I’ve updated the article on extra dimensions that I announced last week. In the original version of the article, I gave you one example of an extra dimension; now I’ve extended it to include another example, of a very different type. You can find all the new stuff by scanning down the article until you find a line in red that says “New additions begin here.” If you haven’t read about extra dimensions at all, you should read some of the other introductory articles first; you can find links to them at the top of today’s article.
What will come next, perhaps in the coming week, is a discussion of the scientific techniques used to look for signs of extra dimensions. Later I’ll add another example or two to today’s article.