Saturday, May 27, 2017

Motors!!!

One of the kids' friends asked about magnets a few weeks ago.  This led to three weeks worth of play dates on electric circuits, electromagnets, and last but not least, Motors!!!  (It's nice to have a physicist in the family).

The motors were amazingly simple to put together, so I’m including the instructions.  Here’s a picture so we have something to talk about.



The parts are:
1 D cell battery
1 pound of 18 awg magnet wire, (you don’t need the whole pound, but Amazon sells It by the pound… seriously)
1 piece of cardboard out of the side of a box,
1 magnet
scotch tape

The How
Tape the D cell to the cardboard so it can’t move.  Next, cut two 4 inch pieces of magnet wire.  The next step is a bit of work, but use a kitchen knife, or a piece of sandpaper to scrape off the red insulation until you just see bare copper wire.  Place a dime size loop in one end of the wire, and then bend it over at a right angle to the rest of the wire to serve as a foot.  In the other end of the wire, make at least two pencil diameter loops to hold up the motor’s rotor, (the large coil of wire shown in the picture).  Tape the feet you made to the cardboard on either side of the battery, then tape the two wires to either side of the battery so that each of them is in contact with one of the poles, (the silver ends), of the battery.  Wrap the tape around a few times, and wrap it tight to make sure each wire is actually touching the pole.

Next, wrap magnet wire around the D cell to make the rotor coil.  Make about 10 turns.  This coil of wire is going to be the motor’s rotor, (a fancy name for the spinning bit).  Tie the ends of the wire through the loop so the loop can’t unravel, and leave about two inches of wire sticking out from opposite sides of the loop as shown in the picture.

Here’s the tricky bit.  Strip half the insulation off the pieces of wire sticking out from the coil.  Make the ends of the wire look like the diagram below.



If you strip off all the insulation, the motor won’t work.  The wire extending from the rotor needs to make electrical contact with the pencil diameter wire hoops attached to the battery only half the time.  It’ll spin through half a circle making electrical contact to the two posts you made earlier, and then during the next half circle it won’t.  Watch the wire on the left side of the rotor in the video . As it spins, you'll see that the side with insulation is visible, and then the side with bare metal.  (More on this in the ‘Why It Works’ section).

Now, insert the rotor into the pencil diameter hoops as shown in the picture.  Place the magnet on the battery pointed up at the rotor.  Then, give the rotor a little spin to get it moving, and it should spin happily around all on its own.




Next Time: Why it works

All the stuff for making motors:


Thursday, May 25, 2017

An Open Thank You Note to the DeYoung Museum Doing & Viewing Arts Docents

Doing and Viewing Art at the DeYoung Museum was an incredible program offered here in San Francisco that, sadly, came to an end last weekend after a 35 year run.  In the program, kids were led on tours of the museum by incredibly talented docents.  After the tour they worked on an art project informed by the tour, led by equally incredibly talented teaching artists.

People often ask what we think our kids aged six, four, and two get out of visits to the DeYoung.  I think the following open thank you note to the Doing and Viewing Art docents sums it up pretty nicely.

To the DeYoung Doing & Viewing Art Docents:

Thank you so much for making Doing & Viewing Art such an extraordinary experience for our three kids!  You were what made the program great, and it won’t be the same without you!
It was your confident, and inclusive tours of the museum that inspired our kids to be confident in the museum.  It was your love of the art that seeded our kids’ love for art.  Your inclusion of every kid, both through asking questions, and listening to their answers helped our kids think about art, and develop the ability to talk about art as well.  Your mindfulness and complete presence in each moment spent with the kids made them feel like their thoughts were truly valued.

It was a pleasure to watch each of our kids grow every time they had the chance to spend time with you.  We treasure the memory of the weekend our four-year-old son began answering questions for the first time on the tour.  Our oldest daughter, who already aspired to be an artist, got to see so many other kinds of art; got to learn so much about them; and built her confidence in her abilities even further through the mantra Lynette and the kids repeated before parting, ‘Everything I do is right…because I am the artist!’.  Our youngest daughter  wasn’t walking for her first several Doing & Viewing Art tours, and wasn’t necessarily awake either.  Still, she traveled with the other kids, strapped to my chest, absorbing everything you said on the tours.  Finally, when she was ready to get down and experience the museum from the ground up, she blended in with the tours, took in the art, and paid rapt attention.  For her the world before your tours doesn’t exist.

Thanks to you, our kids’ minds and attitudes exist in the state that should be proper to all museum visitors: they feel like the DeYoung is their museum, and like the art is their art.  They’re always excited to go to the museum.  Rather than being in awe of the space, or bored by going to a place that’s ‘not intended for them,’ they move confidently through the museum browsing from exhibit to exhibit.   They truly appreciate the DeYoung, and it’s all your fault!

