What you’ll heed:
— a lemon wedge
— dust
— a plastic bag
— water
— an eyedropper
— a clean, empty milk carton
How to do it:
Wipe the lemon wedge across a dusty surface to collect dust on it. When you’ve collected a sufficient amount of dust, drop the lemon wedge into a plastic bag and add five drops of water with an eyedropper. Then plop the bag into the milk carton and seal the carton. After several days, mold should appear on the lemon wedge.
The mold that appears on the lemon wedge is called PENICILLIUM. It’s a mold that really likes citrus fruits such as lemons, limes, and grapefruits. As it grows, a liquid called PENICILLIN is produced. If you were working in a fancy science lab, you could transform this liquid penicillin into medicine—penicillin is an antibiotic used to treat sick people.
What you’ll need:
— a plastic or glass container, such as a used, clean mayonnaise jar, with a lid
— bits and pieces of food (but no meat or fish), such as grapes, bread, cheese, and veggies
— water
How to do it:
Put the food in the jar. Spread it out so it s not all piled on top of each other.
Spray or mist water over the food and seal the jar up tight. Label your jar so no one mistakes it for a snack (!) and put it in an out-of-the-way spot. After four or five days (maybe sooner) you’ll begin to see all sorts of mold growing on the food. Let it rot to your heart’s delight (or for as long as your mom can stand it).
So what happened?
Mold loves moisture and it loves to eat. Unlike other plants, mold can’t make its own food, so it has to find it. Mold breaks down its food by producing chemicals that make the food rot so that the mold can eat it. Yum!
Please note: When you’re done with your mold experiment, don’t open the jar and let the mold spores escape. They can be harmful to breathe. So dump that mold in the trash—you can always make more.
What you’ll need:
— rotting tree bark
— paper towels
— water
— plastic container
— plastic wrap
How to do it:
Grab some rotting bark from your backyard or a tree near your school. Put a paper towel at the bottom of a plastic container, put the bark on top of the paper towel, and cover the bark with water. Cover the container with plastic wrap. The following day, dump out the water and re-cover the container. Make sure the paper towels stay damp throughout the process. Wait a few weeks and you should see some lovely slime crawling across your bark. You can also try this experiment with dead leaves or rotting wood. If slime doesn’t grow on your first sample, try bark from different trees and see which ones are the real slime magnets.
Slime mold loves tree bark because as the bark rots, pieces of it get loose and trap moisture. And as we know, mold loves moisture. By creating a moist environment for your bark, you create excellent conditions for slime mold to thrive.
Check out more adventures from the
best fourth-grade scientist ever.
Available now.
My name is Phineas Listerman MacGuire.
Feel free to call me Mac.
Some people even call me Big Mac, since I’m tall for my age.
I don’t mind being called Phin or Phineas. I had a soccer coach last year who only called me MacGuire.
I thought that was sort of cool.
He never called me Listerman, in case you were wondering.
No one calls me Listerman. Not unless they want to get seriously slimed.
I am a scientist. In fact, I am probably the best fourth-grade scientist in all of Woodbrook Elementary School. I am an expert in the following areas of scientific inquiry:
Up until yesterday I had no idea that I was a potential scientific genius when it came to astronomy, which is, if you didn’t know, the study of planets and stars and everything up in space.
Don’t get me wrong. I have read at least sixty-seven astronomy books and am famous for having eaten a board book about the planets when I was two.
It’s just astronomy wasn’t one of my big things.
Until I heard about Space Camp.
It all started with Stacey Windham, and Share and Stare.
You would think that as a scientist, I would know five hundred times as much about space as Stacey Windham, a bossy girl in my class who thinks she is the queen and has never once shown any interest in anything besides being mean to people.
So how did she know that there are earthquakes on Mars before I did?
Except on Mars they’re called Mars-quakes.
You’d think I would have heard about that.
“Some scientists think that Mars at one time had titanic plates in it, just like Earth does,” Stacey reported for Share and Stare yesterday morning. Share and Stare is what Mrs. Tuttle, our teacher, has instead of Show and Tell. For Share and Stare you have to bring something that’s connected to what we’re studying at school. We have just started a unit on space, and Stacey waved an article torn out of a magazine while she talked.
“I’m interested in titanic plates because I have seen the movie Titanic four times,” Stacey continued. “Even though it is rated PG-13.”
A bunch of girls gasped. I raised my hand. Stacey nodded at me like she was the teacher.
“I think you mean ‘tectonic plates,’” I informed her. “Tectonic plates are what shift around and cause earthquakes.”
“Well, I’ve still seen Titanic four times. And it’s rated PG-13.” Stacey sneered at me. “I bet you’ve never seen one single PG-13 movie.”
Half of my classmates waved their hands in the air. “Oooh! I have! I have!”
Later I asked Stacey where she’d found the article, and she showed me a copy of a magazine called Astronomy. “It’s my dad’s,” she said. “He has a telescope. Except he’s always too busy to use it. Sometimes when I have a slumber party, we use it for spying on the people who live across the street.”
I sighed. Leave it to Stacey Windham to take a perfectly good scientific tool like a telescope and use it for evil.
Tonight at dinner I asked my mom if we could get a subscription to Astronomy magazine. She gave me her best I Spend Ten Zillion Dollars a Year on Stuff for You Already look and shook her head. “You get plenty of magazines.” She listed them on her fingers: “National Geographic Kids, Scientific American, Ranger Rick. …”
‘“To be honest, I think I’m getting kind of old for Ranger Rick. Maybe we could trade that subscription for one to Astronomy.”
“Too old for Ranger Rick?” My mom looked stunned. “I read Ranger Rick until I wan twelve years old. You’re never too old for Ranger Rick!”
My stepdad, Lyle, grabbed another piece of pizza from the box on the middle of the table. “You know, I saw something in the paper the other day about a Space Camp they have down in Alabama. I think it’s connected to NASA. The kids do a lot of stuff on Mars exploration.”
I nearly jumped out of my chair. It was like every cell in my body got electrified at the same time. All of the sudden I knew that my life should revolve around the study of astronomy, space, and all things beyond Earth’s atmosphere. “Space Camp? Mars exploration? I need to go there immediately!”
“It’s pretty expensive,” Lyle told me through a mouth full of pizza. “And pretty far away.”
“I could save up for it! I’ve already got twenty-nine dollars saved up for a chemistry set. I could use it for Space Camp instead.”
My mom looked doubtful. “I don’t know, honey. I think you’re a little young for a sleepaway camp. Maybe when you’re eleven. Besides, I don’t think we can afford to send you to camp this year. The minivan’s almost too pooped to pop. It’s about time to buy a new one.”
Leave it to my mom to put minivans before scientific knowledge.
“What if I pay for everything myself?”
My mom still looked doubtful. “If you saved up enough money for Space Camp—and a round-trip plane ticket—then maybe I’d consider it. Maybe.”
I ran around to the other side of the table and hugged my mom. Well, it wasn’t really a hug. It was more bumping my shoulder against her shoulder.
We scientists are not big huggers as a rule.
But my mom smiled anyway.
She knows a scientific hug when she gets one.
