Still looking for fun things to do with your kids this summer? Check out parts 1 and 2 of our series (HERE and HERE), or today’s new activities, shown below:
1. Play with Oobleck. What is Oobleck, you might ask? Well it is a simple mixture of corn starch and water, and is actually an example of what is called a non-Newtonian fluid (see HERE), which basically means a fluid that doesn’t follow the usual properties of what we would expect from a fluid. Other examples of non-Newtonian fluids that are commonly found in people’s houses are ketchup, shampoo, and toothpaste. For Oobleck in particular, the mixture of corn starch and water is solid-like when pressure is applied to it, but turns into a free-flowing liquid in the absence of significant external pressure. This allows people to walk directly on the Oobleck solution without falling in! Check out this video of someone running on an Oobleck-filled swimming pool HERE. But you don’t have to go that big – even just a small amount of Oobleck is fun to play with, squish between fingers, or try to step on.
Another fun idea is to make Oobleck “dance” by using speakers and adjusting the frequency of vibrations to make the Oobleck respond. Check that one out HERE.
2. Balloon skewers. What happens if you take a balloon and try to stick a balloon skewer through that balloon? Well, it will pop of course, much like any sharp object that pierces the delicate surface of the balloon. If you don’t believe me, of course, feel free to try it yourself (just beware of loud noises if you have kids who are sensitive to that kind of stuff). What if I told you that you can actually use science to stick a skewer through a balloon without it popping? Well, you can! What you need to do is find the darker areas on the balloon (near the knot and immediately opposite that knot at the point), because those are areas where the polymers in the balloon are relaxed enough for another object to slip through. Then, you need to dip a wooden skewer (like you would use for BBQ – blog post on the chemistry of BBQ coming soon!) in oil, because that reduces the friction between the skewer and the balloon. Then, carefully twist in the oiled skewer into the dark parts of the balloon. It may take a few times to practice, but pretty soon you will be able to create all kinds of balloon skewers, and even stack the skewered balloons together to create balloon chains and balloon snowmen! Check out this website online that talks more about the balloon skewers and how to create them for yourself (see HERE). Just be aware, the balloons will slowly deflate, even with the skewers inside them, because you are not able to create a perfect seal with the skewer piercing effect.