Sunday, January 15, 2012
The Cheerio Effect
For Science Sunday (a weekly science themed link-up at Adventure's in Mommydom) we explored Einstein's concept of the fabric of spacetime, with a bowl of Cheerios. I think generally the experiment is carried out in a bowl of milk, usually during breakfast, but we had muffins for breakfast, and milk is too expensive to waste, so we used a bowl of water.
First, we observed how the surface of the water seemed to curve toward the edges of the bowl. Then we dropped a few pieces of cereal into the water.
The cereal made "dents" in the surface of the water.
As we dropped more cereal into the bowl we watched as some of the pieces fell into the dent at the edge of the bowl, and some placed close enough together, fell into each other's dents, making it appear as if the two pieces were being drawn together by an invisible force.
That's sort of the way Einstein described what's happening with our planets. It's not necessarily gravity keeping them in orbit around the sun, or keeping the moons around the planets, but just that they've rolled into each other's dents in the fabric of spacetime, sort of like a marble rolling around the inside of a funnel, but without the friction to stop the motion.
"The Cheerio Effect" is of course, an imperfect example, but still fun to play with. The children spent quite a bit of time dropping in Cheerios and Apple Jacks (to simulate a change in mass)...
...and trying to predict the way the pieces would move, based on the position of the rest of the cereal in the bowl.
It's great to be a homeschooler.