Saturday, March 24, 2007
Owner-operator: 250 hours flight time annually
Commercial operator: 1000 hours flight time annually
Friday, March 23, 2007
Why "Real Physics"?
Without intrinsic meaning, nature has no moral value. If moral values are not part of nature then they are unnatural, which means there are no real constraints on human action. Human rights lose all meaning.
An agenda, perhaps not fully conscious, informs the rejection of intrinsic purpose. Those who deny nature's meaning do so in order to impose their own meaning, and to use this power to manipulate other men.
As Aristotle says, it is quality and not quantity that leads to purpose. Denying the reality of qualities, modern science rejects purpose and the possibility of happiness.
If there is only quantity, then our system of government, which is predicated on the reality of rights-bearing individuals, is meaningless. If there is only quantity, then all is matter in motion. There are no forms, there are no substances, there are no wholes. You and I are not ensouled bodies created in the image of an all-powerful Creator, nor are we simply self-aware bipeds; we are not even animals—as that concept itself is meaningless—but merely an arbitrary agglomeration of matter in motion. Certainly he pulled the lever that caused the explosion that launched the metal projectile that punctured the intervening soft tissues that caused a sudden decrease in blood pressure. But without referring to substances, you can't call it "murder."
Thursday, March 22, 2007
Mark Steyn covers the Conrad Black trial from opening arguments to final verdict
A Meridional Grid on the Middle-Earth Map
My own theory:
Gondor=Italy, Greece, Balkans
Misty Mountains=border between Gaul and Germany, up to Norway
Anduin River=eastern Meditteranean/Black Sea
Sea of Rhun=Caspian Sea
Spain, Morocco, Algeria under water
POV-Ray: Newsgroups: povray.binaries.images: toon-shading using attenuation - includes source code
Wednesday, March 21, 2007
List of uniform tilings - includes some of those hyperbolic tilings on a circle that Escher used to do
NASA Finds Sun-Climate Connection in Old Nile Records
A group of NASA and university scientists has found a convincing link between long-term solar and climate variability in a unique and unexpected source: directly measured ancient water level records of the Nile, Earth's longest river.
[They] have analyzed Egyptian records of annual Nile water levels collected between 622 and 1470 A.D. at Rawdah Island in Cairo. These records were then compared to another well-documented human record from the same time period: observations [in northern Europe and the Far East] of the number of auroras reported per decade in the Northern Hemisphere. Auroras are bright glows in the night sky that happen when mass is rapidly ejected from the sun's corona, or following solar flares. They are an excellent means of tracking variations in the sun's activity.
The researchers found some clear links between the sun's activity and climate variations. The Nile water levels and aurora records had two somewhat regularly occurring variations in common - one with a period of about 88 years and the second with a period of about 200 years.
The researchers said the findings have climate implications that extend far beyond the Nile River basin.
"Our results characterize not just a small region of the upper Nile, but a much more extended part of Africa," said Ruzmaikin. "The Nile River provides drainage for approximately 10 percent of the African continent. Its two main sources - Lake Tana in Ethiopia and Lake Victoria in Tanzania, Uganda and Kenya - are in equatorial Africa. Since Africa's climate is interrelated to climate variability in the Indian and Atlantic Oceans, these findings help us better understand climate change on a global basis."
So what causes these cyclical links between solar variability and the Nile? The authors suggest that variations in the sun's ultraviolet energy cause adjustments in a climate pattern called the Northern Annular Mode, which affects climate in the atmosphere of the Northern Hemisphere during the winter. At sea level, this mode becomes the North Atlantic Oscillation, a large-scale seesaw in atmospheric mass that affects how air circulates over the Atlantic Ocean. During periods of high solar activity, the North Atlantic Oscillation's influence extends to the Indian Ocean. These adjustments may affect the distribution of air temperatures, which subsequently influence air circulation and rainfall at the Nile River's sources in eastern equatorial Africa. When solar activity is high, conditions are drier, and when it is low, conditions are wetter.
Tuesday, March 20, 2007
Public Reason and the Truth of Christianity in the Teachings of Benedict XVI
Right Reason in the Public Square, Part II - comments on the above
It's Not All Relative - reply by the same writer to correspondence
An Opinion About Opinions
From the same article as the last post
The importance of modifying the way people act, instead of programs based on condom distribution, is increasingly being recognized by medical experts.
On March 11, 2006, the British Medical Journal published an article entitled "Risk Compensation: The Achilles' Heel of Innovations in HIV Prevention?"
Authored by a team of writers headed by Michael Cassell, the article observed that while pharmaceuticals and other measures can help reduce the spread of HIV, they may also inhibit the change to safer behaviors by diminishing people's perceptions of risks.
Condom promotion campaigns, combined with a reduction in risk perception, "may have contributed to increases in inconsistent use, which has minimal protective effect, as well as to a possible neglect of the risks of having multiple sexual partners," the article commented.
