Monday, March 26, 2012

Colorful cauliflower

We had some extra cauliflower so we decided to do a capillary action experiment. We filled a small glass with water and food coloring and suspended some cauliflower over it with the stem in the water. We let it sit out overnight and in the morning Jr. scientist A came bounding over to me shouting "the experiment worked!" Clearly a winner.

Tuesday, March 20, 2012

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.

Tuesday, March 6, 2012

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.

Sunday, March 4, 2012

Jr. scientist A's experiment

A day after the anti-gravity pepper experiment where we used electrostatic charge to draw pepper to a balloon or plastic spoon, Jr. scientist A came up with a new experiment all on his own. He decided to try to catch light by rubbing a spoon against his head and holding the spoon near a light. He was off on a couple of details from our previous experiment (the spoon needs to be plastic and it only works with very light objects that can build up a charge), but it was definitely the most sophisticated experiment he's come up with to date.

Friday, February 24, 2012

Anti-gravity pepper

I didn't expect this to be such a cool effect. We put some pepper on a sheet of paper and then built up an electrostatic charge on a balloon by rubbing it against our hair (Jr. scientist A thought that was pretty funny). As we brought the balloon close to the pepper, the pepper became positively charged and started flying up off the paper and onto the balloon. As we held the balloon in place, more pepper kept flying up (and down) for a few seconds. It was so neat we kept repeating the experiment, trying to build up an electrostatic charge in different objects like plastic spoons (worked well) and cups (not so well). Jr scientist A and the senior lab members watched in amazement.

Tuesday, February 21, 2012

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.

Sunday, February 19, 2012

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.