1. The Earth Has More Than One Moon
Like you, I went absolutely cross-eyed with rage when they dropped this bomb in 2003 and subsequent years, periodically updating the number from two to "one or three" to, at last count, 18,000. "No! There's one moon, that's why we call it
the moon!" raged Alan Davies, and so did we all. I grant that I might be overreacting to this one, astronomy nerd that I am, but still.
The goddamn moon. True, the International Astronomer's Union (IAU) has surprisingly lax definitions for what constitutes a moon. There are exactly three: They are distinct, whole objects (i.e. not a piddling collection of space cruft). They are solid objects (i.e. not a ball of gas). They orbit a more massive body, usually a planet or other large body that itself orbits a star. Since the first moon ever observed was our own moon, the larger point is that a moon, strictly speaking,
should behave like our moon. For now. If observation leads us to realize that our moon is an anomaly, the rules will be altered accordingly. And the rule most important to us, in this QI case, is that last one. What, exactly, is an orbit? The 18,000 objects referenced in the K series do not exhibit anything like a typical orbit. The moon has been in orbit with the Earth since its creation 4.5 billion years ago. It hasn't wandered out of our field of vision or out of the gravitational influence of Earth since. This is actually really good news for us, as
the loss of the moon (especially early on in the Earth's early years) would have been (or would be) disastrous. Of course,
it might take a while for us to see the worst of it. Naturally occurring space junk that drifts into the Earth's orbit for ten or twenty thousand years only to wander off again is hardly in the same class as our own moon. Nor are wandering bodies that complete an "orbit" every 700 years or so out of little more than happenstance and blind luck. Remember, again, that the rules for being classified as a moon are based on the behavior of our own moon (the big bright one you can usually see in the sky at night). Pretending otherwise just for the sake of trolling the audience and costing the panel members points, while funny, also misses the point. Or maybe I'm the one missing the point.
Have you noticed any other instances of QI nonsense? Share them in the comments!