Saturday, February 23, 2013

Another ivillage highlight: Balloon Racers

ivillage (NBC Universal's parenting website) recycled the Balloon Racers piece from this past summer (page 6) for a piece on reusing cardboard for fun. It's nice to have new viewers to the blog. They link to the preschool tag, so you have to scroll a bit to get to the balloon racers we did in April 2012.

Here's a better link if you are looking for instructions: balloon racers.

Enjoy your racing!

Friday, February 22, 2013

Egg Maracas

We're approaching Easter. It's a good time to reiterate how much I hate eating just eggs, but I have no problem with using eggs for science experiments. Last year's experiments were fairly extensive, but I'll have some new ones to add this year.

The first one comes from an idea listed on Kiwi Crate's DIY website, Egg Maracas. I enjoyed the idea because somehow we end up with collections of these plastic eggs, and it feels so wasteful to just toss them.

Music is very science oriented. Sound, sound waves, pitch, tone, rhythm, etc all have their place in science. I never played a musical instrument, and I was banned from my elementary school chorus. I stuck to dance, which is deeply rooted in music, in particular rhythm and patterns.

Anyways, the basic maraca is easy to make. For each maraca, we used:
- A plastic egg
- Rice
- 2 matching plastic spoons (we collect these too)
- Masking tape (nothing fancy on our end)

What we did:
1. We filled the plastic eggs with rice. Since we had 3 eggs, we decided to use 3 different amounts of rice to see how that would affect the sound.
2. We taped the eggs shut since they seem to easily split open.
3. We placed the spoons so they cupped the egg and the handles met at the bottom. We needed two sets of hands, one to hold the spoons and the egg and one to tape.
4. While one person holds the spoons and egg in place, the other person tapes around the spoons and the egg (just once should be fine) and down where the handles meet.
5. We covered the whole thing (except Big J's maraca) with tape.
6. We decorated the tape with Sharpies (note that rubbing alcohol takes off Sharpie marker in case you have reservations about handing your little one a permanent marker). Crayola rubs off too easily when placed on masking tape.

Lil J, Big J, and my maracas (from L-R)

-Guess which egg has the most rice? You can weigh them or listen to the sound difference. A fuller egg should sound deeper.
- Play a "Simon" like rhythm game where you give a pattern of shakes and your kid repeats them. Get more complex as you go. Let your kid be the leader too.
- Use other items instead of rice. How do beans or pennies sound in your shaker?

**I apologize for the poor lighting and Craisins (and much more you don't see) on our kitchen floor. We were invaded by ants, so what's normally in our cupboards is sprawled on our counters, table, and floors. Good news was this experiment was able to be done in a very small space (and impromptu - right before bed).

Tuesday, February 19, 2013

Pressure on planes

I know my mantra is cheap science, and by no means I think a $3.50 bottle of water from the airport is "cheap", but when you spewed your guts out 11 hrs prior to hopping on a flight, sometimes you have to bite the bullet.

Anyways, I was drinking my water at cruising altitude, closed it, and then slept for the entire descent.

This is what happened to my water:

It was squished, but I didn't squish it! Why did it squish? Well, the pressure up at 30,000 ft (approx cruising altitude) is much lower (~4.3 psi) than it is at sea level (14.7 psi). We're basically sea level where we live in CA. As we descended, the outside pressure increased, putting pressure on the outside of the bottle. Since the air inside the bottle can be compressed by forces caused by the change in pressure, the increased pressure basically crushed the bottle. *Note, that the airplane cabin is pressurized, so we're not feeling 4.3 psi, though I'm not sure what they pressurize it to or how they pressurize it.

I opened the bottle in the car and it immediately equilibrized to the surrounding pressure, popping the bottle back in shape.

If you reverse the experiment and do it on the way up in the air, you might find your bottle pops open by itself as you get higher. This is because the air at sea level has more pressure and is trapped in the bottle. The air up high is lower in pressure. The forces are higher inside the bottle in this situation. So if your shampoo explodes in flight, it most likely did it during the ascent (going up).

This water bottle experiment has amused our little flier on multiple occasions.

