On the 26th of April 1920, in a bit of canny PR, the Smithsonian Museum of Natural History in Washington, D. C. hosted a debate between the astronomers Harlow Shapley and Heber Curtis. The topic was the question of whether or not the 'spiral nebulae' were actually distant galaxies (implying a universe far more expansive than previously imagined) or simply a part of our own Milky Way (implying that this galactic realm was, in effect, the universe).
Regardless of the immediate value of this slightly contrived discussion, it did help push along the publication of works by Shapley and Curtis and in some ways become a model for bringing the nature of the scientific method (and argument) more into the public eye. In fact, back in 1995 the format was resurrected, again at the Smithsonian, for the first of a new generation of public debates. That one tackled the then-unknown nature of gamma-ray bursts. I was lucky enough to be sitting in the audience, having recently arrived in the US as a postdoc at NASA, and was struck by the pomp and fun of it all.
Now, 100 years on from the first debate, Professor Robert Nemiroff and the Astronomy Picture of the Day (APOD) have pulled together another debate - of sorts. This time the question is how the first evidence of extraterrestrial life is expected to be obtained, and instead of having just two debaters, the APOD folk asked a whole bunch of astronomers and astrobiologists to weigh in. You can look at all of the terrific opinions here. For my part I made a short 5 minute video, embedded below.
To read more and view the video, click here.