Living thing are made mostly of water.  Humans are, on average, are 60-70% water and the water in our bodies helps to stabilize our temperature.  A great way to illustrate this concept requires no more than a balloon, some water and a grill lighter.  (If young kids are doing the experiment, an adult is also required to operate the lighter.)

Simply fill the balloon with water, tie it and hold a flame to the bottom of the balloon.  We did the experiment outside, just to be safe!

What do you think will happen?

Specific heat is the amount of heat required to raise the temperature of a substance by one degree Celsius.  The specific heat of water  is higher than any other common substance, which allows water to absorb and release large quantities of heat with very little change in temperature.  Because of this, the water in the balloon absorbs the heat from the flame, and the rubber doesn’t melt.  Imagine that the balloon is a living cell, and you can see how the fluid in a cell helps keep it safe when the temperature changes!

The balloon will turn black where you flame it, but it will not pop.  When we finished the experiment, you can imagine what happened to the balloon.  Even water can’t save a balloon from a concrete driveway!

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Until this summer, my husband’s parents had a grassy, green lawn running from where their cabin stood down to the rocks which had been placed at the water’s edge many years ago.  Many of the rocks were slipping into the lake, and the shoreline was beginning to tumble into the water too.  Their lake, like many, is susceptible to potentially dangerous blue/green algae blooms, and lawns like theirs contribute to the problem, as fertilizer can flow easily from the lawn into the water.

Last year at the state fair, they spoke with someone who told them they might be able to get a grant through the Atkin County Soil and Water District and the Big Sandy Lakes’ watershed project (originating from the Department of Natural Resources) to help them naturalize their lake shoreline, if they were willing to contribute the labor.  They applied and were able to get a grant, work with a landscaper, and replant their shoreline with plants that will slow runoff, reduce erosion, and filter nutrients that can cause algal blooms in the lake.  The plantings are filling in after being planted in July, and they look beautiful!  Many of the plants have lovely flowers (Lupine, Flox, Columbine) and plants like Swamp Milkweed, which grows close to the water, will be butterfly magnets next summer.

photo taken right after planting

A shoreland buffer strip (also called a filter strip or buffer zone) separates your lawn from the lake. It typically includes taller grasses, blooming plants, shrubs and trees, as well as aquatic plants such as cattails, rushes, and lilies.  The work we did involved killing a strip of grass along the lake shore, cutting pieces of wild willow to bind together and stake at the water’s edge, putting natural mesh along the sloped land next to the lake and planting native plants in the prepared area.  The dead grass served as mulch and my in-laws had a planting party for friends and other residents of the lake who were interested in learning about what they were doing.  I think with 12 people, it took about 3 hours to do all the planting.  Not bad for a day’s work.

If that sounds to intense, according to the  University of Minnesota’s Shoreland Management Resource Guide, “The easiest approach to establishing a buffer strip is simply to do nothing. If you stop mowing, weeding, and raking your shoreland area, many native plants will likely reestablish.”  The link above also lists local nurseries where you can buy native plants and suggests who you can talk to about what to plant on your lake.  Or, get in contact with your local lake association to find out whether they have grant money available to help you naturalize your shoreline.

Our cabin still has a mowed green lawn behind the shoreland buffer strip, but we don’t fertilize it and it’s nice to know that someday our grandchildren may swim in cleaner, safer water and catch butterflies in the swamp milkweed by the lake’s edge.

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Scientists aren’t sure exactly why the Mentos cause such an explosive reaction, but they think it has to do with chemicals in the Mentos 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.

Here’s a funny video you won’t want to miss of a car running on the power of the Diet Coke/Mentos reaction.

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This morning, a friend and I  headed for the Science Museum of Minnesota to see the “greatest archeological find of the 20th century”, the Dead Sea Scrolls.   A Bedouin goat herder stumbled on the first of the ancient scrolls  in a cave near the Dead Sea in 1947.   Eventually, 10 more caves containing scrolls were discovered near the first cave, and near the ancient ruins of a settlement known as Khirbet Qumran.  Later, more scrolls were found in caves around the Dead sea and the Judean Desert.  Altogether, more than 900 scrolls were discovered.

The scrolls were often contained in pottery jars, and though many of the scrolls are damaged, it is astonishing that so many of them are in good enough condition to read, or piece together.  Two thousand years is a long time for a piece of parchment (animal skin) or papyrus (made from plants) to survive.  Scientists attribute the miraculous preservation to the dry conditions in the caves.  After all, you need moisture for microbe growth and decomposition.

Using radiocarbon testing, which takes advantage of the fact that all living things incorporate Carbon 14 when they are alive, scientists were able to determine that the scrolls dated from the centuries between 250 BCE and 68 CE. One of the first things I noticed in the exhibit was the use of the term BCE (before common era) and CE (common era), which correspond to B.C. and A.D., but are terms used by scientists.

On the scrolls were mostly words of Hebrew scripture, law and even poetry.  Not all of the writing on the scrolls is religious, but the scrolls we viewed were copied from scripts  that would one day appear in the Hebrew Bible and included an Apocryphal Psalm, attributed to King Solomon and to David.  One scroll we saw was a passage from Genesis and all of the scrolls were copied down before the Hebrew Bible had been set in stone.

