I find it interesting to contemplate the following: In a recent National Geographic it was reported that inflation theory implies that the actual size of the universe is some 10 to the 42 times larger than the observable universe. Now, this is of course incomprehensible to the human mind. But I found that the size of the observable universe is larger than an electron by about the same ratio. Well, 10 to the 40 power, if you must know. Anyway, it would seem that an electron is the the observable universe as the observable universe is to the actual universe. Although interesting in and of itself, what also intrigues me is why comparative ratios seem slightly more comprehensible than the absolute measurements themselves? Afer all, the electron is absurdly small and the observable universe absurdly large, at least on human scales. Why should their comparison lend understanding to vastly greater absolute sizes?
I think your comparison isn't quite right, you said that the universe is suspected to be 40 times larger than what is observable, but that the universe is 10^40 larger than an electron. There's a big difference there. Still, I think that your point is valid, by comparing the sizes of things we are familiar with, it makes the incomprehensible easy to understand. It's much easier to picture astronomical distances if you have a smaller comparison available. For example, you can tell someone that the sun is very much larger than the earth, and they might understand quite how much bigger. But it you show them the head of a pin representing the earth, and a soccer ball representing the sun, it gives them something to relate to. This way, it is easier to understand the real thing. It all boils down to the fact that it's easier to see something that to be told about it. Since you can't show someone the size of the universe, you do the next best thing and use a comparison.
Hi Nova, read te jen's first paragraph again. It says that the article reported a 10<sup>42</sup> difference between observable at actual (I think that must be a minimum figure... if the universe is flat, then actual size is infinite). On an aside, I find the reasoning behind the classical definition of the radius of the electron to be fascinating! On the original question, we're visual creatures. Visualising things is what we do best, which is why quantum effects get us in a tizzy. On another aside, I'm not sure that either the size of the observable universe or the size of an electron are particularly comprehensible in themselves.
