It is sad that we have so many people thinking they have profound understanding of things they actually know nothing about. It is actually slightly true that all things have a negative aspect but in the case of nano tech and nuclear power they can both do far more good than any harm likely to flow from them. A simple example if we had no nuclear power plants we would have far more coal power plants. The use of coal murders people in large numbers. Take a look at W. Virginia's official sites about fishing. One meal a year is the maximum of fish allowed in a diet in many streams and lakes while the rest is one meal every six months. In essence there is no place in W. Va. that coal has not loaded with mercury and lead to the extent that all surface water is now toxic.