Sinosoidal #Metaphor #maths #mathematics #nerds #geek

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This is the last in a series of posts on mathematical metaphors. Don’t let the topic scare you. We all use these metaphors, most of us use them every day.

This is a graph of a sinusoidal function. It is the most realistic metaphor, and rarely wrong.

This is the metaphor that takes the longest view.


Like so many Russian nesting dolls, it contains all the previous models. This is the metaphor that says whatever goes up, must come down.

This is the metaphor that takes each change in perspective, whether it is a bad day at the gym, an argument with a spouse, or a lost election. This is the metaphor being used when the Buddha says, “His success may be great, but be it ever so great the wheel of fortune may turn again and bring him down into the dust.”


This final metaphor is the one of serenity and peace.


Exponential #Metaphor #maths #mathematics #nerds #geek

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This is the second in a series of posts on mathematical metaphors. Don’t let the topic scare you. We all use these metaphors, most of us use them every day.

This is a graph of an exponential function. It is the second most common metaphor, and almost as often wrong as the first.

This is the graph of compound interest. While the previous linear graph is often misapplied to daily life, relationships, jobs, and happiness, the exponential graph is usually misapplied in business and science.

Scientists take a broader view. Even though a small section of an exponential curve looks linear, the whole picture is radically different. An exponential is accurate over a longer period than the linear metaphor, but still misleading.

The population of earth is an exponential. The growth of a successful start-up company is also exponential. In fact, this is the definition of success for most companies. For years the capability of computers matched this metaphor. (See Moore’s Law).

Some people see the world as exponentials. They expect each success to be followed by two more and then four more, as small successes give birth to large successes.

In politics, this metaphor breeds extreme responses to elections, with the both the winners and the losers expecting dramatic changes.

Reality has never delivered on this model of exponential growth for the long term, yet people continue to hold onto this idea.

Stay tuned. There are better metaphors.

Economy Size

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NPR noticed that larger pizzas are more economical than smaller one. The same can be said for many consumables like ice cream, soap, cereal, milk, flour, meat, toilet paper, etc. The large economy size is a standard fixture on many stores. Costco is famous for large sizes.

But what is the reason for this packaging? Some people point out that this leads to spoilage and waste, or overeating. Others note the irony that those who must need to stretch their budget, can not afford to buy or store this giant packages.

Why do companies continue to market these larger quantities? One possibility is cost saving. Another is that there is a market for bulk purchases. The following argues that neither of these is a satisfactory explanation. A third alternative is suggested.

Cost saving?

In the case of restaurants, cost saving has a basis. Food service costs fall into three categories: facilities, labor, and raw materials. Generally, the smallest category is the food itself. Thus, the profit margin on a larger than average meal is quite high.

Take the example of a pizza. A large pizza requires a minimal addition to the labor and energy budget, and no additional rent or capital. Thus it is very profitable to sell larger pizzas, even if the price per pound or square inch is lower.

The same can not be said for packages purchased in a store. The estimated saving from selling one package in place of two or three is on the order of a few pennies. Not enough to justify the price reduction.

In conclusion, cost saving does not justify the marketing of large sizes.

A market for bulk packaging?

An informal survey suggests that no one really wants to buy in large quantities. I’ve never met someone who likes carrying large, heavy containers of soap, kitty litter, or potatoes. Juggling a package to three-dozen rolls is toilet paper is beyond comical.

Pricing Strategy.

I propose the reason for a large economy size is a market-segmentation pricing strategy.

The basic principle of pricing strategy is to solve two conflicting goals. First, charge as much as the market will allow. Second, not lose customers by charging too much.

The most obvious example is airline pricing. The market is segmented into two general groups. The first is price insensitive; they will pay anything. They are offered the product with the most convenience and service, which incidentally has the highest margin.

The second segment is the price sensitive; they want low prices. They are offered the price with the least convenience and service. This is a lower margin product. This offering is to capture those customers, even though they provide less profit.


Large economy pricing is like discount airline seats. The goal is to discourage those who are willing to pay more from choosing this alternative. If the product seems inconvenient, just recall that is the goal. The large economy sizes are designed to drive those who are not price sensitive to buy the high-margin regular sizes, while still keeping the price sensitive customers.

Making Friends on the Spectrum

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Dear Don, You did try awfully hard… I’ll miss you very, very much… maybe it was all for the best. I doubt it, but MAYBE. Love,

I remember reading this inscription in my high school yearbook as if it was yesterday. My school assigned homerooms alphabetically, so I sat next to this girl for three years. I never imagined that she cared who I was. It was high school. We were in different groups.

This is how it goes for me. Introverted and on the spectrum, making friends is a mystery, and identifying friends that I have is still as much a surprise as it was over 50 years ago.

