the best might be done currently would be to set limits on that variation and see whether the prediction falls in that range.So, as far as I know, there is no satisfactory answer to *why* the universe happens to have (at our, present, energy scale) the strong force stronger than others,......
See the figure at the end of http://hep-www.colorado.edu/~nlc/SUSY_Wa…
(the horizontal axis represents the logarithm of the energy scale, mu, and each line represents the strength of a coupling at a given energy scale). Unfortunately, those energies are too high for the current technology; I don't know whether it'll be possible to test that prediction in the near future, the best might be done currently would be to set limits on that variation and see whether the prediction falls in that range.
So, as far as I know, there is no satisfactory answer to *why* the universe happens to have (at "our", present, energy scale) the strong force stronger than others, and by the amounts that they have.
I'll gladly concede to other responders if they can provide a better, substantiated, explanation. Otherwise, I invite you, if you're so inclined, to take Physics as your career and help answer that (and other) questions. ;-)
"Why" questions don't work for science questions like this. It's just a basic fact of the way things are. And by "basic", I mean that there aren't any reasons for it, there is nothing more fundamental that "causes" the strong force to be how it is.
The best we can do is to point out that if the strong force was much weaker or stronger, we wouldn't be here to discuss it.
"Why" has no place in science. It is a never ending question. Ultimately though "why" would be a philosophical question. Since "why" something is done can only be answered by the person who makes it happen. If you're asking WHY the strong force is stronger then you're implying that some creator of the laws of physics decided to make it stronger. If you mean to ask HOW is it stronger........well that's a good question.
