Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 14/06/2012 09:30:02

Title: What is 3 dimensional space?
Post by: thedoc on 14/06/2012 09:30:02

Rex van der Spuy  asked the Naked Scientists:
   Hello!

What is 3 dimensional space?

I know that matter and energy are made of particles.
But even the smallest particles are floating around inside 3D space, the same way fish float around in an aquarium.
So what actually is this space, and why does it have 3 dimensions?

Thanks so much!!!

Regards,

Rex


What do you think?

Title: Re: What is 3 dimensional space?
Post by: Pmb on 14/06/2012 22:33:37

Quote from: thedoc on 14/06/2012 09:30:02

What is 3 dimensional space?

Its not easy to define what space is so I won't try. I'll assume you know what it is. The 3 refers to the number of "dimensions"  of the space in which we live. The number of dimensions of a space is the minimum number of variables required to uniquely specify the location of a point in that space. For example: To specify a point in the room your sitting in you can refer to the distances the point is from each of three different but mutually perpendicular walls. Each of those numbers are called "coordinates" of the point.

Quote from: thedoc on 14/06/2012 09:30:02

I know that matter and energy are made of particles.

Thinking of energy being made of something is incorrect. Energy does not have a physical exisistance. It's merely a numbering scheme. For details please see
http://home.comcast.net/~peter.m.brown/mech/what_is_energy.htm

Quote from: thedoc on 14/06/2012 09:30:02

So what actually is this space, and why does it have 3 dimensions?

Nobody knows why space has three-dimensions. A friend of mine wrote a web page on the subject. See - http://www.wfu.edu/~brehme/space.htm