real science for today's homeschooler

Inexpensive microscope substitute

Inexpensive microscope substitute

One of the most expensive pieces of science equipment to purchase for home studies is a microscope. A good microscope is really a necessity for middle and high school studies, but there’s a cheaper alternative for the earlier grades. You can purchase an “illuminated pocket microscope” for anywhere from $10-$30, depending on the light source and magnification level. It’s definitely limited in what it will do, and it’s no substitute for a real microscope at the secondary level. But, for elementary studies, it will magnify objects well enough for children to see details they can’t see with a regular magnifying glass.

A quick internet search for “illuminated pocket microscope” will give you many sources from which to purchase one. Amazon has a wide selection. I haven’t found that any one brand works better than another. Just make sure it has a light source, and choose the magnification level based on how much you want to spend.

Be aware that the object being viewed must be held close to the pocket microscope, children must be able to look through a small eyepiece with one eye, and it isn’t made for viewing traditional slides. The light will shine on the surface of the object being viewed, not through it like a compound light microscope. You can check out a few different types being demonstrated by watching this utube video.

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Seed Germination Lab

Seed Germination Lab

Children are fascinated by the fact that a seed can grow into a plant. You’ve probably already planted seeds with your child in order to watch them grow into plants. Here’s a slightly different way to show your child the actual process of germination that allows them to actually see the plant emerge from the seed.

Materials: seeds, paper towel, plastic sandwich bag, magnifying glass

Procedure:

1. Fold a paper towel so that it fits flat inside a plastic sandwich bag.

2. Soak the paper towel thoroughly with water. You want the towel very wet from end to end, but not dripping with excess water. Place the paper towel in the bag and lay flat.

3. Place seeds on the paper towel so that they are spaced out away from each other. Press each firmly into the wet paper towel. (Hint: Although any type of seed will work, small, fast-germinating seeds work best. Whole birdseed such as millet works very well.)

4. Seal the baggie to conserve water and place the bag in a place where it will be undisturbed.

5. Gently slide the paper towel out of the baggie each day and observe the seeds with a magnifying glass. Depending on the type of seed used, you should start to see the seeds germinate within a few days to a week.

6. Between daily viewings be sure to gently replace the paper towel into the baggie and reseal. Re-wet the paper towel if it begins to dry out. You should be able to germinate the plants long enough to see the first leaves develop.

Lab Variations:

  • When the seedlings begin to produce leaves, transfer to soil and continue to grow into a larger plant.
  • Prepare more than one baggie with the same type of seed. Place the baggies in different environments (temperature, sunlight, etc.) to see how environmental factors affect seed germination.
  • Prepare more than one baggie with the same type of seed. Put differing amounts of water into each baggie to see how different amounts of available water affect seed germination.
  • Prepare more than one baggie using a different type of seed in each. Compare germination times of different types of seeds.
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Slinky Waves

Slinky Waves

Have an old slinky collecting dust in the kids’ toy box? Pull it out and teach a quick lesson on the two types of waves.

1. Loosely stretch the slinky across the floor or long table with you holding one end and your child holding the other.

2. Create a transverse wave by shaking one end of the slinky horizontally across the floor or table. Continue shaking back and forth to set up a series of transverse waves that will move from one side of the slinky to the other.

3. Have your child identify the crests and the troughs of the waves.

crest and trough

4. Also explain that in a transverse wave the energy moves perpendicular (at right angles) to the motion of the medium. They can see the medium (the slinky) move side to side while they feel the energy being transferred from your hand to theirs. Help them to see that the motion of slinky and energy are in different directions.

5. To make a longitudinal or compression wave, make a quick shoving motion with the slinky toward the person at the other end. You should be able to see a compression travel along the slinky between your hand and the person on the other end. Continue making compression waves in the slinky for your child to observe.

6. Have your child identify the compression and the rarefaction (see below).

compression and rarefaction

7. Explain that in a longitudinal or compression wave the energy moves in the same direction as the motion of the medium. In this case, they should see that both the slinky and the energy from your push are both traveling in a straight line between your hand and theirs.

If you are trying this with small children it may be difficult for them to identify the motion of the medium vs the energy. At lower grade levels, just focus on the fact that there are two different kinds of waves and how they look different. If your child is ready for new terms, help them identify the parts of one or both types of waves.

Finally, for all children, extend the lesson to brainstorm where they have observed (or how they can make) transverse and longitudinal waves in different types of media (water, rope, air, etc.)

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