Take Home Labs

view of lake oil experiment

“What are we doing to help kids achieve?”

A couple of years ago I was involved in a professional development program at Miami University called “Project TIMU”. As part of the inquiry program I worked to develop some inquiry lessons. Part of one lesson was an experiment inspired by Phillip Morrison in the video series “Ring of Truth”. Phillip Morrison took a teaspoon of olive oil and carefully poured it on a lake. The oil spread into a thin round slick. He converted the teaspoon to milliliters. This is the starting volume and it is the same as cubic centimeters. He then estimated in meters the diameter of the round oil slick at its maximum diameter. From the diameter, he calculated the radius. He reasoned that the oil slick is similar to a cylinder with a really small height (thickness). So, the volume of a cylinder equals pi times the radius times two times the height. Phillip Morrison had in cubic centimeters, the diameter in centimeters and then solved for the height of the oil slick. He reasoned that whatever the pieces were that made up the oil could not be larger than the thickness of the slick. He quickly showed how to prove with extremely simple methods the approximate size of molecules and compounds. He concluded that the particles that make up “stuff” must be small....and he was able to quantitatively show an order of magnitude of "small".

I thought this was so clever I tried to incorporate it into a project. You can watch the video I created below. Word of caution....Phillip Morrison is a professional and a scientific genius. I have been told I have the perfect face for radio. However....I still like the experiment. I got to thinking....why am I doing this experiment? Why not have students do it?

Lately there have been several factors that are forcing me to stretch my imagination. Several teachers I know have had circumstances present themselves in which they may not always be able to provide lab experiences in a traditional lab setting. They still want to provide students with rigorous problem solving situations that require students to use the scientific method. Could rigorous take home labs possibly be the answer? Can students do great problem solving outside of the classroom? So I got to thinking, what would a rigorous take home inquiry lab experience look like? Could a student estimate the order of magnitude of the size of a molecule with a pond and a teaspoon of olive oil? What other ideas are out there? What about cooking and chemistry? How cool would it be to do quantitative and qualitative analysis on something that you could ultimately eat? So....I am putting out an “all call”. Does anyone have any great take home labs? Please share...I promise I will also...and I am sure the kids will love what we come up with...