Note: This story originally ran on March 13, 2012.
Superstitions and talk of paranormal activities tend to sweep in at Halloween.
There are the ghoul-filled holiday's ghost stories, black cats and haunted houses. But what about free-standing brooms?
Do a quick search on the Internet or listen to broadcast media reports and you'll hear about "researchers and scientists" who are saying that a broom can stand on its own because of things like the moon's gravitational pull, the equinox or the way the planets have aligned.
Some even suggest spirits are at work.
But Joe Ross, a professor of astronomy and physics at Texas A&M University, said it's easy to explain why a broom can stand on its bristles unassisted, and it has nothing to do with the planets or anything -- or anyone -- beyond the planets.
It's simply a balancing act, he said.
"One thing I can say with certainty, the pull of the moon has nothing to do with this phenomenon," said Ross.
If the moon's pull was enough to cancel the force of gravity and make brooms spontaneously stand up, Ross said, they would also be able to float.
There is a small reduction in gravitational force when the moon is directly overhead, he said, but it isn't enough to change the behavior of a broom. Nor is the free-standing broom related to the alignment of the sun, such as the equinox, the two times of the year when the sun crosses the equator and day and night are about equal in length.
The broom can stand by itself, he said, because the center of gravity is directly above the edge on which it balances. And the bristles are soft enough to spread out a bit at the contact point with the floor and provide a stable base to support the handle and allow the broom to balance.
Ross said the idea that gravitational force plays a role may be so widespread because it sounds more exciting than the real explanation.
The changes in gravitational force as the planet moves relative to the sun and moon can be measured at about one-million times the average gravitational force, he said.
"I suspect that there may be some misconceptions to the effect that gravity becomes noticeably 'tilted' as the Earth and moon move, but that effect is so minute as to be nonexistent," he said.
So, mystery solved.
Now, if we could just get the broom to sweep the floor by itself.