Awesome Modern History: Inventions and Industrial Revolution

 These were chapters 82 and 83 in  A Child's History of the World.

For our active activity, we got the kids up at 5am and made them do dangerous work for 18 hours. 

Kidding! 

We built marble run "machines."

I set up a board (a large picture frame in this case) propped up at an angle, and put out an assortment of wooden blocks and things to build with.

I also put out the geared marble run in case the younger kids weren't interested in constructing their own machines.
Everyone liked that, but they spent more time (and had more fun) building their own!

For our art activity, Shelli set up cyanotypes.

She had some acetate printouts which the kids could use,


and some black markers to add their own embellishments.

This and other objects were laid on paper treated with  chemicals, and then everything was set in sunlight.

They came out beautifully!

For our snack, we made salt potatoes, a byproduct of the Industrial Age!  They started with Irish salt workers in Syracuse, NY some time in the 1800s. They extracted salt from the waters of a local lake by boiling away the water in large evaporation vats. The workers would slip their potatoes into the evaporation vats to cook and 20 minutes later it was lunch time!

Kids' Chemistry: Phase Changes

I think the 2 most essential things for kids to understand about phase changes is that atoms and molecules are attracted to ("stick to") each other, and that phase changes require energy.

The reason that everything isn't solid is that energy (which we perceive as heat) makes the atoms and molecules move, and the faster they are moving the harder it is for them to "stick" to each other.

To illustrate this, I had the kids play Crack the Whip.  If you haven't played in a while, the kids hold hands in a line and one kid on the end starts walking, then running, making curves.  When they are moving slowly, it's pretty easy for all the kids to stick together.  As they speed up, it gets harder and harder, and eventually, the kids on the end go flying off.

That's a lot like what happens when water boils!

We talked about the phase changes:
Freezing (liquid to solid)
Melting/thawing (solid to liquid)
Evaporation/boiling (liquid to gas)
Condensation (gas to liquid)
Sublimation (solid to gas - think dry ice)
Deposition (gas to solid - this is how artificial diamonds are made)

Then I had them all be molecules and, as I called out phase changes, they altered their motion to suit the change.  Very fun!

We next worked on altering phase changes.  I had put a pot of water on to boil, and we measured it's temperature: 212 degrees.  The idea that water doesn't get any hotter than that, even if you add more heat, was a bit of a new concept for them, so I stayed with that for a while.

I also explained the Fahrenheit and Celsius systems.  Then I dumped 2 cups of salt into the boiling water and got the temperature up to a whopping 227 degrees!

Never one to be wasteful, I then put the potatoes in to cook for dinner.

Next we altered things in the other direction.  I had two jars with ice and a little water.  I put rock salt into one, and then had the kids feel the difference in temperature between the jars. Given enough time, and a cooler room, the salt water jar would have gotten frosty.

Breaking the bond between sodium and chlorine in the salt takes energy, and the salt gets that energy from heat in the ice.  This doesn't make it warmer, it makes it colder because more energy has been absorbed.(converted from heat into chemical energy).

I used to wonder why the ice would melt if the salt was making it colder.  The answer is that the charged sodium and chlorine ions pull the polar (charged) water molecules away from the ice crystals, back into a liquid state.  Interestingly, 0 degrees Fahrenheit is the temperature at which a saturated salt solution freezes.  I still like Celsius better.

Anyway, to get back to the greater significance of salt lowering the temperature of ice, this is how we make ice cream by chilling the container below the freezing point of cream by harnessing the power of ice and salt! Mmmmm.  Ice creammmm.

Anyway, we also picked up ice cubes with thread.  We had mixed success with this because the room was very warm, but the idea is to lay the thread on the ice cube, then sprinkle salt over it.  The salt melts the ice, but chills it enough to refreeze around the thread.  You need cotton thread for this.

Lastly, we looked at evaporative cooling.  This is a good way to concretely experience the need for energy in order to make a phase change.

I had a bottle of alcohol and a bottle of water at room temperature.  I put some of each on cotton balls, then rubbed them both on kids' arms.

I happened to have a scanning thermometer that records surface temperatures (thanks Mumpy!), but you can feel the difference in any case.  The water feels one temperature as it goes on your arm, then the whole area feels cooler as the water evaporates.  In order to make the jump from liquid to gas, the water has "stolen" heat energy from your arm.  You feel the loss of heat as "coolness." That's why sweating works!  The alcohol does the same thing, but, since it evaporates faster, it removes energy more quickly and feels cooler.

Happy Valentine's Day!

Or, as we like to say, "Happy feast of Sts. Cyril and Methodius!"

You did remember to create a new alphabet for your sweetheart, didn't you?

Oh, yeah, although the current Roman Calendar only lists those guys, we also celebrate the old feast of St. Valentine today.

Boy, do we!

We added hearts to all of our snowflake decorations on the ceiling and windows!

Klenda painted our other windows with hearts.

We made Valentine holders earlier this month and have been busily filling them up!







And what would Valentine's Day be without food that was pink, heart shaped, or both?!










We did a special Valentine home school packet based on the great stuff from Enchanted Learning. The kids particularly like their Valentine Venn Diagrams.

We had a treasure hunt!

We bought a dozen heart shaped balloons!

Dinner will be raspberry pork chops with salt potatoes!

To finish things off, we will be bringing back the Pink Burping Cows of Love!

