DO try this at home!

Homemade catapult

The other day I received a newsletter from Home ScienceTools, a supplier of science materials for teachers, parents, and anyone who wants to do science at home.   This company was started in 1994 in the garage of a chemical engineer and his wife, when they couldn’t find materials for their own children.  Their letter got me thinking about learning science and the value of doing science at home with your children.

Science begins with questions and kids are natural questioners.  We all know that kids have millions of questions and feeding that curiosity helps them build a lifelong habit.  The questions that they ask about are the important ones to start with.  And the ones that come from their observations and interactions with the world provide a natural entryway into hands-on science.  Encouraging these questions and having the tools nearby to explore their ideas, empowers them and removes it from the realm of a homework assignment.

You learn science by doing science, by actively investigating the world around you. Reading about science is wonderful and rewarding.  For really learning how to do science, however, nothing beats looking at a bug under a microscope, digging up some compost and watching the critter, or mixing up cornstarch and water and playing with it.  It is a well-established principle that active involvements with real materials leads to more and deeper learning that simply watching a demo, live or on YouTube, or just reading about it. See How People Learn.  Nothing is wrong with reading science or watching science shows; they are just not as effective as doing hands-on science. Both definitely have a role, especially when they encourage kids to try things out for themselves.

Learning science actively naturally leads to developing skill in the inquiry process used by scientists. When children learn to form their own questions and then to try things out, to experiment in order to gather evidence, they are doing science.  They are doing science the way scientists do science.  It is a short step to recording data, interpreting that data, and sharing their discoveries with others. 

Science is not about amassing facts; science is a process of discovery that generates new knowledge.  For a child trying to make her baking soda and vinegar bottle rocket go higher, she is discovering knowledge new to her that expands her world.  If she is encouraged and supported, then maybe one day, she may be at Stanford experimenting with a new idea in rocket propulsion.  She is now discovering knowledge that is new to the entire world and that expand the possibilities for all of us.

Summer Fun – Simple, Safe Rocket

Blast Off!

Everyone loves rockets.  My students and I never get tired of them.  Besides the fun, there is a lot of good physics learning in carbon dioxide rockets.  There are many ways to make a rocket. 

The simplest rocket I’ve ever found requires only some Alka-Seltzer tablets, an old film canister, and some water.  You just put the tablet in the film canister, pour in a bit of water, and snap the cap back on the film canister.  Then step back.  It only takes a few seconds for the pressure to build up enough for the lid to come flying off with a pop.  How high can you get a lid to fly?  Try varying the amount of water and the number of tablets.  Are more tablets always better? 

Film canisters are the perfect size for the tablets to fit in flat, but any vial with a cap will work.  These film canisters used to be everywhere and you may still have some around the house.  A store that develops film may have them or you can now buy them online.

Add some math to this by making a graph.  Try one tablet, then two, then three, and so on.  Or use fractions, but breaking tablets in half and measure by halves.  Tape a yardstick to a wall nearby so that you can better estimate the height the lid reaches by eye.  Maybe you can catch the lid at the top of its flight near the yardstick with your phone camera from a side angle.  This is a nice use of a new technology to aid in a formerly hard to measure experiment. 

Record how high the lid flew, your Y variable, for each number of tablets, your X or experimental variable on a piece of paper and then try making a coordinate or Cartesian graph.  Make multiple tries, maybe three, for each number of tablets.  What can you learn from looking at your graph?

The graph isn’t necessary to have some fun with science this summer and it may be best to just start by just exploring what happens with the film canister rocket.  After the excitement wears off a bit, you might introduce the idea of the graph.