Online Homeschool– Sky Blue

We’ve all recognized that the sky is blue throughout the day, then red during sunset. During this experiment, which works really well with many online homeschool programs, you’ll learn more about why the sky has different colors – and will even create your own color spectrum right at home. No matter what online homeschool course you’re currently taking, this is a fun experiment for all grade levels.

In order to get started, you’ll need a few key materials:
    •    A flashlight
    •    One clear container with flat sides that are parallel (such as an aquarium)
    •    One cup of milk

Once you have these materials gathered together, it’s time to get started with the project. Ready? If so, then follow these simple steps:
    •    Place the container on a surface where you can see it from all sides, such as the center of a table.
    •    Fill the aquarium 2/3 full with water.
    •    Hold a lit flashlight against the side of the container so that the beam of the light shines through the water. Try to see the beam through the water. You will probably be able to see some particles in the water when you shine the light through it. These are likely to be particles of dust in the water and should appear to be white. You may also notice that it is not very easy to see exactly the light beam as it passes through the water.
    •    Record your observations.
    •    Add about ¼ cup of water to the water.
    •    Stir.
    •    Hold the flashlight (turned on) to the side of the container, just as you did before.
    •    You should notice that the light beam is much easier to see as it passes through the liquid.
    •    Observe the beam from the side of the beam and at the end of the beam, where it shines on the outside of the container. Record your observations. You should notice that the light beam appears to be slightly blue from the side. However, in the middle, the beam appears to be yellow at the end. Record your observations.
    •    Now add another ¼ cup of milk.
    •    Stir the water and milk together. Don’t think watered-down milk looks very tasty? Don’t worry – you won’t need to drink the mixture for this online homeschool experiment! By the way, you might want to download a free copy of the Homeschool Science Experiment Guide and workbook to find more great experiments
    •    Record your observations. Notice that the beam of light appears to be blue from the side and even yellower (maybe even orange) towards the end of the beam of light.
    •    Now add the rest of the milk (another ½ cup) to the water.
    •    Stir the milk and water together.
    •    Record your observations. You’ll notice that the beam appears to be even bluer from the side and even more orange from the end. You will also notice that the beam is spread out more and is not as narrow as it was before.

Understanding what you observed:
First, it’s important to understand that light generally travels in straight lines. Therefore, the light from the flashlight traveled in a straight line. When the light beam travels from the flashlight through the air, we don’t see the beam because the air is usually uniform and the light travels straight. The water is the same as air.

However, what happens when the water isn’t uniform? The beam can’t travel in a straight line. Instead, we can see the beam of light when it is scattered around the edges of the dust particles within the water (or milk and water). Adding milk to the water also adds more particles to the water, including protein and fat, which scatter the light from the flashlight even more.

Light is not always scattered the same. In fact, different colors of light scatter in different amounts. Blue, in fact, is scattered more than red light. The light beam appears blue from the side because we see it from the side of the beam. The orange (or red) light is less scattered, so it travels in a straight line down the beam of light. That’s why the light appears to be orange or red when you look at it straight-on.

So what can we learn about a blue mid-day sky and an orange sunset from this experiment? Remember that the atmosphere scatters sunlight. When you look at the sun through the sky, you’re looking through scattered particles. However, when you look at the sky during a sunset, the sunlight is less scattered by the particles in the atmosphere, so it’s like looking into a light beam directly.

This is a great project for any online homeschool course and will surely provide you with an explanation about why the sky changes color that you’ll remember for the rest of your life!