Customizable Bread

Realistically, I don't look up a recipe, I (or the kids) just do this:

4 c warm water
3 t salt
1 T oil or butter
1T yeast
7-9 c flour

You can add sugar, ground flax seed, soy flour, wheat germ, oats, potato flakes, honey, eggs, seeds, other flours, or anything else you can think of to this recipe in place of some of the flour.

Mix it all together, knead it 10 minutes, oil it and let it rise.
Shape it into a loaf, let it rise 30 minutes, then bake it 30-40 minutes at 350 degrees.

Things I've learned:

Skipping the oil will give you a lovely crackly crust, but it will stale quickly.

Adding some milk instead of water will give you a more tender, denser "crumb."

If you add a lot of stuff you need to use bread flour, or add gluten.

You can use left over breakfast oatmeal to make oat bread, and leftover mashed potatoes to make potato bread.

A wetter, "slack" dough will give you big holes inside - lovely when toasted, or for "artisan" bread.

You can bake at 400 degrees for 30 minutes, as long as you don't have much sugar in the dough.

Dough is fully kneaded when it passes the "windowpane" test. Stretch a small amount of dough to form a flat "window." If you can see light through it, you pass, if it tears and looks ragged, you need to knead...

If you can't manage to knead it enough to make it really smooth and elastic, let it rise twice and the yeast will do it for you.

If you're pressed for time, you can put a loaf that has mostly risen (20 minutes) into a cold oven and it will finish rising as the oven heats up.

If you have time, the slower the rise, the more flavor. An overnight rise in the fridge (just slip it in a gallon ziplock bag) will give you fantastic bread - try baking it at 400 degrees and you'll get the best crust ever!

Spraying the crust with water right before you bake will give you a crisp crust with the best rise.

Buttering the crust when it comes out gives you a soft crust that kids love! (This tip courtesy of Klenda!)

Museum Opening

This is our friend Bill.
Bill can do anything.
OK, almost anything!
He's a computer engineer and he donated an entire wing of our museum, so he was the logical choice as the ribbon cutter.




This our main museum.
The top is cool stuff we've found.

The left side is sea shells.

The center is fossils (including the shark teeth in the white cabinet).

The bottom center shelf has our rock collection.

On the upper right we have crystals (including some from the salt potatoes!).

We also have a bird nest with various feathers and egg shells and a blank shelf for further expansion.
And here is Bill with the wing named after him. We are also very grateful his last name is simpler than Udvar-Hazy.

We have rotating exhibits related to space (particularly the Apollo program) on the top shelf.

The second shelf is dedicated to science fiction models.

The third has boats and submarines.

The bottom shelf has aircraft and a working model of a car engine.

Syracuse Salt Potato Science!

Now this is a great recipe from Cook's Country magazine: It has history! It tastes fabulous! Best of all, it has science! Lots and lots of science!!

Here's the history: It started with Irish salt workers in Syracuse, NY some time in the 1800s. They extracted salt from the waters of a local lake by boiling away the water in large evaporation vats. The workers would slip their potatoes into the evaporation vats to cook and 20 minutes later it was lunch time!

Here's the recipe:
Boil 8 cups of water
Add 1 1/4 cups of NON IODIZED salt or 1 1/2 cups of Kosher salt
(do NOT try this with iodized salt)
put in 3 lbs of small whole potatoes (don't cut them!) and boil for 20- 30 minutes.

Science break:

First notice that the potatoes float! There is enough salt in the water to change its density. The potato is less dense that the salty water. Try a potato in plain water, too.

Now boil some plain water and take the temperature of the pure water: 212 degrees, right? Take the temperature of the boiling salty water. Ours was 221 degrees. It gets better. As the water evaporates, the water in the pot gets saltier. Ten minutes later it was boiling at 223 degrees.

Ok, in 20 or 30 minutes, when your potatoes feel a little soft (use tongs, not a skewer or the salt will flood the inside of the potato), lift them out with tongs (don't drain the water!) and set them on a wire rack if you have one (or a plate!).

Stare at your potatoes.

Science break:

Watch the incredible crystal formations on the potato skins! Grab a magnifying glass and verify that each crystal is square! Talk about crystal lattice structures!

Now look at the water. The evaporation of the water concentrated the salt so that you now have a super saturated solution. The crystals are forming so quickly that you can watch them! The salty water is so dense that the salt crystals float! Remember that a hot liquid can hold more than a cold liquid. As it cools, the salt falls out of suspension more quickly. Once the entire surface is covered (click picture above for a super-large view!!), you can poke holes in the crystal covering and watch the crystals reform and push each other up and apart. Plate tectonics, anyone?

Now, cut open your potatoes. Be careful, these are hotter than regular boiled potatoes! They also have a luscious creamy texture because the higher temperature has more completely cooked their starch. The skins do not allow the salt into the potato (compare this with cell membranes). The skins are about as salty as potato chips. Traditionally they are served with melted butter. Mmmmm.

Lets look at the statistics:
3 out of 6 Zoomlians dislike potatoes in any form except fries.
6 out of 6 wanted more salt potatoes...

A highly successful experiment. The only draw back was that I only got to eat three. Next time I may need to do 2 pots. We could experiment with varying salinity... We could cut one of the potatoes, or poke holes in it and see if the inside of that potato is salty.

Kitchen. Science. Madness!