stream flowing ever onward, bending in response to objects in its path, carrying everything in the univers along its twists and turns'. Of course the effect of gravity on time is miniscule at low velocity - it is when you approach the speed of light that its effect is greatest (gravity being equivalent to motion - the gravitational pull of the earth is the same as no gravity but instead travelling upward in a lift at the rate of 32 feet per second.) Travel at the speed of light would distort time as would a black hole - from which the escape velocity is greater than the speed of light, which is why it is 'black'. Spacetime is curved by both events. An observer far from a black hole would observe time passing extremely slowly for an astronaut falling through the hole's boundary (event horizon). The observer would never see the victim fall in, time would appear to stand still from the observers viewpoint. The same can be said of travel at the speed of light - the traveller would not age relative to stationary observers. This is true of travel at *any speed* but of course at low velocity the difference in the flow of time is unnoticeable. Then there is the measurement and perception of time. To the hunter-gatherer time was largely unimportant, other than the passage of summer into winter for which he or she must stockpile food to some extent. Agriculture increased the importance of seasonal variation, with attention being paid to sowing time, harvest time, ploughing time. Although measuring the passage of time was an interesting study for pre-industrial societies, its function was mostly one of philosophical ponderance rather than a need to know what the time was. It is with early industrialisation and the Enclosures Act (in England) that the need to know time becomes most important - people moving away from agriculture and being forced into industrial labour - where the industry owner is dependent upon a workforce turning up at the same time and working for a certain number of hours. Since then the measurement of time has become more and more accurate, with people more fixated upon minutes and seconds, and will I be late for my meeting. Hope that's the sort of comment you wanted Yorick! Sorry it's so long, I find the subject utterly fascinating.

The Black hole theory is fascinating. How have they ascertained that? That time would appear to stand still?

Re. the moving clock, that is unfathomable. How is that possible I wonder? You mention the theory of relativity, but I don't see why that would be the case regarding time. Surely it's a measurement flaw, not an indication of...

Acyually I have heard that travelling at light speed, someone would age slower than another who didn't. But surely if the same universal moments pass, this is just in theory. The person wouldn't experience less time, just decreased aging deterioration... still perhaps they do. The closest to going backwards in time is to have no time pass at all. Wierd.

Ack! It's 5:45am and I haven't slept. I've been working on the song in question most of the night, and my head is fried.

I'll look at this again tomorrow. You head tripper Laura! [img]smile.gif[/img]

[Yorick]

Originally posted by 250: I believe time has something to do with perception. I believe we cannot understand time for time, but through a reflection of perception. If one exists in an extra dimension, then of course the being possess a greater perception than we of our physical world. Can you explain the meaning of a third dimension to someone who lives on a paper? on a line? and likewise, can you even perceive what it is like to live in two dimensions? sure, you can have models and theories but they are far from a comprehensive answer if there is one. The changes of understanding, based on an increased "perception", does not add to each other, not even mutiply. It increases at a rate greater than exponetiatial, that is why our brains cannot comprehend "time" of its truest form, simply said, we humans lack the perception. time is both changes and stops, one point at any position or all positions, infinitely large or small. Time is like a diamond of infinitely faces. One can view it from any direction and reach the same conclusion but never as a whole. Any of its faces is only a reflection, a glipse. My math teacher once gave me an example "Imagine a line infinitely long, SO long that its both ends came together and formed a circle." There could be many ways to explain this. For one, the length is so great that we humans perceive any part of it, in our life's time, as a line. Perception.

Interesting take on it Leo. [img]smile.gif[/img]

[Epona]

Originally posted by Yorick: The Black hole theory is fascinating. How have they ascertained that? That time would appear to stand still? Re. the moving clock, that is unfathomable. How is that possible I wonder? You mention the theory of relativity, but I don't see why that would be the case regarding time. Surely it's a measurement flaw, not an indication of... Acyually I have heard that travelling at light speed, someone would age slower than another who didn't. But surely if the same universal moments pass, this is just in theory. The person wouldn't experience less time, just decreased aging deterioration... still perhaps they do. The closest to going backwards in time is to have no time pass at all. Wierd. Ack! It's 5:45am and I haven't slept. I've been working on the song in question most of the night, and my head is fried. I'll look at this again tomorrow. You head tripper Laura! [img]smile.gif[/img]

Hugh, get some sleep!

Although I do find pondering Einstein's theories and Quantum Mechanics can keep me awake at night.

Alas my maths isn't advanced enough to be able to explain it (and of course the whole black hole/speed of light thing is postulation based on practical experiments at lower velocities combined with some very complex calculations and may never be proven), I'll try digging something up off the net for you.

Despite my maths not being up to it, the philosophy of Quantum theory I find absolutely fascinating. Here's another thought, courtesy of the insane Quantum world:

If time is at a standstill at the speed of light, that means that a proton (light particle) which obviously is the only known thing in the universe which travels at the speed of light, exists at every moment in time simultaneously! That is absolutely mindblowing.

It's possible to slow protons down so that they are travelling slower than the speed of light - in which case they are moving forward in time. This appears to happen naturally, since of course protons canon off each other the same as any other particle. Other particles not only slow down when they bounce off each other, some of them speed up. So in theory, if protons are bouncing off one another all the time, some of them must speed up - in which case they are (in theory) travelling backwards in time.

Work that one out! It gives me a headache just thinking about it.

