# how many dimensions

When you attempted to define how many dimensions could exist, you talked about time as a dimension and the creation of the universe. You overlooked one simple idea. You have a straight line, representing 1 dimension, you can move up and down. You take right angles, and you have, in essence, a circle. “up” “down” “left” “right”. Take another right angle, you have a sphere. In, and out, are added. ( 2nd grade terminology here). Each time you take right angle you get two new directions. If you try to take a right angle off a sphere, it could be contained in a larger sphere. Seemingly, the end of the road. But. If I were a 2-d creature, wouldn’t I think THAT was wht end of the road? How could we possible determine if their weren’t other directions, meaning dimensions, existing right now? Anything in 4-d would have parts of our 3-d. Just as a sphere has a circle in it. But, jsut as somethign existing only in a plane could not understand anything “above” or “below” it, we could not percieve these other directions in which somethign could protrude. The circle, or the object we percieve, only acts as a cross-section. input?

the_factr-praeclarus et sanctus

The link to the column is: [url=http://www.straightdope.com/mailbag/mdimensions.html]How many dimensions are there are and what are they?

As you’ll note, we said there were different answers depending on whether you were talking mathematics, physics, or common sense. The comments you make are pure mathematics, and are covered in the section of the article called “Footnote” because such additional dimensions only “exist” in a theoretic construct. It can be a useful construct, for example, if you want to track temperature or barometric pressure or whatever as separate coordinates; but nonetheless it’s a math-theoretic construct.