Lee.org

“You can’t manipulate someone with candor and truth. That is called enlightenment.”

– (slightly paraphrased) from the book Changes by Jim Butcher

I had to stay home sick. Blah. Just lots of mild “blah” symptoms all over my person. I’m laying low so I feel better for my trip to Florida over Thanksgiving break!

Hypothetically, if you had three student loans totaling about $100,000 at different interest rates… say $3%, 5%, and 6%, would you push to pay them off or invest the “extra” money in the stock market?

My first thought was that the stock market generally pays 7% interest so I should pay down the 6% loan and put all the rest of the money into the stock market, but now I’m second-guessing myself. Thoughts?

Of course, first priority is to make a rainy day fund and pay into any matching 401(k) programs.

…

I found some answers for myself….

Look at this cool chart (via) (local copy). This chart shows how the S&P 500 index performed over the past hundred years. There is a “20 year” diagonal line, I highlighted it in red in the image to the right. Read the numbers on that line. For investments put in from 1930 until today, the S&P 500 has made pretty reliable 7% interest (as low as 4%, as high as 14%) per year. If you can wait 30+ years (highlighted in yellow in the image to the right), it’s a VERY reliable 7-9% interest rate, you can see that by looking at the far right side of the chart. Looking at the 10 year diagonal, the interest rates are more variable, -4% to 14%.

I’ve got about 20 years to retirement. With a 20 year window, the S&P 500 should always beat a 4% loan. Everything else is a crap-shoot. For example, with a 10 year window, $100,000 could balloon into $370,000 (that’s 14%, compounded yearly) woo hoo! That’s a nice nest-egg to retire on!   Or, it could eviscerate $100,000 into $66,000 (4% loss, compounded yearly). [sad trombone] enough to get me into a chichi cardboard-box retirement community.

So what to do?

Since I’ve got 20 years left, invest in the stock market (claiming my 4 – 14%), making sure to diversify enough to match the S&P 500. But in 5 years, it’ll be time to switch to the safer (3 – 6%) investing of paying down student loans instead of continuing to invest in a riskier 10 year plan that pays (-4% – 14%).

There was this awful noise that I’d sometimes hear in my room at school. It sounded like a machine in the walls suddenly turning on. Sometimes for a half a second, sometimes for a minute. On and off, on and off! It’d come on a bit more around 11am or so so I thought it might be related to kids going to the nearby bathroom. When it was happening and I had the opportunity, I’d run around the building looking for the source. It wasn’t the air conditioning, wasn’t the bathrooms, wasn’t the heaters, wasn’t the neighboring classrooms playing with power tools. I talked to the school custodian, to the neighboring teachers. But they all thought I was mad. I wasn’t mad! I wasn’t! I swear it!

Then, a few days ago, more than a YEAR after first noticing the sound, I found it! A water hammer in the sink of the classroom two doors down. So simple! When the kids were cleaning up from morning work, they’d turn on the water. Curiously, it was quieter in the room with the offending sink than in mine.

I got the most joy when Ms. S. the teacher one door down told me how for the last DECADE she was explaining-away that horrible sound to her students. We were both beaming!

I went to the custodian and explained what was going on. We wrote up a work order for the plumber together. And 3 days later, with one gentle turn of a wrench, the problem dissolved into the mists!

My in-laws’ two homes are each about 1 mile away from the flames of the Kincaid fire in Santa Rosa. Please send good wishes!

TL;DNR: Keeping the humidity at 40-60% dramatically decreases airborne infection rates!

Here are snippets from an article in Forbes, shown to me by Winnie Chen.

Oct 17, 2019, 09:30am
This Inexpensive Action Lowers Hospital Infections And Protects Against Flu Season
Leah Binder
Healthcare

“Harvard Medical School graduate and lecturer, Stephanie Taylor” heads this research…

“The one factor most associated with infection was (drum roll): dry air.”

“Taylor finds one of the most interesting studies from a team at the Mayo Clinic, which humidified half of the classrooms in a preschool and left the other half alone over three months during the winter. Influenza-related absenteeism in the humidified classrooms was two-thirds lower than in the standard classrooms–a dramatic difference.”

“They used to assume the microbes in desiccated droplets were dead, but advances in the past several years changed that thinking.”

In looking up hand research for work, I came across this super-cool machine learning article. In brief: a computer can read an X-Ray and tell if a person is a boy or girl really accurately and (at least some) doctors can’t! Maybe by paying attention to what the computer sees, doctors can figure out how to determine the gender of the hand in the X-ray.

https://link.springer.com/article/10.1007/s10278-018-0148-x

Abstract
Despite the well-established impact of sex and sex hormones on bone structure and density, there has been limited description of sexual dimorphism in the hand and wrist in the literature. We developed a deep convolutional neural network (CNN) model to predict sex based on hand radiographs of children and adults aged between 5 and 70 years. Of the 1531 radiographs tested, the algorithm predicted sex correctly in 95.9% (κ = 0.92) of the cases. Two human radiologists achieved 58% (κ = 0.15) and 46% (κ = − 0.07) accuracy. The class activation maps (CAM) showed that the model mostly focused on the 2nd and 3rd metacarpal base or thumb sesamoid in women, and distal radioulnar joint, distal radial physis and epiphysis, or 3rd metacarpophalangeal joint in men. The radiologists reviewed 70 cases (35 females and 35 males) labeled with sex along with heat maps generated by CAM, but they could not find any patterns that distinguish the two sexes. A small sample of patients (n = 44) with sexual developmental disorders or transgender identity was selected for a preliminary exploration of application of the model. The model prediction agreed with phenotypic sex in only 77.8% (κ = 0.54) of these cases. To the best of our knowledge, this is the first study that demonstrated a machine learning model to perform a task in which human experts could not fulfill.

Please help me find a good noisy-environment speech recognition microphone. I have students that want to use speech-to-text in their classroom, the microphone should pick up the student’s voice but not stray voices in the room. Best if it’s on a headset.

Megan, Abigail and I just saw the summer fireworks show at The Butchart Gardens near Victoria, BC. It was an even more beautiful show than we had seen 5 years ago on our honeymoon! The show is a gorgeous, playful, exposition of light-art, part representative, part interpretive, all pleasurable! A youtube search turns up some nice displays at Butchart Gardens but be forewarned that no fireworks show well on a screen.

I spoke with a few people in Victoria, BC about this and they said that Canadians use fireworks differently than Americans.  American fireworks are almost universally a monosyllabic ejaculation of sound and color while Canadians use it as a medium. Curious! Wonderful!

How did it take me 20 years to figure out this “one weird trick” to know which way is up on a USB cable? All hail the sharpie clown nose!