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Once again, our weekend science fun is inspired by a children's book. As announced today, the winner of the 2009 Cybils award for nonfiction picture book is The Day-Glo Brothers by Chris Barton
 and illustrated by Tony Persiani. If you are interested in children's and young adult books, you might want to see the winners in all the categories. I reviewed The Day-Glo Brothers at Wrapped in Foil this week.Day-Glo

The Switzer brothers, Bob and Joe, were fascinated by science, probably due to the fact their father was a pharmacist. Their interest in glowing colors started when Bob had a bad accident which kept him confined to home. His brother Joe kept Bob company by playing around with an ultraviolet lamp (also called a black light). Joe, a magician, realized he might be able to use fluorescent paint and ultraviolet light to create an illusion, so the brothers began to experiment.

Knowing that there were commercial uses for fluorescent paints, the brothers started to investigate paints that would glow in regular daylight, not just under ultraviolet light. They eventually created the eye-popping Day-Glo colors found today in products as diverse as highlighters and traffic cones.

Let's do some investigations with glowing light sources of our own.

1. Glowing under ultraviolet light


  • a black light
  • petroleum jelly
  • paper
  • tonic water
  • kitchen or latex gloves (optional)

Here in Arizona, black lights are easy to obtain from virtually any hardware or home supply store, and for a good reason. It turns out that one of the best ways to find scorpions, which are active at night, is to shine an ultraviolet light on them. Scorpions glow under UV light. For those of you who are curious, Firefly Forest has a great photograph of a glowing scorpion.

How Stuff Works (site has ads) has an explanation of how a black light works.  Under normal conditions humans can't see ultraviolet light, but when ultraviolet light from a black light hits certain objects it releases forms of light that we can see.

Turn off the lights at night, and explore with the black light. What glows? Turn the lights back on and write a simple message in petroleum jelly on a sheet of paper (using the gloves if you don't like the feel of the jelly). What happens when you turn the lights back off? What happens if you get petroleum jelly on your hands? Take a look at the tonic water and other household items under the black light, too.

For more black light science experiments, check Home Chemistry.

2. Light sticks

Light sticks can glow in the dark without being exposed to light or ultraviolet light to work. The light they give off is the result of a chemical reaction. How Stuff Works has a section about how light sticks work.

You can experiment by comparing the speed of the reaction when you activate a glow stick in warm water versus ice water. You'll need a timer to time the reaction.

Steve Spangler has a video about light sticks and glowing.

3. Day-Glo Bugs

Entomologists who want to study insect movement sometimes use Day-Glo powders. They mark a group of insects with the bright powder, release them and then recapture the insects after a given period of time, to see where they ended up. This type of experiment is called a mark-recapture experiment. Insects may be recovered with simple equipment, like a butterfly net, or elaborate collecting equipment, such as a huge insect vacuum.

Get some glowing insects, hide them and let the children "re-capture" them.

4. Glowing plastic stars

Younger children love the glowing plastic stars. Use them to create constellations, patterns, etc. My son used to enjoy throwing light-charged plastic stars into the bathtub water and turn off the lights (briefly and with adult supervision). It was fun to see the stars swirl through the water.

Have fun. Who knows where an interest in light and chemistry will lead next?

Disclosure:  As a round II Cybils judge, I received a copy of this book for review purposes.

It's National Chemistry Week this week, from October 18–24, 2009. If you are in the mood to do some chemistry activities to celebrate, here are some helpful links.

When I found the Home Chemistry blog, I was excited because there was a post about the "Chemistry of Colored Bubbles." I have been wondering if you could make a colored bubble for ages. Now I know you can!

I think I mentioned this in a previous post, but Off the Shelf Chemistry has hands-on activities for teaching high school level chemistry with things more or less from around the house.

The home of National Chemistry Week 2009! is the American Chemistry Society. Their 2009 theme is “Chemistry—It’s Elemental!” They have a lot of resources, so plan to spend some time looking around. has a whole list of projects as well as good basic chemistry information.

Finally, Robert Krampf at the Happy Scientist has a number of chemistry experiments. Some of his experiments are free, but most require a subscription. He does have a free newsletter that has general science topics called Experiment of the Week.

And of course we have some chemistry experiments here, like Colors with Acids and Bases.

Hope you enjoy chemistry week!

If you have any great chemistry sites that I have missed, please leave them in the comments.


Thinking of the lovely spring colors, the pastel blues, lavenders, yellows and pinks? Why not try a few really fun experiments creating and changing colors using chemistry?

The first experiment requires some fresh red, blue or purple flowers (purple petunias work really well); a jar big enough to hold a few flowers with a lid; some twist ties, string or yarn to suspend the flowers; household ammonia; and for the optional last part, vinegar (any kind). The ammonia is pretty strong, so this will require help from an adult.

Have an adult pour about 1/2-inch ammonia into the bottom of the jar. Wrap a twist tie or yarn around the stems of the flowers, enough that will fit comfortably into the jar. Suspend the flowers upside-down into the jar so that they are close to, but not touching the ammonia, by wrapping the yarn or twist tie over the lip of the jar. Put the lid on the jar as much as you can. Wait about 15 minutes and you should see the flowers start to change color.

This part of the experiment is based on one by Robert Krampf in his excellent Experiment of the Week series, although I couldn't find it in his archives. Edit: Robert Krampf has revamped his site, and so this link is no longer valid. Check out the fun stuff he has to offer at the Happy Scientist.

Now comes my addition: once the flowers have changed color nicely in the ammonia (which is a base) then try to change the color back by dipping the flowers in a bowl of vinegar (an acid). Using purple petunias, I was able to turn them a bright teal blue in the ammonia, and then back to purple in the vinegar. You can actually dip them into the vinegar, because it won't bleach. It you dip the flowers into the ammonia, however, it may bleach or discolor them. That is why they need to be suspended in the fumes instead.

The second experiment is the classic use of red cabbage as a pH indicator. If you haven't done this, it really is fun. All you need is red cabbage from the grocery store, a blender (ask for an adult's help), glasses or plastic cups and items to mix with the red cabbage solution, such as lemon juice, soda, vinegar, baking soda, dish detergent and laundry detergent.

Some recipes call for boiling the cabbage (smelly!), but I just ground up the fresh red cabbage in small batches with just enough water to allow the blender to work properly. Pour the batches together in a pitcher (which can be placed in the refrigerator for use later in the day if necessary.) Pour about 1/3 cup of the red cabbage juice into testing containers such as clear glasses or plastic cups. Then mix in about a Tablespoon of one of the testing compounds. Does the color change? Try another material in the next glass. Does the color change more if you add more test material? What happens if you mix two materials, like vinegar and laundry detergent? Have fun admiring the wild colors you can make.

What is happening? The pigment molecules in the red cabbage change shape, and thus color, when in the presence of acids versus bases. Lemon juice, vinegar and soda are acids; detergents and soaps are bases.

For the grand finale, create more wild colors with markers. Fold up a diaper wipe that contains alcohol and tie in bunches with rubber bands. Color with Sharpie-type markers. Allow it to set a few minutes and then unfold to reveal a rainbow of colors in a cool tie-dye pattern. Experiment with more wipes to see what you can create. Note: allow to dry suspended on a line so the dye doesn't move onto other surfaces.

If you don't have diaper wipes, then try white fabric. Tie with rubber bands, if desired and then color with markers. Drop or dribble on some rubbing alcohol and the colors should separate and move through the fabric. Once again, keep on a line or suspended until dry. Once you have the technique refined, you might want to create your own tie-dye T-shirts or socks.

Spring colors rock!