During my teen years, my mother who had similar struggles passed on some advice she’d read in a book. “You can’t meet anyone if you stay at home.”

I took this advice to heart. I remember attending school dances where I initially sat alone. In later years, some people sat with me. A strong recollection was a dance where I spent the entire time expounding on tesseracts. Yes, I was that guy.

In retrospect, the people in that group must have been my friends, but that was lost on me and I never made any overtures to spend time with them.

Over the years, that single piece of advice dominated my relationships. I showed up, but rarely sought or recognized one-on-one relationships. Unfortunately for me, I went to a virtually single-sex college with little opportunity for my low-key approach to have much success with women.

That said I’ve had successes. I’ve been married for over 45 years, have a nice family, and had a successful career. At work, I spent enough time with people to make friends. I also learned to recognize my friends. I developed a small cadre of people interested in working with me and together we formed a small itinerant band of engineers and managers moving from one start-up to another in Silicon Valley.

Still today, my primary way to meet people is to show up. Every day I walk around my neighborhood and after five years, people know who I am and wave, talk and smile. These are my friends. I am a substitute teacher. The other day at the county fair, some college students recognized me and came up to say hello. In a similar way, a parent stopped me on my walk and told me how much her child liked me as a teacher.

In conclusion, I found how to meet people and make friends even though I still have difficulty reading reactions and asserting myself in interpersonal relationships.



Tire Pressure Fiction #CarTips #Geek #Nerd #Science

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Tire pressure hoax #1 – I mentioned low tire pressure to my car dealership and they recommended Nitrogen. http://www.pedrosgarage.com/Site_5/Nitrogen_or_Air.html

Tire pressure fallacy #2 When I mentioned low tire pressure to my friends they mentioned weather. I’m in Southern California so this means a drop from 90F to 40F. Sounds like a lot, but in Kelvin which is what matters, it is only 10%.  https://en.m.wikipedia.org/wiki/Ideal_gas_law

Tire pressure confusion #3 When filling tires I remember being warned about hot and cold tires. The same Kelvin scale as before says that at highway speed heating is only about 10% pressure increase.  http://m.caranddriver.com/columns/a-look-behind-the-tire-hysteria


“Forcible sex offenses” Words you don’t want to see at your #college #women #rape

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What do Amherst, Vassar, Swarthmore, Williams, Princeton, Stanford, Wesleyan, Loma Linda, Claremont McKenna, Brown, Skidmore, and Harvard all have in common? You might think of their high academic standards, prestige, or tuition. All those might be correct, but they also all share a place on the American School Search .com list of 100 Most Dangerous American Colleges.

For people who follow this issue, they might not be surprised that the safety concern is “forcible sex offenses,” which I presume is Department of Education speak for rape. The data from the Department of Education comes with interesting caveats.

The crime statistics found on this website represent alleged criminal offenses reported to campus security authorities and/or local law enforcement agencies. Therefore, the data collected do not necessarily reflect prosecutions or convictions for crimes. Because some statistics are provided by non-police authorities, the data are not directly comparable to data from the FBI’s Uniform Crime Reporting System which only collects statistics from police authorities.

Regardless, when the data was analyzed for 6,694 campuses, only 194 received a score of F, and presumably the 100 at the bottom of the F group made the above list. For comparison, the majority of the campuses (over 4,000) were graded A.

No idea what to think? Fortunately for me, my daughters are long ago graduated, and my grand daughters are not yet old enough.

#Code. #Coding. #Coder. What is Code?

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This is an IBM 1620. I didn’t learn to program on this computer, but it was my first computer. My first project was to program the game of dots. I programmed the game in Fortran using recursive algorithms. Fortran did not support recursion: FAIL. My second projects was a graphical simulation of a four-bar linkage. FAIL AGAIN.

This was 1964 and these were ambitious projects, even for a freshman at MIT. Both recursion and graphics were still research topics for machines designed for bookkeeping and sometimes used to replace rooms of calculators. Recall that calculator originally referred to a person (aka mathematician).

Here we are a half-century later and all of a sudden, (as in deja vu all over again) the people in charge are interested in computers. Chief Technology Officers (CTOs) are rising in power and both the Millennials and Boomers feel the pressure to understand whats it all about.

Well coders, programmers, software engineers, or computer scientists have earned their reputation as asocial elitists. If you are wondering, I love to explain it to you, but old habits die hard. But give me the benefit of the doubt, maybe there is not simple explanation.

Here is a pretty good explanation: http://www.bloomberg.com/graphics/2015-paul-ford-what-is-code/

It is so good, I wouldn’t attempt to compete with it. The catch? It is about 40,000 word, plus exercises, so a longish novella. Go on intrepid explorer, give it a try. It is excellent.