Month: February 2011

I had a few experiments in my back pocket for this week, but when I asked Sam what kind of thing she wanted to try, she raised her fist in the air and said “Something with FIRE!”

Okay. I can do that.

Here’s the setup:

• oil
• A glass bowl
• a short candle
• Something to prop the bowl up between (I used two rectangular dishes per the picture below)
• food coloring

I poured a few inches of oil into the bowl, propped it up between the dishes, and put the lit candle underneath it. I then explained to Sam that when the oil at the bottom, nearest the flame, heated up, it would rise up to the top. Then, as it cooled, it would move back down. To help us see this, I used the dropper to put a few blobs of red food coloring in the oil.

At first I was kind of worried, because nothing seemed to be happening at all. I added a second candle, though, and before long the little red blobs began to “blorp” up to the surface in sputters, then scatter and slowly descend just as promised.

I explained to Sam that this kind of hot/cold circulation happens all over in nature, including in the air (which affects weather) and the ocean. Here’s her journal entry:

Experument 9: circulating het …It blrpt up all the letl dots. Its lic ther’s a invesable lin that the bobles go up. It blorpt. Hot oyl flots to the top.

As a bonus, Sam drew a little picture of the setup, which was nice.

Continuing my blogging project for 2011 where I do a science experiment per week with my seven year old daughter.

Okay! Science experiment! Let’s see, Sam was asking about sunsets the other day, so let’s do this one about diffusion of light. Supplies:

1. Jar of water
2. A flashlight
3. Milk

The idea is that the flashlight shines straight through regular water, but mix in a little milk, and the solution starts to diffuse the light, turning it from cloudly white to brownish red.

Only …it totally didn’t work. What we got was light shining through white, milky water. This is hardly exciting nor educational. I declare the experiment a failure, and Sam scribbles through the notes she had in her journal and writes “FAIL!!!” at the top. I chide her for her overuse of exclamation points. Multiple exclamation marks are a sure sign of a diseased mind, a great man once said. I think it was Jesus.

Anyway, while Sam drew frowny faces in the margins of her journal, I set up a backup experiment: Making a Rainbow! Supplies:

1. Shallow pan of water
2. A small mirror
3. That flashlight again
4. A thick piece of white paper

I angled the mirror in the dish of water and shined the flashlight at the submerged part while holding the white paper above the dish. Instantly, a brilliant, sharply defined rainbow sprang to life on the crisp white paper …is what the book said would happen. Instead, nothing happened, and in copious amounts.

Sam sighed loudly and started scribbling “FAIL AGAIN!” in her journal while I muttered halfheartedly about null results and the file drawer problem. I then flipped through the book some more until I found something that was both simple and had to be foolproof: the refraction of light.

Take glass. Fill halfway with water. Put friggin button in the friggin glass. Look, two friggin buttons. It’s friggin refraction!

BEHOLD!

Sam’s final journal entry, in full:

Experumint 8 FOR THE LAST TIME: Seeing dobl. It looks like thar are two butins. This is becas light bens wen it goes throo wotr. This is cald refraction.

I’m going to have to put a bit more thought into next week’s activity.

Continuing my blogging project for 2011 where I do a science experiment per week with my seven year old daughter.

This week I continued rooting through the pantry for supplies, and decided to team Sam about density and why some things float. This was really simple as far as experiments go, but it turned out to be Sam’s favorite yet, plus I was able to get her sister Mandy involved as well. Here’s the supplies:

1. A tall glass
2. Water (I added red food coloring to mine)
3. Dishwashing soap
4. Cooking oil
5. An assortment of small objects that you don’t mind getting oily, oily and wet, or oily, wet, and soapy.

Any three (or more) liquids of different densities that don’t dissolve in each other would work, but these three worked for me. And yes, it’s too bad I couldn’t get them to go green, yellow, red like a traffic light, but I am unable to control the density of these liquids. FOR NOW.

