# Problem with Understanding Dimensions!

1. Aug 5, 2012

### RiddlerA

Here's what i know about Dimensions...
Infinite stacks of a 1D world makes a 2D world, And Infinite stacks of a 2D world makes a 3D world and Infinite stacks of 3D world makes a 4D world and so on...
So if we humans are 3D creatures, then we perceive 4th D as time,
Same goes for 4D creatures who perceive 5th D as time but 4th D as Distance just like We observe 3rd D as Distance...
Also 2D creatures would observe 2nd D as distance but 3rd D as time, And so on...

So my real question is that
What are the effects of
1. 4th D on 2D creatures
2. 5th D on 3D creatures and so on..

We humans perceive Length, breadth, Height and Time, but where is the 5th Dimension?
How can we perceive it?
We know for sure that there exists a 4th D(time), so how a 2D creature would experience 4th D?

2. Aug 5, 2012

### Muphrid

If you have 3 apples, how can you add a 5th apple to it before adding a 4th?

3. Aug 5, 2012

### HallsofIvy

Staff Emeritus
What do you mean by "infinite stacks in a 1D world"? In fact, what do you mean by "a 1D world"? If you cannot answer those questions clearly, then what you are saying you "know" doesn't make sense.

What reason do you have to believe that there are "4D creatures" or "2D creatures"? If those do not exist, what you have written here also makes no sense.

Your real question should be 'what is meant by dimensions'? Physics studies "events"- things that happen a specific point and specific time. It takes three numbers to designate a point in space so that is "3 dimensional". It takes one number to designate a time so that is 1 dimensional. Putting those together, physicists work with four dimensions. If you mean anything other than that, you will have to say what you mean by "dimension".

You are welcome to postulate "two dimensional creatures" for the sake of arguement but since you are no longer using the word "dimension" in a non-standard sense you will have to say what you mean by "two dimensional".

4. Aug 6, 2012

### RiddlerA

Sorry for being unclear..
Heres where i learned about those dimensions...

5. Aug 8, 2012

### GarageDweller

Your question is the subject of philosophy, it is non physical and cannot be answered with mathematics or physics because the question itself is not defined quantitatively.

6. Aug 8, 2012

### RiddlerA

Well, in that case, i have to ask is there any current study in this philosophical topic?
Can you give me any links to any site that explains dimensions in detail?
This problem is messing with me ever since i started learning relativity.. Cant able to get past it...

7. Aug 8, 2012

### Vorde

Actually you can answer some of these questions physically.

First of all, time is not the 4th dimension. Time is a dimension, but it is not a spatial dimension like the other three. This is an important difference.

You asked how we are affected by higher dimensions. Well if these higher dimensions existed we would see objects appearing out of nowhere and disappearing into thin air all the time. The fact that we don't see this is really good evidence that these higher dimensions don't exist (or if they exist, are very small. Research string theory and extra dimensions to get a sense of what this means).

8. Aug 8, 2012

### Naty1

We can't. Maybe there isn't one. String theory is an approach utilizing extra dimensions....often 10 plus time:

So in a very real sense, a string (representing matter [particles], energy, forces) requires certain space-time characteristics, like the number of dimensions, and some curled up dimensions, and these create required symmetries. So you could say geometry (spacetime) creates matter here. A theory like heterotic strings which is inherently a theory of gravity, the particles of matter as well as forces emerge in the same way that gravity emerges from geometry in Einstein's GR.

The huge difference is that Einstein's geometry is dynamic; string theory dimensions must be fixed to ascribe fixed characteristic observables.

9. Aug 9, 2012

### RiddlerA

In the video i posted above, it is shown that we 3D creatures perceive 4th D as time.
The same goes to 2D creatures(assume there exists one) who perceive 3rd D(depth/height for us) as Time.. So that means Time is in fact not so different from spatial dimensions...
Atleast that is what i understood so far...

10. Aug 9, 2012

### RiddlerA

String theory sounds like a really complicated theory, Im sure as hell that i cant understand it... I will try to get a good grasp on relativity first.
Thank you so much for the information. Will look into it really soon...