Saturday, January 26, 2013

Side effects

Last night, I noticed that the soap was not lathering.  Huh?  What happened to my soap?  Then I realized it wasn't the soap, it was the water!

We received significant rainfalls of .75" and then .5" in the last 72 hours.  I pulled this graphic from the Water Resources Precipitation Page.
I recalled that our local water district changes water supply depending on conditions (economic and natural).  The rainfall this week probably recharged our local aquifer just enough to enable us to draw (very hard) well water out of our underground aquifer instead of purchasing (moderately hard) imported river water.
To meet the needs of our customers in Hermosa Beach, Redondo Beach, and the Hollywood Riviera section of Torrance, we use a combination of local groundwater pumped from the West Coast groundwater basin and purchased surface water. The surface water is imported by the Metropolitan Water District of Southern California (MWD) from the Colorado River and the State Water Project in northern California.

Learn more about our aquifer and water recycling at World Water Day 2012 and Walking My Watershed.

We planted a line of 10 camellia bushes along the north facing edge of our back yard/patio. A portion of our neighbor's townhouse roof drains onto that area so it gets double the rainfall. The camellias responded well to the rain and cold weather. Stay tuned for pictures.

Thursday, January 24, 2013

Ship Tracks 3

Cliff Mass posted some ship tracks pictures in Strange lines over the northeast pacific.  He showed examples from the GOES (the G stands for geostationary) satellite, which flies over the equator.  The imagery at high latitudes can be distorted. I was surprised at the lack of distortion at Seattle's latitude.
He also showed a swath image from MODIS instrument on the polar-orbiting Terra satellite at 20:05 UT.  Below that, you can see the next granule* in the satellite data stream, off the coast of California, at 20:10 UT.

The ship track region is more centered in this granule from the MODIS instrument on Terra's twin, Aqua.
I'm so grateful that professor Mass kept NASA's name for the image files when he uploaded them on his blog.  That made it easy for me to find the date and time of the files.

For instance, the filename
says the image was taken off Terra in 2013 on Julian Day 015 at 20:05 to 20:10 UT. It's the 2 km resolution file. To look at it in higher resolution, set your browser to
and then use the pulldown menu to toggle to January 15.  Visit that link to see the images in fantastic 250 meter resolution.

BTW, days are numbered sequentially from 1 to 365 in a Julian calendar.  It's much easier than keeping track of months and dates in software.  January is easy because the Julian day is just the date.  But, for subsequent months, this Julian day calendar comes in handy.

* NASA downloads and processes satellite data in chunks they call granules.  Whenever you shoot a continuous movie, you have to chunk it down somehow, and granule is a good, descriptive name.


Monday, January 21, 2013

Done and done!

2 final exams in one week. Add volunteer work at my daughter's school: math tutoring and math team coaching 3 times each, nutrition docent for two classes and staffing the CSA booth at the school wellness fair.  I was a stress monster this past week.

Oh, I also ordered supplies for the sets for the school play and made half of my daughter's costume.

How did I do?  Grade wise, I did ok.  Keeping my cool and not snapping at people?  Room for improvement.

CS 600x, Intro to Computer Science and Programming (with Python), allows students to resubmit homework code many times until the software passes the suite of software tests.  Thus, 100% on homework is not difficult to attain. The exams, however, are not so easy and offer more limited checks.  I passed the course even before the final so there was less stress.

PH207x, Biostatistics and Epidemiology, gave much more limited checks (only one try at vaguely-worded multiple choice problems--even for homework), so I wasn't sure I would pass.  I needed 78% on the final to attain the 85% overall average required to pass.  Fortunately, the final was not any harder than a typical homework from the latter half of the class.  Whew.

Biostats is definitely a class that starts out easy and then builds to some very deep and difficult stuff.  Some favorite things I learned:
  • The visual explanation of what's going on beneath "turn the crank" linear regression.  I've never seen it presented that way before.  Why didn't someone explain that to me 25 years ago?
  • What are the odds?  I didn't know and I never before cared because I preferred my statistics stated in probabilities.  But, I had never before pondered the beautiful symmetry of odds tables. Now, I will keep both odds and probabilities in my toolkit and use the one appropriate for the situation.
  • The application of Bayes' theorem to experimental design.  Suppose you are interested in cancer research, but it's unethical to give people cancer just so you can study them.  With Bayes'  theorem, you can just flip the conditional probabilities around to design an experiment that you can perform without giving people cancer (or some other disease).
  • Soft skills are more highly valued in the biological sciences than in the physical sciences.  One professor began .each. lecture segment with, "Welcome back everybody.  Thank-you for coming."  I can't recall any physics professor saying that*.
* The nicest thing any physics professor said was when I asked him why he always picked on me in class.  He looked kind of taken back and then replied, "Because you are my benchmark student. You are the kind of student that should be able to follow the lecture, if I am doing my job.  So, if you are confused, then I know I have to backtrack."

