real science for today's homeschooler

Don’t Miss the Supermoon!

Don't Miss the Supermoon!

On November 14-15, 2016 we’ll experience a “Super Moon.” A full moon that is bigger and brighter than usual because the moon will actually be about 400,000 kilometers closer to Earth than normal. The last Super Moon occurred in 1948 and you’ll have to wait until 2034 for the next one. So, take your children outside tonight so they can experience their first Super Moon! For more information about the phenomenon, go here.

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Roadcuts – Windows to the Past

Roadcuts - Windows to the Past

The next time you’re traveling with the kids and need to stop for a break, look for a roadcut with a large safe shoulder to walk around. Call attention to the rock layers visible on the surface of the cut, and ask children for their ideas about what caused the layers. Depending on the age of the child, topics of discussion can include:

 

  1. the type of rocks and how they formed (most formed as sediments deposited as they settled out of water)
  2. fossils that may be found in the rocks (type of organisms give further hints about the conditions under which the rocks formed)
  3. the angle of the rock layers (sediment laid down underwater would form horizontal rock layers; if there are angled rock layers, how did they get that way?)

Help children understand that the farther below the surface, the older the rock layer. An analogy about building a brick wall may help younger children understand . . . the bricks at the bottom of the wall were put down first and the bricks at the top where added last. If fossils are present in the rock layers, talk about which of the organisms are older than others.

When you’re back on the road, encourage children to use their imaginations to draw what the area might have looked like when the rock layers were forming. If you found fossils, have them draw what the living organism might have looked like based on the fossil remains.

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How do colors affect temperature absorption?

How do colors affect temperature absorption?

We’ve all heard the fashion sayings . . . “never wear white after Labor Day” . . . “pastel colors should be worn at Easter” . . . etc. You know the traditions, but did you know they are actually based on science? The color of the clothing you wear can affect how hot or cold you feel when standing outside during the day.

The light reaching us from the Sun is known as “white light” and it is really made up of all the colors of the rainbow. Each of those light rays coming in contains energy. White materials reflect all colors away from their surface, absorbing none of the light energy. Similarly, light pastel colors reflect almost all the incoming light energy. Black materials absorb all light rays, allowing none to be reflected into our eyes. (That’s why it looks “black.”) Dark colors absorb almost all the incoming light energy.

So, you wear light colors in spring and summer to stay cool, and dark colors in the winter to stay warm. Fashion traditions are based on science! You can investigate this phenomenon with your children to prove that it works:

1. Select two t-shirts. Ideally, use one black and one white. If you don’t have black and white, use one that is as dark as possible, and one as light as possible. Also, select t-shirts that are similar in size and fabric type.

2. If possible, do the experiment outside on a warm, sunny day. Select a spot where you can lay the t-shirts out flat, side-by-side. Try not to set them on metal as this will affect the temperature.

3. If you have two similar thermometers, you can just insert a thermometer inside each t-shirt, wait for a select amount of time, and then read the thermometers. Try waiting about 15 minutes and then check for a temperature difference. Increase the time if necessary. Time will depend on the intensity of the sun that day.

4. If you only have one thermometer, try putting some water in two plastic baggies. Be sure to use the same type and size baggie, and the same amount of water. Place one of the baggies of water into each t-shirt at about the same place. Increase the time to about 30 minutes since it will take longer for the water temperature of the water to change noticeably. Be sure to check the temperature of the water in place. Bringing the water into the cool house can drop the temperature significantly while waiting to check the second bag.

To extend the experiment, especially for older children, repeat with different “medium” colors or prints to see what effect each has on temperature. You might also want to test how different types of fabric affect the absorption of light energy. Your children can then write their own “fashion rules” based on science!

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Learning about Buoyancy in the Pool

Learning about Buoyancy in the Pool

Buoyancy seems like a simple concept, but to fully understand it on a scientific level can be a challenge for students. Introduce the concept to your younger elementary kids in a fun way while playing in the pool this summer!

Buoyancy is based on Archimedes’ Principle that states, “Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.” Very confusing language for kids! Here’s how to explain Archimedes in their language . . .

When you get in the pool, your body shoves some water out of the way to make room for you. Let’s say you could collect all the water your body moved out of the way and weigh it. Now, pretend that you lie down on the ground and have someone put all that water on top of you. You would feel the water pushing down on your body, right? That push you feel is a force. So, when you get in the swimming pool, the water you move out of the way starts pushing back. But instead of it pushing down on you, it pushes up trying to push you back out of the water. That force of the water trying to push you back out of the pool is called buoyancy!

Relate Archimedes’ Principle to what your child “feels” while in the pool. You feel lighter in water than you do out of the water because the water is actually pushing up on you . . . holding you up a bit!

If your child is able to understand the basics of Archimedes’ Principle, go a step further with the concept. If the weight of the water displaced is more than the weight of the object, the object will float. If the weight of the water displaced is less than the weight of the object, the object will sink. Ask them to explain why they sink in the water (when they don’t swim), but float when they lay on a float.

