Engineering for Children - Compression, Tension and Toilet Paper Tubes

The children have been doing a lot of building with the empty toilet paper tubes we have out this week.  Watching them experiment with different towers and techniques...

...I realized they were really working through their own sort of lessons on the forces of gravity, compression and tension.  For instance, they learned quickly that they could build a taller vertical tower if they added supports around the base...

...and after watching a BrainPop video on skyscrapers (which I innocently suggested they might enjoy) they realized the problem they had encountered while building pyramids, of having the sides push out and collapse...

...after the third or fourth layer of tubes were added...

...could be solved...

...by simply placing a sheet of toilet paper...

...between the layers of empty tubes...

...to act as girders...

...dispersing the compressive force of gravity on the structure.

In fact, even one layer of paper, between the first and second layers of tubes, was enough to stabilize the entire construction.

The BrainPop video I referenced above is part of a subscription service, though there is a free trial available for the site.  BrianPop does not reimburse me for recommendations, but I do recommend the site every so often.  It's one of the few subscription services we've found useful enough to renew year after year.  It is filled with short, educational, animated videos on a wide variety of topics, that come in handy for quick reinforcement of lessons just like this.

Exploring Perimeter and Area

While we still had the cardboard tubes out, we used them for a quick lesson on perimeter and area to go along with an episode of PBS' Cyberchase...



...exploring the possibility of shapes with the same area having different perimeters.

Toppling Toilet Tube Towers - The Scientific Method

I noticed, this week, that our recyclables were starting to overflow in the craft room, especially the toilet paper tubes.  With eight of us in the house, those sorts of things can really pile up.

Before clearing them out, I thought we should put them to some use for fun, and maybe a little learning, too.

First off, I built the tubes up into a tower (triangles on top of triangles) and asked the younger children (ages 8-12) if they were to fling a pompom into the tower, which size pompom would they use...

...and where would they need to hit the tower to do the most damage?

They each picked a spot on the tower to hit...

...and explained, based on what they knew about gravity, and stacks of items, why they thought hitting that spot would do the most damage to the tower as a whole.

After a few practice shots with a hairband...

...for a slingshot...

...they were ready to take on the tower.

Finally, after several turns, destroying...

...and rebuilding the tower...

...they leaned enough about how a tower of cardboard tubes actually acted when hit by pompoms...

...in contrast to how they had originally thought it would come down, to be ready to use the information gathered through their experiments to modify their original assumptions.

In the end, they found that hitting the tower low in the middle was a good plan, but that they needed something heaver and wider than a pompom (like an extra toilet paper tube) to throw at the tower, if they really wanted to topple it over.

Vacation - Unplugged

The Man of the House is on vacation for the entire week.  Fun family face time is calling.  Cells phones are off, Kindles set aside, and the computer is shutting down.

Have a great week.  See you on the other side, when we power back up, hopefully refreshed, and ready to go.

Peanut Butter Cookies with Chocolate Chip Hearts

Roll peanut butter cookie dough into 1/2 balls.  We prefer the three ingredient recipe - 1 cup peanut butter, 1 cup sugar, and 1 egg.  I'm not sure where this recipe originated, I think we found it in a community cookbook a decade or so ago, but I've seen it around on various recipe websites, too.

Bake the cookies.  In our case, for 8-10 minutes at 350°F on an ungreased cookie sheet.

As soon as the cookies come out of the oven, press two chocolate chips together, tips down, into each cookie.

Use a butter knife to press, and spread down from the bottom of the chips to a heart point.

Allow the chocolate to cool and harden before stacking the cookies together on a plate, or serve them warm and molten, in a single layer.

Valentine Pun and Idiom Challenge

I called the children to the table today, and presented them with a brainstorming challenge.  I told them they were the marketing department for the Cheesy Cheap Toy Company.  For some strange reason sales for the company have been down.  With Valentine's Day approaching the company execs were asking for the marketing department to come up with a campaign to boost sales by attaching their toys to Valentine cards.

They had a sample of Cheesy Cheap Toy's offerings (a sack full of quarter machine toys from the grocery store), and a copy of Riveting Valentine Jokes for Kids (accessed for free through our KindleUnlimeted account) for inspiration (any Valentine pun or joke book would do).

They worked together brainstorming Valentines for their finds.  Admittedly, their ideas were not all that original...

...but for an off the cuff effort, they did pretty well...

...especially considering not all of the toys were easy to identify.

And, if nothing else, it gave us a chance to talk about puns and idiomatic phrases, while honing creative writing skills, and knocking of a few Valentines for family and friends, at the same time.

Reading - Recognizing Fact from Fiction

"When she was young, often her grandfather would use anagram games to hone her English spelling.  Once he had written the word "planets" and told Sophie that an astonishing ninety-two other English words of varying length could be formed using those same letters.  Sophie had spent three days with an English dictionary until she found them all."

I've been passing the long winter afternoons listening to an audio version of Dan Brown's The Da Vinci Code.  I know I'm a little late to the party, and probably the last person over 40 left in America who has not read this novel, or seen the film.  At the height of the anti-Brown fervor, I simply wasn't in the mood for a controversial read, and then later on, I didn't have the time.

