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Category: Fun Science Activity (Page 68 of 112)

Doable Renewables Book Review

November 29, 2010 / / 0 Comments

Our book today, Doable Renewables:  16 Alternative Energy Projects for Young Scientists by Mike Rigsby, is full of creative new ideas and information. Do you remember in our post about smart materials (the materials that respond to the environment), we were looking for a source of nitinol (nickel-titanium alloy) wire? This book not only lists a source, but also uses nitinol springs in projects.

Mike Rigsby is a professional electrical engineer and he has a noble cause for writing this book. He has come up with projects to investigate various forms of renewable energy in the hope at least one of them will spark a young person to discover something that will change the world. His projects include making engines that use heat as a source of energy (including one with nitinol springs), solar energy, wind energy and wave energy. Each project is explained clearly, with a detailed list of supplies and numerous black and white photographs showing the assembly, as well as the finished project.

Before we get too excited, though, let’s do the reality check. Safety is one concern. Some of these projects have steps that could potentially cause injuries, especially those that involve cutting. Unlike many of the activities found in children’s science books, some of these projects are not made from items lying around the house. Many will require the purchase of specialized pieces of equipment or supplies from science and technology suppliers. For example, the nitinol springs are available from Jameco Electronics, part number 357835. As of today, they cost $45.95 for a 4 pack. The bottom line is that this book is for serious older children or young adults who enjoy engineering and inventing, and who preferably have an experienced adult mentor.

That said, do you have a science fair coming up soon? Doable Renewables: 16 Alternative Energy Projects for Young Scientists is a wonderful resource sure to generate innovative science fair projects.

In fact, the book inspired us to do some of our own investigations:

1. Stirling tin can engine

In chapter 4, Mike Rigsby suggests purchasing a Stirling engine to explore this technology investigated by Reverend Dr. Robert Stirling way back in 1816 (see our Amazon suggestions below). The Stirling engine uses heat to do work, and is known to be very quiet in comparison to the internal combustion engine.

Rigsby also mentions that there are instructions for building your own on the Internet, so of course we had to look. We found quite a few examples of Stirling engines you can make at home plus numerous videos of the engines in action. Here is one example of a fan Stirling engine (note: there is a pop-up ad).

The instructions can be found at Easy to build Stirling engine

There is more about how Stirling engines work at How Stuff Works.

2. Radiometer

We already had a radiometer, so we dusted it off and tried it out. A radiometer is a glass bulb that looks like a light bulb. Inside are 4 tabs suspended from wires. Those tabs are reflective on one side and black on the other. When placed in sunlight, the tabs rotate like crazy.

The Crookes radiometer caused quite a stir in its time, because no one was quite sure how it worked. Several hypotheses were proposed and shot down. Eventually the idea of thermal transpiration was found to be the one most generally accepted. It involves the movement of gases from the warmer side of the tab (the black side) to the cooler, reflective side. In any case, the only energy supplied is that from the sun.

3. We have a previous post on Windmills and wind power that also relates to this topic.

We hope this inspires you to try a few new projects with renewable energy. Be sure to let us know how they turn out.

Reading level: Ages 9-12 (Amazon)
Paperback: 224 pages
Publisher: Chicago Review Press; Original edition (October 1, 2010)
ISBN-10: 1569763437
ISBN-13: 978-1569763438

This book was provided for review.

Stirling Engines at Amazon

Other scientific supplies suggested in the book:

Weekend Science Fun: Rocks and Minerals

November 14, 2010 / / 0 Comments

What child doesn’t go head over heels for rocks and minerals at some point? Today let’s take a look at a new book from National Geographic Kids in their Jump into Science series:  Rocks & Minerals by Steve Tomecek and illustrated by Kyle Poling.

Written and illustrated in a fun and energetic style, Rocks & Minerals is spot on for the target age group, 4 to 8-year-old children. The text lightly covers some common rocks, the rock types and how they form, the rock cycle and a few things humans have used rocks for. And it turns out the author, Steve Tomecek, is actually a geologist who studies soils. How cool is that?

