Four great science projects
Before Victor Frankenstein created a monster, we bet he made a heck of a mess. But, hey, that's what science is all about, isn't it? After all, Sir Isaac Newton's mom probably wasn't crazy about her son messing around with her apple tree, and Mr. Edison couldn't have been pleased when young Tom, trying to create a human balloon, tricked a friend into quaffing a huge baking-soda cocktail. But kids will be kids...and budding scientists will be budding scientists. And the two seem to go hand in hand. What child hasn't been caught pouring his sister's grape juice into his orange juice, just to see what happens? Kids have a natural desire to understand how the world works, long before anyone tells them that's science.
Now, we know that when some parents hear science they see goofy high school teachers, Bunsen burners and a poor pickled frog on a dissection tray. But science is much more than that. As the following experiments show, it's full of pops and sparks and amazing reactions: clay monsters that attract lightning, colored fluids that don't mix, lemons that power clocks. Even those of us who understand how these things work can't help feeling there's a little magic involved. So, grab your best lab coat and walk this way to the laboratory. We guarantee you'll get a reaction.
Maybe it's the spirit of experimentation, but something about science reminds us of the very groovy seventies. So, it's only fitting that we offer this retro-vention, which uses the principles of immiscible liquids (fluids that just won't mix) and density to create a homemade version of that classic mind-expanding device, the Lava Lite.
Water with food coloring added
Shaker filled with salt
DIRECTIONS: Fill a glass jar with about 3 inches of water and add food coloring until the shade matches the tapestries in your pad. Add 1/3 cup of vegetable oil and wait until the layers settle. Watching carefully, shake salt into the jar while you count to five. The oil and salt should form a glob and sink to the bottom of the jar. As the salt dissolves in the water, the oil should float back to the top. Keep adding more salt to watch the action repeat.
WHY IT WORKS: At first, the oil floats on the water because it's lighter--or, more accurately, it's less dense than the water. It also doesn't mix with water, so it won't dissolve. The salt, however, is denser than the water and does dissolve. When you shake it onto the oil, it clings and drags a glob to the bottom. In time, however, the salt starts to dissolve in the water. At a certain point, it can no longer hold down the oil blob, which then floats back up to the surface.
It was a dark and stormy night, and Dr. Frankenstein was pondering how to bring his monster to life. Chilled, he yanked a woolen sweater over his head, and as the sparks flew, he suddenly cried out, "Eureka!" Not the way you remember it? Well, we may have gotten a few details wrong. But we do know that the force that frizzed the good doctor's hair can certainly be impressive. See for yourself with this tribute to static electricity.
Large metal paper clips
DIRECTIONS: The first step is to create a monster--literally--out of clay. Any shape creature will do, just be sure to insert paper clips somewhere into its body (we favor the side-of-the-neck look, like you-know-who). Bring your monster--and your lab assistants--into a darkened closet, and rub an inflated balloon against a piece of wool for 30 seconds. Hold it close to, but not touching, the paper clip, and watch the spark jump between the balloon and the paper clip.
WHY IT WORKS: All that rubbing causes some electrons from the wool to collect on the balloon, giving it a negative charge. Holding the negative balloon near the neutral paper clip causes the electrons in the clip to move away (the two negative forces repel), leaving the metal surface with a positive charge. When the charge is great enough, the air between the balloon and paper clip becomes charged, too, creating a path where the electrons can move--and letting the sparks fly.
NOTE: This experiment works best in low humidity.
Ladies and gentlemen, children of all ages, behold the phenomenal power of ... a plastic spoon? Hard to believe, but this simple piece of disposable flatware possesses properties that can truly amaze those who aren't in the habit of playing with their eating utensils. Even more miraculous, it can keep everyone happy if the restaurant kitchen is slow in bringing out your food.
Ground black pepper
DIRECTIONS: Sprinkle salt and pepper on a tabletop and mix them together. Challenge a lab assistant to use the spoon to separate the pepper from the salt. Have pity on him after a few seconds (hey, we said seconds, not hours!). Retrieve the spoon and rub it vigorously on a wool scarf. Then hold it about an inch above the mixture (but not touching). The pepper will leap to the spoon and stick to it.
WHY IT WORKS: Rubbing the spoon gives it a negative charge, which attracts the pepper. It also attracts the salt, but the light flakes of pepper rise up before the heavier grains of salt. If you lower the spoon, the salt will jump up too.
ANOTHER TRICK: Hold the rubbed spoon over some puffed rice cereal. The grains jump up to the spoon, hang there and then--if there's enough static charge--suddenly fly off.
WHY IT WORKS: The grains are attracted to the negatively charged spoon and cling to it until they, too, become negatively charged. Then, because like charges repel, they shoot off.
You'd think that forcing a hard-boiled egg through the mouth of a milk bottle would be darn near impossible (or at the very least, result in egg salad). But with some hot water, you can harness the laws of physics to do the work for you. So, go suck an egg. You'll be amazed.
DIRECTIONS: First, try it yourself: Set a peeled, hard-boiled egg on the open mouth of a glass milk bottle and try to push it inside without breaking the egg (or the bottle!). Give up? Here's a better way. Place the egg into a bowl of cold water. Have an adult place the milk bottle under a stream of hot tap water for a minute or so, then, wearing dish gloves to protect her hands, empty the water down the sink. Immediately place the egg, tapered side down, on the mouth of the milk bottle. Watch carefully. The egg slowly gets sucked through the neck and--with a satisfying thunk--drops into the bottle.
WHY IT WORKS: The hot air inside the glass bottle is less dense (and thus at a lower pressure) than the cooler outside air. The difference creates suction, which pulls the squishy egg through the bottle's neck.