The authors also noted that studies in a number of Western countries show that the promise of increased access to antiretroviral treatment "has been associated with significant increases in risky behavior."
Prior to this confirmation of the need to change sexual behavior, came from a study carried out in Zimbabwe's rural population between 1998 and 2003. An article entitled "Understanding HIV Epidemic Trends in Africa," published Feb. 3, 2006, in Science magazine, reported on the study's findings.
Authors Richard Hayes and Helen Weiss wrote that a reduction in HIV prevalence was achieved due to changes in sexual behavior. The changes involved delaying the onset of sexual activity by adolescents and a reduction in the number of casual sexual partners.
A related theme in the debate is the question of promoting abstinence. The negative consequences of initiating sexual relations at an early age was highlighted in an article published in the February issue of the Journal of Youth and Adolescence.
The article, "Adolescent Sexual Debut and Later Delinquency," by Stacy Armour and Dana Haynie, observed that the question of ill effects resulting from sex outside marriage is a controversial point in the debate over whether to promote abstinence. Up until now, however, there has been little research on the topic.
Armour and Haynie used data from the National Longitudinal Survey of Adolescent Health to examine interconnections between the age of sexual debut and subsequent delinquency problems. The study covered some 12,000 students and the findings were controlled for variables such as age, race and family structure.
Among the conclusions from the study was the finding that premature initiation of sexual activity increases the risks of delinquency. Similarly, delaying sexual activity later than one's peers "offers a protective effect and reduces the risks of engaging in subsequent delinquency." The corresponding negative and positive effects go beyond adolescence and persist until early adulthood.
The Achilles' Heel of Condoms
On March 2 the Washington Post published a lengthy article examining the experience of Botswana in dealing with AIDS.
The newspaper noted that a number of studies single out the practice of having sex with multiple partners "as the most powerful force propelling a killer disease through a vulnerable continent."
The Washington Post cited a July report by southern African AIDS experts and officials that put "reducing multiple and concurrent partnerships" as their first priority for preventing the spread of HIV. The region accounts for 38% of total HIV infections in the world.
The article described how Botswana has followed for many years the policy recommended by international experts of promoting condoms and distributing antiretroviral drugs. All to no avail. The contagion rate for HIV in the country is the among the fastest growing in the world. Around 25% of the population is currently infected.
Fidelity campaigns were never seriously promoted in Botswana, the Washington Post observed, but condoms were. A $13.5 million campaign for condom promotion was launched in the country, thanks to the financial support of the Bill & Melinda Gates Foundation and the Merck pharmaceutical company. The amount spent on promoting condoms was 25 times more than what was spent on abstinence programs.
"Soaring rates of condom use have not brought down high HIV rates," the article concluded. "Instead, they rose together, until both were among the highest in Africa."
Speeding HIV's Deadly Spread - the Washington Post article mentioned above
International experts long regarded Botswana as a case study in how to combat AIDS. It had few of the intractable social problems thought to predispose a country to the disease, such as conflict, abject poverty and poor medical care. And for the past decade, the country has rigorously followed strategies that Western experts said would slow AIDS.
With its diamond wealth and the largesse of international donors, Botswana aggressively promoted condom use while building Africa's best network of HIV testing centers and its most extensive system for distributing the antiretroviral drugs that dramatically prolong and improve the lives of those with AIDS.
But even though the relentless pace of funerals began to ease in recent years, the disease was far from under control. The national death rate fell from the highest in the world, but only to second-highest, behind AIDS-ravaged Swaziland. Men and women in Botswana continued to contract HIV faster than almost anywhere else on Earth.
Twenty-five percent of Batswana adults carry the virus, according to a 2004 national study, and among women in their early 30s living in Francistown, the rate is 69 percent.
Researchers increasingly attribute the resilience of HIV in Botswana - and in southern Africa generally - to the high incidence of multiple sexual relationships. Europeans and Americans often have more partners over their lives, studies show, but sub-Saharan Africans average more at the same time.
Nearly one in three sexually active men in Botswana reported having multiple, concurrent sex partners, as did 14 percent of women, in a 2003 survey paid for by the U.S. government. Among men younger than 25, the rate was 44 percent.
The distinction between having several partners in a year and several in a month is crucial because those newly infected with HIV experience an initial surge in viral loads that makes them far more contagious than they will be for years. During the three-week spike - which ends before standard tests can even detect HIV - the virus explodes through networks of unprotected sex.
This insight explained what studies were documenting: Africans with multiple, concurrent sex partners were more likely to contract HIV, and countries where such partnerships were common had wider and more lethal epidemics.
