Full Moons and Lunacy
Published on Nov 17, 2005 at 8:03 pm.
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Filed under sky lore.
Yesterday was the full moon. This occurs roughly every 29.5 days when the Moon is on exactly the other side of the Earth from the Sun. Thus, the face of the Moon that we see gets full sunlight, which is reflected back towards Earth. —> Full Moon
Most people don’t really realize how bright the full moon can be. When I got home from teaching my night class, I went out to the mail box to collect my mail. I was able to read it by moonlight, and was able to determine that the mailman had put one letter in my mailbox that really belonged to someone of the same number address, but on a different street. Now, you wouldn’t be able to do that after just walking out of a brightly lit building, but it is easy to read by moonlight after you let your eyes adjust. The full moon is about 30,000 times brighter than the brightest star in the sky, Sirius. It is nowhere near as bright as the Sun, of course, being only about 1/444,000 as bright. However, the human eye is capabable of detecting an absolutely amazing range of light intensities.
As for the old stories about the full moon making people act crazy, I don’t think that there is lot of credence to that. Often doctors and nurses in hospital emergency rooms, police officers, etc., will say something like “Wow, we are busy tonight! It must be a full moon!” Then, without even checking, everone else assumes that it actually is full moon, and so they think that they have evidence that the full moon makes people act crazy. If they do happen to go outside and look up and don’t see the Moon, then they just figure that it must be behind a building or something. The actual scientific studies that I’ve seen don’t really show a lot of evidence supporting this contention, with only a couple of exceptions. One problem is that most studies done are done with poor sampling procedures, no real control groups, etc, so any results are suspect. I try to look at only the really well done studies. I did read a few such studies done some time back that indicated that there was a very slight increase in violent crimes around the full moon, but only in urban areas. My feeling is that people are simply more comfortable being out at night if the Moon is full or nearly so, making it easier to see outside. With more people outside, particularly drunk people right after a night of drinking, then you simply have more interactions, which leads to more fights, arrests, etc, and an increase in violent crime statistics. Even so, it is marginal. More recent studies don’t even show this increase, and that may be because there has been a significant increase in outdoor lighting at night, so the Moon lighting things up has had less of an effect. Just my hunch, completely unsubstantiated.
-Astroprof