T(age 17) asked me about the book, the other day, while reading a magazine article for a class he's taking, and I realized I had time now - so why not.  It turns out to be a good book for a cozy afternoon read (or listen), or rather several cozy afternoons, as it is fairly long.  And, much to my surprise, I am finding it disturbing.  But, not for the reasons I expected.

The story does contain a good deal of fiction about Jesus, the Council of Nicaea, and the Catholic Church.  However, it is all pretty obvious fiction, so far from the truth, as to be easily dismissed.  What has really amazed me is the art Dan Brown has for presenting fiction as believable fact.

Apart from the religious aspects of the novel, it appears to be a piece of "living fiction" filled with art, history, geography, math, and brain teaser type puzzles.  I love those type of books, and I was really loving this one, enjoying all the little bits and pieces of trivia shoved in between the plot points.  Then, it dawned on me (more slowly than I'd like to admit), that if certain aspects of the book were pure fiction, being presented convincingly as fact, maybe all the little details I was enjoying so much, were made up too.

I started by doing some quick checks on a few of the Leonardo facts in the book (you can read about more of them here).  Did Da Vinci really design a cryptex - a box, meant to hold a secret, written on papyrus, locked by combination, that if broken open without the combination would release vinegar to dissolve the papyrus inside?

photo credit - see http://en.wikipedia.org/wiki/Cryptex

No.  It is a Dan Brown invention.  In fact, as far as I can tell, vinegar wouldn't dissolve papyrus anyway, so it is a silly invention at that.  But, it sounds really cool.  Moving on from Leonardo, are there really 666 panes of glass in the pyramid in front of the Louvre, as one of the characters states very matter of factly?

http://en.wikipedia.org/wiki/Louvre

 No, there are 673.  And, what about something as simple, and straight forward as the anagram puzzle from the quote at the top of the page?  Can you really make 92 words of varying lengths out of the letters of "planets"?   

I'm giving that one to my children to decide.

When T was studying for the SAT, we read about test takers who had written essays for the test, using fictional historical events and figures for examples, made up on the spur of the moment.  I remember thinking that would take some real skill to pull off.  I bet Dan Brown could do it.  I'm impressed by his writing, and disturbed by my own gullibility.

Valentine Rolls

After nearly a week of spring-like weather, winter returned with a vengeance.  Add the sound of howling wind against the windows, and temperatures dropping so fast the house was popping, to the view below, and you'll have the idea. Being February in Montana, it's not like we were surprised, though.

On the upside, the gloomy, cloudy day meant the groundhog didn't see his shadow.  If he was smart, he didn't bother getting out of bed.  We stayed inside ourselves...

...with warm bowls of steaming soup...

...and rolls, fresh from the oven, formed from white bread dough, mixed in the bread-maker...

...and shaped and baked into to funny, free-form hearts, following super simple instructions from Rhodes.

If the groundhog ends up being right, or for that matter, even if he's wrong, it's time to enjoy warm and cozy lunches in front of our wintery windows, while we can.

Corn Starch Molds and Another Go at Gummies

Not ones to be defeated by a candy, we decided to try to think through the problem of our gooey gummy hearts (from yesterday), and see if we couldn't come up with a solution to the stickiness problem.

First of all, we took a closer look at the gummy worm segments we had melted down and remolded into the hearts.

They were smooth, and dry on the outside, but on the inside, where we had broken them apart, they were very sticky, too.

We checked the ingredients list, and found it more akin to the homemade gumdrops we'd made ages and ages ago.  They were also sticky on the inside, and needed to be coated in something, such as powdered sugar, in order to be handled.

The gummy worms seemed to have a powdery coating, so that made sense. 

We also noticed carnauba wax on the ingredient list, thanks to a comment from Karen, yesterday.  Her thinking was that once melted the wax was blending in with the ingredients, making for a gooier candy.  Carnauba wax, used to make the candy shiny, and also to wax cars (yuck!), is solid at room temperature, so even if it were in the candy instead of out of it, it should not cause quite so much gooeyness (at least that's our thinking).

Finally, we looked up an episode of "How It's Made" dealing with gummy bears and worms.  In the episode we watched the candies were squirted with mineral oil, rather than wax, to make them shiny - so that was a little different.  But, we also noticed, the factory made candy was poured out into cornstarch molds, and left to dry for a lot longer than the half an hour we had given our hearts.



Corn starch would make for a powdery, but tasteless coating on the candy, so we decided to give it try by filling a bowl with 1/2'' layer of cornstarch, and then pressing a heart shape into it with a cookie cutter...

...as a mold for our melted gummy (melted the same way as before, by holding a gummy candy filled, heat resistant, squeeze bottle down into bowling water for ten minutes).

This time, we placed the bowl in the refrigerator for 18 hours, before removing the candy, and brushing off the excess cornstarch with a clean dish towel.  And sure enough...

...we ended up with a heart shaped gummy, that was firm enough to hold its shape, and dry enough on the outside to handle...

...while still retaining all its store bought gummy goodness on the inside.

Unfortunately, in the time it took our test candy to set up, the children had eaten all of our remaining gummy worms, so there was nothing left to melt down, and remold.  Not that anyone was complaining, we had our answer, and the children had had their fill of gummy candy (worms or hearts - it all tastes the same), so everyone was happy.