Secrets

I have a treat for you all this time. I'm assuming that if you're reading this post you know little or nothing about modern-day physics and the "out there" ideas physicists are actually entertaining. This post is specifically about extra dimensions. Many physicists tell us that there are, in all, 10 dimensions. (Yes, you read that right, 10...ten...9+2-1.)

What's a dimension? It's a degree of freedom. In other words, a dimension is room in which you can move. The 3 dimensions we experience ever day of our lives (and the first 3) are up-down, left-right, forward-back. Those are the only directions in which you can move.

Let me rephrase: Those are the only directions in which you can sense that you're moving. To make sense of this idea, I'm going to start with dimension zero and work my way up to the 10th. This will allow your mind to better imagine higher dimensions. So....here wo go!:

Dimension zero-I'll start with a point. A point is just that, a point. You know it from geometry as a position in a system. A point is of indeterminate size; it has no length, width, or depth.

Dimension one-
A line is made by connecting two points. A line is a 1-dimensional object, it has no width or depth.
Dimension two-
If we draw a second line over the first, we enter the 2nd dimension. Our object now has length and width. It'll be more convenient for us, though, when talking about higher dimensions if we enter the second dimension by drawing a line that branches off from the first one. So now we have a shape that looks like a "y."

Now let's imagine a race of 2-dimensional creatures. A 2-dimensional creature would only have length and width; no depth. So think about them this way: these creatures couldn't possibly have a digestive tract because the pipe from their mouth to their bottom would divide them into two pieces.

The amazing thing about dimensions being stacked on one another is that when we move down here in the lower dimensions we are unaware of our movement in the dimensions above. Think about it this way. If you take a Mobius strip (take a strip of paper, give it one twist and tape the ends together) and draw a line down the middle of it you will, somehow amazingly, end up at the beginning of the line you started. This means that a Mobius strip must be a representation of a 2-dimensional object.

Now, let's think of our 2-dimensional creature traveling down the line we just drew. You can imagine that right? The Mobius strip involved taking a strip of paper and giving it a twist. This creature, when traveling down the line, would be unknowingly moving with this twist around the paper until it ended up where it began. You could also think of this by imagining a human circumnavigating the world. To the human, it would seem he was moving in a straight line, but he is actually following the curve of the earth all the way around until he ended up when he started.

Dimension 3-
The 3rd dimension is the easiest for us to imagine because we experience it every day of our lives. We can move in those 3 directions I mentioned in the intro. It'll be easier for us to think of higher dimensions though if we think of the 3rd dimension in this way: the 3rd dimension is what you fold through to jump from one place to another in a 2-dimensional world. Let me give you an example. Think of an ant walking on a flat (2-dimensional) newspaper. If we fold the paper in the middle, it'll bring both ends of the paper together. The ant, that was on one of the edges, can now instantaneously jump from its current position on one edge to the other edge without having to travel across the whole length of the paper. Here's a visual:

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I'm going to stop here for now. I'll continue further with the next 3 dimensions (4, 5, and 6) in the next post (probably 2/18). If I didn't, this would be one hell of a long post. I hope to see you here tomorrow! Interesting topic isn't it?!


Some sources:
Michio Kaku, Lisa Randall, Rob Bryanton, Brian Greene.