He further went on that he can see the confusion written plainly on my face, and the (mostly much taller) male students leave a front row seat open for me, which makes for a handy benchmark student.

Friday, January 18, 2013

Travertine and Malachite

I'm showing the most unflattering photo of myself because it shows off the beautiful color of this silk sweater best. My eyes look like I had too much wine at lunch.

In sunlight, you can see the complex texture and blue-green color of the Habu tsumugi silk. BTW, I used Berroco's free pattern, Jujuba, 2 cones of tsumugi silk and size 7 needles.

First course at the Getty Center restaurant.

After lunch, we toured the Florentine art and Mapplethorpe exhibits, then strolled the grounds.  We went mainly to see the Florentine art.  It's not every day that you can see seven Giottos.  However, I discovered that I prefer Daddi.  The Mapplethorpe was fantastic.  Go!

The travertine turns pink at dusk.

Bad Dad checks out the traffic on I-405 and says we better get a move on. 15 miles in 25 minutes during Friday afternoon. Not bad.

The color of this sweater reminds me of malachite.  The Getty center is completely faced in Italian travertine.  The stone travelled across the Atlantic, through the Panama canal (after being transferred to smaller boats that fit in the canal) and then transferred again to a larger ship for the Pacific journey.

A very fun date with Bad Dad.

Wednesday, January 16, 2013

Sweater Weather

Cold weather has an upside--an opportunity to wear thick hand-knit arans. That ghostly pale land form to my right is Catalina.

Sunset cliché.

Have you ever seen sunglint off the side of an oil tanker before?  That saves this photo of an iconic lifeguard platform from cliché status.  Yes, that is Malibu in the background, behind the tanker.

Monday, January 14, 2013

How cold was it?

It hit 34 F (1 C) at the beach today.

The rest of the year has been chilly, too.

Most remarkably, the temperatures remained low, even with a mild easterly wind, which usually brings us air warmed by adiabatic compression as it moves downslope.  Notice that we never reached 70 F in January.

Nor in December.

It's nail-biting season for California citrus growers.  We are not out of the woods yet.  The cold will linger for a day or more.

SFGate reports that Redondo Beach officially hit 33 F, not the 34 F at the personal weather station above.
FRESNO, Calif. (AP) — California citrus growers began to see some damage to the mandarin crop Monday while winds up to 50 mph add to the misery in cities, where residents have been bundled up against record cold for several days.
Temperatures in downtown Los Angeles plummeted to 34 degrees overnight, breaking the previous record of 36 degrees set on Jan. 14, 2007.

Elsewhere Monday, it was 13 degrees in high desert Lancaster; 25 degrees in Fresno; 27 in Temecula; 29 in Claremont; 33 in Redondo Beach and Sacramento; 34 in Palm Springs; 36 in Van Nuys; and 40 in San Francisco.
Visualizations courtesy of Weather Underground.  Data courtesy of the generosity of the thousands of  owners of personal weather stations that share data with Weather Underground.  Let's hope that survives the merger with the Weather Channel.

Saturday, January 12, 2013

What nesting articles don't tell you

I'm a design fan and I (mostly) enjoy reading about great design in fabulous settings.  Often, though, there is a catch that the real estate equivalent of hagiography rarely mentions.   The most problematic lots get built last.   This time, I knew exactly why this lot was available.

I am intimately familiar with this view as I used to across the alley from this lot, on the quieter Pearl street side.

This type of modern aesthetic really appeals to me.  As does the view.  I lived in a nearby run-down Victorian sub-divided into four small apartments.  We used to dine al fresco in the backyard and enjoy a similar view.

I am surprised that the NY Times didn't even mention that these townhouses front a .very. busy arterial road, Canyon bouldevard. How were they able to photograph the homes without passing traffic?

The most appalling thing about this "journalism" is the lack of mention that they built underground in a flood plain. Take a look at the city of Boulder's flood plain map.  Ok, technically, this block--at ground level--is not in the flood plain. The homes featured in the story are on the lot shown as an aqua rectangle.  I lived on the quieter Pearl street side of this "island" in the flood plain.

