The dog days of August are here.  It’s hot and humid and summer sports and activities are coming to an end, which can only mean one thing: bored kids.  I know that boredom is good and sparks creativity, but sometimes it’s nice to have an activity planned to break up the day.

My kids have nothing scheduled in the afternoons this week, so we’re going to do an impromptu science camp.  It won’t be elaborate, well-planned or even all that time-consuming.  We’ll just find a few easy projects that we can do using stuff we already have. (There will be no trips to the store to buys special ingredients.)  It may be as simple as taking a walk to the park with notebooks to count how many different kinds of trees we can find.  We’ll see what happens and I’ll report on what we do, beginning tomorrow!

Why not have a little science camp of your own, even just for an afternoon?  There are lots of easy projects listed in my archives under chemistry, physics and biology.  I’d love to hear what you tried!

Culturing microbes (bacteria and fungi) on petri dishes lets you test different surfaces for microbes and grow your own germs.  It’s also a great reminder of why it’s important to wash your hands.  Even very young children will have fun helping with the Q-tips and seeing what grows in their microbial zoo.  It’s fun, easy, and you might even already have what you need in your kitchen cupboard.  If not, the ingredients are readily available at any grocery store.

You will need disposable containers to grow cultures in (see below),  beef bouillon cubes or granules, plain gelatin or agar agar* (seaweed gelatin), water, sugar and Q-tips. (*Agar-agar can be found with Asian ingredients in some grocery stores.)

Note: Gelatin will melt if it gets too warm,and some bacteria make enzymes which can liquefy it, which is why scientists in labs use agar to make their plates.  The idea to use agar for plates originally came from the wife of a famous microbiologist who used agar for canning food. Try to keep petri plates away from hot lights, etc. so they won’t melt.

For containers, you can use foil muffin tins, clear plastic cups covered with plastic baggies, clear plasticware with lids, or real petri dishes to grow fungi and some bacteria.  We’re going to use clear deli containers, so that we can recycle while we learn.  (They look like they will be heat-resistant enough to pour warm agar into.)

You’ll start by making microbial growth medium (or germ food, as we like to call it.)

Mix together a little less than 1 cup water, one and one half packages gelatin (Or 1 and 1/2 Tbs. agar-agar), one bouillon cube (or 1 tsp. granules), and 2 tsp. sugar.  The next step is for an adult to help with, since it involves very hot liquid.  Bring the mixture to a boil on the stove, stirring constantly, or boil in the microwave, stirring at one minute intervals and watching carefully until the gelatin or agar is dissolved.  Remove the boiling liquid from heat and cover it with aluminum foil.  Let the growth medium cool for about fifteen minutes.

Pour the medium carefully into clean containers, until 1/3 to 1/2 full.  Loosely place lids, foil or plastic baggies over containers and allow dishes to cool completely.  The geltin or agar should make the growth media hard like jello.  When your plates have hardened, store them in a cool place, like a refrigerator, before using.  Plates should be used in 2-3 days.  When you are working with the plates, try to keep the lids on loosely whenever possible, so that they are not contaminated by the air.  If you’re planning to use muffin tins, simply place them in a muffin pan, fill them with agar, and when they’re cool, put them in individual zip-lock baggies.  With other containers, put the lids on tightly once the plates harden.

When the plates have hardened  and you’re ready swab, shake the condensation off the lids of the containers and put them back on.  Then, draw a grid of four sections on the bottom of the plate with permanent marker. (If you are using muffin tins, you’ll just label each bag with the surface you are checking.)  Decide which surfaces you’d like to test.  It’s always fun to label one section of the grid “fingerprint” to see what grows when you touch your finger to the plate.

Label each section with the surface you want to test.   Be sure to label the bottom of the plate since the lid will move.  You should be able to see through the agar to see your lines and your writing.  If you want to, you can label a separate plate for each surface, but we had three kids and three plates, so we made sections.  TV remotes, kitchen sinks, computer keyboard, doorknobs and piano keys are great surfaces to check.  You can even cough on a plate or leave one open to the air for half an hour to see what’s floating around!  (See the photo at the top of this post for a better picture of how your plate might look.)

Now comes the fun part.  Rub a clean Q-tip around on the surface you want to test.  Then, remove the lid from the plate and gently rub the Q-tip across the section of the plate labeled for that surface.  If you are careful, the agar shouldn’t break.  If it does, it’s no big deal.  When you have finished, set the plates on a flat surface with their lids loosened and taped on (do not invert them.)  I set our plates on a countertop where they wouldn’t be in the way.  Check your plates every day, and soon you will observes colonies of different shapes, sizes and colors starting to grow.

You will mostly see fungi (molds), but you may also see some tiny clear or white spots that are colonies formed by millions of bacteria.  Record and draw how your plates look in your science notebook.  Older kids can keep track of how long it takes things to grow and the shapes, sizes and colors of the microbial colonies that grow on their plates.  If you want to learn more about microbes, search for the words fungi and bacteria on the website cybersleuthkids.com and it will give you some great links to microbiology websites.  Microbes are everywhere, but that very few of them are harmful, and many of them are essential for good health.

Be sure to wash your hands after handling the plates, and throw the plates  away when you are done.  Remind your kids that if they wash their hands with regular hand soap for the length of time that it takes to say the ABCs, they’ll remove most of the harmful bacteria and viruses on them.  (For adults, a severe side effect of this experiment is the sudden urge to disinfect computer keyboards and remote controls.)

