# Do we see in 3 dimensions?

Hi,
its been quite long time since I wrote about dimensions. Just a quick recap since people do not click on links much: 0th dimension is point, 1st dimensions is line, 2nd dimension is plane and 3rd dimension is space. We are talking about spatial dimensions, another thing is atime dimension, but that is not important here.

So I got into this argument if humans see in 3 dimensions or not, I got no clear conclusion though so I am just going to discuss it here. We live in 3 spatial dimensions, proof, cubes exist. How do we see though? We can see cubes but I would argue that we see in 3rd dimension.

1. Retina does not capture depth, it is 2 dimensional detector so we simply can not have a 3 dimensional vision.
2. We have two eyes though, lot of people seem to like to point this out. With second eye you have what is called a stereoscopic vision.. the second eye has little bit different point of view and when brain combines it stuff gets depth. This does not mean that we see in 3D though. Still it is just two 2 dimensional pictures put together. Brain interprets this picture as 3 dimensional and based on experience judges distance. Also colors and shades can help us with that.

This is stereoscopic picture, disalign your eyes and match the pictures so you see 3 of them.

3. You can draw anything you see on piece of paper and it will be exact representation of what you see, all angles same and so on. This I think would be impossible if you actually wanted to transfer 3D image to 2D plane because by definition 3D space is made up of infinite 2D planes put on top of each other. Same as you can not take infinite picture and store it in 1D line.
4. If we could see in 3D we would see all angles as they actually are. If you look into corner you do not see 90° angles though because you remember the way that walls work you know that they are there.

Dragallur

# Dimensions: Short Expansion

Hi,
here it comes, here it goes, again seemingly very favorite topic about dimensions. Last time I wrote about imagining higher dimensions and how they work and that we have 3+1 dimensions. 3 are space dimensions and one time dimension. Actually I should have added that there is and option of much more dimensions. Thanks to Joseph from Rationalising The Universe reminding me of this through his post which I recommend you to read.

Fine if you read his post you know that I want to talk about dimensions that can exist in string theory.

So there are two main theories: Theory of Relativity and Quantum theory.
What we know for sure that both are wrong. This is because TOR is not able to predict stuff on small scales and QT on large scales while they are both very good on their fields.
Then there is third guy called String theory. This theory says that on very small scale fundamental particles are one dimensional strings, which mean lines and when you are looking at them “from above” they look like particles.

String theory predicts a lot of dimensions on extremely small scales (check Joseph`s post to read about gravity etc.).
There are two most important ST theories. Boson and Superstring theories. The first one predicts 26 dimensions and second 10, now choose :D.
The thing is that actually for some stuff it is much better to have more dimensions.
Since for me it is so extremely complex I can just advice you for wiki page for start.
Still String theory is just theory as are others and I am totally looking forward to Theory of Everything!
Dragallur