Dumb it down for me: How many dimensions are they and what are they called?

Question

Please be simple, I don't understand physics much, but I'd like to understand dimensions.. and how we know they're real, and how paper is two dimensional but living in a three dimensional world.

Answer 1

There are four, and their names are Harpo, Chico, Groucho, and Firpo.

And paper does have three dimensions -- use a micrometer to measure its thickness.

Although if your paper really is alive, look out.

Answer 2

Provisionally, we believe our world to be four dimensional, with three spatial dimensions (typically called length, width and height) and time as a further dimension. To specify a meeting with someone, for example, you have to say where (eg the 23rd floor of the building at the intersection of 15th Street and 3rd Avenue), and when (eg 16:15 on 3rd November 2006). That's all that is needed - that's why we think (provisionally) that there are no other dimensions - and without all four of these pieces of data you may not rendezvous - that's why we think there are this many dimensions and no fewer. Having said that, recent ideas in physics (String Theory) suggest that there may be 11 other very tightly curled up dimensions, on the sub-atomic scale. Paper, by the way, like every other real-world item, has three spatial dimensions (one of them is just rather small). Only mathematicians think about two or one dimensional things.

Answer 3

You can use a common yardstick to measure dimensions such as the dimensions of a hope chest or a room. If you measue a crate, there are only three measurements; height, width and depth needed to get the volume of the crate (V = H x W x D). You can also measure the dimensions of the diagonals, but you don't need them to calculate the volume. Therefore, dimensions have utility and purpose. Mathematicians can extend the process if it has utility and purpose for them in solving a particular problem. They might say that R = A x B x C x D x E and R has five "dimensions" but that does not mean you can measure any or all of them with a yardstick. Scientists often refer to "time" as the 4th dimension in describing space - time relations but you must measure time with a clock and not a ruler. Noneththeless, space and time are real. I have read that in "string theory" some people work with as many as 22(?) dimensions and it is difficult to find solutions to their equations, let alone prove all the dimensions are "real." They are in fact all "real" in the mathematical sense used to model their problem, but not necessarily real in Nature. That is to be proved. BTW, paper has three dimensions (length, width and thickness) and is only used as a model for a two-dimensional space (area) which exists in a three-dimensional room (having volume). Of course, a line has only one dimension (length) although it may be represented by a string having width and volume. Also, a point has no dimensions (only position) but may be represented by a dot of ink having a tiny thickness and volume. Therefore, dimensions can be both real (length of a rope) or purely mathematical (distance between two points). Hope that helps a little.

Answer 4

Dimensions are mathematical functions. There can be as many as you want or your math skills can take you. Integral calculus is the minimum you will need to fully understand. Differential equations would be better.

Answer 5

dimensions are those that define a physical body...
dimensions like length height and width...
these dimensions provide a physical meaning which are of much interest to scientists...
but some also have no physical meaning....
another dimension is time... which makes us able to recognize changes or related rates of bodies in motion or phenomena...
hope i did'nt confuse you.