There are so many times that you might be watching television when you hear the phrase "Please do NOT try this at home!" or something like "We take every precaution, we consult with experts, we have years of experience and have people who keep us safe..." But for now, let's throw those warnings out the window because I'd love nothing more than for you to do as the title suggests and please try these at home.
Here you will find a few of my personal favorite safe-to-do-at-home science activities and experiments. These will have all of the materials and instructions necessary for you and your child(ren) to do at home. Some will require more time than others to complete and one you can even eat when you're done!
Human Sundial
Materials:
Multi-colored chalk (if possible), sunny outdoor surface like a sidewalk or patio, compass or other way to find North, partner, flashlight (optional)
Procedure:
This is an “all day” experiment and will require you coming back to it.
First, find North on your device or compass and stand facing that direction. Have your partner trace your feet. This will be where you stand each time for the rest of this experiment. Do the same for your partner. Now have them make a pose (be silly!) and trace their shadow, then have them do the same for you. After you’ve traced both shadows, note the time and write it next to the shadows (like the picture below). Come back a an hour later, stand in the same footprints, pose and trace the shadows again (noting and writing the time next to the shadow). Repeat the same process an hour later, and every hour for 3 more hours for a total of 5 traced shadows (or as many times as the sun allows), noting the time you traced the shadows each time – otherwise it’ll just look like abstract art. When you’re done, you’ll have a unique art that tells you the time!
The Science:
Your shadow is moving because of the Earth’s rotation. Because of this rotation, shadows have different lengths throughout the day. The spinning of Earth on its axis causes the shadows to grow and shrink throughout the day. It appears as if the sun is moving across the sky, but it is really your position that is constantly moving, due to Earth’s rotation (at 1,000 mph at the equator!). If you were on the Equator at 12:00pm today, your shadow would look different than if you were in NY at the same time.
Additional Notes:
Don’t have a partner? You can trace a tall object or a toy’s shadow throughout the day, a tree would work too, just make sure that you put it in the same spot each time. It's sort of like tracing a partner's shoes. Try using a flashlight indoors to simulate shadows changing!
Edible DNA
Materials:
Twizzlers, toothpicks, soft candy (something that comes in 4 colors of the same type) such as mini starburst or gummy bears, cups to separate candies by color
Procedure:
First, sort your candy: each color will represent a different nucleotide (a molecule in DNA). Assign a color to represent the four different nucleotides: Adenine (ad-neen), Thymine (thigh-meen), Cytosine (sy-toh-seen), Guanine (gwa-neen). In a DNA molecule, Adenine and Thymine are ALWAYS together, just like Cytosine and Guanine ALWAYS go together. (However, in RNA, which is a single strand, Thymine is replaced by a different chemical, Uracil. But that is beyond our scope here and is something you should look into if you're more curious about DNA.) Using a toothpick, take two matching "nucleotides" and push the toothpick through both. Repeat this with matching nucleotides for as many can fit on the length of a Twizzler, which represents the DNA’s Phosphate group or base. Add a Twizzler on both sides to connect all your toothpicks and give it a twist to create the double helix of a DNA molecule; it should look like a twisted ladder, like the example below.
The Science:
DNA stands for deoxyribonucleic acid and is what makes up the instructions that tells EVERY cell what to do. Whether a heart or, lung cell, a cell in a plant root, every living organism has it. A molecule of DNA is composed of two backbones and four types of chemical bases (nucleotides). DNA is also unique to every individual and creates the genes that give us brown hair, green eyes or a woody stem (if you’re a plant)!
Genes make up chromosomes, and humans have 46 of them: 23 from mom and 23 from dad. These genes are passed from one generation to the next, which is why you might have blue eyes like one of your grownups or pink flowers if you’re a plant.
Additional Notes:
DNA is super, SUPER coiled: just one cell’s DNA would stretch over 6 ½ feet in length! All of the DNA in your whole body would stretch to Pluto and back! Have your child draw the organism their DNA is from or tell you about them!
Mummification
Materials:
Apple, 1 cup of baking soda, ½ cup of salt, a deep container (Ziploc bags also work well), and a popsicle stick or bamboo skewer (something to poke into the top of the apple), knife or spoon to carve apple
Procedure:
First, mix the baking soda and salt solution and set aside. With a adult’s help, carve a spooky face into your apple. If your apple is soft enough, you can do this with the popsicle stick. Then attach the stick from above (so it looks like a candy apple) and place it into your container. Pour in the baking soda/salt mixture over your apple, making sure it is fully covered. Leave the container upright and open so that moisture can escape. Check on your apple every few days. How does it look different? When does it start to look like a “mummy”?
The Science:
Salt and baking soda are desiccants: they remove water and moisture from surfaces they contact. The lack of water makes it very hard for bacteria to survive on the apple. These bacteria would normally cause rot and decay, but without moisture they are unable to do so, leaving us with a preserved apple!
The Ancient Egyptians used a very similar process with a naturally occurring desiccant: natron. Natron, a chemical salt, was created out of ash from plants that grow in salt marshes (halophytic plants) or mined from natural deposits. In the mummification process, it drew out moisture, degreased body fats, and served as a microbial disinfectant. As one of the first steps in mummification, it was left on the body for 40 days!
Additional Notes:
Try weighing your apple before, during, after the mummification process. How does the weight change over 1, 3, 5, and 7 days? Why is it changing?
The above is an ideal preservative mixture, but what about other ones? You can try just baking soda or salt, vinegar, or wrapping your apple in gauze. Which way works best or fastest?
Building with newspaper
Materials:
Newspaper (3-5), tape (masking works best), patience
Procedure:
Find all the newspaper you can, three or four will be fine for most engineering (more might be needed for more ambitious projects). With either a full or half sheet of paper, roll as tightly as you can before taping the end to the roll itself. (If you need to use a pencil to start the wrapping, that's okay.) The taller you want to build the more you’ll have to roll. Half sheets make for great cross pieces - necessary items to keep your structure stable. Once you have plenty of each type rolled, start assembling. Create your base by simply taping your “cross pieces” into the shape of your preferred base, typically square or triangle. From there, tape your “large pieces” together and start to build up! As you go, you’ll have to add cross pieces in the shape of an “X” on the sides to help prevent twisting. The tighter you roll the pieces, the stronger they will be. Find something heavy around your home and see if your structure can hold it!
The Science:
The object of this is to build strong structures using what is considered a flimsy building material. When architects design structures they use shapes of strength. In nature, the triangle is one of the strongest shapes as any force applied to a corner will distribute that force to the rest of the triangle. If you look at the picture at right, you'll see many triangles that were made in the building process. To build a free-standing tower the newspaper must be rolled as tightly as possible before starting to assemble your base; tightly rolled paper will add strength to your pieces. Cross bracing can increase a building's capability to withstand seismic activity (and twisting in the case of a newspaper tower). Bracing is important in earthquake-resistant buildings because it helps keep a structure standing and transmitting loads.
Additional Notes:
After building something that is free standing, experiment with what kind of weight your structure can hold. There is a way to build strong enough to hold a child; experiment to see if you can do it!
------------------------------------------------
There are lots and lots of experiments you can do at home, a little internet searching will provide you with a plethora of activities you can do with your young learner. With a little time, effort, patience and dedication, activities can be fun and filled with learning that can help inspire a lifelong love of all things STEM... and you never know where that will lead your child(ren).
Happy learning!