Why no Magnetic Monopoles

Why is it that magnetic monopoles do not exist in nature, though their existence has been confirmed theoretically?
- Vishnu (age 14)
Hyderabad, AP, India

The best guess is that magnetic monopoles could not be created after the universe cooled down to some extremely high temperature. After that time, it seems there was a period of very rapid inflationary expansion, which stretched out the universe so much that the monopoles would be extremely rare in any region. There are lots of pieces of evidence that fit with the inflationary picture, so it's not just an excuse for not finding monopoles. However, other physical pictures may turn out to have similar implications. One proposal is that there was a very energetic collision between 3-dimensional worlds in some higher-dimensional space. It turns out the consequences would look a lot like the aftermath of inflation. Some very subtle differences in the predicted ripples of the background radiation in fact favor this collision picture, but it's still to early to call.

Mike W.

(published on 04/07/2008)