sar·coph·a·gus (särˈkäfəɡəs/) noun-
a stone coffin, typically adorned with a sculpture or inscription and associated with the ancient civilizations of Egypt, Rome, and Greece
Two weeks ago, we mummified some apples, a hot dog and a game hen (see previous post). Today, we dug the mummies out (see video above) and found that they’re drying out nicely! I thought it would be fun to add some science art to the project! After all, pigments are molecules that give things color and paint is made from pigments like Zinc Oxide (white), Black Iron Oxide, and Silicate of Sodium and Aluminum with Sulfur (blue.)
The ancient Egyptians were amazing artists, and historians think they made paint using materials and pigments they had on hand, including eggs, casein glue made from milk, wax and gum from local trees. This paint was used to decorate everything from tombs to coffins.
We covered one of our plastic ware “coffins” with masking tape, used plaster of Paris to make it more stone-like and made casein glue from milk and vinegar using this glue recipe (casein science on this link). To the glue, we added pigment until we achieved the desired color, and then stirred in a little bit of water to get the paint-like texture we wanted. We bought the pigment at Blick art store, but didn’t buy red or yellow pigment, since they were pretty toxic. The brownish-yellow is made from Curry spices. I’d like to try the spice turmeric for a more pure yellow!
Can wait to see how our sarcophagus turns out! I’ll post a photo when we finish painting it!
When mixing up materials to make a mummy, don’t forget the salt!
Natron, which was used in Ancient Egypt to preserve mummies, is a natural salt mixture containing sodium carbonate decahydrate (soda ash), sodium bicarbonate (baking soda), sodium chloride (table salt), and another salt called sodium sulfate. Salt is a dessicant, which is a chemical that removes water from things. It also has anti-microbial properties, which means it kills bacteria and fungi. When you remove water and microbes from the picture, mummies bodies’ don’t decompose.
Today on WCOO, we mummified some apples, hot dogs and even a game hen, which is like a small chicken. Here’s an old post on how to mummify apples.
First, we’ll weigh everything we’re going to mummify, so we can see how much water weight they lose during the dehydration process.
We’ll rinse and blot the game hen with alcohol to kill some of the microbes on the outside, add aromatic spices like cinnamon and cloves, and put it in a container filled with a 50-50 mix of baking soda and salt (Kosher salt or table salt will work), where we’ll let it sit for about 40 days, changing the salts once or twice over that time period.
Real mummies are coming to the Science Museum of Minnesota! Mummies: New Secrets of the Tombs opens at the Science Museum of Minnesota on February 19. The exhibition, which features mummies from the preeminent collection of the world-renowned Field Museum in Chicago, juxtaposes ancient specimens with the modern science that has given us new glimpses into ancient Egyptian and Peruvian cultures.
Today on WCCO MidMorning, I’ll be talking microbiology! According to the CDC, hand washing is the best way to remove microbes from your hands.
You can see what bacteria and fungi are hanging out on your fingertips by touching homemade petri plates to grow colonies. Test your fingers before and after washing with water alone, soap and water, and finally hand sanitizer. You can find the experiment in my book, Kitchen Science Lab for Kids, and here on my website. The video below shows you how to make plates.
It’s simple to stir up some Halloween magic with a head of red cabbage and some baking soda and vinegar.
Chop us half a head of red cabbage (with adult supervision, of course), put it in a sauce pan, cover it with water and boil for 10 minutes or so, until the water turns purple. Let it cool, strain out the cabbage and save the purple juice, which is your Magic Potion.
Pour about half a cup of the purple juice into each of two clear cups or bowls.
To one cups, add 2 tsp. baking soda and stir. What happens?
To the other cup, add 1/4 cup vinegar. Amazing!
Now, put the two cups on a tray or cookie sheet and pour the pink cup into the blue cup quickly. Woo Hoo!
Here’s a video, if you want to see how the experiment works.
Everything in our world is made of very tiny pieces called atoms. When atoms bond to other atoms, they form groups of linked atoms called molecules.
Purple cabbage juice is called an acid-base indicator. The molecules in the cabbage juice magic potion change when exposed to an acid or base, making the potion change color. Vinegar is an acid (acetic acid), which turns the potion pink and baking soda (sodium bicarbonate) is a base, which turns it blue or green.
When you mix the vinegar potion and baking soda potion together, a chemical reaction occurs and you make Carbon Dioxide gas. That’s why you see bubbles!
Soak coffee filters in leftover cabbage juice (if you have any) to make Homemade Litmus Paper!
Have fun experimenting! Happy Halloween!
This week, I did some sound science experiments with the kids at my daughter’s school and it was literally a blast (of noise.) Here’s how it sounded (times 50.)
The kids had already done some cool experiments with their teacher, and told me that the sound we hear every day is energy that travels through air molecules as vibrations. We talked about the fact that you can’t hear sound in outer space, since there’s no air.
When I pulled out my trombone, the kids could see that the tube that carries the air from my lungs and the vibrations from my buzzing lips got longer when I extended the slide, making the sound lower. My daughter played her violin, and we heard how string instrument can make short sounds by plucking the strings and continuous sound when a bow makes them keep vibrating. We also saw that shortening the strings by pressing them down made the pitch higher as the string vibrated faster.
