Spider for the Day

I found this one by the garage door, lying on his back, waving his legs in the air. I think he fell off the garage door when I opened it. I set him right side up. He wasn't moving too fast, probably because it was a little cool out today.

Okay, now here's something I don't understand. This image is 400 × 363 pixels. It is a scaled down version of the original. If you click on it, you get a bigger version. It is so big that it won't fit on the screen. It is like twice as wide and twice as tall as the screen. My screen is 1280 x 1024. But the original picture is only 920 × 834 pixels. So somebody is blowing up the picture beyond it's original resolution. Now it that Firefox, or Blogger? Something ain't right.

Update March 2016 replaced picture with larger version. Problems with resizing continue to pop up, just not right here, right now.

YouTube-isness Part Deux

The Adventures of Lil Cthulhu
One of Roberta's posts sent me out wandering around where I stumbled over this cartoon video. It played fine for a while, but then it stalled.

[This section no longer applies since the image has vanished.] Look at the indicator bar below the image. It has gone beyond what it has received. Is this an indicator of the power of Cthulhu? Or just some kind of weird techno-glitch?

Update January 2017 replaced missing image with video, removed dead link.

Gear Teeth & Involute Curve

So I'm messing with some algebra, geometry and trig, trying to sort out Stu's angle trisection technique and I remember looking at the way gear teeth are shaped. It's kind of curious and until recently I didn't really understand it. With Marc and Optimus Prime and my old gear program that I am supposed to be working on and some conversations with Jack, it all kind of came together in a heap.

Gear teeth can take a variety of shapes. If you are making a gear you can make the teeth any shape you want. However, one of the more popular/successful shapes is the involute curve. The face of the tooth is bowed out slightly, and the shape of this bow is this curve. Theoretically speaking, this curve is generated by taking a string and winding it around a cylinder. Then take the end of the string and unwind it while keeping tension on it. The path the end of the string takes is an involute curve.

Common diagrams of gear trains often include the "pitch circle", and if you look at these diagrams you will see that the pitch circle runs mid-way through the face of the teeth, half way between the root of the tooth and the tip. The pitch circles of two meshed gears will be tangent to each other. If you take this diagram as gospel you might think that force is transmitted between the gears along this line, i.e. tangent to the pitch circle. This is wrong.


Here is a fine gif animation by Claudio Rocchini that shows what's going on. Notice the the blue line running at a diagonal from the upper left to the lower right. This line is tangent to the base circle of both gears. Note the short, solid blue, double ended arrow sliding along this line. The center point of the arrow coincides with the contact point between two teeth. This dotted line is like the string being unwound from one gear. As the gear on the left hand side of the picture turns, it is paying out string along this dotted blue line. The gear on the right hand side of the picture, the driven gear, is taking up this imaginary string. If the gears were not moving, and we were unwinding the string from one, the end of the string would coincide with the face of the gear tooth. It would form the "involute curve". Slick.

Anyway, I had been messing around with numbers and drawings, and I wonder if I can get a Google Spreadsheet to plot an involute curve for me. I mean it does charts for all kinds of numbers, it should be able to do this. So mucked about for a day or two and didn't really get any results I liked. I finally decided this was another intractable equation. Someone with a better knowledge of trigonometry might be able to come up with a better equation, I had spent enough time on it, so I decided I would use brute force. I set up a program to use root finder to find the angle that coincides with a specific X coordinate, then used that angle to compute the Y value. Print out the X and Y coordinates (from X = 1 to X = PI/2) and import that file into a Google spreadsheet. Point and click and presto, the graph.

Update September 2016 replaced missing pictures.

A Man Of Constant Sorrow

A Man Of Constant Sorrow
Best song in the whole dang movie. So good, I went out to buy the soundtrack, but I could not find it. All I could find was Down From The Mountain, and it didn't have this tune. I never did figure out what was wrong with the people who put that record together. Why would you leave out the one killer tune? If you can answer that, then you might be able to tell me what caused this tune to pop into my head this morning, on account of I have no ideer.

Update September 2015: Replace the missing video.

Update March 2021: Replace the missing video.

