The Economist June 16th 2011 DURING the four centuries that it has been studied in detail, the sun has usually behaved in a regular manner. The number of spots on its surface has waxed and waned in cycles that last, on average, 11 years. Such cycles begin with spots appearing in mid-solar latitudes and end with them near the equator. And the more spots there are, the more solar storms there are around………….