Skip to main content

The Farmers' Market Goes Cerebal

4:30 AM
"Get up.  It's time to get ready to go."

Every weekend, seven year-old No. 1, and five year-old No. 2 get up with me at midnight.  That's what they call it: Midnight.  Since it's the middle of the  night, it's clearly midnight!  We bundle up if we need to and we feel like it; we find out which by stepping out the front door to check.  Then we head out on the mile long trek to the bus stop with our backpacks and shopping bags.  Usually our walk down the hill to Lisbon and Silver where we catch the 44 involves skipping, running, skunk-spotting, and racing down the last block.

Today though, with the clouds blowing across the starry sky in air so chill that my fingers aren't quite awake typing this, today, things took a more academic turn.  I spotted the Big Dipper so we took a moment to look at that.  2, who I didn't think knew the word dipper, but who's visual acuity is through the roof, looked at it, and said, "Oh yeah, it looks like a cup."

2 wanted to time how long our walk took, so we noted that we were starting at 4:48.  Motion detectors kept flashing on to take pictures of us.  2 asked how they worked, so we talked about light detectors and sonic rangers.  (NOTE:  We need to pick up some Cadmium Sulfide photo-resistors this week.)

Before making our turn down Lisbon to Silver, inspired by 2's new found love of reading, we stopped to look at the letters L-I-S-B-O-N etched into the sidewalk.  We talked briefly about each of the letters and the sounds they make.  1, who's been reading for a couple of years, noted that o can make a short or a long sound.  Then she recalled that two o's make an oooo sound like in room and cool.  That brought us to what sound o makes in words like 'down'.  2 said, "It's like in Nǐ hǎo!"

你好 Wow!  (No phonic pun intended there.)  We've worked on and off on Mandarin for the lat few years.  2 was picking it up all along!  Then, he started the game 1 and I usually play on the way back: calling out house flavors based on their colors.  "Blueberry house!" 2 called out, immediately after flooring me with his off-hand Nǐ hǎo comment.

We sauntered down the last block to the bus stop. I said "We have 9 minutes for the bus."

2 asked, "How long did it take us to get here?"

We worked through the 12 minutes from 4:48 to 5:00 on my fingers and then added in the 13 minutes to 5:13.  Drawing the numbers in the air, we added them up to get 25 minutes.  "Is that a long time or a short time?" 2 asked.  (As an aside, I spent the first year of my life living in Hotevilla, a Hopi pueblo surrounded by the Navajo nation.  The story I was always told is that the Navajo concept of time differs from the European one.  e.g. being late for a meeting has a different connotation.  I love that the gang is growing up, so far, with little concept of time spans.)  (By the way, fact checking the time concept comment led down a fun rabbit hole.)

Walpi near Hotevilla (photo by Ansel Adams 1941)


1 answered, "That's a short time."

We hopped onto the 44, which we'd ride over the hill to San Bruno where we'd walk the rest of the way in to the market.  At the market, I asked 1 for the prices of raisins.

"Four dollars a pound."

"How much can you get for a dollar?"

"I don't know."

"How many dollars in four dollars?"

"Four."

"How many pounds can you get?"

"A quarter pound!"

And so our years old fractions narrative continued.  It occurred to me a few weeks ago when I tried to host our first math workshop that 1 and I do almost all of our learning/teaching/sharing verbally.  It makes for a different environment when other kids are involved, but it might work out in the end.

Well, that's our Saturday morning spent in a typical unschooling way, goofing off, learning, getting things done, and playing.  How'd you spend yours?  Oh, and what's your favorite information delivery method?  Verbal?  Written?  Some other cool way?


Comments

Popular posts from this blog

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems, there seem to be fewer explanations of the procedure for deriving the conversion, so here goes!

What do we actually want?

To convert the Cartesian nabla



to the nabla for another coordinate system, say… cylindrical coordinates.



What we’ll need:

1. The Cartesian Nabla:



2. A set of equations relating the Cartesian coordinates to cylindrical coordinates:



3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system:



How to do it:

Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables.

The chain rule can be used to convert a differential operator in terms of one variable into a series of differential operators in terms of othe…

Lab Book 2014_07_10 More NaI Characterization

Summary: Much more plunking around with the NaI detector and sources today.  A Pb shield was built to eliminate cosmic ray muons as well as potassium 40 radiation from the concreted building.  The spectra are much cleaner, but still don't have the count rates or distinctive peaks that are expected.
New to the experiment?  Scroll to the bottom to see background and get caught up.
Lab Book Threshold for the QVT is currently set at -1.49 volts.  Remember to divide this by 100 to get the actual threshold voltage. A new spectrum recording the lines of all three sources, Cs 137, Co 60, and Sr 90, was started at approximately 10:55. Took data for about an hour.
Started the Cs 137 only spectrum at about 11:55 AM

Here’s the no-source background from yesterday
In comparison, here’s the 3 source spectrum from this morning.

The three source spectrum shows peak structure not exhibited by the background alone. I forgot to take scope pictures of the Cs137 run. I do however, have the printout, and…

Unschooling Math Jams: Squaring Numbers in their own Base

Some of the most fun I have working on math with seven year-old No. 1 is discovering new things about math myself.  Last week, we discovered that square of any number in its own base is 100!  Pretty cool!  As usual we figured it out by talking rather than by writing things down, and as usual it was sheer happenstance that we figured it out at all.  Here’s how it went.

I've really been looking forward to working through multiplication ala binary numbers with seven year-old No. 1.  She kind of beat me to the punch though: in the last few weeks she's been learning her multiplication tables in base 10 on her own.  This became apparent when five year-old No. 2 decided he wanted to do some 'schoolwork' a few days back.

"I can sing that song... about the letters? all by myself now!"  2 meant the alphabet song.  His attitude towards academics is the ultimate in not retaining unnecessary facts, not even the name of the song :)

After 2 had worked his way through the so…