But, anything underground is liable to flood.  In fact, Canyon boulevard did flood one late spring day in the early 1990s when a heavy rain coincided with snowmelt season.  We're not talking about shallow puddles.  We're talking kayaking along Canyon boulevard.  The city called that one a 50-year flood, a term of art which means that there is a 2% chance of such a flood occurring in any year.  I explained the statistics of that in The myth of the 100 year flood.

Many, many homes throughout the city flooded that day and it took weeks for the water to recede in many people's basements and ground level spaces.  The article mentioned that one of the owners moved to Boulder in the mid 1990s.  Did she know about that flood?

So they built $3M showcase homes on a busy street, adjacent to a flood plain, and then put the garages underground to maximize square footage.  I hope they have amphibious cars.

Remember Rolfing?   The Rolf Institute used to own several of the ramshackle homes on the Pearl street side of this block.

Related posts:

  • Fire is a river that runs uphill Killer views are also deathtraps for their occupants and they cost the rest of the taxpayers a mint to protect.
  • Recycling shipping containers Another high-ceilinged and high-volume home that robs their neighbors of light and air flow.  Large homes are a socially communicable disease.  Remember my favorite Jacaranda tree in the front yard of the adjacent small home?  The tree and small house were razed to create another huge house.  Now there is an entire row of these huge homes, without their stately old trees.

Thursday, January 10, 2013

Mommy dearest moment

Remember "No wire hangers, ever!"?

I'd taken my daughter to Lands End last week to buy her a new jacket.  But, she was so cranky and tired, she didn't want to shop for anything else.  I was doing (more thankless) volunteer work today nearby so I swung by LE again to peruse the clearance racks.  I bought her four things and showed them to her this evening.  She liked two of them and asked me to return the other two.

Anyway, one of the items fit right now and went into her bureau.  We agreed to hang the slightly large shirt in a corner of her closet until the next growth spurt, when it should fit.  (She grew from 4'11" to 5'2" in less than a year.)  I went to my room to fetch an appropriate hanger.  When I returned, she asked what was wrong with the hangers in her closet.

I replied, "They are all the wrong type."

She probably thinks I am crazy, but they really were all the wrong type.

The shirt is too large to stay on her child-sized hangers and all the wider non-slip hangers were being used by her wider-necked tops.  I really did have to walk to my closet and fetch an adult-sized plastic hanger.  Really.

Of course, we don't use wire hangers in our house.  That would mean dry-cleaning, which we seldom use.  When we do send stuff to the dry cleaners (every spring when we put away the wool clothing that can't be hand-washed), I gather the wire hangers and return them to the dry cleaners for reuse.

Just in case you have never read the book or seen the movie, here's a clip. I read the book and skipped the movie. Reviews were negative, portraying it as a campy, over-the-top movie that failed to capture the nuances of the relationship explored in the book. The book made me so uncomfortable, I wouldn't have been able to watch it, even had it been a good movie.

References to "Mommie Dearest" in pop culture tend to get the story wrong.  Yes, Joan Crawford could have been a better mom.  But, she worked damn hard in an unforgiving business--a business notorious for pumping it's talent full of drugs and booze to make them work on demand.

Her daughter had very few household responsibilities.  She had been told repeatedly that it was her responsibility to take her clothes off the wire hangers used by the dry cleaners and rehang them on padded hangers.  That was her single household responsibility, requiring mere minutes each week.   Yet she failed to do it week after week.

By her own admission, Christina had a loving grandmother, housekeeper and many maids, nannies, cooks, gardeners and drivers.  She was not neglected.  She was loved (but, perhaps, not by her mother).  But, she also came across as too narcissistic to be lovable.  Publishing the book is only one among many transgressions against her mom.

When I was eight, my mother showed me how to use the washer and dryer and put me in charge of all of the family laundry--including ironing and planning washday around the weather because we used an outdoor clothesline.  My eleven year old sister and I traded responsibilities weekly.  One person was responsible for laundry and cleaning both bathrooms.  The other was responsible for doing all dishes and cleaning the kitchen.  We swapped every weekend.  When we were the age of Christina during that scene, we were the gardeners as well, swapping care of the front and back yards on the weekly schedule.