The kids told me that we have a “drum” in our ears called an eardrum, or tympanic membrane that picks up sound vibrations in the air and transfers those vibrations to tiny bones in the middle ear, which then move them on to our inner ear, sending a message to our brain.
We made a model “eardrum” out of a cup, saran wrap and sugar sprinkles, and then made two musical instruments: a straw “clarinet” and a kazoo from a comb and tissue paper. Finally, we made the sugar crystals on our model eardrums jump around using sound vibrations from our kazoos.
Click on this link to learn how to make straw “clarinets.”
To make comb kazoos, fold a piece of tissue paper in half the long way (see photo), place it over a comb with the teeth towards the fold, and place your lips on the tissue paper. Sing doo doo doo doo into the paper (don’t blow.) The vibrations from your voice will make the thin paper vibrate and buzz. It will tickle if you’re doing it right!
At home science offers an opportunity for kids to have fun and be creative thinkers. This holiday season, help your kids take a break from screens with an activity they’ll love, like blowing up balloons with baking soda and vinegar!
Wrap up Kitchen Science Lab for Kids (available wherever books are sold) with a box of baking soda, a bottle of vinegar and some balloons for an instant holiday hit.
Better yet, put together a homemade science kit for the kids on your list and let them choose and experiment a day to do over break. (Many of them are easier than baking cookies.)
Put kids in charge of the experiments. Let them try whatever they want, as long as it’s safe, even if you don’t think it will work. We learn to be creative when we’re given freedom to make mistakes and go beyond the instructions.
In addition to some of my neighborhood friends,two awesome chemist friends helped me out with this song: the amazing Dr. Raychelle Burks (with the Bronsted-Lowry line) and bassist Ryan Williams, who happens to have a PhD in Chemistry, with his awesome bass-playing.
The video quality isn’t top-notch, but you’ll get the idea, and hopefully learn a little chemistry!
I got together with some friends this weekend to do a quick iPhone recording of a chemistry song (on my Kitchen Pantry Scientist YouTube channel soon) and these awesome kids were nice enough take a break from playing to sing the Science Song with me. They had me laughing so hard that I could hardly get the words out!
Can you make up a song about science?
There’s going to be a solar eclipse this afternoon, so I’m re-posting directions on how to make some simple solar viewers!
NEVER look directly at the sun, since you can permanently damage your retinas (the light sensors on the back of your eyeballs.)
You can safety view the sun (and therefore a solar eclipse) using a shoe box by standing with the sun BEHIND you. All you need is a shoe box without a lid, a piece of white paper, aluminum foil, a pin and tape. It’s perfect for viewing a solar eclipse, like the one coming up this afternoon. It will be visible from around 4:30 CST until 6:00 PM CST here in Minnesota!
A solar eclipse happens when the moon passes between the sun and the earth, blocking the sun from view.Go to this eclipse calculator to see when and where you can best view the eclipse with your viewer! Here in Minnesota, we’ll see a partial eclipse.
First, tape white paper over one end of the shoe box (on the inside.) This is your viewing screen.
Then, cut a big notch out of the other end of the shoe box and tape aluminum foil over it.
Use a pin to poke a hole in the center of the foil. If you mess up, you can always put new foil on and try again. The smaller the hole, the better the focus, but we made ours a little bigger than the actual size of the pin.
Now, stand with the sun BEHIND you. (See photo at top of post. The sun is behind her, high in the sky.) NEVER LOOK AT THE SUN THROUGH THE PINHOLE ITSELF.
Hold the box upside down so the pinhole is pointed at the sun behind you. The foil should be behind your line of sight so it’s not reflecting the sun in your eyes. Light rays from the sun will shine through the pinhole and project an (upside down) image on the white paper.
Practice on a sunny day (or when the sun peeks out between the clouds) so that you know what to do when it’s time for the eclipse. Small children should be supervised so they don’t try to look directly at the sun.
You can do the same thing using two white index card, poking a hole in one you hold nearest to you and projecting the image on the one you hold away from you (with the sun behind you.)
Enjoy! Watching an eclipse in the 70s after my dad came to school and helped us all make these boxes is one of my earliest “science” memories!
Mix a cup of cornstarch and around half a cup of water together for instant Halloween fun! Cornstarch and water mix together to form a strange concoction, called a shear-thickening fluid, that behaves like a solid when you agitate it, but behaves like a liquid when you let it sit still.
To make your Goblin Goo more Halloween-y, add a drop of food coloring, but you’ll risk staining hands and other surfaces. You can experiment with adding more water or cornstarch to get your goo to the consistency of thick syrup.
The molecules in your mixture are sort of like long ropes. When you leave them alone, or move them slowly, they can slide past each other. However, if you squeeze them, stir them or roll them around in your hands, the ropey molecules look and feel more like a solid. Materials like cornstarch goo are known as non-Newtonian fluids, since they don’t have the normal properties of either a liquid or a solid.
Here’s a “watch and do” video for kids: