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Science, Climate Change, and the Greenhouse Effect

Mon ,13/12/2010

In the 1800’s, scientist began to understand the role greenhouse gases  had in keeping the Earth warm. The greenhouse effect is now a well established scientific principle. Both the science and the data show that  current global warming is caused by the increasing CO2 in the atmosphere.

Greenhouse Effect: Most gardeners know how greenhouses work.  In the daytime, the sun’s radiation (visible and UV) comes in through the glass and warms the plants and soil.  The glass stops the heat radiation in the infrared (IR) region from passing back through and the greenhouse stays warm enough to keep the plants from freezing, even at night. The Earth works much the same way except greenhouse gases, primarily water and  carbon dioxide, play the role of the glass and trap some of the leaving IR radiation. Winter nights on Earth would be very cold without greenhouse gases.

Earth’s Energy Balance: Of the Sun’s energy coming to Earth, 30% is reflected immediately back into space by particles in the air, by clouds, and by the surface. Another 20% is absorbed by the atmosphere where it runs the weather cycle. The remaining 50% heats the land and oceans. All the absorbed heat is eventually radiated back into space as infrared radiation. It’s a balanced energy budget, 100% in and 100% back out. Anything that reflects more light back into space, such as an increase in particulate matter in the air, would cause the Earth to cool. Anything that delays the energy’s trip back to space, such as an increase in greenhouse gases, would cause the Earth to warm. There are many small things that affect the Earth’s energy balance, but the main three are the Sun, particulates, and greenhouse gases.The ash from the explosive eruption of Mt.Tambora in 1816 caused that year to be called the year without a summer, worldwide.

The Sun: Certainly a change in the Solar radiation the Earth receives would cause a change in  the Earth’s temperature. Small wobbles in the Earth’s orbit, the Milankovitch Cycles, are variations in the eccentricity, axial tilt, and precession of the Earth’s orbit. They affect the amount of solar radiation the Earth receives in predictable cycles. Both scientists and skeptics agree that these cycles are responsible for the Ice Ages that occur in roughly 100,000-year intervals. In the part of the cycle where the Earth receives more solar radiation, the oceans slowly warm and release CO2. The CO2 further amplifies the warming by the greenhouse effect. As the Earth moves into the part of the cycle where it receives less solar radiation, the oceans slowly cool, the CO2 dissolves back into the oceans and another ice age starts. The patterns of wobble in the Earth’s orbit are predictable and the model predicts that a minor cooling trend, which began some 6,000 years ago, will continue for the next 23,000 years. The current warming trend is too rapid and in the wrong direction to be a part of the Milankovitch Cycles.

The Sun also has cycles where its output varies slightly such as  Sunspots activity. They cause the amount of solar radiation to vary in approximately 11-year cycles. However, the effects of Sunspots are so small that they do not show up above the other small variations in NASA’s temperature record.(see below). Long term variations in the Sun’s intensity are not responsible for the current warming. The graph of solar irradiance from 1880 to the present in this article shows that the Sun’s intensity increased slightly from 1880 to 1960 and then has declined slightly since 1960.   Satellite measurements of solar radiation show also that the solar radiation reaching Earth has declined slightly over the last 30 years – yet the Earth still warmed.

Temperature Data: The best temperature data we have clearly shows the Earth is getting warmer. NASA has compiled the Earth’s average temperature for each year since 1880 by using ships logs, weather stations, and satellite measurements. In the graph below , each square dot shows how far that year’s average temperature was above or below the 1970 value.  Although the data varies widely from year to year because of random factors such as sunspots, weather events, ocean current, and particulates from volcanoes and man’s activities,  the trend is clearly upward. The solid red and blue lines are  moving averages, which make the trend easier to follow.