[Barry the Sprout]

I kind of agree with 250 about the nature of time - its a bit of a contradictory ideal in the way a lot of people see it. Time is infinite, so what is to say at which point of that time line we exist, consciousness exists for an infintesimally small point along that line, a line that it would be impossible to end. OK, so time could end tomorrow could it? What on earth would happen then? The Universe requires time to exist, so without time we don't get a universe. Whilst it might be possible for matter to stop existing, it would be impossible for the entire of existance to stop existing. This is a concept I find very difficult to explain... Argh!

My second point is slightly concerned with what some people say about "living in the moment", bascically that that is impossible too sadly. The "moment" that we perceive at any instant has already gone, replaced by a new one which we will not perceive until a fractionally small amount of time later. The relationship between subject and object necessarily requires that the object that we see (the world in general, for example) is never the same object as the one that exists at the time of our perceiving it. OK, so maybe little has changed, but you don't know that.

Of course, you can come back by saying that the only object that ever actually exist is the one that is perceived, the sensory data is the only really provable part of the process. So it would be possible to live surely in the moment, as the moment consists of only subject and subjects sensory data, no object at all. The problem with this is that it opens the door to rationalism that in turn denies the proof of the existance of time itself, which kind of makes the argument pointless. We now consider time to exist as it is a natural assumption, like the existance of matter. It is a priori knowledge. Yet if we reject the existance of a priori knowledge and reject the existance of objects in the first place then we also reject the existance of time, as unproven.

Hows that for a headache then...

[*\Conan/*]

Originally posted by Yorick: How do you perceive time? Cyclic? Linear? Spirally? After writing a song about familiarity and repetition of a negative experience, I determined to see time as linear, not even spirally which I had done. Thoughts anyone?

This thread blew me away last night when I first read it Yorick. Hadn't really thought to much about it but since you asked.
I view time as Linear. Even thow all of us get emotionally stuck in a moment time still goes.
Reprobate minds are a physical reality not a time stopping element IMO.

The reality of time for me is linear, and the true aspect of it is what you cant see, feel or hear. Many refrences in the Bible talk about a time for this and that, specific points, events. Never to be repeated again.
Just me- S

[Thoran]

Originally posted by Yorick: The Black hole theory is fascinating. How have they ascertained that? That time would appear to stand still? Re. the moving clock, that is unfathomable. How is that possible I wonder? You mention the theory of relativity, but I don't see why that would be the case regarding time. Surely it's a measurement flaw, not an indication of... Acyually I have heard that travelling at light speed, someone would age slower than another who didn't. But surely if the same universal moments pass, this is just in theory. The person wouldn't experience less time, just decreased aging deterioration... still perhaps they do. The closest to going backwards in time is to have no time pass at all. Wierd.

It's actually been experimentally proven that it's not our perception of time that changes at relativistic speeds... it's the flow of time itself. So a person travelling close to light speed is experiencing less time than the same person standing still. If he's got a watch on, then that watch will come back to earth reading a different time as all the watches on earth.

That all flows out of Einsteins work on relativity... the equation that I found on the internet is deceptively simple:

t1 = t2/SQRT( 1 - (v^2/c^2))

t1 = Ground based observer time
t2 = time experineced by relativistic traveller during the ground duration t1
v = velocity of relativistic traveller
c = speed of light of course

so solving this at both limits :
as v approaches c, t2 will approach 0
as v approaches 0, t2 will approach t1.

pretty cool stuff. Can't say it all makes sense to me but it's pretty cool. The stuff that gets me is again around the edges...
- Relativity says basically that you can measure yourself only relative to someone else... BUT the speed of light is fixed... and never changes irregardless of the velocity of the light source (just frequency shifts), this would seem to be an absolute measure in the world of relativity.

This all makes sense. But where I get tripped up is the age of the universe stuff. Everyone is trying to figure out how old the universe is, but given our above equation it seems to me that there IS NO "age of the universe" since depending on your velocity your age will vary. For instance, I found a site that said that our velocity relative to the Virgo Cluster is 375 miles per second. I ran the calculation and it said that the difference in time between us is 1.000002 or thereabouts. Sure that's not much of a difference but over billions of years it becomes a fair amount of time... and what about galexies that are far away and moving away from us at relativistic speeds (the big bang theory says they're out there), compared to someone standing at the big bang location (v=0) those guys will be experiencing only a small fraction of the time change that the guy at the center of it all is experiencing.

How can you figure out the age of the universe when that very age is a variable. [img]smile.gif[/img]

[ 10-15-2002, 09:07 AM: Message edited by: Thoran ]

[Epona]

Thoran, thank you so much, you have saved me a lot of work trying to find that equation!

It is absolutely fascinating isn't it? I read quite a lot of 'popular science' books on cosmology and quantum theory, and just as you think you're starting to get your head round it your brain dissolves under the strain and nothing seems to make sense any more! We don't need science fiction, it's all here and far more fantastic than most of us are able to comprehend.

[Yorick]

Originally posted by Thoran: This all makes sense. But where I get tripped up is the age of the universe stuff. Everyone is trying to figure out how old the universe is, but given our above equation it seems to me that there IS NO "age of the universe" since depending on your velocity your age will vary. For instance, I found a site that said that our velocity relative to the Virgo Cluster is 375 miles per second. I ran the calculation and it said that the difference in time between us is 1.000002 or thereabouts. Sure that's not much of a difference but over billions of years it becomes a fair amount of time... and what about galexies that are far away and moving away from us at relativistic speeds (the big bang theory says they're out there), compared to someone standing at the big bang location (v=0) those guys will be experiencing only a small fraction of the time change that the guy at the center of it all is experiencing. How can you figure out the age of the universe when that very age is a variable. [img]smile.gif[/img]

That is a wild concept! LOL!