Dr Phil JudgeHigh Altitude Observatory
National Center for Atmospheric research
Boulder, Colorado, USA
In 1950, Enrico Fermi and friends were having lunch, looking over a cartoon showing aliens cheerfully emerging from a flying saucer. Fermi asked, "Where is everybody?", referring to the lack of space ships. Fermi speculated that interstellar flight is impossible, or judged to be not worth the effort, or technological civilizations don't last long enough for it to happen. While none of the diners thought Fermi was questioning whether extraterrestrials exist, this story has evolved, mostly into answering this very question. "If we are we alone, why?" has become known as "Fermi's paradox".
I will discuss this question from a physicist's point of view, and what might be our best shots at a (negative!) answer, and why now is an especially exciting time in this area. We will meet several surprises along the way.
Philip Judge is a Senior Scientist at the National Center for Atmospheric Research, Boulder, Colorado, USA. He works on the physics of the Sun's atmosphere, having previously worked on the atmospheres of giant stars.