Lead, iron and uranium are nothing compared to ununseptium, the temporary name for element 117, an extremely heavy combination of berkelium and calcium isotopes created in a particle accelerator in Dubna, Russia. The new element existed for only the tiniest fraction of a second before vanishing again — and it must be independently created elsewhere before it earns a permanent spot on the periodic table of the elements — but the fact that it remained stable for even the fleeting instant it did is promising. The heavier artificial elements get, the less stable they become, until they reach a point at which the curve turns back up and they begin to last longer and longer. Ununseptium is on the upward part of that arc suggesting that what physicists call "islands of stability" may exist, at which the heaviest elements of all could last for months or years. The periodic table, it seems, has yet to be fully set.