Sam was extremely curious as to why the liquids separated out and didn’t mix, especially after I poured a bit of water on top and she watched it flow down through the oil to join the red layer:

I explained that the three liquids all had different densities, which kind of meant that they were more or less packed together in the same space. Denser liquids weight more than less dense materials, and less dense materials float to the top of denser ones. Sam seemed to get it and inspected the glass carefully while I had panicky premonitions of trying to clean up oil, soap, and water from the kitchen table:

The next part of the experiment was to drop various items into the glass and see where they settled. I explained that this would tell us how dense the objects were, since like the liquids the solids would float on top of anything that they were less dense than. The objects I gathered included a penny, a piece of carrot, a plastic bead, a rock, a marshmallow, a piece of potato, a Lego block, a piece of rubber, and a piece of macaroni. For the first few, I had Sam make predictions about how far down they’d sink, then I had her record her observations.

She absolutely loved doing this, and since this was an activity that basically involved dunking things in other things, Mandy was both able and willing to participate. I think part of the appeal here is that kids love making predictions and repeating trials with slightly different conditions. In this way, they’re natural scientists, and it’s not far removed from how babies learn to do, well, everything. When you’re a kid, most of what you encounter is new, and the only way to figure it out is to do trial after trial and make observation after observation.

Once they had exhausted my supply of small objects, they asked if they could find other stuff to drop in. When I said they could, the first thing Sam nominated was my iPod, which was one sacrifice I was not prepared to make for science. At any rate, not only did Sam love this, she proclaimed that it was the most fun experiment we had done to date. Here’s her journal entry in full:

Experiment 7: Density.
Things that are less density float on things that are more dense. I prdect the marshmallow will float on the oil. I prbekt that the rock will go to the dotem. The peanut floated in the water. The butt rock fell to the botem.

And, as a footnote, Sam did indeed write “The butt rock fell to the botem (sic).” She and Mandy have named the rock in question thus because a streak of quartz in the lower half of the rock does indeed look like a generous backside. Since it was for science, I allowed it.

Continuing my blogging project for 2011 where I do a science experiment per week with my seven year old daughter.

Since we consumed a gas in last week’s experiment, I thought this week we could do the opposite and create a gas using those old standbys: vinegar and baking soda. Since we were at Grandpa’s house this week, it made for a nice easy experiment and I got to raid his kitchen cabinets for supplies:

• Vinegar
• Baking Soda (sodium bicorbonate)
• A balloon
• A bottle or vase with a narrow mouth

(Sorry for the quality of the photos. I forgot to bring a CF card for my camera, so I had to use Ger’s point-and-shoot and backlit lighting to boot.)

I explained to Sam the concept of a reaction –that some things change when they mix with or even just touch other things. That change create a lot of interesting things, including creating a gas. I told her that baking soda and vinegar would make a gas when they mix, and asked her what she thought would happen if I mixed them together and put a balloon over the mouth of the bottle. Sam wrote in her journal:

Experument 6: Makeing gas. I prdikt that the dlon will explode.

Yes! Explosions! With that in mind, I poured a few cups of vinegar into the bottle, filled the balloon with baking soda, and stretched the tip of the balloon over the mouth of the bottle without letting any spill in. I then told Sam to upend the balloon and dump the powder in:

The reaction –in all sense of the word– was pretty great. The mixture fizzed violently and the balloon started to expand like a big fat exclamation mark, which actually caused Sam to shriek and dive under the table, fearing that her prediction was seconds from coming woefully true:

Honestly, I got kind of alarmed myself for a second; the book hadn’t provided any guidance on the amount of mixture to create, and I had just begun worrying about the best way to get globs of baking soda and vinegar off of a ceiling when it finally eased off. Instead, I ribbed Sam about her squeamish reaction and made her practice her maniacal mad scientist laugh and give me ten good shouts of “I’LL SHOW THEM! I’LL SHOW THEM ALL!” to make up for it.

Then she finished writing in her journal:

The ballon bloow up. The vineger and the baking soda made a gas.

Next week: we waste more foodstuffs while learning about density.