What fascinated me most about the exhibit was that the scrolls were copied down during such a tumultuous, pivotal time in the heart of a culture experiencing an uprising of the common people and the birth of Christianity.   Archeaologists believe that even as scribes copied the some of the sacred texts onto the scrolls, Jesus was walking through the Holy Land with his disciples.  Rome was gaining power in the region, and the Pharisees, representing the common people of Judea, were beginning to rise up against the Priests, or Sadducees, who tended to come from aristocratic families.  The Pharisees believed in maintaining an oral tradition so that common people, many of whom could not read, had access to “God’s Word”, while the Sadducees believed in a written tradition, which they interpreted very strictly.

Archeologists and Biblical scholars tell us that Jesus was crucified and Christianity was born as modern Judaism was being shaped, the Judeans rose up against the Romans, and the Temple fell, for the second time, in 70 CE, shattering a way of life for many.  Scholars don’t know for sure who hid the scrolls in the caves, or why.  It’s a mystery, but there the ancient manuscripts sat, right before my twentieth century eyes, words marching across the page.  They stared at me from the Minnesota Science Museum, a world away from where they were penned, a testament to a people who would not be forgotten and a time that changed the world.

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What is this nasty bacteria that makes us wonder whether we should let our kids eat raw chocolate chip cookie dough, even as we sneak several spoonfuls when they’re not looking?

Salmonella enterocolitis is one of the most common types of food poisoning and is caused by the bacteria Salmonella Enteriditis. You can get a Salmonella infection by swallowing  food or water that is contaminated with the salmonella bacteria.  Often, the culprit is surface contamination from raw chicken and raw or undercooked eggs.  In most people, it causes diarrhea, fever and abdominal cramping, but young children and those with weakened immune systems are at greater risk of dehydration and more serious infections.

Why don’t they just wash the eggs better?  Salmonella bacteria live in the intestinal tracts of animals and birds and can infect the ovaries of healthy-looking chickens.  This allows bacteria to infect the eggs even before the shell is formed and voila- you have a pathogen that can’t be washed off of the egg because it’s inside.  Organic and free range chickens have less disease than factory-”farm” raised chickens, partly because of healthier diets and less crowding.  Cooking eggs until the yolk is solid kills Salmonella bacteria.

How can you make your cookie dough and eat it too?  Buy pasteurized eggs (you can find them at most grocery stores) that have been heat-treated to kill bacteria, but are still essentially raw for all cooking and baking purposes.

Also, remember to wash cutting boards you’ve cut meat on with soap and water before cutting anything else on them, or just have separate cutting boards for meat.  Don’t forget to wash your hands after handling raw eggs!  Pet food and reptiles can also harbor salmonella bacteria, so have your kids wash their hand after handling either!

Bacteria are everywhere.  Some keep you healthy and some make you sick, but making good decisions in the kitchen can keep you and your family from being affected by food-born illness!

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The facts speak for themselves:

• Every 20 seconds, a child in a developing country dies of a water-related illness (World Health Organization)
• Waterborne diseases remain the leading cause of illness and death in the developing world. (World Health Organization)
• 46 percent of people on Earth do not have water piped to their homes (National Geographic)
• Women in developing countries walk an average of 3.7 miles to get water (National Geographic)

Shocking, isn’t it?  It should at least give you pause as you fill up your child’s glass with clean tap water, or maybe even filtered tap water.  Now, try to imaging walking 3.7 miles in the dark or the hot sun to bring home water that may or may not make your child sick, or even kill them.  What choice would you have though?  Water is life.

I recently signed up to participate in the Clean Water Blogivation campaign.  If my blog receives the most votes, I could win an opportunity to be a change agent and join Dr. Greg Allgood on a clean water expedition to Africa and a $15,000 donation to my favorite charity tackling water issues.  Much more importantly, each time someone votes for my blog post, P&G will donate a day’s worth of clean drinking water (2L) to a person in need in a developing country. Click on the “vote for this blogger” button above and clean drinking water for a day will be donated each time you vote! (You can vote once a day.)

The task of fetching water defines life for many people on this planet.  National Geographic tells the story of an Ethiopian woman named Aylito who dropped out of school when she was eight to help her mother carry water from a dirty river.  She spends eight hours a day walking to and from the river, up and down a mountain, three times to carry 50 pounds of water on her back.  It is a life almost beyond imagining for most of us who live in developed countries.  However, one can imagine that people who work so hard to get so little water have very little water to spare for sanitation, like hand-washing, or washing clothes.  According to National Geographic, proper hand washing alone can reduce diarrheal disease by 45%.  Many people cannot afford soap though.

What diseases are carried by dirty water?  You name it:  bacterial diseases like E.coli and Vibrio Cholerea, parasites like Guinea Worm,  viruses and protozoa.  Some of these pathogens can be killed by boiling, but for many, firewood is scarce. Sometimes, it’s too much water from flooding that causes drinking water to be unsafe.  (The floods in Pakistan are causing problems right now.)

There’s a fairly comprehensive list of water-born microbes on Wikipedia, and if you’d like to learn more, the World Health Organization and the Center for Disease Control are great resources.

The obvious question is, “what can I do to help?”   Many aid organizations and churches have programs to help people get access to clean water and proper sanitation, whether it’s by helping dig wells or sending bars of soap.  WaterAid is a U.K.-based international non-profit organization that is helping bring not only clean water, but sanitation and hygiene programs to many villages desperate for clean water.  The organization makes local women an integral part of the process.  Proctor and Gamble, who is running the Clean Water Blogivation campaign, make a PUR powder which can be mixed with contaminated water to make it safe to drink.  They have a Children’s Safe Drinking Water program and have been working with a number of organizations to distribute the PUR powder around the world to those who don’t have access to clean water.

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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.

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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!

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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.

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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”.

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