Saturday, April 12, 2008
The Wheels of Science
One of the points I'm going to make in my current nonfiction project is that science is self-correcting, although the process is not necessarily fast. Consider the story of the Martian canals. Initially, it appears that an Italian astronomer named Giovanni Schiaparelli observed channels on the Martian surface in 1877 that he referred to as “canali,” which was translated into English as “canals.”
An amateur American astronomer named Percival Lowell became fascinated with the topic and had an observatory built in Arizona through which he studied and mapped Mars. Lowell published a book in 1903 that included detailed maps of Mars, including an elaborate canal system. Lowell suggested that the “canals” were irrigation waterways used by the Martians to bring water from the poles down to the rest of the planet.
The public’s imagination was captured, and two writers who were strongly influenced by the story of the canals were Edgar Rice Burroughs and Ray Bradbury. There was, however, intense disagreement among scientists as to whether the canals existed at all, and, if so, what that existence meant. Some astronomers claimed to see them; others did not. Some thought that they were natural features or mere optical illusions, while others believed them to be genuine evidence of intelligent life on Mars. It wasn’t until humans sent the Mariner probes to Mars that we discovered that the “canals” appeared to be nothing more than optical illusions aided by wishful thinking among some observers.
The scientific story of the Martian canals finally ended in 1971 when Mariner 9 obtained close range photographs of the Martian surface and showed no canals. From 1877 to 1971 is almost 100 years in which the possible existence of canals on Mars remained ambiguous. But in the end, the evidence triumphed. An error was corrected. This is the way science works.