Having grown up in the Flint Hills and tall grass prairie of Kansas, I was in awe when when we moved to Minnesota, with its 10,000 (or 11,842) lakes dotting the landscape.  The fact that I now have a lake within walking distance of my house boggles my mind.  It’s like a dream to live in a state where you don’t have to be a millionaire to own, or spend the weekend, at a cabin by the water.

I don’t think Minnesotans realize how lucky they are.  We take our lakes, and rivers and streams, for granted.  Sadly, instead of being stewards of our precious waterways, many property owners build structures that harm our lakes, allowing chemicals and fertilizer to wash into the pristine water every time it rains, interfering with the natural wildlife and vegetation.  Not only that, people refuse to replace old septic systems which often cause the lakes where our children swim to be contaminated with human waste. Somehow, we expect our lakes to remain clean and healthy, existing purely for our weekend fun.

Recently, we had a chance to make people take more responsibility for keeping our lakes healthy, so it was depressing to read in last week’s Star Tribune that our governor has once again refused to take measures to care for our local treasures.   “It’s like a parting shot out to Minnesota — thumbing his nose at clean water after all these years, which is a dirty legacy to leave,” said Sen. Ellen Anderson, DFL-St. Paul and chair of the Senate environment, energy and natural resources budget committee.   In fact, our governor is taking care of his own political aspirations and his friends with environmentally-unfriendly lakeside mansions, while pretending to represent the average Minnesotan.

In the book “The Lorax”, by Dr. Seuss, the Lorax speaks for the trees.  Who will speak for our lakes, so that we can continue to enjoy them?  Who will speak for the natural resources you enjoy with your family?  It’s something to keep in mind come November.

For the next week or so, I’ve decided to blog about water.  National Geographic did an amazing job of writing about water and our world in April, and I’m going to participate in P&G’s Give Health “Clean Water Bloggivation”, not to win the trip to Africa, but because they’ll donate clean drinking water to people who need it, in return for participation in the program.  I’ll also blog about how you can make your own lake-front more environmentally friendly by planting a strip of native plants and grasses beside the water.

Sometimes experiments work and sometimes they don’t.  The kids have been begging me to do the “Soda Geyser” experiment with Menthos for as long as I can remember, so we finally tried it on day 5 of Science Camp.

It was a flop.

We did everything right, as far as I could tell, but we used 7-UP instead of Diet Coke, since that’s what I had on hand.  Some scientists think the artificial sweetener in Diet Coke helps create a more violent reaction.  I’m not sure, but all we got when we dumped the Menthos into the soda was a very small geyser.  Let’s just say I felt really silly for yelling at the kids to stand back.

We’ll try again soon with Diet Coke and I expect we’ll have better results.

If you want to try this experiment, you’ll need a two liter bottle of Diet Coke, a roll of Menthos mints and a piece of paper.

Remove the lid from the soda and set it on a flat surface (outside!)  Roll the paper so it will fit into the mouth of the bottle and fill it with the Menthos.  Quickly dump the mints into the bottle and stand back.  Hopefully, you’ll see a huge gyser of soda shoot up from the mouth of the bottle!

Scientists aren’t sure exactly why the Menthos cause such an explosive reaction, but they think it has to do with chemicals in the Menthos breaking the surface tension at the same time that carbon dioxide (CO2) bubbles form on the surface of the mints, causing a huge, very fast release of carbon dioxide bubbles.

Try it and let me know how it works!

We discovered two easy experiments you can do with milk and vinegar.  One is hot, and requires adult supervision, and the other is done at room temperature.  Who knew you could make plastic and glue from milk?

Milk Plastic

The first experiment we tried was making “plastic” from milk curds.  Heat about a cup of milk in a pan until it gets a scum on top or gets lumpy.

The scum that forms looks like plastic wrap!

Our milk curds before adding the vinegar

Skim off the scum (curds) with a spoon and put them into a small bowl to cool. Eventually, we got tired of skimming and just let a thick layer form on top of the liquid.  Then, I poured the hot milk out of the pan and scraped out the curds with a spoon, adding them to the curds we’d already collected. Add a tsp. of vinegar and let the mixture cool for about an hour.  Then, slowly pour off the liquid (we blotted some off with a paper towel too) and knead the “plastic”.  You can shape your plastic into anything you want- beads, balls, animals and allow it to dry on a paper towel.  When it’s dry, you can even paint it!  Our plastic was very soft and gooey, so we rolled it into small balls on toothpicks to make beads.

