Floating bubbles

This has to be one of the coolest experiments we've done. Since Jr. Scientist E loves bubbles, I've been trying to find some more bubbly experiments to do with her (although she never gets tired of watching baking sod and vinegar fizz, I sure do). I ran across a cool one where you create carbon dioxide by mixing baking soda and vinegar and then you use bubble mix and blow some bubbles into the container. Since carbon dioxide is heavier than the air inside the bubble mix bubbles, the bubbles go into the container and then come to a rest in mid-air (resting on top of the invisible carbon dioxide). The bubbles will pop if they hit the edge of the container, so you need to do this in a large container with a lot of baking soda and vinegar (ah Costco, the kitchen scientist's best friend). The effect is absolutely jaw dropping and both Jr. scientists A and E loved it.

Noisy noisy balloon

I found a fun sound experiment where you drop a nut (the metal type) into a balloon and inflate the balloon. When you shake the balloon you can get the nut to circle around inside, making a neat whirring sound (thanks to the repeated pattern of the edges). Jr scientists A and E had fun playing with this one. Making the sound is clearly easy enough for a baby - Jr scientist E had no trouble making it go. The only downside is that the nut starts to make tiny tears in the balloon after a few minutes, resulting in an increasingly small (and less fun) balloon. Maybe we should start buying balloons in bulk.

The curious case of gak

We made a batch of gak - mixing cornstarch and water to make something between a liquid and a solid. Jr. scientist A had fun playing with it and making quite a mess. Jr. scientist E's reaction was very interesting. I dipped her hand into the gak slowly (making the gak act like a liquid) and then dipped her hand into the gak quickly (making it act more like a solid). She got a very curious look on her face when the previously liquid gak suddenly seemed solid. I think it dawned on her that something surprising was going on. It was pretty neat to see.

Parachutes

We decided to try our hand at making parachutes. Once again our brave gingerbread men rose to the occasion. Our first attempt used a coffee filter (nicely hyperbolic), and resulted in a slightly slowed descent. Jr scientist A came up with his own design (on the right), which worked better than mine (what does it say when a 4 year old can design a better parachute than you!). Jr scientist A wanted us to make parachutes for him and his sister, but I think such an endeavor might be a little premature.

Hidden bubbles

We found this effect quite by accident. One of Jr. scientist A's new favorite things to do is to mix various ingredients together to see what happens - I think we have a budding chemist! We were adding things to red cabbage-dyed water (a pH indicator). As expected, when we added baking soda, the mixture turned blue, and adding vinegar to the same mixture caused it to bubble and then turn red. What caught us by surprise was that we next added salt and the mixture bubbled again. I had never heard of salt causing a chemical reaction resulting in bubbles, so we did some more investigating. Adding more salt turned the mixture from red (acidic) to purple, as would happen when you added a base, making us think that salt was a base (it's actually neutral). We tried combining vinegar and salt in another cup and got a rather unexciting cup of salty vinegar with no bubbles. After some google-ing, we found out that the salt wasn't actually creating bubbles, it was releasing the carbon dioxide bubbles trapped in our mixture after the baking soda and vinegar reaction. We decided to try adding salt to soda and got instant bubbles again. We even were able to create a little soda fountain (nowhere near as big as the mentos and diet coke reaction, but still cool). Jr scientists A and E both got quite a kick out of this accidental experiment, and I think it will become a new regular experiment.

Rafting

As a first step towards making an air- or rubber band-powered boat, we took some small pieces of corkboard and turned them into rafts (that is, we put them in a pool). Our brave gingerbread man once again sailed out to sea as Jr. scientist A made waves to get the raft to go to different ends of the pool. As for Jr. scientist E, she just giggled every time the raft sailed by her. An unexpectedly fun first step towards a bigger goal.

Paper boats

After some attempts to make floating canoes with paper and glue, which inevitably sunk when the glue dissolved, friend of the lab Arthi provided us with an origami paper boat. We sailed (and sank) our boat in the bathroom sink, much to the delight of jr scientists A and E. The experiment also turned into a surface tension experiment when our paperclip passenger stayed afloat after our boat sank. Remembering back to an old experiment, we added some dish soap and watched the paperclip plummet.

High flying fun

I swear there was a time when I could make paper airplanes that flew, but that time has clearly passed. So I got a book on making paper airplanes (recommended by friend of the lab Arthi). We were able to make a bunch of really cool airplanes (some of which actually took decent flights). Although I got this book for Jr. scientist A, I was surprised at how much fun the younger Jr scientist E had watching the airplanes fly by. She eventually started toddling over to where they fell and bringing them back for another flight. We had a lot of fun seeing how different designs and different modifications resulted in different flight patterns (I have to confess that I started making two of each design because I wanted more turns!). At some point, Jr. scientist A must have decided that the planes were flying because they were made of paper and insisted on trying to fly an (unmodified) paper bag. This isn't the first time that he's gone from observer/participant to actively guiding experiments in new directions, and I have to say I'm a bit proud of that!

Fizzy colors

Looking for a good experiment for Jr. scientist E, at my wife's suggestion I went back to an old fizzy standard - mixing baking soda and vinegar. To make it more interesting, I put down a drop of red food coloring and a drop of blue food coloring, with the baking soda and vinegar in the middle. As the fizzy mess spread, it took up the food coloring. Jr. scientist E just stared intently at the bubbly concoction (I think with interest!), getting transfixed each time I added more baking soda or vinegar to restart the fizzing.

Good clean fun

Today we did an experiment that Jr. scientist A named the messy messy experiment. We made some bubble mix (water + dish detergent)and headed outside to play with bubbles. We used a funnel to make different sized bubbles (depending which end we blew into) and tried out a new bubble maker -two straws connected with string- with mixed results. The experiment ended with playing around in puddles of bubble mix and lots of fun.

Paper helicopter

We did a science experiment I found in the book "The Usborne Book of Science Fun." We made an easy-to-build paper helicopter (takes less than 5 minutes to make). We also made a more durable version out of art foam. Because of the way the wings stick out, the helicopter spins around as it makes its way to the ground - just let it go from a height and it does the rest. We even tried dropping it over a third floor balcony for an extra long spinning flight. A fun little experiment.