As is always the case, we appreciate that the book contains two hands on activities. The first shows how mineral crystals can form when salty water dries up. The rocks that form this way are called evaporites. The second gives a recipe for making a rock at home (using pebbles and white glue). The author then asks, “What type of rock have you created?” In a stroke of pure genius, the answer on the next page is printed backwards, so you have to go find a mirror to read it. What a wonderful way to make sure the child actually thinks about the answer before having it appear.

To celebrate Rocks & Minerals, here are some of our activities:

1. For beginning geologists – Exploring a rock

A super way to learn more about rocks is to explore a few samples with all your senses. Pick up a rock that catches your eye. Close your eyes and hold it. What does it feel like? Is it cold? Is it rough? Is it heavy or light? Can you scratch it with your fingernail? Is it soft or hard?

You may feel silly at first, but smell the rock. What does it smell like?

Now, look at it very closely. What colors do you see? Is it sparkly or dull? Is it all the same over the entire surface, or does it change in places?

If you have one available, look at your rock under a hand lens or a microscope. What can you see now?

2. Making a rock collection – for many age groups.

Most young children seem to want to bring home rocks from their daily explorations. Use these as opportunities to learn about classification. Keep the rocks in a box or other container.

When you have accumulated a few, pull them out and ask your child to sort them into groups. He or she might make up his own categories at first, such as red versus brown or big versus little. Gradually, you can introduce the ideas of rocks types:  sedimentary, igneous and metamorphic (see video below if you are rusty on these terms).

Later your child may want to identify rocks and minerals he or she has collected in a more scientific way. At this point, it is important to begin to label each rock with such information as where and when it was collected. Take your child to see a geology museum or gem show to see how others display their rock collections. We are lucky to have a wonderful Arizona Mining and Mineral Museum in Phoenix, as well as some world famous shows, like the one in Tucson, plus a number of active organizations.

amethyst

3. Exploring the rock cycle – a noisy activity

Gather:

  • plastic container with a tight-fitting lid
  • a few small rocks, the rougher the better (polished rocks won’t work)
  • piece of white paper or paper towel

Place the rocks in the container, and make sure the lid is shut tightly. Then let the children shake, shake, shake. After they tire out (or your ears tire out), open the container and pour the rocks out onto the paper. You should see the original rocks, plus bits of smaller particles that have broken off. Explain that when rock are tumbled around by action of water and wind, they break down over time. This is part of erosion.

obsidian

4. Now make a type of sedimentary rock called a conglomerate rock

Gather:

  • sand, pebbles or bits of rock from the last activity
  • Model Magic modeling compound or salt dough

Have the children press pebbles or sand into the modeling compound or salt dough and allow to dry. They have made a model conglomerate rock.

Mica

Pyrite

5. Float a rock

Obtain some pumice, a light volcanic rock with many air pockets, and a bowl of water. Ask the children whether rocks can float. Then place the pumice in the water to show that some rocks can indeed float.

Pumice

In this video from NASA see the rock cycle on earth and how it compares to the types of rocks found on the moon.

Do you have a rock collection? What is your favorite rock?

More about Rocks & Minerals by Steve Tomecek and illustrated by Kyle Poling:

Reading level: Ages 4-8
Publisher: National Geographic Children’s Books (November 9, 2010)
ISBN-10: 1426305389
ISBN-13: 978-1426305382


American Educational Classroom Collection of Rocks and Minerals

Disclosures: Book was provided for review. Also, I am an affiliate for Amazon. If you click through the linked titles, covers, or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.

Genes and DNA for Kids

November 7, 2010 / / 9 Comments

I am excited to report that the experiment for this week are inspired by a new book, You Can’t Wear These Genes by my friend Shirley Duke, who blogs at SimplyScience. Be sure to look for my interview with Shirley and more about the book over at Wrapped In Foil. Shirley will be celebrating her 100th blog post this week at SimplyScience, so you might want to stop over and say hello.

About the book:
You Can’t Wear These Genes is an easy-to-understand overview of genetics for children in grades 4-7. Reading this book is a perfect way to introduce a lesson on genes and DNA.

