Is Time Necessary?

[alan2here]

No, it's really a dimension. As you speed up the dimensions rotate into each other. So you have time becoming space and space becoming time.

 

Speed up relitive to what?

 

Which space dimention? all three at once?

 

How? Im having trobble visualising this process.

 

A simmer idea to this is expressed btw in the book Pyrimids by Terry Pratchett.

[Dr. Physics]

But is it really a dimension or has the dimension of time been invented?

 

to me, time is a dimension, and a vital one at that. With out time, there will be no motion. To me time is the dimenion that allows things to change. So motion is changing over distance. If time is not a dimenion, then motion is impossible.

[Klaynos]

Speed up relitive to what?

 

Which space dimention? all three at once?

 

How? Im having trobble visualising this process.

 

A simmer idea to this is expressed btw in the book Pyrimids by Terry Pratchett.

 

Relative to a stationary observer. The observer will see the moving frame, and the space dimensions are defined arbitrarily, and depending on how you've defined them it depends on the direction of the velocity. And this variation will be defined by the 4-vector.

[alan2here]

So.

 

As the thing you are looking at speeds up relitive to yourself (or the diffrance in speed between you are it increses) the dimensions rotate into each other. So you have time becoming space and space becoming time.

 

the space dimensions are defined arbitrarily, and depending on how you've defined them it depends on the direction of the velocity. And this variation will be defined by the 4-vector[/Quote]

You've lost me.

 

I changed you'r text a bit to take out unneceraly difucult words.

 

"

The space dimensions are defined randomly, and depending on how you've defined them it depends on the direction of the velocity. And this variation will be defined by the acceleration in the forth dimention.

"

 

I think i may leave the thread for a few years untill I understand it more.

[Klaynos]

So.

 

As the thing you are looking at speeds up relitive to yourself (or the diffrance in speed between you are it increses) the dimensions rotate into each other. So you have time becoming space and space becoming time.

 

 

You've lost me.

 

I changed you'r text a bit to take out unneceraly difucult words.

 

"

The space dimensions are defined randomly, and depending on how you've defined them it depends on the direction of the velocity. And this variation will be defined by the acceleration in the forth dimention.

"

 

I think i may leave the thread for a few years untill I understand it more.

 

Basically it means I can point the x,y,z axis in any direction I want, so if we consider the earth to be a stationary frame, as long as I'm consistent in what I do and I tell me what I'm doing there is no reason why I cannot define the y axis as pointing towards the earth's surface, the x-axis pointing north and the z-axis pointing west. In the case of Cartesian coordinates (x,y,z) all 3 axis are orthogonal (at right angles) to each other, but the direction they point doesn't really matter. So in reply to your "which space vector changes" it could be any of them depending which way around I've labelled them or pointed them, it could even be all three of them, it's dependent on the direction of travel relative to your stationary coordinate set as to which changes.

 

It's hard going stuff, and I know physics degree students who stumble at this so don't feel bad

[alan2here]

Ahh, I understand what you meant more now :¬) Thanks.

 

I still think the "time and space rotating into each other" needs a diagram.

[insane_alien]

any idea how to draw a 4D event on a 2D screen?

[alan2here]

That sounds like a chalenge :¬)

Im on it.

 

Edit:

Okay Ive got it

See Next Post

[alan2here]

I can think of 2 ways.

 

 

There is this way

 

1st Dimention

Name: X

 

2nd Dimention

Name: Y

 

3rd Dimention

Name: Z

(Using Prespective, Offset (Think about a photo taken on a large amount of zoom) or the method with Red\Green Glasses)

 

4th Dimention

Name: Focus

 

 

Well thease are 2D drawings over time. But they could just as easely use (perspective, offset, Red\Green etc...) to represent 3D objects over a forth dimention.

 

The samples need to be closer together, It would suck if this image was 6 pixels wide or 6 pixels tall or the individual drawings used 6 layers to represent the 3rd dimention. Additional aplha could be used to enshure that backfaces in both the 3rd and 4th dimentions could be viewed.

 

 

Alternitvly

 

Here are 3 2D views are being used to represent a 3D view

 

 

Therefore (I think probbably 4) 3D views could be used to represent a 4D object.

 

This again is not the best example image as this shape is rather symmetrical.

[alan2here]

I just saw sevaral problems with my last post.

 

With the first way I had drawn my diagram so that it looked like all the timeframes where on top of each other in the z dimention and the blur was 2d as opposed to 3d and the slices where 2d not 3d as they should have been just that would have been too hard to work out what should have been occluding what. But I think the concept works even if my implentation was pritty bad.

 

The seccond method dosn't as the example picture shows 4 3d views. The first 3 are 3d also they are just shown from one side. This would only work as showing 4 3d objects to get a 4d silloete of the object instead of a good reprentation of it.

