To continue the theme of beach science from the last few weeks, today let’s investigate something else found at the beach.
Boats!
Children are fascinated by boats and floating. You can do a lot of interesting science projects with boats, starting with some basic questions: How can huge pieces of heavy metal float? How are boats propelled? Can you really make a boat out of paper?
We already have covered some floating and boat topics in previous posts.
Why Things Float contains some experiments on floating and sinking.
The Bathtub Buoyancy Challenge asked kids to find ways to propel boats across a bathtub without using their hands or electrical motors. The Bathtub Buoyancy results show several ways to propel toy boats.
It is always fun to build bathtub-sized boats. This video shows two handmade boats powered by battery packs and small electric motors that my son invented recently. A modified toy car powers the paddle boat; the air boat fan is a modified toy airplane propeller.
This week we are continuing our series at the beach. Check previous posts for sand science and seawater science.
Have you ever found something plant-like on the beach and wondered what it was?
Seems like a lot of beach plants are hard to classify. Are they algae, a sort of seaweed, or are algae and seaweed the same thing? Are algae plants or do they belong to a different kingdom? These are all good questions, and scientists are just beginning to answer some of them.
Many of the plants and plant-like creatures you see at the beach are technically algae. For example, kelp are giant brown algae.
Algae come in many colors, like these red ones.
The green algae are often found in freshwater ponds and lakes.
Ready to learn more? Here are some suggestions for activities to investigate algae. I’d love to hear your ideas, as well.
Activity 1. Make an algal collection
Gather algae on the beach and keep it moist in seawater. If you have never worked with algae, the Hawaii Botany Department tells you how to make an algal herbarium. Or if you don’t want to disturb nature, you can take close up photographs of what you find.
Once you have a collection, visit these websites to help you identify what you have.
Find out as much as you can about food chains in the oceans. Gather, print and cut out pictures of ocean critters to illustrate your own posters of food chains or webs.
Once you have an idea what to look for, head to your kitchen and check to see if you have any foods that contain carrageenan or other products made from algae. Look at the cookbook listed below (or a similar one), and make some of your own dishes using algae. Asian markets are often an excellent source of ingredients.
If you are interested, a fun research project would be to investigate all the ways people use algae for food throughout the world.
Activity 4. Other important uses for algae.
See if you can make a list of other uses for algae. Here are some I found:
Algae are thought to make much of the oxygen we breathe.
This video shows a camera zooming in on the leaves and then the cells of a common water plant, Elodea. In the cells you can see the chloroplasts moving around. The chloroplasts are the sites of photosynthesis, the process that turns sunlight into chemical energy we can use as food. A by-product of photosynthesis is the release of oxygen. Although Elodea is actually a vascular plant, the process in green algae is the same.
If providing food and oxygen weren’t enough, now scientists have discovered ways to use the oils found in algae to make biodiesel. In fact, algal oils can be made into jet fuel. See this previous post for more information about algal research at ASU.
If you are interested in algae, here are a few books you might want to try:
Today we are going to continue our series on beach science by looking at sand. Although not all beaches are sandy, if you are lucky enough to visit one you can do some interesting science activities and experiments.
1.   Where does sand come from?
Find a tough metal or heavy plastic container with a tight-fitting lid. Add some relatively clean pebbles inside (a mix of different kinds works best). Close the lid tightly and let the kids shake it for as long as they want. Even after a few minutes, if you pour the pebbles onto a white piece of paper you will begin to see chips of rock that have broken off.
Or if your child has some rocks in a rock collection that have been jumbled together, you will often see “sand†starting to build up in the bottom on the container. When rocks bang against rocks they break apart.
Now think about where rocks might tumble against each other in nature. Where might sand form?
2.   Sand grains “from an ant’s eye view.â€
One of our favorite exhibits at the local Arizona Mining and Mineral Museum shows different types of sand from “an ant’s eye view,†that is magnified so the grains look like boulders. When you pack for the beach, consider taking a sturdy magnifying glass to explore the sand up close (and any creatures you might encounter).
If you don’t have a magnifying glass or microscope to study sand grains, check out A Grain of Sand Picture Gallery. Wow! These pictures are from a book of the same title listed in the books for adults and older children below.
Quite by accident we discovered that if you roll a magnet through sand, you can pick up bits of particles that contain iron. Note: it is really hard to get the iron bits off again. Put your magnet in a plastic sandwich baggie and it will make clean up much easier. You’ll be amazed at what your children will pull out of the sand.
4.   Sand and Water
Sand and water play is so important for children, even older ones. All you need are a few buckets, old plastic tubs and maybe some shovels and you have the recipe for some serious study.
by Patricia Lauber and illustrated by Holly Keller
by Rose Treat and Randy Duchaine
by Ellen Prager
by Gary Greenberg
by Michael Welland
