Dumbing down the history of science.

The man who brought history of science to America, George Sarton, spent many years studying science before turning to its history. The best historians of science have always been people with deep knowledge of the science whose history they write about, such as Thomas Kuhn and Owen Gingerich.

Stanford computer scientist Donald Knuth once gave a lecture titled "Let's Not Dumb Down the History of Computer Science". What he meant by that was that computer scientists should follow the example set by mathematicians, who have taken charge of the history of their own subject, rather than leaving it in the hands of historians who not only lack significant knowledge of mathematics, but have no interest in acquiring such knowledge. The sort of histories of science written the scientifically illiterate are so bad that they have brought tears to Knuth's eyes.

Unfortunately, the history of science in general is now dominated by scientific know-nothings. Typically employed in history departments, not departments of history of science, they cater to and are judged by other academic historians with little knowledge of and little interest in the technical content of science. And what's worse, they celebrate their "externalist" views of science. Like Bart Simpson, these underachievers are "proud of it, man".

This message was self-deluded by its author.

Did you read that carefully?

Here's the music that should have accompanied the Republican debates.

Yosemite sleep deprivation

Sleep has always been flaky under Windows, but it has always been solid under Mac OS X until I "upgraded" to Yosemite. For the first time ever, I am having trouble putting a Mac to sleep. Sometimes it goes to sleep and stays asleep. Other times it wakes up almost immediately. Then I have to shut it down instead.

Color vision and X-inactivation.

Normal color vision in humans is said to be trichromatic, since there are normally three types of cones in our retinas. The most common types of color deficiencies result from abnormal or missing genes on our X chromosomes. Most of the readers in the Science Group have probably heard that many men, but few women, are "red-green colorblind". This trait is said to be sex-linked and recessive, like baldness and many other abnormalities that affect more men than women.

Roughly speaking, if a man has such a trait and a woman is not a carrier for that trait, their children will not have the trait, but half of their daughters will be carriers. If a woman is a carrier and a man does not have the trait, half of their sons will have the trait, and half of their daughters will be carriers. If a woman is a carrier and a man has the trait, then half of their children of either sex will have the trait, and the daughters who don't have the trait will be carriers. These statements follow from the facts that every female cell has two X chromosomes and every male cell has only one X chromosome.

But the real situation is more complicated. In very precise color-matching experiments, women who are normally considered to be carriers have been shown to have a slight deficit compared to women who are not carriers. In other words, the genes for color deficiencies are not completely recessive. This has to do with the fact that one of the X chromosomes in each cell of a woman's body is inactivated, i.e., most of its genes are not expressed. The reason for X inactivation is to prevent a mismatch between males and females in the amounts of messenger RNA (and hence the amounts of protein) that are produced. In animals (but not plants) if the level of gene expression is off by a factor of two, the results are usually deleterious and often fatal. Even if the level is only off by 50%, as in trisomy 21 (Down Syndrome), there are serious consequences.

A female "carrier" of a sex-linked trait will have clumps of cells in which the X chromosome inherited from her father is inactivated, and other clumps in which the X chromosome inherited from her mother is inactivated. The patches of fur in a calico cat are similarly explained. The retina in each eye will have abnormal patches and normal patches. It's not surprising that such an eye does not perform quite as well as a completely normal eye.

Oscar Peterson Trio plays "Down here on the ground"

Oscar Peterson - Piano
Sam Jones - Bass
Bobby Durham - Drums

Our broken jury servitude system

Our jury servitude system provides an almost unlimited labor force which is forced to work for almost nothing. The court system wastes jurors' time in many ways: keeping jurors idle for hours in jury assembly rooms, sending hordes of them to courtrooms where they sit idly once again, waiting for the interminable voir dire process to exclude most of them, etc. The court system does all this because it has little incentive to use jurors' time efficiently.

An integral part of this economic distortion is excessive use of what are called peremptory challenges (defined below). We Americans pay little attention to how similar problems have been solved elsewhere in the world. Once when my time was being wasted in a jury assembly room and a judge came by to give the usual pep talk, I asked him what he thought about peremptory challenges. He said that of course he had his opinions but declined to say what they were. I mentioned that peremptory challenges had been abolished in England. The judge said that was interesting - he hadn't been aware of that. (!)

Today's LA Times has an editorial about peremptory challenges:

http://www.latimes.com/opinion/editorials/la-ed-peremptory-challenges-in-misdemeanor-trials-ab87-20150621-story.html

Is there any limit to the greed of pharmaceutical companies?

The following story from the LA Times shows some consequences of our ridiculous drug prices. Only in America does the government encourage this abuse. For a private citizen, printing money is called counterfeiting and is prosecuted by the feds, but big pharma practically has a license to print money.

http://www.latimes.com/business/hiltzik/la-fi-hiltzik-20150621-column.html#page=1

Happy solstice-eve everybody!

Tomorrow will be the longest day of the year (for those of us in temperate regions of the northern hemisphere), but today is almost as long. (By "day" I mean the interval from sunrise to sunset, not the 24-hour period which is also called a "day".) For those at mid-latitudes in the southern hemisphere, it's the shortest day. Our summer solstice is their winter solstice, and vice versa.

The sun will rise at 23.4 degrees north of east, and sunset will be at 23.4 degrees north of west. Hey, that's almost the title of a Hitchcock movie. (Actually sunset is roughly West by Northwest.)

For those at very high latitude there will be no sunrise or sunset today or tomorrow. But it will still be the "solstice" in the original sense of the word: that the sun is as far north in the sky as it will get this year. This can be observed by those above the arctic circle, but not by those who are wintering over in Antarctica (brr....).

Why some saturated colors are darker than others.

Have you ever noticed that blue is darker than red, whereas red is darker than yellow? This gives blue ink the greatest contrast, and yellow the least contrast, against white paper. I've often wondered why this is, and I think I've figured it out.

Color vision involves cones (as opposed to rods). Humans with normal color vision have three types of cones in their eyes. I will refer to them as blue, green, and red cones, although the proper terms are short-wavelength (S), medium-wavelength (M) and long wavelength (L) cones. The following diagram shows the patterns of cones in the foveas of an eye with a normal retina (on the left) and one lacking red cones (on the right). The person with the latter eye suffers from a severe form of red-green colorblindness called protanopia.



The brightness of a color depends on the density of cones that are excited by light of that color. Red and green cones are dense in the normal fovea. Blue cones are very sparse and don't contribute much, if anything, to brightness. Blue light excites mainly the blue cones and has low brightness, i.e., it appears dark. Yellow light excites the red and green cones equally (or approximately so) and has high brightness, since it excites most of the cones. Red light excites mainly the red cones and is intermediate in brightness, since it excites only about half the cones.