the "edge" of the 3-ball is the outside layer(which is a 2-sphere). in a 3-sphere, you have a 3-ball where every point on this outside layer is the same as every other point. you can't picture it in 3-d, but a 3-sphere is kind of like a 3-ball that you can fly around inside and when you get to the edge you're at ALL the edge at the same time
If you want to get an intuitive grasp of what a 3-sphere is...
A mathematical sphere of n-dimension is like a mathematical ball (a ball is like a solid sphere) of n dimension where the edges have been glued together. For example, a 2-ball is a disc, and if you glue all the edge of a disc together at one point you get a 2-sphere, which is like a hollow baseball. So to get a 3-sphere, you start with a 3-ball (solid baseball) and glue all the outside edge together at a single point.
Slashdot Mirror
the "edge" of the 3-ball is the outside layer(which is a 2-sphere). in a 3-sphere, you have a 3-ball where every point on this outside layer is the same as every other point. you can't picture it in 3-d, but a 3-sphere is kind of like a 3-ball that you can fly around inside and when you get to the edge you're at ALL the edge at the same time
If you want to get an intuitive grasp of what a 3-sphere is...
A mathematical sphere of n-dimension is like a mathematical ball (a ball is like a solid sphere) of n dimension where the edges have been glued together. For example, a 2-ball is a disc, and if you glue all the edge of a disc together at one point you get a 2-sphere, which is like a hollow baseball. So to get a 3-sphere, you start with a 3-ball (solid baseball) and glue all the outside edge together at a single point.
Multiple inheritance, operator overloading