NASA's Temperature Data  Credit: NASA JPL GISS

Credit: NASA/JPL/MSSS

Temperature Trend: The greenhouse effect links some of the causes of the temperature trend to man’s activities. The trend took a turn upward in about 1920. That was when the automobile, industrialization, and energy production began further increasing the carbon dioxide concentration in the air. The trend was flat from about 1945 to 1975 and  that can be attributed mostly to particulates. There was an increase in particulates after 1945 from many sources such as WW II, atmospheric nuclear testing, and increased industrialization. Research during the early 1970’s showed a huge increase in aerosols from power production, increased industrialization, and vehicles and some alarmists even speculated that we might be causing another ice age.  Particulates are visible and cause immediate health problems so by 1980 most industrialized countries had restrictions on particulate release. During the period from1945 to 1975 the CO2 concentration had continued to rise but its effect had been masked by the particulates. Reducing the particulates in the air allowed the full effect of the CO2 to be felt, causing the Earth’s temperature to begin to rise again. The effect of particulates and the reliability of the temperature record can clearly be seen in the graph above. In 1991, Mt. Pinaturbo erupted spewing about 10 cubic kilometers of ash into the air which caused an immediate 0.3 °C temperature drop  for the entire Earth, lasting until about 1995.

Causality: Although the greenhouse effect is a well accepted principle, skeptics sometimes claim the correlation between global warming and CO2 does not constitute causality. However, G.N. Plass, in 1956, calculated the climate sensitivity of the Earth to CO2. He found that doubling the concentration of CO2 in the air would cause a 3 to 4 °C increase in the Earth’s temperature. A number of more recent studies have confirmed his work and have shown that, though the concentration of CO2 in the air is small, it accounts for about 25% of the greenhouse effect. No natural occurrences such as volcanoes, sunspots, fires, or dust storms can account for the major trend in the data. Certainly, the increasing amount of CO2 in the air is causing the Earth to warm.

Man’s Role: Man’s activities, mainly through deforestation and burning fossil fuels, have released large amounts of CO2 into the air. In the last century, man’s emission of CO2 from fossil fuels have increased to over 30 billion tons annually and the concentration of CO2 in the air has risen from 280 parts per million (ppm) to 385 ppm. The processes that remove carbon dioxide from the air takes decades or longer so as the carbon dioxide concentration slowly built up, the Earth became a better greenhouse. The concentration of carbon dioxide in the air is now 38% higher than in 1880 and the Earth’s temperature is about 0.8°C (or 1.3 °F) higher. Clearly, man’s activities are mainly responsible for increasing the CO2 concentration in the air – and the increasing CO2 concentration is causing global warming.

(C) 2010 J.C. Moore

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Bits and Pieces 4: Is It Safe to Fluoridate Water?

Sun ,07/11/2010

Fluoride is toxic at high levels but has health benefits  at low levels. Fluoride  is added to water at concentrations less than 1 ppm as it  helps to prevent tooth decay by hardening tooth enamel.  Tooth decay can allow bacteria to enter the bloodstream where they cause heart disease and other infections.  There are places where fluoride occurs naturally in water at ten times the concentration used to fluoridate water and there have been no long term effects except fluorosis, a brown stain on children’s teeth.

Fluoride is chemically about like chloride ion in the body – except that at high concentrations it forms a precipitate with calcium and ties it up. That’s the reason it is toxic at high levels. Fluoride can be used at fairly high doses to treat osteoporosis as it will keep calcium from leaving bones.  At 0.5 to 1 ppm, the amount usually used to fluoridate water, there have been no serious side effects. At above 1.5 ppm, fluorosis, a brown stain on the teeth may form in a few % of the population. There are places where natural sources of fluoride are as high as 10ppm and fluorosis is the only health effect found. Fluoride is toxic at high levels with an  LD50 of  125 ppm in rats and it is assumed to be about the same in humans. For comparison, the dose rate for aspirin is about 5 ppm  and the  LD50 in rats is 200 ppm (1 ppm is 1 milligram per kilogram of body weight).

There are very few sources of fluoride in people’s diets except water or products where it is an additive. The source of the fluoride doesn’t really matter as most inorganic fluorides hydrolyze to form fluoride and bifluoride ion in water. Many toothpastes use stannous fluoride. Many countries add fluoride to salt or even to milk as tooth decay  is considered to be a much more serious health risk than fluoride exposure. The exposure from all sources should be kept below 1.0 pm so those who have fluoridate water or salt should not use other fluoridated products or toothpaste. If you are worried about fluoride in you water, there are water filters that remove it from drinking water and it is easy to avoid it from other sources.

Update, 3/14/2011: The U.S. Department of Health and Human Services is announcing a proposal to change the recommended fluoride level to 0.7 milligrams per liter of water. The standard since 1962 has been a range of 0.7 to 1.2 milligrams per liter. There was no health risk at the higher level, but fluorosis has been observed in kids teeth, particularly those who may get fluoride from other sources.

Update, 11/13/2012  Poor oral health, dental disease, and tooth pain can put kids at a serious disadvantage in school, according to a new Ostrow School of Dentistry of USC study. “The Impact of Oral Health on the Academic Performance of Disadvantaged Children,” appearing in the September 2012 issue of the American Journal of Public Health, found that  73 percent of disadvantaged kids in Los Angeles have dental caries, the disease responsible for cavities in teeth. Children who reported having recent tooth pain were four times more likely to have a low grade point average—below the median GPA of 2.8—when compared to children without oral pain. Poor oral health and dental problems also cause more absences from school for kids and more missed work for parents. Treating tooth decay is prohibitively expensive for some and tooth decay has been implicated in a number of later health problems, even heart disease.

Update, 04/11/ 2014: Some people are concerned, not about the toxicity of the fluoride, but of arsenic in the fluorosilic acid that is used to fluoridate most city water supplies. The fluorosilic acid from fertilizer manufacture, used to treat most water supplies, comes as a 20% solution and one source was analyzed to contain about 3.3 ppm of arsenic. By the time the solution is diluted to 1 ppm of fluoride, the concentration of arsenic is diluted to about 1 part per trillion. That is about 10,000 times less than the EPA standard for drinking water, which is 10 parts per billion (ppb) arsenic. It is difficult to see how that can be a health risk.

For perspective, some lakes near older coal-fired power plants have been found to have upward of 200 ppb of arsenic in the water. If I were concerned about arsenic in my city’s water supply, I would look at the concentration in the water from the lake, if that is the water source.

(C) 2010 J.C. Moore

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Personal Styles, Learning Styles, and Politics

Sun ,12/09/2010

Personal styles reveal something about how we learn, think, and relate to the world.

Not long ago, National Public Radio reported that 29% of the US population was considered to be on the left politically. That is interesting as about 28% of the population is abstract /random, a description that is related to “personal style”. The study of personal styles usually includes thinking styles and learning styles. The studies are designed to improve education, self-awareness, relationships, mental health, and productivity. There seems to be little research available on whether personal styles are related to political views, but the possibility is interesting. Personal styles reveal something about how we learn, think, and relate to the world. Knowing a little about personal styles is a useful thing.

“Personal style” is a description of how we receive, store, and use information.  A simple, but useful, model for personal style was developed by Alexander Gregorc. (1) His model uses two perceptual qualities, “abstract” and “concrete”, and two organizational methods, “sequential” and “random”  (or “nonlinear” ) . Gregorc couples these to form four possible style categories: concrete/sequential (CS), abstract/sequential (AS), abstract/random (AR), and concrete/random (CR). Although everyone has all four qualities, most people are predisposed toward one or two of them. A survey found that about 51% of the population prefers CS, 28% AR, 13 % CR, and 8% prefer AS. These refer to a person’s dominant style. It is important to remember that everyone has some of each style and there is no “best style”. Still, personal styles can be fun and enlightening to investigate.

What’s Your  Style? A person’s dominate style can be related to preferred occupations, satisfying hobbies, and even things they might find difficult. An extensive description of all four styles is available at this link (2).  A simple, 15-question test can determine approximately a person’s style. It takes about 10 minutes and is at this link if you are interested. (3) Please note that these are very approximate categories that may change with time and that they may be situational. A person may prefer one style at work and another for leisure, such as a surgeon who is CS at work may much prefer AR type activities for hobbies.

Learning Styles: Although personal styles change with maturation, it is useful to consider that a student has a preferred learning style. Students with a CS style tend to prefer programmed instruction, workbooks, lab manuals, field trips, and applications while students with an AS style tend to prefer lectures, books, syllabi, and guided individual study. Students with a CR learning style prefer independent study, games, simulations, and problem solving, and students with an AR style usually prefer television, movies, assignments with reflection time, and group discussions. (2) There have been some efforts made to match teaching styles to student’s learning styles but it is impractical except in the largest of schools. Teachers are encouraged to be aware of the different learning styles and to use a variety of methods directed to each style. There is much more to know about personal learning styles and a good reference for that is Thelearningweb. (4)

Political Styles: Perhaps political discourse could be improved by a knowledge of personal styles. The most polarizing divide in politics lately had been between Conservatives and Liberals. A 2009 Gallup Poll survey found that 40% of Americans describe their political views as conservative, 35% as moderate, and 21% as liberal. (5) That’s not quite the same as the breakdown in the personal styles categories, but the similarity is interesting. From considering personal styles, we know that CS and AR dominant people perceive and organize information differently, that everyone has some of each style, and  that personal styles vary with the situation and maturation.  Rather than there being a big Liberal/Conservative divide, perhaps issues could be considered a personal style difference. Then, rather than calling each other elitists and ignoramuses, we could just say “That is certainly an abstract/random approach to the problem.” or “My, aren’t we being concrete/sequential today?”

(1) http://gregorc.com/gregorc.html

(2) http://www.floatingneutrinos.com/Message/arcs/links_on_abstractrandom.htm

(3)  http://www.thelearningweb.net/personalthink.html

(4) http://www.thelearningweb.net/learningstyles.html

(5) http://www.gallup.com/poll/120857/conservatives-single-largest-ideological-group.aspx

Science Literacy and Religious Beliefs

Wed ,11/08/2010

Scientific literacy cannot be measured by a litmus test such as belief in the Big Bang or evolution.

Every two years the National Science Foundation produces a report, Science and Engineering Indicators, which surveys the public’s attitudes toward science. (1) The report found for instance, that the public’s opinion of scientists ranks at the top of 23 other occupations and there is broad support for public funding of science research.  In spite of that, Dr. Lawrence Krauss, is unhappy because a section of the 2010 report about the public’s  science literacy was omitted.

In a Scientific American article, he responds:

“And every two years we relearn the sad fact that U.S. adults are less willing to accept evolution and the big bang as factual than adults in other industrial countries. Except for this time. Was there suddenly a quantum leap in U.S. science literacy? Sadly, no. Rather the National Science Board, which oversees the foundation, chose to leave the section that discussed these issues out of the 2010 edition, claiming the questions were ‘flawed indicators of scientific knowledge because responses conflated knowledge and beliefs.’ In short, if their religious beliefs require respondents to discard scientific facts, the board doesn’t think it appropriate to expose that truth.”

However, the National Science Board was right that the section  confused knowledge and beliefs. For example, there is evidence for the Big Bang theory and many people know about it, but they have not incorporated it into their beliefs.  Only physicists and mathematicians would likely know what a singularity is, let alone believe the universe arose from one. Then, there is the problem of how the singularity came to be. Likewise, many people know of the adaptation of species to their environment such as resistance of viruses and bacteria to antibiotics and of insects to DDT. They may also be aware of our ancestors such as Luci and Ardi and know of the evolution of the horse. However, if you insist that the spontaneous generation of life is part of evolution, it may be rejected.