My mom worked as a charge nurse (senior registered nurse) at a small hospital.  She had Wednesdays off, which she spent cleaning, shopping, cooking and schlepping us to music lessons.  She also had every other weekend off, and she planned outings for each of those weekends.  (Ordinary people would have spent that time sleeping.)

I don't know how my mom did it.  I would never have dreamed of treating my mother the way Christina Crawford treated Joan Crawford.  I can't believe that people got the story so wrong; did we read the same book?

There are so many ways that a mother-daughter relationship can go wrong.  Give me strength because I  need it to get through (her) puberty.

I got another call today about an interesting job in another city.  Is it wrong to dream about getting my own apartment in another city and being a mom only on weekends?  Is it wrong to dream about her lifting a finger around the house?

Tuesday, January 08, 2013

Frida Kahlo's closet

It's worth watching the video to the end to hear curator Circe Henestrosa discuss Kahlo's belongings and how much they inform us about her.  I had known about her disability and seen her thorn paintings.  But, it really hit home when I saw the leather contraptions she had to wear to help support her torso and to hear Henestrosa describe the medicines they found among the artists' belongings.  (I assume they were pain medications.)

Dressing can be a political and feminist act.

Hat tip to LA Observed for bringing this to my attention.

Monday, January 07, 2013

Winter Strawberries are arriving this week!

I just got news from Tanaka Farms that super sweet (ambrosial is not an overstatement!)  winter strawberries will be in this week's Tanaka Farms CSA boxes.  Sign up now to eat your veggies, and strawberries, and support your local schools.

Eileen, CSA manager at Tanaka Farms, sends this update:
I spoke too soon about the strawberries being in the boxes this week. One of our strawberry patches suffered damage from the crows. The birds were eating many of the strawberries. We do not have enough strawberries for this week , we hope to have more in the next week or two.

Sunday, January 06, 2013

Self-learner project: Friendship Paradox

Your friends have more friends than you.  It't not you, it's the friendship paradox.  Your friends are not random.  They are more likely than you to be social butterflies or they wouldn't have met you (or maintain ties with you).

One of the professors teaching MITx: 6.00x Introduction to Computer Science and Programming stated that his goal was for us (the students in the class) to learn enough to break down problems and write python programs to solve them.

In the introductory chapter of my PhD thesis, I wrote that one of the reasons for modeling is to help explain the results of physical experiments.  Sometimes, modern experiments (not to mention, nature!) are so complex, it can be hard to interpret the data.  Through modeling, we can break problems down into simpler components and then add effects in until we match the observed data.  Then we can explain what actually likely happened.

Anyway, I wrote a python program to clarify the friendship paradox because it also explains why I, with a BMI of 22.5, am often the fattest person in Pilates or spin class.  Steven Strogatz explained:
For example, imagine going to the gym. When you look around, does it seem that just about everybody there is in better shape than you are? Well, you’re probably right. But that’s inevitable and nothing to feel ashamed of. If you’re an average gym member, that’s exactly what you should expect to see, because the people sweating and grunting around you are not average. They’re the types who spend time at the gym, which is why you’re seeing them there in the first place. The couch potatoes are snoozing at home where you can’t count them. In other words, your sample of the gym’s membership is not representative. It’s biased toward gym rats.
So back to the friends problem.  I started by thinking about the shape of the distribution of the number of friends one might have.
  • The distribution should be self-similar; the shape of the distribution of the friends of friends should resemble the shape of distributions of friends of friends of friends.  
  • The distribution must be positive; you can't have less than 0 friends.
  • The distribution should have a long right tail
A gamma distribution of shape = 2-3 looks about right.
My intuition was not bad.  In 2003, Bronius Grigelionis wrote a paper about the self-similarity of the Euler Gamma Function.  Gamma distributions are useful in modeling computer networks--why not people networks?

I sorted people by number of friends, from hermits on the left to social butterflies on the right. The number of friends for each person is in blue.  The average number of friends of friends for each person is in red.  Note that, for the first 400 or so of the 500 people, their friends have more friends than they do.

I had a heck of a time assigning friends to the social butterflies in a computationally efficient manner.  If you sort people by numFriends (taken from the Gamma distribution) from hermits to butterflies, than go up the sequential list, assigning them more friends from those remaining until they reach numFriends and having those people friend them back, you will eventually reach a problem.

There are simply not enough people leftover to fill up the friend lists for those social butterflies.  In that case, I had them friend everyone to their right and then randomly select friends from those on the left that had not initially selected them.  I assumed that those on the left friended them back out of politeness, which added slightly to the total friend count.

