Oh, hey—you’re just in time!

Squeaks and I were just getting ready to test our new cheese-serving machine! You see, Squeaks and I both love eating cheese together.

And we also love going outside and having adventures! So we invented a way to keep our cheese cool while we’re out, and then put it on the table so it’s all ready to eat by the time we get home. We’ve learned before about simple machines that help us get things done by making our work a little easier.

Our invention uses two of them: a lever, and a pulley. Check it out! To make our machine work, the first thing we do is put our cheese down on top of this piece of cardboard.

The cardboard is sitting on top of a glass of ice, so the cheese stays nice and cool. Then, while we’re outside, the ice melts and turns into water. So this string that’s been caught under the ice cubes comes loose, which will activate our lever!

A lever can help you lift heavy things. It’s made out of a long, straight object, like a ruler or a board, balanced on top of another object called a fulcrum. One type of lever you might have used before is a see-saw!

You might not be able to pick your friend up off the ground but if they’re sitting on a see-saw, you can push down, or sit down, on the other end… and up they go! Our lever is made out of this board, balanced on top of a water bottle. This end of the lever will flip the cheese onto the table for us, and this end, the one with the sharp pencil on it will fall onto the balloon… and pop it!

The balloon has a heavy marble inside, along with some confetti, just for fun. And when it pops, the marble will fall through this funnel here, and turn on the fan! Then, the fan will blow this rubber duckie across our little canal here … until it bumps into this marble.

The marble falls down this track here, and knocks over these dominoes, which bump into another marble over here, and that marble rolls down this track, and it’ll knock our golf ball off the tee. Which will release this string, which is part of our pulley! That’s the other simple machine we’re using in our invention.

A pulley is a wheel with a groove along the middle of it, where a string or a rope fits in. Our pulley has the golf ball on one side, and a little cup of orange juice on the other. Squeaks loves orange juice.

And now that we’re home, it’s about time for the ice to melt and release the string! Ready to see if our machine works? Ooh, look!

The string is loose… and here comes the pencil! Let’s see if the rubber duckie makes it … yeah! And there go the dominoes, and your orange juice, Squeaks!

And some cheese for both of us … and a nice glass of ice water for me. Our invention works, buddy! (Squeaks squeaks). You’re right, Squeaks.

Instead of building this whole invention, we could have just put our cheese in the refrigerator earlier, and taken it out when we got home. That would have been easier than building this whole invention … but building it was so much fun! See, our invention is a type of a Rube Goldberg machine.

Rube Goldberg was a real person: an artist, who was born over a hundred years ago! He went to school to study engineering – that means using science for designing and building. But what he really loved was drawing.

So when he became a cartoonist, he used his engineering knowledge to draw cartoons about some really wacky inventions! These cartoon inventions used a chain reaction – that’s when one action causes another thing to happen, which causes another and another. Just like one domino makes the next one fall over, and then the next and the next!

And all of Rube Goldberg’s very complicated reactions were invented to do something very simple – like wipe your face with a napkin, or open an umbrella, or button your shirt. To an engineer, the best machine is the simplest one. A machine with lots of complicated parts is a lot more likely to break than a simple design with just a few parts.

Rube Goldberg was using his cartoons to laugh a little bit about machines, which were supposed to make everyone’s lives easier and simpler, but the machines in his cartoons were really complicated, and that made them funny! And his inventions had some really silly parts, like frogs, umbrellas, cats, parrots, banana peels … sometimes even people! [Squeaks squeaks]. I don’t know if Rube Goldberg ever used a rat in one of his machines, Squeaks.

But maybe we can! Rube Goldberg’s inventions were imaginary. They only existed in his mind, and in the cartoons he drew.

But today, people remember his silly ideas by building their own Rube Goldberg machines. You can make one too! And you can use science to do it!

When you’re inventing your own Rube Goldberg machine, first you’ll need an idea for a simple job that needs to get done. Like hanging up your jacket, or turning off the light … or anything you can think of! Then, you’ll need a design, or a plan.

It’s a good idea to write down or draw what your machine will look like, and how it will work. Having a plan will help you figure out how to put it together. Here’s the design Squeaks and I used for our machine!

You can go back and learn with us about levers, pulleys, and other simple machines, to give you some ideas. And remember, when it comes to Rube Goldberg machines… sillier is better! You may want to see if a grown-up can help you with your design.

Once it’s finished, you can gather the materials and build your machine together. It took us a long time to get our machine working exactly right. Our invention went wrong a lot of times before we got it working.

But then, when it finally worked, it was so cool! So what do you think, Squeaks? Should we eat this cheese, and then get some more and run the machine all over again? [Squeaks squeaks].

Thanks for joining us! If you build your own Rube Goldberg machine, we’d love to see it! Grab a grown-up and send us an email at kids@scishow.com Thanks, and we’ll see you next time, here at the Fort!