Dr Krauss is missing something important.  Aristotle established science as a method for understanding nature by using observation and reason. It is not a body of facts to be memorized and believed. As scientists gather more evidence, what we now regard as fact may be replaced with better ideas. We should not make “accepting evolution and the big bang as factual” a litmus test for science literacy. Just as scientists think religion should not be dogmatic, scientists should also refrain from dogmatism. Insisting people accept scientific theories which conflict with their religious beliefs  just makes them more likely to mistrust science on issues where it really matters.

As a practical matter, it is not likely that someone’s mind can be changed by claiming their beliefs are wrong or that they are based on mythology. Science teachers must deal with students who already have a belief system established. Their strategy should be to present science as a method that uses observation and reason to understand the physical world. Teachers must focus on the background knowledge and the evidence, and hope that at some point the student would see any conflicts and try to resolve them.

1)http://www.nsf.gov/statistics/seind10/c7/c7h.htm

2) http://www.scientificamerican.com/article.cfm?id=faith-and-foolishness

Bits and Pieces

Fri ,16/07/2010

This article contains bits and pieces, usually short comments on recent science  articles and issues. Other bits and pieces will be added with the newest at the top.

The High Cost of Doing Nothing: A  report by the National Academy of Sciences details the high economic cost of inaction on environmental legislation (2). It’s relatively easy to figure the cost of regulations to protect the environment, but relatively hard to keep from inflating the cost for political purposes.  As a Republican, I am a little ashamed that Republicans have adopted the grossly inflated annual figure of $3200 per  household. That is useful for sticker shock and propaganda, but totally inaccurate. The CBO has estimated that it would cost around $300 and that there would be added savings that would reduce the deficit.

The cost of regulations  should  be compared to the cost of doing nothing. Estimates by the World’s top economists such as Britain’s Nicholas Stern or the US’s Paul Krugman are that right now it would cost about 2% of the worlds GDP to mitigate environmental damage – but if delayed, that amount could rise to 20% or more. That also doesn’t take into account intangibles such as clean air,  clean water, and a more sustainable economy.

Ocean Acidification is Serious: Since preindustrial times, the concentration of CO2 in the air has risen from 280 ppm to 385 ppm, a 38% increase.   As the amount of CO2 in the air increases, the amount that  dissolves in the ocean increases proportionately.  When the CO2 dissolves in seawater, it makes it more acidic, just as adding CO2 to soda makes it acidic. The pH of sea water has  been measured to be  more acidic by 0.1 pH unit than a century ago. Since the  pH scale  is logarithmic, the decrease of 0.1 unit means the oceans are now over 20% more acidic than a century ago and the cause is most certainly CO2.

To put that in perspective, human blood has a  carbonate buffer system similar to that of the oceans.  Normal blood pH is from 7.45 to 7.35 , and a blood pH less than 7.1 would require emergency treatment. Increasing the carbon dioxide in the blood by 38% will decreased the blood pH to about 7.25, not critical, but surely a sign that something is wrong. If the oceans get much more acidic, the coral, the fisheries, the shellfish, and the oxygen-producing plankton that give life to the oceans are threatened.

Complaints about the “scientific secrecy” are disingenuous: There is very little secrecy in science. Scientific papers are presented and openly debated at meetings where anyone can attend. The peer reviewed papers include the data, the results, and the reasoning and are available at public libraries and many are now online. Also:

Researchers are required to keep records of their research so that any other scientist with comparable training and skills could reproduce the research. The “reproducibility” of the research is an important factor in the reviewer’s evaluation of the research. The public has a right to information produced by publicly funded research and that may be requested through the Freedom of Information Act (FOIA). Usually a “Gatekeeper”, such as the project’s director, is designated to handle FOIA requests. That Gatekeeper has a responsibility to see not only that the public’s rights are upheld, but also to see that the FOIA process is not abused and that the scientists are protected. (1)

Only a few things are kept confidential to preserve the integrity of the peer review process.  The main barriers preventing a better understanding of science by the public is not “secrecy”, but poor science education, the lack of responsible and informative reporting by the media, and an ongoing campaign to spread misinformation by those who find the conclusions of science inconvenient to their ideological or financial interests.

