If you ask most kids what bones are made of, they would quickly answer “calcium!” Though it’s not incorrect, years of us telling them to drink their milk for strong bones has hidden an amazing feature of nature, biomineralization by proteins. Calcium is only half the story of bones. Though the semi-crystalline mineral that contains calcium, oxygen, hydrogen, and phosphorus, called hydroxyapatite, provides strength and rigidity, our bones also need to be elastic to help absorb shock. This is where proteins come in. Your bones are made of living tissue that spew out networks of protein that trap and crystallize the calcium in your body. Together they form the strong, resilient biomaterial we know as bones.
You can feel the flexibility of the protein network for yourself by reacting and dissolving the hydroxyapatite from the bones in vinegar. What’s left are entertaining, wiggly bones the kids will love to play with (except my daughter, who was too grossed out and didn’t want to touch them which is why all these pictures are of my hands ¯\_(ツ)_/¯ ).
Continue reading “How to Make Bendy Bones”
Have you heard of milk plastic before? Not only is it a project you can do with kids, but it’s also how they made many plastics before the advent of synthetic plastics! Many of those old buttons in a jar you have from your grandma are probably milk plastic (actually called casein plastic, Galalith, or Erinoid). They have a beautiful marbled or tortoise shell look, and are often pastel colored or two toned. The milk plastic you will make with this project won’t be exactly the same as the old casein plastics, the main difference being a pretty toxic step where you would need to wash and harden the plastic with a formaldehyde solution. That’s not something kid-friendly, soooo crumbly squishy curds it is!
This is a very easy project. All you need is milk, vinegar, and some basic household items.
Continue reading “The Science Behind Milk Plastic”
Oh it’s fall in the Northeast again- the perfect time to switch from iced coffees to silky lattes, cappuccinos, and macchiatos. When I was younger, I remember wishing there was something warm that tasted as good and had a mouth feel as good as ice cream. Luckily, I’ve pretty much lost my sweet tooth and these coffee drinks have fulfilled that wish. Though espresso alone is one of the most delicious things on Earth, add some foamed milk and those tiny velvety bubbles transform it into perfection.
I was making a latte for myself one morning and my daughter asked if I could froth her milk, too. What a great idea, I thought! So these first few chilly mornings of the fall, we’ve been cuddling up and sharing some warm, silky drinks together. I’ve included some coffee-free recipe ideas for you to try with your little ones, too. It’s a great way to bond and also explain a little science. So, what is special about milk that allows it to foam?
Continue reading “Why does milk foam? The science behind your latte.”