Shirley starts out with an idea a child can relate to, how we inherit traits from our parents. Further inside are explanations of common terms, like chromosomes, alleles, and what a genome is. The crisp clear, illustrations of the structure of DNA, for example, complement the text. Not only does Shirley review the background of what we know so far in the field of genetics, but she also gives us a glimpse of the future by looking at the Human Genome Project, genetic engineering and cloning.

I know I will be using this book when I present the following activity to a group of children next month.

Activity: DNA Extraction From Strawberries and/or Bananas

Believe it or not, these days you can extract DNA from common fruits and vegetables right in your own home.

You’ll need:

  • strawberries, bananas or both (these fruit contain extra copies of DNA making extraction easier)
  • plastic bags that seal (or something to mash the fruit in)
  • water, preferably distilled
  • a device to measure liquids in ml (optional for a single test, see 1 below)
  • dish detergent
  • table salt and measuring spoon
  • a container to mix the extraction buffer in
  • isopropyl alcohol and a way to keep it cold. Most recipes call for 90%, but 70% is acceptable.
  • glass container, like a beaker
  • funnel (optional)
  • filter material such as cheesecloth, coffee filter, paper towel or any old piece of cloth
  • test tube or spice jar, and some type of holder to keep it upright
  • A medicine dropper (optional)
  • wooden stick that will fit in the test tube, such as a craft stick or wooden skewer

Method:

Before you start, put the isopropyl alcohol in the fridge or on ice so that it is cold when you need to use it. Note:  you can use ethanol, but isopropyl (rubbing) alcohol is cheaper and easier to obtain.

1. If you are working with a group you will need to make the extraction buffer, which is the solution that helps break down the strawberry cells and release the DNA. The basic ingredients are water, dish detergent (or shampoo) and table salt. One common formula is 300 ml water, 25 ml dish detergent, and 1 Tablespoon table salt. Note:  Stir this mixture gently. Excessive bubbles will interfere with the extraction process later on.

If you are doing a single test on one strawberry or one piece of banana, there’s no need to make up a big container of buffer. Try 2 tsp water, 1 tsp soap, and 1 pinch salt for each berry.

2. Place a single strawberry or 1/2 a banana in the plastic bag, seal and mash it up. You can do one kind of fruit, or do both separately and then compare your results. The plastic bags works well if you are doing this with a group of children because each child can mash his or her own. You can simply mash the fruit in a bowl, too. This should only take a minute or two. If the banana is somewhat green, you can add a bit of water to make it easier to mash.

3. Add up to 10 ml of the extraction buffer to the bag, and mash some more. Again, try not to create excessive bubbles. Remind small children not to taste the fruit after this step.

4. Set up some sort of filtration system. This can be a simple as a coffee filter over a cup or cheesecloth over a funnel. The idea is to separate the fruit juice from the pulpy material. The DNA should now be in the juice that passes through the filter. You can throw away the pulpy remains. The videos have more details about filtering if you have never done it before.

5. Pour your juice into the test tube or spice jar. If you have a lot of bubbles on top, remove these with a medicine dropper. Now slowly pour in 8 to 10 ml of the cold isopropyl alcohol. It should form a layer on the top of the juice.

6. With the wooden stick, stir at the interface of the alcohol and juice. A thick, globby material should form on the stick, which is your DNA. If it doesn’t appear right away, give it a minute or two and try again.

There’s nothing like being able to watch someone do a demonstration to help you figure out what to do. Here are two videos that show how to extract DNA, each using slightly different techniques.

DNA Extraction from Strawberry Video

DNA Extraction from a Banana Video

These are sure to give you some ideas for further experiments. What happens when you add the alcohol to the test tube first versus second. Does the order change the amount of DNA you obtain?

Once you are confident of your technique, go ahead and try other fruit or vegetables, such as kiwi or onions. You can also compare room temperature versus cold alcohol to see whether it really needs to be cold. Have fun and I’d love to hear what you find out.

For more information about genetics online, try Learn Genetics at The University of Utah.

You Can’t Wear These Genes

Reading level: Ages 9-12
Paperback: 48 pages
Publisher: Rourke Publishing (FL) (August 2010)
Language: English
ISBN-10: 1615905634
ISBN-13: 978-1615905638

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