[Spyman]

The Tesseract is the four-dimensional hypercube or 4-cube.

http://en.wikipedia.org/wiki/Tesseract

 

Animation -> http://en.wikipedia.org/wiki/Image:8-cell-simple.gif

[alan2here]

Interesting yet confusing

[insane_alien]

okay, i'll rephrase. draw a 4D diagram on a 2-D surface in a away that doesn't make the mind explode and implode simultaneously while whistling the tune to spiderman

[someguy]

well you can fake 3 dimensions on a piece of paper easily enough if you're good at drawing. the 4th dimension is time so you can do the flipping of the pages trick like how cartoons are made to make the object move or grow or whatever your function is. on a computer all you need to do is make a 3d object and move it. Any 3d object with motion is a 4d object. I don't know how you'd go about faking a 5d object though.

[Killa Klown]

Without time there is no past, present, or future. Without the past, present, or future there can be no universe (which practically runs on time).

[bored_teen]

i saw a documentary once about black holes. apparently astronauts were able to launch a clock at a black hole and record what happened to the clock's readings. as it got closer, it took 2 minutes to pass a minute. which means that time does exist, but differently than we think of it on a daily basis. time as a measurement is a convenient tool created to explain concepts that we otherwise couldn't. but on that basis, we are really recording the rotating of the Earth.

 

on a philosophical level (which lends itself to this debate), everything is Now. there is no tomorrow, only a Now yet to come. there is no yesterday, only a Now that has come to pass. what does it matter if you passed through a door at a past Now, you aren't currently in the doorway, and i am able to pass through.

[Killa Klown]

If we are only recording the rotating of the earth then the Earth rotates at how many miles per hour?

[Killa Klown]

there no true now, only the passing of time.

[Cap'n Refsmmat]

i saw a documentary once about black holes. apparently astronauts were able to launch a clock at a black hole and record what happened to the clock's readings. as it got closer, it took 2 minutes to pass a minute. which means that time does exist, but differently than we think of it on a daily basis. time as a measurement is a convenient tool created to explain concepts that we otherwise couldn't. but on that basis, we are really recording the rotating of the Earth.

That's probably hypothetical, as the nearest black hole is light-years away.

 

The concept is correct, however. Atomic clocks on fast-moving airplanes record slight differences in time depending on their movement.

[bored_teen]

there no true now, only the passing of time.

 

can you prove that?

 

if there is no true now, yet all takes place in now, nothing truly happens, which i'm now using as a metaphor attesting to the futility of man's daily routines in contrast to a lasting legacy. maybe i should be a philosopher?

[someguy]

the most useful thing about time is it allows for motion. if there was no motion in the universe at any level the universe would be essentially paused and there would be no time. you need time for motion and motion for time, they're pretty much the same thing. In fact the faster you move the faster you travel through time compared to slower moving things, and that means you would age at a slower rate than those things moving slower than you. So then time is just as essential as space is as far as existence of the universe is.

 

ya i agree there is a true now, in fact there is only a now. it's now all the time. I'm always trying to catch up with the future but i can never get away from the now and the past keeps up with me relentlessly.

[bored_teen]

the most useful thing about time is it allows for motion. if there was no motion in the universe at any level the universe would be essentially paused and there would be no time. you need time for motion and motion for time, they're pretty much the same thing. In fact the faster you move the faster you travel through time compared to slower moving things, and that means you would age at a slower rate than those things moving slower than you. So then time is just as essential as space is as far as existence of the universe is.

 

ya i agree there is a true now, in fact there is only a now. it's now all the time. I'm always trying to catch up with the future but i can never get away from the now and the past keeps up with me relentlessly.

 

wait, if you're moving faster through time, you age more slowly? why wouldn't you age more quickly? like that guy on Clockstoppers, who kept the watch on to long?

[swansont]

wait, if you're moving faster through time, you age more slowly?

 

I think (hope) he meant traveling faster spatially slows your time (as measured by a stationary observer)

[someguy]

ya swanson that's what i meant. if you look at a spaceship moving really fast through space you gain ground. if you look at a spaceship moving really fast through time you would be "carried" to a further point in time ( compared to the stationary object ) so you in the spaceship age normally and time inside the spaceship is normal from your perspective but when you get out of the spaceship or for example come back to earth, the stationary observer, you would find that everyone else aged much more than you.. like if you were carried to a further point in time. I prefer to look at it this way rather than time slows down for the person moving faster but essentially they are saying the same thing. like if i was walking towards you you could say from a physics standpoint that you are moving towards me. both would be right

 

as for why in an absolute sense, like what is the purpose of life kind of why, the answer i guess is that it just is that way. as for why like how einstein figured it out, he used an imaginary scenario knowing already that light is constant. basically as i recall in his scenario he imagined a beam of light shining down in a moving train, a really really fast moving train. if you saw it from the outside, it would form a diagonal. in a still train just a beam straight down. if you timed the trip of the beam from top to bottom looking from outside it would take the same amount of time for the beam to reach the bottom in both trains. But a diagonal beam is longer than a straight beam. so the moving train beam covered more ground in the same amount of time. this could only occur if either the beam moved faster in the faster moving train or if time was different in the faster moving train. since the speed of light is constant then it must be that time is changing. If i'm not mistaken it was some other guy.. i think a french guy that figured out the speed of light is constant before einstein came up with relativity.

[Farsight]

http://en.wikipedia.org/wiki/Henri_Poincar%C3%A9