3 Pillars of Civilization

I read something not too long ago about how the government and business form the basis of civilization. Government levels the playing field, or at least sets some rules, that allows businesses to operate. Government keeps the pirates out of the marketplace, punishes thieves, and collects taxes to pay for these "services". Governments can be democratic, autocratic, socialist, corrupt, or honest. Businesses will adapt to survive. With "bad" governments, some businesses may be crushed while others are given licenses to print money. With "good" governments, all businesses are free to compete on their merits.

On top of this we have civilization: art & science. It takes a certain amount of surplus to fund things like music, painting and microbiology studies. Having an organized society is one way to generate a surplus.

There is a third element that is necessary for a civilization to flourish and that is indoctrination. It comes under a variety of names: education, brainwashing, socialization, cultural conditioning. It gives people the basic behaviors that allow them to interact with other people in their society.
Reading, 'riting and 'rithmetic are a step up from this.

This is why converting the Mid-East to democracy is going to take a long time. Those people are still living in the Middle Ages. Bringing them into the present is not something can be done overnight. We will be lucky if it can be done in a hundred years.

Wages & Politics

For some time I have trying to figure out some justification for the enormous salaries/bonuses/other compensation being given to some of the people on Wall Street. I have come to the conclusion that it is politics. From a technical standpoint, I don't think any of those people who are getting millions of dollars a year or any more qualified than any number of other people. They don't "deserve" their huge bonuses and whatnot, they were simply able to convince someone to agree to give them the money. They are essentially con-artists.

For people who work for a living, the amount they earn is generally in some way related to how difficult their task is, how much time it takes, and their level of responsibility. Grocery store checkers may make $10 to $20 an hour, Doctors and lawyers may make $100 to $200 an hour, and I don't think anyone begrudges them their earnings.

The more responsibility that comes with a job, generally the higher the pay. You don't want the guy who is cutting you open, or landing your plane, to be worried about how he is going to pay the plumber.

People who are making millions of dollars a year are not getting paid for what they do. They are getting paid because they convinced someone to give them the money, and that's politics. Some people are just natural born political animals, they are easily identified in any group of people. They are the ones who care nothing for whether the job gets done, or how well it's done. They only care about who gets credit for it, and they will go to great lengths to see that they get the credit and someone else gets the blame. Lying and flattery are their stock in trade.

We all do it to some extent, but for most people it is a very small piece of their personality. For political animals it is the be-all and end-all of their existence.

Just like every other line of work, there are good and bad people in positions of power in this country. There may even be some good people making tons of money, but I think the only way you can justly "earn" huge amounts is because of the vicious, cut-throat thugs you have to deal with.

Health Insurance Debate, er, Smear Campaign

Health insurers' 'obscene' profits smaller than Hershey's

This was the title on an Associated Press story in the paper this morning. I am not going to bother looking for it since my previous experience with AP tells me I won't find it. They have their copyright rules. This story was on page 2 and not on the front page since The Oregonian puts up a PDF of their front page every day. Can't go putting AP copyright stuff on-line. Anyway it got me steamed, so I wrote a letter to the editor:

Hoo boy! You have really done it this time. What a load of hogwash. Who paid you to print this garbage? And to do it under the banner of "FactCheck | Your Report Card On Accountability" is unconscionable.

Since you seem to think your readers are very stupid, I will explain it to you as though you were very stupid. You are comparing apples to oranges. All of the companies that you are comparing the health insurance companies against all make things. Making things is difficult. You need buildings, equipment, staff and inventory. Your profits have some relation to how much stuff you actually produce.

Insurance companies do not make things. They are essentially glorified bookkeepers. They have no inventory, they have no equipment. Their goal should be to minimize the the amount they charge for administering their health insurance plans. And your article is only talking about their profits. It makes no mention of their expenses. How much are they charging to process claims? And where are the executive bonuses getting counted? Under expenses, or under profits?

How would you feel if your tax accountant was basing his fee on the amount of taxes you paid? You paid $10,000 in taxes last year, my fee is $1,000. $500 for my actual time spent working on this, and $500 for my profit. Or maybe grocery store clerks should be paid this way. You bought $100 worth of groceries, your checkout fee is $10, $5 for my time, and $5 for my profit.

Go back to school, and take the Associated Press with you.