Milk contains a protein called casein, which is a polymer, or a chain, or long molecules which can bend and move until the plastic hardens.

Homemade Glue

We also made glue using milk and vinegar.  Just add a cup of milk and 1/3 cup white vinegar to a clear jar or bowl.  Mix gently and allow the mixture to settle until you can see two layers.  The curds are the white layer on the bottom of the jar and the whey is the liquid on top.  Fish some of the curds out with a spoon or sieve, or just pour off the whey.  The curds can be used as glue.  We tried it and found that our homemade glue worked pretty well for gluing paper together!

Our glue works!

The vinegar separates the milk, allowing the fat, minerals and casein protein to form curds.   White glue is made from caseins of milk curds.  Cheeses, as you probably already know, are made from curds.

I wonder how hard it is to make homemade edible cheese curds.  Maybe that will be a project for another day.

Day 3 of Science camp was ninety-five degrees and humid, so we spent most of the afternoon studying the cooling effect of water at the city pool.

When we got home, we did an easy experiment using water, fruit juice and baking soda and found that by adding baking soda to different juices, you can see which juices contain citric acid.  You can even taste the results! Baking soda is a base, and many fruit juices contain citric acid.  When the two are combined, carbon dioxide gas is formed as bubbles in the liquid, carbonating it. My kids loved this experiment!

Just pour about a cup of lemonade, orange juice, grape juice, or any other juice into separate glasses.  Pour a glass of water as a control. Water doesn’t contain citric acid, so won’t produce bubbles.  Then, add about half a teaspoon of baking soda to each glass and taste the results.

We were surprised to find that our grape juice produced bubbles, but discovered that it contained added citric acid when we read the label!  A side effect of this experiment is kids asking to add baking soda to their juice at breakfast so that they can have “pop”.

Not only are Sun Chips bags the noisiest chip bags ever manufactured, but the company claims that they’re biodegradable and will break down completely in about 13 week, in a hot compost pile.

Yesterday, the kids and I became consumer detectives as we buried a Sun Chips bag to see how well it breaks down in our own back yard.  All we needed was a Sun Chips bag (which had been quickly emptied by my chip-deprived children), a few fruit scraps, and a shovel.  (Be sure to dig in a spot where there are no power lines buried.  You can check with your local electric company if you’re not sure.)

First, we dug a shallow hole near our garden, in a spot that gets lots of sun and put our chip bag in the hole.  We’re lucky enough to have a curbside organic recycling program in our neighborhood, so we don’t have a compost heap of our own. To make up for the compost deficit, and add some heat and microbes from rotting vegetation, we threw in a few watermelon rinds, tomato scraps and avacado skins from the compost bin in our sink.  Then, we put dirt on top of our little “compost heap” and put a rock on top to mark the spot.  Finally, we watered the dirt to get the process started.

In about three weeks, we’ll dig under the rock to see what is happening.  According to the information on the Sun Chips bag, it should be starting to break down.  After that, we’ll check it every four weeks or so.  The bag says it takes about 13 weeks to break down completely.

Do you have a compost heap?  Composting is a great way to make beautiful, nutrient-filled dirt for your garden and reduces greenhouse gas emissions.  According to the Environmental Protection agency, 26% of the solid waste we produce is made up of yard and food waste.  You can go to their website for more information on composting.

It’s been a stormy summer in Minnesota, and we’ve seen more than our fair share of tornadoes.  As a kid, I was always fascinated by stories of pieces of straw from a field being driven into  wooden planks in barns and houses by the swirling winds.

With a potato, plastic drinking straws and a glass of water, we were able to see for ourselves how this could happen.  Like drinking straws, real straw is hollow and although a potato is much softer than a piece of wood, we got the picture.  I was skeptical about the experiment, but it worked!

Just soak a potato in a glass of water for about 30 minutes.  We used a red, boiling potato, because that’s what I had on hand.

Then, grasp a straw tightly, near the middle and stab it into the potato.  We were surprised to find that, instead of breaking or bending, the straw can be driven quite a way into the potato.  This happens because objects in motion, like the straw, tend to stay in motion and objects at rest, like the potato, tend to stay at rest.  This is known as inertia.  In addition, the thin edges of a drinking straw don’t offer much resistance.

Try it!

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!