From surface tension to evaporation, science come into play every time you blow a bubble.
Water molecules like to stick to each other , and scientists call this sticky, elastic tendency “surface tension.” Soap molecules, have a hydrophobic (water-hating) end and (hydrophilic) a water-loving end and can lower the surface tension of water. When you blow a bubble, you create a thin film of water molecules sandwiched between two layers of soap molecules, with their water-loving ends pointing toward the water, and their water-hating ends pointing out into the air.
As you might guess, the air pressure inside the elastic soapy sandwich layers of a bubble is slightly higher than the air pressure outside the bubble. Bubbles strive to be round, since the forces of surface tension rearrange their molecular structure to make them have the least amount of surface area possible, and of all three dimensional shapes, a sphere has the lowest surface area. Other forces, like your moving breath or a breeze can affect the shape of bubbles as well.
The thickness of the water/soap molecule is always changing slightly as the water layer evaporates, and light is hitting the soap layers from many angles, causing light waves to bounce around and interfere with each other, giving the bubble a multitude of colors.
Try making these giant bubbles at home this summer! They’re a blast! (It works best a day when it’s not too windy, and bubbles love humid days!)
To make your own giant bubble wand, you’ll need:
-Around 54 inches of cotton kitchen twine
-two sticks 1-3 feet long
-a metal washer
1. Tie string to the end of one stick.
2. Put a washer on the string and tie it to the end of the other stick so the washer is hanging in-between on around 36 inches of string. (See photo.) Tie remaining 18 inches of string to the end of the first stick. See photo!
For the bubbles:
-6 cups distilled or purified water
-1/2 cup cornstarch
-1 Tbs. baking powder
-1 Tbs. glycerine (Optional. Available at most pharmacies.)
-1/2 cup blue Dawn. The type of detergent can literally make or break your giant bubbles. Dawn Ultra (not concentrated) or Dawn Pro are highly recommended. We used Dawn Ultra, which is available at Target.
1. Mix water and cornstarch. Add remaining ingredients and mix well without whipping up tiny bubbles. Use immediately, or stir again and use after an hour or so.
2. With the two sticks parallel and together, dip bubble wand into mixture, immersing all the string completely.
3. Pull the string up out of the bubble mix and pull them apart slowly so that you form a string triangle with bubble in the middle.
4. Move the wands or blow bubbles with your breath. You can “close” the bubbles by moving the sticks together to close the gap between strings.
What else could you try?
-Make another wand with longer or shorter string. How does it affect your bubbles?
-Try different recipes to see if you can improve the bubbles. Do other dish soaps work as well?
-Can you add scent to the bubbles, like vanilla or peppermint, or will it interfere with the surface tension?
-Can you figure out how to make a bubble inside another bubble?
Every fossil has a story to tell.
Whether it’s the spectacular specimen of a dinosaur curled up on it’s eggs or a tiny Crinoid ring, mineralized remains offer us a snapshot of the past, telling us not only what creatures lived where, but about how they lived and the world they inhabited.
Growing up surrounded by the flat-topped, windswept Flint Hills of Kansas, it was hard to imagine that I was living in the bottom of an ancient seabed, but there was evidence of the Permian period all around.
Now, when my kids and I return to my hometown, a fossil-hunting trip is always part of our routine, and we hunt for shells and coral where roads cut through crumbling limestone and and chert (flint.) Looking up at layer after layer of rock and shells, I can almost feel the weight of the water that once covered the land.
An episode of RadioLab we heard on the drive North from Kansas to Minnesota explained that coral keeps time and that by comparing modern coral to ancient coral fossils, scientists discovered that millions of years ago, years were about 40 days shorter than they are now. Can you guess why? Give the podcast a listen here. My mind was blown!
A visit to the Flint Hills Discovery Center in Manhattan, KS gave us more insight into the amazing geology, ecology and anthropology of the Flint Hills and the Konza Prairie that blankets them. Most people don’t know that the great tallgrass prairies of the United States wouldn’t exist if not for humans, who have been burning them for thousands of years.
What do you know about where you live? What’s it like now? What do you think it was like long, long ago? Are there fossils nearby?
Here are some fossil-hunting resources I found online, in case you want to go exploring:
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?
My book, “Kitchen Science Lab for Kids,”is finally out, and over Labor Day weekend, I traveled to Dragon Con in Atlanta to talk about it and do science with the kids at the convention. At the convention, I got to meet lots of fantastic scientists, science writers, science entertainers and science enthusiasts. One of them was the amazing Paul Zaloom, of “Beakman’s World.” I checked out his “Beakman Live” show and learned some awesome new experiments.
I tried one of them out this morning. Check it out, and then try it out! All you need is a playing card, a glass and some water. The science explanation is in the video.
Be sure to catch some episodes of Beakman’s World online!
It’s been a busy summer, but we’re working on some sweet new experiments to share with you soon!
Last week, the kids and I got an advance copy of my new book “Kitchen Science Lab for Kids,” which will be available September 15th and we love how it turned out!
If you pre-order a copy from Amazon, Barnes&Noble, IndieBound, or Indigo before August 15th, I’ll send you a personalized, signed bookplate for each copy you order. Just email your receipt number and the address where you’d like the bookplate(s) sent. My email address is firstname.lastname@example.org. (Be sure to include the name(s) you’d like the book signed for!)
At-home science provides an environment for freedom, creativity and invention that’s not always possible in a school setting. In your own kitchen, it’s simple, inexpensive, and fun to whip up a number of amazing science experiments using everyday ingredients. Science can be as easy as baking. Hands-On Family: Kitchen Science Lab for Kids offers 52 fun science activities for families to do together. The experiments can be used as individual projects, for parties, or as educational activities groups. Kitchen Science Lab for Kids will tempt families to cook up some physics, chemistry and biology in their own kitchens and back yards. Many of the experiments are safe enough for toddlers and exciting enough for older kids, so families can discover the joy of science together.