Peer Review, Science Data, and the Public's Right to Know

Tue ,13/07/2010

Does the public’s “right to know” extend to the peer review process and to the scientist’s data?

Peer review: Reputable scientific journals have a peer review process to ensure that published papers are free of errors in reasoning and methodology and that they report only the best research. Upon submission of a paper, the editor of the journal removes the name of the authors and sends it to expert researchers to be reviewed. The names of the authors are kept confidential by the editor to ensure that the author’s reputation, past personal differences, or factors other than the quality of the work cannot affect the review. The editor of the journal considers the reports of the reviewers and decides whether the paper should be published or returned to the author for corrections. Few papers receive outright rejection and the papers returned for correction are usually returned with reviewers comments.

The names of the reviewers are kept confidential by the editor to ensure that the author does not directly contact the reviewer to argue or does not retaliate against a reviewer. In a recent case, John Christy was able to discover through the stolen CRU e-mails who reviewed one of his papers and why the editor published it as he did. The paper was controversial in nature and contained opinions not held by most other climate scientists. The editor, in an attempt to present both sides of the issue, published Christy’s paper alongside a paper that presented the opposite view. Using information to which he should not have been entitled, Christy publicly attacked the reviewers, the editor, the peer review process, and climate science in general. His actions violated the integrity of the process and also the professional ethics required of scientists as he released his opinions to the public before the matter could be impartially investigated.

The Public’s Rights: The claims that the names of the reviewers and the editor’s reasons should be made public are invalid. Scientific journals are funded by subscriptions and dues of members and not publicly funded. The review process is set up as it is to ensure the integrity of published science papers and “peer reviewed” is the gold standard of quality in science information. The editor of the journal has the right to choose the reviewers and decide what is published just as the editor of a newspaper has the right to publish or reject articles without divulging the reasons.

Scientific Data: The public’s right to the data of researchers is another matter. Researchers are required to keep records of their research so that any other scientist with comparable training and skills could reproduce the research. The “reproducibility” of the research is an important factor in the reviewer’s evaluation of the research. The public has a right to information produced by publicly funded research and that may be requested through the Freedom of Information Act (FOIA). Usually a “Gatekeeper”, such as the project’s director, is designated to handle FOIA requests. That Gatekeeper has a responsibility to see not only that the public’s rights are upheld, but that the FOIA process is not abused and that the scientists are protected.

Scientists are understandably reluctant to release their data – as some who did release it later came to feel as if gremlins had seized their work and their lives. Some researchers have been harassed by numerous and frivolous  requests for information  meant only to impede their work. That is particularly true in climate science where there are apparently well-funded gremlins, some of them ex-scientists*, at work. Worse, scientists have been criticized publicly for reasonable practices that can be misconstrued. For example, good research requires the calibration of equipment, yet that has been led to accusations  of “adjusting the data”. And, a math ‘trick” used to simplify a computation, was mischaracterized as “tricking the public”.

Even worse, when Phil Jones, the CRU director, released his raw data for a 1990 research paper to a former London financial trader, Douglas J. Keenan, Keenan combed through the data and then tried to have the FBI arrest Jones’ co-author for fraud. An investigation cleared the researchers of any wrongdoing but it took a toll on their time and work. Incidents like that have  a chilling effect on the willingness of scientists to release their data. Some scientists who released their raw data, have seen it “recalculated” in such a way as to reach conclusions contrary to their findings, yet attributable to them. Reputable journals will not publish the erroneous conclusions of “recalculated” data , but some newspaper articles, blog sites, and even Congressional hearings will use them to promote a controversy manufactured by someone who actually did no research. And, once the fallacy is “out there”, it is hard to correct.

