Time in the 4th dimension

[maddog]

But, assume that our universe was two dimensional - that we were all two dimensional beings, and that we only knew of two spatial dimensions. But we discovered that TIME was a dimension, and that we were travelling through it. So now we would know of three dimesions - two spatial and one time. Now, imagine that the universe was a flat plane, and that the third dimesion consisted of all of these universes piled on top of one another, in such a way that each dimesion was only affected by the dimensions before it. To the beings within the 2D universe, we would be "moving" through time, while in reality, that sense of "motion" comes only from the fact that events can only affect other events in one direction within the third dimension. In reality, all of "time" would exist at once, stationary. This is how I view the time dimension - continuous third dimensions with cause and effect happening only in one direction.

 

I am sorry, I wasn't able to comprehend some of it. I will state what I think was your

thought experiment and highlight where I fell short on comprension. Please clarify when

you can. Let's see three total dimension, two spatial, on scalar (time). So all motion

would have coordinates in (x,y) and one scalar (t). OK. Are you now bringing in multiple

universes here (I missed that) ? I don't understand what the effect "dimension before it"

means ? A metric as you describe in this space time would be:

 

ds^2 = (dx^2 + dy^2 - (cdt)^2)^(1/2)

 

I'm differentials for picking some compact neighborhood ds of the this universe moving

through time. That is what I have so far. What were saying after that... ?

 

Maddog

[lindagarrette]

Time IS the fourth dimension.

Only for discussion purposes.

We live in a world of three dimensions. Well, we only perceive three dimensions. We can hypothesize many more dimensions. but they are mathematical constructs.

 

Because of Einstein, we often call time the fourth dimension. Special relativity shows that time behaves surprisingly like the three spatial dimensions. The Lorenz equations show this. Length contracts as speed increases. Time expands as speed increases.

Time never behaves like a spatial dimension. You cannot go backward in time. And you normally cannot go forward at different rates. But, there are surprising parallels. For some purposes, it is handy to call time a fourth dimension. For other purposes, it is not.

[pgrmdave]

I don't know much about it, but I don't believe that we move through time at all. Since cause and effect only work in one direction, our brains are only wired to know what happened at points before any given point. In other words, all of time exists, and we only are aware of "motion" through time because that is how our brains are set up. Assume that "time" flowed erratically, we would still consider time to move steadily in one direction, the direction of cause and effect.

[CHADS]

Im no expert but a 4 dimentional representation would be a 3 d cube for example with a one dimentional object that has a link with every point in and on our 3d object simultaneously. The one dimentional object would change its scaler value in accordance with the the 3d objects change ... when the 3d 0bjects parameters become zero so would the one dimensional scalar also be zero with the possibility to advance towards infinity always preserved...... for example if cm where the lowest measurments known ... then a cube measuring 2cmx2cmx2cm would have 27 points that the one dimensional object would be able to represent simultaneously ..... 26 external points and one internal point ....... A three dimensional object plus a one dimensional object equals 4 dimensions ....... i suppose a five dimensional object would be with a 3d cube and a 2d square perhaps represented by 2d image being represented in 3d form by a holographic teqnuique ... like the model in Stephen Hawkins ..The universe in a nutshell