Whoa, amasci.com traffic spike!<p>Heh, wasn&#x27;t there a Larry Niven SF story where an alien weapon would zero out the charge of electrons, so the nuclei would fly apart?  Our undergrad phys-101 had calculating the force between two (copper!) pennies 1M apart, with all electrons removed from one and deposited on the other.<p>Later I realized that it would have been even more impressive to estimate the energy-equiv of kilotons of TNT which would be released when the meter-long spark brought the two pennies back into equilibrium.<p>Another:  calculate the width of one coulomb.  It&#x27;s about half a mm, like a grain of sand.   That&#x27;s assuming its the mobile electrons in copper wire (so, not Cu&#x27;s electrons, but just one free electron per atom.)