Over the past few weeks, the students have been learning about simple machines. Earlier this month, we put on our engineering hats and worked on creating a Mars landing device for our eggs…er, I mean, rovers!
This week, scientist Eakins came to visit the young scientists to talk about mechanical advantage and focused on the importance of using simple machines as tools. The measurable way that machines and tools make our work easier is called the mechanical advantage. Obviously, most tools make a job easier but will the total amount of work change if we use a machine or not?
From simple machines, more complex machines can be made. Students performed experiments to see how the force changed using an inclined plane and lever. If we change the slope of a ramp that affects the advantage we get.
During class, Rube Goldberg was introduced with the following video:
Students, after this lesson, should be able to identify a couple of simple machines used to form complex machines in that music video!
Additionally, if you’d like another video, look at this one: https://www.youtube.com/watch?v=_ve4M4UsJQo
HOW MANY SIMPLE MACHINES CAN YOU FIND? WHICH ONES??
ALSO REMEMBER TO BE FILLING OUT YOUR MOON CALENDARS!
Questions of the day:Since you guys had so many earth science questions, I’ll start them in this entry! There’s only two this time because they’re a bit complex and we haven’t had time to go over it in class. They’re related to each other – you’ll need to understand the first question to understand the second one. It’s something you can experience everyday – I love these types of questions!
1. Why is the sky blue?
The light we receive from the sun is what scientists call “white light” – it contains all the colors combined! When something gets in the way of white light, the light scatters and forces the colors to bend and separate through something called refraction. That’s how we sometimes can see a rainbow! [You guys didn’t ask about rainbows, so I’ll challenge you to discover – What causes rainbows?!]. Light is made by very small waves – they’re SO SMALL that your eyes “interpret” them as color. The colors can separate because they are all made up of different lengths of waves. During the day, when the sun is the brightest, all the colors are “seen”. However, our atmosphere (we’ll learn this word soon!) has A LOT of oxygen and nitrogen. These atoms are SUPER TINY and smaller than these waves of light. Because they’re so small, they can only separate out the smallest, shortest wave lengths, which are blues and purples! You can think of these atoms like ultra tiny atmospheric filters of light. Colors that are NOT absorbed and reflected or bounced back, we see. The blue and purple light is bounced back and not absorbed into the earth, which is why we see it. However, our eyes are most sensitive to green colors, so we have an easier time seeing the blues than the purples.
2. Why does the sky turn pink and purple at night?
If during the day, the blue wave lengths get “filtered” out by refraction off of nitrogen and oxygen, what do you think happens to these wave lengths at night? Well, during our night time, another area of the world is experiencing daytime. During their daytime, when the sun is shining directly overhead for them, the shorter blue wavelengths are scattered into their skies. That means that during our sunsets (and sunrises!), the sun is a bit further away from us and the light takes a longer distance to travel. All the blues have already been scattered somewhere else and we’re left with the longer wave lengths. And what colors have longer wavelengths? Orange and red!
Pink might happen when the sun is still pretty visible, so there is still a lot of white light that we see. Just as the sun sets in the horizon, we see the most bright red and orange colors! Until we no longer have any sunlight from the sun. Then we only experience some sunlight from the reflection of the moon (we’ll talk about that in our next lesson!).
When the sunsets are super colorful, that means that there isn’t anything blocking the colors from being observed. Drier and cleaner air will create more beautiful sunsets. During autumn and winter here in New England, when you have drier air, you’ll be able to see some beautiful sunsets!
Also, remember, we see colors other animals can’t (remember dogs?). That also means that some animals see other colors we can’t! Imagine what their sunsets and sunrises must look like![for more information: http://news.nationalgeographic.com/news/2013/10/131027-sunset-sky-change-color-red-clouds-science/]