Between my website, Facebook, and other social media, I tend to get into a LOT of conversations about science, especially controversial topics such as climate change, genetic engineering, evolution, vaccines, nuclear power, electromagnetic fields, etc.
Understanding chemical and physical changes is a strange part of science. Once you learn to use chemical equations, it is so simple that no one even thinks about it. Before you learn to use chemical equations, it is so complex that most people don't really understand it. For a better view of that, you might also read Changing How We Look at Changing.
Notice that the definition of a rock does not say that it has to be inorganic. Some sedimentary rocks are organic, made up of materials that were once part of a living organism. Since minerals cannot be organic, organic rocks may not contain any minerals.
In looking at the food web, we are trying to see how energy is transferred from one living thing to another. As part of that study, we need to be able to measure that energy. Luckily that involves something that you are probably very familiar with.
This experiment started out as a Science Photo Challenge and got such a great response that I wanted you to experiment with it yourself. It is a wonderful physic puzzle, and offers interesting insights into the science of force and motion.
To try this, you will need:
a paper plate
a marble or other small ball
Lets start with the question from the Science Photo.
This is another of those fun bits of science that many of us think we understand until we really start to look at it, or even better, try to explain it to someone else. Then we reach a point where it becomes obvious to ourselves, and to our audience, that we don't understand it as well as we thought we did.