Welcome to Geo42!

Geo42 is a term that John and Tina Callahan conceived as an homage to Douglas Adams’ “The Hitchhiker’s Guide to the Galaxy” five-book trilogy and the quest for the “The Answer to the Ultimate Question of Life, the Universe, and Everything.” After some very deep thought, the answer was ultimately determined to be 42. As to what exactly is the ultimate question???? Well, that’s different story, and required a long-term experiment called…Earth. The idea that the question and the journey it entails is more important than the answer, is something that we believe is true. The “Geo” part, of course, meaning “relating to Earth”. Not only in the sense of land/ground, but also the atmosphere, oceans, biosphere, and ice. (I guess the people too…) You could look at Geo42 meaning “everything Geo” or simply as a catchy (domain) name that is easy to remember.


This site is a joint personal website for John and Tina Callahan, climate scientists in the Newark, Delaware region.