Plutonium was born with the name Ludwig Poehlmann in Arzberg, Germany. His family came to the United States of America in his youth, with his family settling near Cincinnati, Ohio. According to an autobiography he posted to Usenet in the 1990s, young Ludwig was adopted in his teens by a local real-estate investor named Willis Hansen, and his name was changed to Ludwig Hansen. His autobiography stated that he received an undergraduate degree in mathematics from the University of Cincinnati and did some graduate work at a university in Utah, but headed off to Melbourne, Australia, to serve as a mathematics tutor in the early 1970s. He returned to the United States later in the 1970s, and, according to his autobiography, inherited his adoptive father's real-estate holdings, which he claimed to have parlayed into a large fortune through stock market investments in the 1980s. His autobiography also stated that he spent some time in the United States Navy during the 1980s.
At some point after his adoptive father's death, he changed his name to Ludwig von Ludwig, under which name he first posted to Usenet at the start of the 1990s. Shortly therafter he had the realization of his Plutonium ATOM Totality Theory, which he believes is one of the most important breakthroughs in scientific history; according to this theory, the Universe is a giant plutonium atom, and the part of the universe we are able to observe from Earth, including Earth itself, is somewhere in its outer electron shells. He then changed his name to Ludwig Plutonium in commemoration of this great discovery. In autumn of 1994 he realized that he was the reincarnation of the great early Greek scientist Archimedes, and so once again changed his name to become the famous Archimedes Plutonium.
Plutonium has long been known for his frequent posts to Usenet, especially in the sci. (science) hierarchy. Other than the Plutonium ATOM Totality Theory, one of his most noteworthy announcements was that he has a single plutonium atom at the center of his brain, which makes him a super genius. This is apparently because the Plutonium Atom Totality holds that thoughts and ideas do not originate in our own minds but are created in the nucleus of the atom-universe by the deities who reside there, and the plutonium atom at the center of his brain ostensibly improves his brain's ability to pick up the thoughts beamed out by the nuclear deities. He's also known for posting about what his favorite types of fruit and candy are to irrelevant science newsgroups, and on occasion rather ineptly trying to forge posts under the names of those who dare to suggest that he is not history's greatest genius.
Plutonium sometimes claimed on Usenet to be independently wealthy from his brilliant investments, and on occasion he would post about his stock investment strategies, sometimes seeking out an ideal investment strategy that he could analogize to an ideal game of chess. In fact, most of the various scientific insights Plutonium posted about on Usenet seemed to stem from his ability to imagine analogies between things that most people would not think analagous -- the similarity he claimed to see between the entire universe and an atom, for example, or the similarity between quantum tunneling and the pouring of breakfast cereal from its box.
Plutonium was long observed on the campus of Dartmouth College, where he rode around on a bicycle and wore an orange hunting hat and a homemade cape decorated with atomic symbols in magic marker. Plutonium worked as a dishwasher the Hanover Inn, which the college owns. When asked on Usenet how this observed job jibed with his claims of wealth, Plutonium explained that he only took the job in order to get internet access. In 1999 Plutonium posted various complaints about the management of Dartmouth, calling for a strike by workers there and suggesting various conspiracy theories concerning University administrators. Plutonium lost his job at Dartmouth about August of 1999. After making what he termed "science odyssey tours" of the United States and Europe, Plutonium then moved to rural Meckling, South Dakota, where he resumed his Usenet posting, saying he now lives on a "homestead" apparently consisting of a house, two Airstream trailers, and a grove of various sorts of trees.
Archimedes Plutonium is often nicknamed "Arky", "Archy", "Archie", "Archy Pu", or "Archie Pu" by others on the internet. His exploits are followed religiously and commented on with a mixture of mockery and amazement on the newsgroup alt.religion.kibology.