Here’s what grew on one of our plates: The large, fuzzy colonies are fungi and the small, whitish ones are probably bacteria.  The grid with the most fungi was cultured from our piano keys.  The one with both fungi and bacterial colonies visible was cultured from our bathroom sink.  One grid has mostly small, white bacterial colonies and was cultured from a water-glass my son drank from.  The fingerprint grid has only a single fungal spot.  My daughter must have washed her hands before touching it!  Our other two plates were pushed too close to the under-counter lights in our kitchen and the gelatin melted, so we threw them away.

It’s August and Minnesota is crawling with Monarch caterpillars!  They’re on the swamp milkweed and the ditch milkweed almost everywhere you look!  We brought one home from the cabin with us last weekend and it’s happily munching milkweed and growing fat on our screened-in porch, soon to be dreaming in a chrysalis.  If you get a chance, check out my post on finding and taking care of your own monarch caterpillar and go on a hunt for your own caterpillar!

Metamorphosis from caterpillar to butterfly is truly one of nature’s more spectacular exhibits and is absolutely free of charge!

Aug.8th…

Our caterpillar has attached itself to a leaf and is hanging upside down in a J.  We’re watching for it to change into a chrysalis and will try to capture it on film, although it happens very fast!

Now that it’s summer, move your science lab outside and try doing the Tablecloth Trick or Throwing Eggs.  If you’d rather check out the power of the sun, try making a solar oven from a pizza box!  You probably have everything you need for these experiments right in your kitchen, and if you don’t have a pizza box, just save one next time you order out.

What are you waiting for?  Have fun!

“Mom!  I caught a big Northern!”  my son screamed at me.  I ran to get the net, excited that he’d finally hooked a big one, right off our dock.

When I got the net around the fighting fish though, I was sure it wasn’t a Northern Pike.  We took pictures of the huge, gray creature and were lucky enough to have it wriggle off the hook before we donned gloves to try to get it off ourselves.  I guessed that it was a bowfin, based on the long fin running down its back and a neighbor’s report of catching one on the same lake.  We confirmed it online when we got home.

Along with gar and sturgeons, bowfin are in an order of primitive, ray-fin fish that have survived since the time of the dinosaurs.  They can grow to 43 inches and weigh up to 21 pounds.  My son’s weighed between 5 and 10 pounds and I’m glad we didn’t have him try to hold it up for a photo, since bowfin have very sharp teeth and will bite anyone who attempts to handle them.  We released the fish and watched him disappear  into the deep.

The kids were a little afraid to swim off the dock after that.  I don’t blame them.  Who wants to go swimming in the lair of a prehistoric monster?

Imagine pieces of matter (too small to see) called atoms that will only fit together in a certain way, like a puzzle.  These atoms can attach to each other to form small three-dimensional shapes, or larger ones, but the shape will always be the same, depending on what kind of atoms make up the “puzzle pieces.”

This is what happens when crystals are formed.  Diamonds and salt, for example, are crystals shaped like cubes, while quartz crystals are formed in trigonal shapes, sort of like three-dimensional kites. You can have very small diamonds, or huge ones, like the Hope Diamond, which is as big as a silver dollar and blue from impurities in the stone, but they will all have the same basic shape.

We grew alum crystals in a jar last week and I am amazed at how beautiful they are.  I couldn’t get a very good picture, but they look like a string of real gems and were simple to grow.

To grow these spectacular crystals, you will need a small jar of alum, which can be found with the spices at the grocery store, water, a glass, a jar, a stick and some thread.

Fill the glass with about 3/4 cup of water and add a few teaspoons of alum powder.  Stir until the powder dissolves and repeat until no more alum will dissolve and you can still see some floating around in the glass.  Then, let the glass sit overnight or until some small alum crystals form in the bottom or on the sides of the cup.  It took two days for us to get some decent crystals, but we got several small ones that were fun to look at!

Fish a large crystal out of the glass with a spoon and tie a thread around it.  Tie the other end of the thread around the stick (we used a BBQ skewer) and wind it up so that you can rest the stick over the mouth of the jar and the crystal will hang down about half way.  Then, pour the remaining liquid from the cup into the jar.  There is still alum in the water, which will add more “puzzle pieces” to the crystal and make it grow bigger.

Now you can watch your crystal grow.  What shape is it?  Look at your crystals under a magnifying glass.  Take a picture of them, or draw them your science notebook!  Here is a link to a great Smithsonian website where you can learn more about gems and crystals.

Here’s a quick experiment for bored kids:

You’ll need a button, a glass, water, and a carbonated beverage.

Pour some water in the glass.  Drop the button in.  What happens?

If it sinks*, dump the water out and fill the glass with carbonated beverage.  Drop the button in.  Now what happens?

The button is more dense than the water and sinks in uncarbonated water, but in a carbonated beverage, carbon dioxide bubbles form on the button and make it buoyant, so it floats to the top.

What other sinking objects can you make float with carbonation?

If your kids like this, check out this Float or Sink experiment that even very young kids can do!

*If your button floats, the experiment won’t work, so try to find one that sinks!

This morning, Twitter led me to a great website filled with science news for kids.  Check it out at  http://sciencenewsforkids.com/.

The Society for Science and the public, who sponsors the site, is having a contest for kids in grades 6-12 where they can enter their own podcast talking about what they’ve learned about science from the website.  Go here for more details.

It sounds like a great way to keep your kids reading about science this summer!