Polygamy once was common in the region, and in some parts still is; Swaziland's king has 13 wives. In generations past, even Batswana with just one spouse rarely expected monogamy. Husbands spent months herding cattle while their wives, staying elsewhere, tended crops, Mosojane said. On his return, a husband was not to be quizzed about his activities while he was away. He also was supposed to spend his first night back in an uncle's house, giving his wife time to send off boyfriends.
In Setswana, the national language, "the word 'fidelity' does not even exist," Mosojane said.
On a hospital wall here, not far from the AIDS clinic that Khumalo visited with his friend, the painted image of a condom shimmers like a comic-book superhero. Giant, colorful block letters declare, "CONDOMISE AND STAY ALIVE!!"
In cramped black script below, it adds, "Abstain first."
Yet rarely seen among Botswana's AIDS prevention messages is one that has worked in other African countries: Multiple sex partners kill. Dubbed "Zero Grazing" by Ugandan President Yoweri Museveni, this approach dominated in East Africa, where several countries curbed HIV rates.
Fidelity campaigns never caught on in Botswana. Instead, the country focused on remedies favored by Western AIDS experts schooled in the epidemics of America's gay community or Thailand's brothels, where condom use became so routine it slowed the spread of HIV.
These experts brought not just ideas but money, and soon billboards in Botswana touted condoms. Schoolchildren sang about them. Cadres of young women demonstrated how to roll them on. The anti-AIDS partnership between the Bill & Melinda Gates Foundation and drugmaker Merck budgeted $13.5 million for condom promotion -- 25 times the amount dedicated to curbing dangerous sexual behavior.
But soaring rates of condom use have not brought down high HIV rates. Instead, they rose together, until both were among the highest in Africa.
How To Run a Perfect Audition - includes info on hiring casting agents
I Don't Know Art, But I Know What I Write - some articles from "Creative Screenwriting" and "Reel Independence"
IDtension Project: Interactive Drama - has links to a few papers on this topic
The Murthly Hours
The Murthly Hours is one of Scotland's great medieval treasures. Written and illuminated in Paris in the 1280s, it also contains full-page miniatures by English artists of the same period, and was one of the most richly decorated manuscripts in medieval Scotland. Medieval additions include probably the second oldest example of Gaelic written in Scotland.
The entire manuscript has been reproduced here. In the Folios section, you can browse page by page or select a folio from the complete list of titles.
Monday, March 19, 2007
Schooling at Home - "an account of a day in the life of a homeschooling mother, and it emphasizes the surprising efficiency of the education."
Laboratory of the States - finds correlations among demographic variables in the US.
Sunday, March 18, 2007
An excerpt on the Jeffreys-Lindley paradox (PDF)
7.1 Hypothesis testing and "significant" scientific evidence
Most of us would be familiar with standard claims regarding the "statistical significance" of data with respect to a particular test. According to commonly used "objective" statistical methods, it is typically regarded as powerful evidence against a null hypothesis if it can be rejected at a very small significance level based upon a large number of observations. Let me refer you to a very striking analytical result that lets us know that such "significant data" do not necessarily amount to evidence in favour of rejecting the specified null hypothesis at all!
The result is called the Jeffreys-Lindley paradox, named after two English statisticians who generated it midway in the past century (Lindley, 1957). Suppose you decide to reject a null hypothesis in favour of an alternative once you are able to reject it at some specific significance level, as small as you like. (Some journals which support such a decision procedure print a star next to parameter estimates that are significantly different from zero at the .05 level, two stars if they are significantly different from zero at the .01 level, and three stars if at the .001 level!) Under very mild assumptions regarding prior expectations, it can be shown that the posterior probability in favour of the null hypothesis being true, conditional on data that leads you to reject the hypothesis at this desired significance level, becomes arbitrarily close to 1 as the number of observations involved increases. This is and should be really a shocking result to anyone who is aware of the ubiquitous use of so-called significance testing in medicine and engineering. It was one of the motivating factors for the technical development of subjectivist Bayesian procedures in the past half century. But these have been regularly rebuffed by academic scientific claims to "objectivity" that have mistakenly but proudly denied the role of beliefs and values in the conduct of science.
Serious attention to the foundation for the now too common practice of hypothesis testing will show that there are two types of possible error that characterise any statistical decision – the one of them viewed as rejecting a hypothesis when it is true (called type I error), and the other that of accepting a hypothesis when it is false (called a type II error). However, the common practice of significance testing today typically ignores the relevance of type II errors and their probabilities, because these are very difficult to compute, if not impossible, according to standard conceptions. The Jeffreys-Lindley paradox revolves upon this fact. Without careful consideration of the entire array of possibilities, the fact that some observed data are unlikely when the null hypothesis is true can disguise the fact that they are even more unlikely when the null hypothesis is false! Further research on this type of result has been developed under the provocative name of procedures for "testing to a foregone conclusion." See for example, Cornfield (1970, pp. 18-22).