Can kids in middle school come up with world-changing inventions? Absolutely.
Most 5-8th graders don’t have free access to labs full of chemicals and equipment, which is probably a good thing, but they’re armed with more curiosity and creativity than most adults. When given the opportunity and encouragement to let their imaginations run wild, kids come up with the most amazing ideas.
The Discovery Education 3M Young Scientist Challenge helps address the gap between idea and reality, and offers kids amazing incentives to come up with big ideas. The competition encourages kids in middle school to make two-minute videos about their ideas for using science, technology, math and engineering (STEM) to solve real-life problems. The videos are judged based on
- Creativity (ingenuity and innovative thinking) (30%);
- Scientific knowledge (30%);
- Persuasiveness and effective communication (20%); and
- Overall presentation (20%).
3M‘s Innovation Page gives overviews of how their scientists are impacting our daily lives, and some of their scientists will mentor the contest’s ten finalists, helping them envision how to take their creations from dream to reality. Ten finalists will travel to the 3M Innovation Center for the final competition.
Want to enter? Here’s the link: http://www.youngscientistchallenge.com/enter.
It seemed like the best way to learn about how kids come up with ideas was to ask my own two middle schoolers if they’d like to enter the contest, so I asked them to think about problems that they could help solve with STEM. They were less than excited until I showed them a few of the videos from the Young Scientist Challenge website. Like me, they were blown away by what Peyton Robertson and Deepika Kurup created to win the 2012 and 2013 Young Scientist Challenge and decided, without any prodding from me, that they wanted to come up with their own ideas.
My son, who is a voracious reader of all things science, and is somewhat obsessed with meteorology, immediately knew what particular area he wanted to focus on. It took a few days, but now he’s got a great idea and is working to make a model to test.
My oldest daughter was another story. She likes science, but spends much more time thinking about acting, basketball, photography, her friends, and our German Wirehaired Pointer. She quickly got frustrated and worried that she didn’t know enough about science to come up with a good idea. To encourage her, I asked her to think about how she could solve a health problem in animals, prevent basketball injuries, make a camera app, or solve an environmental problem. She decided to try to think of something people throw away and use it for something really great. While researching ocean trash, she came up with another idea, addressing a water pollution problem and is excited to test out her idea.
They need to get going, since the entry deadline is April 22nd, but I know they can do it, and love the ideas they’ve come up with!
If you’re on Twitter, you can follow the contest @DE3MYSC and join us for #STEMchat on Twitter April 8 from 9 – 10 PM Eastern as we talk about How to Raise America’s Top Young Scientist (this is the title earned by the winner of the DE 3M YSChallenge.)
Although I don’t usually write sponsored posts, I made an exception for this contest, since I think it’s a fantastic way to get kids excited about STEM. This post is sponsored by the Discovery Education 3M Young Scientist Challenge.
How would you safely land a spacecraft on a planet with no atmosphere if you couldn’t use rockets? A parachute wouldn’t work, since there’s no air resistance. You’d have to design your craft with a protective shell so the impact wouldn’t destroy it.
Pretend a raw egg is your spacecraft and Voila: you have a science experiment. Besides being lots of fun, an egg drop experiment is a great way to try your hand at engineering and is a fantastic STEM (Science, Technology, Engineering and Math) project for kids and adults alike!
The kids and I dropped holiday decoration-encased eggs from a crane in the Kare11 studio on Kare11’s Sunrise News to test our own engineering skill. Click here to see what happened.
The law of motion says that the faster you change the speed of an object, the greater the force applied to the object will be. We demonstrated this concept with our egg-throwing experiment by smashing eggs against a table, which stopped them fast, and watching them survive being hurled against a hanging sheet, which slowed them down. This same law explains why, if you drop an egg on the floor, it will break. When you change the speed of the egg slowly,by suspending it or surrounding it with material that helps absorb or redirect the force, less force is applied to the egg and it may remain intact. Can you design a container to protect an egg?
Why not have a holiday egg drop competition with your out-of town cousins, or other friends and family? Here are the rules we came up with. (We have a no parachute rule, but if you’d really like to design a parachute for your egg, that would be fun too!) I’m thinking an egg nogg carton might be a good place to start.
-Container made up of 100% holiday material like wrapping paper, bows, cardboard, tinsel, food, glue, toothpicks, wood, tape, plastic and string. No Styrofoam, bubble wrap or packing peanuts are allowed.
-Container must contain one RAW egg.
-No Parachutes (defined as any material attached to your egg craft in such a way that it will expand outward as it falls, catching air.)
-Container should be no larger than 20 inches in any direction
-No tape or glue must touch the egg.
Drop your egg from different heights to see how well it survives. (Make sure you’re supervised by an adult when you do your egg drop!)
You can calculate the force of gravity on your egg and container by multiplying its weight in kilograms by 9.8meters/second (the acceleration due to gravity.
If you live in the Twin Cities, I’ll be on Kare11 Sunrise on Tuesday morning Dec.18th with Kim and Tim. We’ll be dropping our containers from a studio crane. Should be fun!
Carin Bonder recently wrote a great post for Scientific American’s PsiVid about an autistic boy named Jordan Hilkowitz who is storming YouTube with his fantastic science videos! Parents will enjoy Carin’s post, and kids will love his Doctor Mad Science videos!
If you’re on Twitter, we’ll be chatting about STEM (Science, Technology, Engineering and Math) tonight at 8 Central under the hashtag #STEMchat. Click here for more information if you’re interested in joining us as we talk about kids science at home and in schools.