Sunday, May 21, 2017

May's Reading List

I've been reading books by and about awesome women this month!  One's set in modern times, the other is set at the beginning of the last century.  Both tell the tales of women who built extraordinary media empires.  One was born into privilege, the other into homeschooling in the South.  They both did things the way they wanted to!

You're Never Weird on the Internet (Almost)

What a fun book to read! I found out about Felicia Day first when my future wife told me about Dr. Horrible and later, on Eureka. This book details Day's experiences through the present day: what it was like to be home schooled, how she started started a successful internet company, and what it's like to be a fan icon. The stories are entertaining and funny even when they deal with serious subjects like depression and creative burnout.

I approached the book from a curious perspective. What does it take to be an internet sensation? This book was remarkably clear on just how much work it takes. It didn't shy away from descriptions of the massive amounts of effort expended by Day and others as some biographies/memoirs do. An awesome read with plenty of detail!




The Huntress: The Adventures, Escapades, and Triumphs of Alicia Patterson: Aviatrix, Sportswoman, Journalist, Publisher
Alicia Patterson founded Newsday. Before that, she was a wild game hunter, accomplished equestrienne, wild game hunter, and aviatrix. Born into privilege as the black sheep daughter of the family that owned the Chicago Tribune Ms. Patterson lived a life full of adventure and journalistic accomplishment. The book entertains while it educates by detailing the fascinating historical backdrop of Patterson's life.





Friday, May 19, 2017

Binary Math Lessons: The Secret Origin

Unschooling?  How did my last post have anything to do with unschooling?  As soon as I saw the title on the screen, I cringed.  The benefits of binary math, check, anything to do with unschooling?  Nada.

As it turns out, I’d started in the middle of the story.  Our six year-old, No. 1, and I started heading towards binary math—in more proper unschooling form—because she wandered into the room one day and said, “Dad, I want to learn what you do at work.”

All I do at work is test machines whose sole job it is to move ones and zeroes around: microprocessors and other digital devices also known as computer chips in the vernacular.  So, since one and zero are pretty simple concepts, and as it turns out, the logic gate building blocks of digital devices are also really simple, off we went!

The first thing we need to nail down were the handful of logic gates I encounter.  What’s a logic gate you ask?  It’s just an electrical embodiment of a logical construct, (you know like the one’s you had in philosophy 101).  Take the ‘and’ gate we started out with for example.  The device takes two inputs that can be either a one or a zero, and outputs a single number in return, again either one or zero.  If both the inputs are 1, (known as logical true in the vernacular), then the device outputs a one, if not, then the device outputs a 0,(a logical false value).  Hence, if one output AND the other are both true, the ‘and’ gate gives a true output aka 1.  Otherwise its output is 0, aka false .

No. 1 and I made up some homework sheets for her to play around with.  Her homework was to fill in the logic gates on the page with any sets of inputs and outputs from the table.

Did I mention we talk about this stuff all the time too?
"Hey, what's 1 AND 1?"
"1"
"What's 1 AND 0?"
"0 Dad," and so on.

I personally think our constant conversations drive things home more than the homework, but who knows?  In any event, there are a lot of MUNI riders who know more about logic gates than they used to or maybe wanted to.

In case you wanted to play along:

And as a picture:

Tuesday, May 16, 2017

Unschooling Math: Binary Addition

Faced with the specter of having to memorize addition tables, and with the reward of building a calculator from scratch, our six year old—aka No. 1—and I have been working on math from a slightly different tack.  We switched to base 2 numbers.  Base 2 numbers, also known as binary, are the numbers all computers use.  For those unfamiliar with binary numbers, the binary system, (technically referred to as a ‘base 2’), only gives you two numbers to work with: 0 and 1.  Consequently, the binary addition table is far easier to memorize:


Addition Table
+
0
1
0
0
1
1
1
10


In contrast, the number system we’re all familiar with, (known as ‘base 10’), gives us 10 numbers to work with: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.  Given a single digit in our ‘normal’ base 10 system, we can represent up to 9 things.  If we have ten things, we have to add a new digit—known as the ten’s place—hence 10 uses two digits.  In base 2, given one digit, we can represent at most one thing.  So, when we want to represent two things, we have to add a new digit—known as the two’s place—so in the table above, when we add one with one, the result—two—is written as 10 in base 2.

The concept of ‘carrying’ was easier for us because we didn’t have to use such large numbers to practice.  You might not think adding 4 to 6 is a big deal, but you also might have memorized your addition tables more than a decade ago. 


No. 1 and I discovered that we when needed to carry what had really happened was that we’d run out of room adding two digits together.  In other words, when we add two one digit numbers together, and need to write the answer as a two digit number, we’ve carried.  For normal base 10 numbers, you ‘run out of room’ when you add two numbers and wind up with an answer larger than 9.  In base 2, you carry when you add two numbers and come up with an answer larger than one.  Consequently, we wind up carrying in almost every math problem.  No. 1’s getting all the benefit of practicing carrying without having to memorize a 100 entry addition table first.