Chanukah science...spinning tops

What do bicycles, frisbees, yo-yos, hula hoops, dreidels, and even the earth have in common? They all spin, and so long as they spin the better they are at resisting what gravity is trying so hard to get them to do, which is tumble and fall.

This week we talked about how dreidels work and then we observed the optical illusions produced by spinning tops with different colorful patterns. We finished up by making our own tops using old CDs.

Daffodiaries

The daffodils we planted in the yard are just starting to emerge from the ground. We can see a few tiny shoots. On the other hand, the bulbs growing inside show visible changes day-to-day. That's why we decided every kid should have a bulb of his own to plant and observe at home. Weekly observations just aren't enough! The kids made special diaries, "daffodiaries," to keep track of how their bulbs develop.

You can plant a daffodil outside in the soil, but we decided to "force" our bulbs to grow indoors without soil, so that we could better observe the changes.  The downside of doing it this way is that the daffodils will take in fewer nutrients for NEXT year's growth. With the exception of water and sun, everything the flower needs is already packed inside the bulb.

With that in mind, here's what we're going to do when we get home:

1. Find a small glass bowl. 
2. Fill it with some rocks, marbles, legos, etc. 
3. Place the bulb on the rocks/marbles/etc. pointy side up.
4. Pour just enough water into the bowl, so that ONLY the base of the bulb is under water.
5. Leave the bowl in a sunny spot, and wait and see.

Within a day or two we hope to see roots, and not long after, a shoot coming out of the top. We just need to make sure that the roots have water, and that the plant gets enough sun.

Make like a tree and LEAVE

Continuing our unit in plants, we started to discuss leaves and their role in producing food for the plant. We took a walk outside and collected leaves, and then we classified each one according to its

• general anatomy: simple or compound

and

• margin: simple, serrated, or lobed

Next week we'll finish graphing our results to see which leaf types are the most common.

It's only been a week!

Not much going on with the bulbs we planted outside, at least not much that we can see, but WOW...the bulbs growing inside are unstoppable. After a day or two, we could already see the roots coming down from the basal plate, and after 3 or 4 days, a tiny shoot started to emerge from the top of each bulb.

How many 3rd graders does it take to change a bulb?

This week we started our unit on plants with a discussion of bulbs, that is a type of plant that uses an underground storage system for everything it needs to grow. After comparing and contrasting different kinds of bulbs including onions, garlic, and daffodils, we dissected a daffodil bulb, noting the scales, providing food for the young plant to eat as it grows; the basal plate, where roots develop; and most amazingly, the miniature leaves, stems, and flower parts.

Finally we planted daffodil bulbs both in the soil and in a glass bowl, which will remain indoors.We're looking forward to tracking their progress

.

Separating Inks

This week we separated yet another mixture - in this case, the ink you find in a typical water-based marker. To do this we used a technique called chromatography. Using the marker we wanted to investigate, we drew a line on a piece of filter paper. Then we dipped one end into a bowl of water. As the water traveled up the paper, it dissolved some of the dyes in the ink. Because each dye has different properties, they travel through the paper differently, and as a result separate into bands of different colors.

Hot and Cold

This week we learned how to use a thermometer. First we measured some temperatures in and around the kitchen: the freezer, the fridge, room temperature, etc. Then we went out into the yard to find the hottest and coldest spots. We were surprised to find as much as a 5 °C difference between sunny and shady areas.

Tipping the scales

Do you have too many skirt hangers lying around?

In the mood for cream of mushroom soup?

Wondering what weighs more: a daffodil bulb, a AA battery, or a vertebra from a wild bore*?

Then I've got the perfect DIY project for you!

This week we learned about mass. Each lab group built a scale using a skirt hanger with an empty mushroom package suspended at each end. We compared the masses of various small objects by placing them inside the baskets. Finally we checked ourselves using a digital scale.

* a daffodil bulb

Un-mixing Milk

This week we tried 2 different ways to "un-mix" milk. The first way involved brute strength! We poured some heavy cream into a jar, and we shook it and shook it until it separated into a clear liquid and a creamy solid, better known as butter.  The second way we extracted solids from the milk was through a few chemical reactions. First we added some vinegar to the milk to curdle it. Then we separated the solid proteins using filter paper, and neutralized any extra vinegar with baking soda.  Finally we added a little water, resulting in our own home-made glue.  

Milk Mixer

What happens when you add a few drops of food coloring to water? What about milk? If you're in the mood for some psychedelic action, see what happens when you put some soap on the end of a toothpick and gently touch the surface of the milk.

We got off to a great start this week exploring these questions. First the kids had to learn how to measure liquid volumes using a dropper and a graduated cylinder. Graduated cylinder's kinda tough to say, but we counted, and it's still one less syllable than fancy schmancy measuring cup, so we all agreed to use the more scientific term. And of course, like all good scientists, we recorded our observations, results, and conclusions in our notebooks.