Wednesday, February 13, 2013


J's been super excited to help out around the house, so I've been letting him sort the silverware (minus the knives) while I empty the dishwasher. To my surprise, he is good, and I don't have to redo. He is able to sort things by size and shape, a very scientific process. Think of how we label/name animals or plants; it's all one big sorting game. He's learning at 3.5 years old that he can classify objects by using knowledge he's gained from previous experiences, observation, and scientific reasoning - "This is a fork. It's not a knife. It's a big fork, not a little one." He's nailed the silverware; I think he's ready for classifying animals. They might be a little trickier.

Win for an unintended science lesson and getting items checked off of my to-do list around the house.

Sunday, February 10, 2013

J's Window Writing

J wrote his name backwards on fogged up windows, unintentionally. He still learning. I took him outside to look at it. The only thing that didn't look right was his upside down Y, but he was happy with this quick and easy science lesson.

You can also try sitting across the table from someone and writing their name so it's correct for them. It's harder than you think. It's a lesson tutors learn really quickly.

Thursday, February 7, 2013

Evaporation, according to a three year old

My three year old on evaporation: "Sometimes we spill things (like water) outside, and we don't need to clean it up because the sun will sip it up with a straw."

I love his imagination.

I think we might have an evaporation experiment in our near future. Stay tuned.

Sunday, February 3, 2013

Colored Celery Sticks

This colored celery experiment has been on my pinterest list for a long time. I finally decided to buy some celery, and we had some free time last weekend to try a 24 hr experiment. I also consulted this celery experiment for toddlers post our experiment to see their results.

Basic take home message:

Plants need water and use it during photosynthesis (plants need water and light to grow). We can see how the plants take in the water if we use colored water. It also turns the celery different, cool colors!

The experimental set-up:

We decided on 3 colors for the celery experiment: yellow, red, and blue. We filled the cups 3/4 full and used 4-5 drops per color.

J was a great helper.

We also at the last minute decided to add a control, which is something we can use to compare the other celery sticks to when the experiment is over. This celery stick had just water with no food coloring. We only had a small celery stick left at this point.


Big J and I asked J to guess what was going to happen. He had no idea why we colored the water, and his hypothesis had nothing to do with the colors. He did guess that the water was going to go down.

I thought that was a great hypothesis, and I wanted to make sure that J was able to see if he was right. You can barely see it in the beginning, but we used a dry erase marker on the cups to mark just above the water line (it's green on the yellow cup). The dry erase markers washed off in the end, in case you are worried.

Methods continued:

The experiment I pinned on pinterest ended up waiting 24 hrs, but we weren't seeing great results. We documented results at 24 hrs and 48 hrs.

Results, aka what happened:

At 24 hours we were able to see blue spots on the celery in blue water.

Our celery in red had a scratch on it. The scratch turned red and you could see the water leaking out, but there were no colors on the leaves at 24 hrs.

After 2 days (48 hrs), we extracted (took out) all of the celery sticks from the water. Here they are from left to right, no color, yellow, blue, red:

The control (no color) ended up looking healthier after 2 days. It was the smallest and weakest looking celery stick at the beginning. Yellow didn't really have anything to report on. You could see a little yellow in the celery veins leading up to the leaves, but there were no spots on the leaves.

Blue was our favorite. Here's a close-up of a leaf with blue spots and a blue vein behind it, so neat:

Red also gave us some interesting results. Here's a close-up of minor red spots:

And I (carefully) dissected the celery stick to get a better picture of the innards of the celery:

As for J's hypothesis:

All of the colors of water went down. J hypothesis was correct! We didn't compare which one went down more than others, maybe next time. Looking at the pictures from the experiment, there was no super visible difference between the three colors.

Note, that I took the celery out. The height of the water was slightly higher with the celery stick in it, but it was definitely visibly lower than the initial height of the water.

Potential problems with our experiment:

We didn't put the celery sticks in direct light (no space for it in our small apartment). Maybe if we repeat this experiment, I can clear out a space next to the windows.

For older kids:

Definitely don't forget the control. Preferably, your control will look like your other celery before you start. It would make for better comparisons when the experiment is over.

Dissect (cut apart) your results and document everything you see.

Repeat the experiment in different places. Try a dark closet, a window sill, and normal room lighting.

Try different plants. This site says carnations also work.