Dr MARK DENNY pursued research in theoretical physics at Edinburgh University and Oxford University, before embarking on a 20-year career in the aerospace industry as a radar and sonar systems engineer. He authored over fifty technical papers on many subjects in physics and engineering. Mark is now retired and lives on Vancouver Island in western Canada, where he has written fourteen popular science books.
Dr ALAN MCFADZEAN conducted research in Astronomy and Astrophysics at the Universities of Saint Andrews, Central Lancashire and Birmingham, UK which gave him his first exposure to space-based platforms. He then moved on to a career in engineering, working on both airborne radar and metering systems for oil and gas production, although not at the same time. Alan lives in Edinburgh, Scotland. This is his second popular science book.