The distribution of number of friends for a sample population of 500 people:
The initial number of friends taken from the Gamma distribution is shown in green.  The distribution of adjusted friend counts is shown in blue.

The commands to run the program:
numf = pickNumFriendsRecur(500, shape=3, scale=5 stretch=8)
flist = assignFriends(numf)
fof = howMany(flist)

The output:
max(numf) > nsubj:  501 500
trying reducing scale to:  4.9
avg numf after iteration:  115.732
Target average friends:  115.732
Adjusted average assigned friends:  121.724
Average friends of friends:  151.410319998

I encourage you (and your kids!) to view and download the sample code from pastebin and play around with it.

Tuesday, January 01, 2013

Free Range Kids 7

This is a follow up to Free Range Kids 6.  I did some searching in my memory archives and in search engines and found How children lost the right to roam in four generations.  Here's the money shot:

While there are many journal articles going back decades, I don't have access to them.  Perhaps a reader with university library access can read and summarize some of them?  Here are a couple of recent ones:

Sex Differences in Spatial Competence: the ability of young children to map ‘primed’ unfamiliar environments

Spatial Ability and Home-Range Size: Examining the Relationship in Western Men and Women

Free Range Kids 6

I never would have expected that Boulder would be less permissive than the Beach Cities when it comes to letting kids go Free Range.  But, life is full of surprises.

Recall that, in our area, kids 8-11 can be left alone in the library for up to two hours.  Kids 12 and older can stay alone as long as the library is open.  Only kids 8 and under need to be accompanied.  The Boulder Public Library just instituted new restrictive rules:
No person may leave children, age 11 and under, or dependent adults unattended.

First we would like to clarify for you that children of all ages are welcome in the Boulder Public Library, and, that children are not banned from the library. Library staff are happy to assist children with selecting and checking out library materials, and, providing reference and readers’ advisory service.  The reasoning behind instituting this new rule, which is consistent with many other public library systems across the nation, is, to address concerns about children being left alone in the youth area, or in the library in general, while parents or caregivers were either absent or in other sections of the building.

Our library staff values the safety and wellbeing of children, however, our resources do not make it possible for us to provide constant supervision and oversight of children, especially if they were to wander off inside or outside our buildings.

The libraries are public buildings, and, open to everyone.  Because the library is a public place, a child’s safety cannot be guaranteed.Children may encounter hazards such as stairs, elevators, doors, furniture, electrical equipment, or, other library patrons.  At the Main Boulder Public Library alone, almost one million patrons walk through the doors each year. The safety of our patrons, especially children and dependent adults, is our highest priority.
I don't expect my kid's safety to be absolutely guaranteed anywhere, including inside my messy home (lots of stairs, doors, furniture, electrical equipment and eccentric adults).  I just expect that reasonable precautions are taken after a rational risk-benefit analysis.  Why would the library be any different?

Libraries are libraries, not daycare centers.  Any reasonable parent knows that.  But I want to wander the stacks at the library and let my child wander on her own, too.  That's how kids discover things.

Can you imagine having to hover over your child at the library, and then drag them along with you to the adult stacks?  Library visits would take twice as long.  Since library visits tend to happen after school and before dinner, we are talking about a recipe for total child melt-down.

A British newspaper (I can't find the link found it and added the link) published a visual story showing the shrinkage of range for children over generations.  I also read an education study that looked at sex differences in mathematical and spatial reasoning.  While boys tended to have better spatial reasoning than girls, there was large variability within the sexes.  When they looked at what distinguished the high-performing girls from the rest, they discovered that spatial skills didn't correlate with sex; they correlate with roaming range. On average, boys are allowed twice the roaming range as girls of the same age.

[Addendum: I found many articles on the subject. You can try Spatial Ability and Home-Range Size: Examining the Relationship in Western Men and Women or Sex Differences in Spatial Competence: the ability of young children to map ‘primed’ unfamiliar environments.]

Correlation does not imply causation, and it was a small study. But, cognitive psychologists are investigating if the process of forming mental maps of one's surroundings while navigating through them improves overall spatial reasoning and processing speed.  Could helicopter parenting be a cause of the decline in STEM skills in American children?

I don't need another excuse to avoid driving my kid to school in the morning amid the crazy traffic around the school.  But, perhaps you are sitting on the fence and need a handy excuse.  ;-) Besides, Iris says that the walk is her time to think and clear her head.