Finally, if your child swims well enough to “dive” for objects underwater, introduce a challenge. It’s them against the water! When they try to go underwater to get a object at the bottom of the pool, the water is trying to push them back up. The challenge? Who is stronger, you or the water? 🙂

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Backyard Ecology

Backyard Ecology

No matter whether you live in the country or the city, your child can observe nature close to home. Help your child be a nature detective to discover the ecosystem existing right in their own backyard.

First, help your child identify what types of plants and animals they are realistically likely to see. If you have land in the country they’re likely to observe large mammals such as deer and racoons. If you have a tiny backyard in the city, help your child realize that they will be looking for small animals such as insects, lizards, birds, etc.

Depending on the age and interest of your child, prepare a plan to capture an image of the plants and animals they find. A digital camera works well, but if your child likes to draw they can turn the ecosystem hunt into an art project.

Over a span of a week or two, sit quietly outside with your child and observe nature. Have them find as many different plants and animals as possible. To find some of the more shy animals, help your child turn over rocks and other objects in the yard or on the porch. Try observing at different times of day, and even go outside with a flashlight at night to find animals that come out after dark.

For younger children you may just want to print out the photos and identify the different types of plants and animals found. They can make a collage or a notebook to display what’s living in their backyard. Older children may also want to research what each type of animal eats and design a food web based on that information. One method is to glue the images on a poster board. Then draw arrows going from the prey (or plant) to the predator. Older students can then examine their food web to infer other animals that might be a part of their backyard ecosystem that were never observed.

Whether you focus on the exploration or turn the project into an in depth ecology lesson, your child is sure to gain an appreciation for nature’s ability to sustain life anywhere!

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Calculate Speed While Encouraging Exercise

Calculate Speed While Encouraging Exercise

We all know that kids have a lot of energy. Put that energy to good use by combining a physics lesson, a math lesson, and some good exercise! All you’ll need is an energetic kid, a tape measure, a stopwatch, and a safe place for your child to run.

Calculating Speed

1. Pick out a “track” that your child can run safely. Select a distance appropriate for your child to run several times.

2. Help your child measure the distance of the selected track with the tape measure. You can measure with any units: yards, feet, meters, etc. Have your child record the track distance.

3. Measure the time it takes for your child to run the selected track. If possible, measure the time in seconds. Record.

4. Introduce the formula used to calculate speed:  speed = distance / time

Depending on the math level of your child, help them calculate their speed by dividing the distance of the track by the time it took to run it. Older children can calculate speed using long division. For younger children you may want to introduce the usefulness of technology by showing them how to get their answer with a calculator.

5. Repeat the run with the same track, or a different one as long as your child is interested and energetic. Challenge them to improve their speed with each run.

As an extension of the lab, students can compare their speeds when a) wearing different types of shoes, b) running on different surfaces, or c) running courses of different lengths. Any of these options will increase your child’s interest in the lab, as well as give them extra practice with division . . . and a little more exercise!

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Making Rocks Fun!

Making Rocks Fun!

Okay, I have to admit, rocks sound boring to most people. But here’s a way to get kids interested in the topic of rocks and minerals!

Kids (and adults) love to find treasure. Purchase a bag of “mining rough” and you have a ready-made treasure hunt for your kids. Mining rough is the left over material generated by the mining process. To a mine that recovers and sells gemstones, it isn’t cost effective to spend time going through the left over material to pull out the small gemstones. They bag it “as is” and sell it at very reasonable prices. Going through the bag is literally a treasure hunt and you can find some very nice samples of amethyst, crystal quartz, and other gemstones including small samples of rubies and emeralds. Nothing that’s really worth much money, but pieces that will excite your kids!

There are many mines that sell this “mining rough,” but here’s a link to the one I order from: Cold River Mining Company. They do sell wholesale, but this link will take you to their “store” where you can buy individual bags. If you have a cave attraction nearby, you can probably purchase bags of mining rough there.

You’ll also need a sieve to separate the dirt from the larger rock and mineral specimens. You can purchase one from the mine, but it’s much cheaper to make your own. I would suggest getting a 1-foot x 1-foot piece of window screen to use as a sieve. The fiberglass screen works much better than the aluminum wire screen. The cut ends of the aluminum around the edges can puncture the skin!

The mining rough is dirt and rock straight out of the ground, so it can be messy. This is a great outdoor activity when the weather’s nice! Put the kids in their bathing suit or old clothes you don’t mind getting dirty and wet.

Here’s how to mine for gemstone treasure:

1. While your child holds the screen, add a small amount of mining rough to the center of the screen.
2. Spray the rough with a garden hose set on a low setting. The dirt will wash off revealing the rocks and minerals. (You can also dip the screen in a bucket of water, but the garden hose is much more fun!)
3. Collect the large pieces from the screen and let them dry.
4. The bags of mining rough usually come with an identification guide that kids can use to identify their gemstone treasures.

Be sure to explain to your budding geologists that gemstones are rocks and minerals that formed deep inside the Earth. Because the Earth is always moving and changing, sometimes these rocks and minerals get pushed up close enough to the surface for us to dig them up.

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