Certainly, the public has a right to openness in public funded research. Much of the scientific debate take place at scientific meetings and those wishing to hear the research debated may attend . The FOIA Gatekeeper has an important role to see that the FOIA requests are valid, that scientists are not harassed, and that those who wish to use the data for unscientific, or even malevolent purposes, do not have easy access to the data. The next step for those who do not like the Gatekeeper’s decision is to seek redress in the courts – not by illegally hacking the researcher’s computers.

* The author considers those scientist who abandon the methodology, ethics, and objectivity of science; especially for money, notoriety, or political purposes, to be “ex-scientists”.

The Gulf Oil Disaster: Where Were the Engineers?

Fri ,04/06/2010

Where were the engineers? At the Deepwater Horizon , a number of key decisions may have led to the disaster and affected the outcome. The role of the management in the decisions was to make a profit for the company and to weigh the benefits and risk against the costs. The most important responsibility of the engineers in performing their duties, according to Engineering Code of Ethics, was to

” Hold paramount the safety, health, and welfare of the public.” (1)

Questions that need to be answered as the investigation continues are : Could the ignition sources for the explosion have been avoided? Why were the workers quarters not explosion proof? Why did Halliburton proceed with cementing the well when the results of the pressure tests were inconclusive? Who made the disastrous decision to replace the drilling mud with seawater? Why were problems with the blowout preventer not addressed? Were early efforts directed at trying to save the well or to prevent a major oil spill disaster? Obviously, what has happened cannot be changed but, as the investigation into the cause continues, it is important to know who answered those key questions and why they were answered the way they were. When those key decisions were made, where were the engineers?

The Challenger, A Different Disaster. One of the most studied disasters is that of the Challenger Space Shuttle. (2) Most people think that an engineering failure led to the disaster, but in fact, it was a failure of ethics. One difficult problem in the design of the space shuttle was how to transport the large fuel tanks to the launch site. Morton Thiokol won the contract by designing fuel tanks that could be transported to the site in sections and sealed back together with rubber O-rings. The O-rings were effective down to 40°F, but below that, the rubber stiffens and its ability to seal the tanks had not been tested.

The January 1986 Challenger launch was to carry Christa McAuliffe, the teacher the year, into space. The weather had been cool and uncooperative in Florida that January and there had been several delays in the launch. President Reagan was planning to include the education aspect of the shuttle launch in his State of the Union speech and, for that and other reasons, pressure was building on the shuttle team to proceed with the launch. However, the temperature was predicted to be 29°F on the morning of January 28 and the engineers strongly recommended against the launch. The decision whether to launch was the responsibility of Bob Lund, the vice president of engineering for Morton Thiokol. On the advice of his engineers, he recommended against the launch.

However, Jerald Mason, the general manager of Morton Thiokol, called a meeting to discuss the decision. He asked Bob Lund to “Take off your engineering hat and put on your management hat.” He was asking Lund, in effect, to put aside his engineering ethics and weigh the very unlikely possibility of an accident against the public relations benefits of launching on schedule. Apparently, that argument worked as Lund approved the launch, despite the fact that the predicted launch temperature was outside of the operational specifications. At 59 seconds into the launch, the O-rings failed and the rocket exploded, plunging the Challenger into the ocean and killing all seven astronauts. It was the worst disaster in the U.S. space program’s history.

“Hold paramount the safety, health, and welfare of the public.” In our increasingly technical and complicated world, we often use products and devices designed by engineers. The public, you, me and everyone else, must trust our safety to the engineers who design, test, and make decisions about those products. Engineering schools now include the study of professional ethics in the curriculum and try to convey to students their importance. However, in some instances, engineers do not follow their ethical code because of financial rewards, job security issues, peer pressure, or company loyalty. Often, small ethical violations go unnoticed and unreported unless, or until, they grow into a major problem. Many violations are only discovered and investigated when they lead to a public relations fiasco, a death, a lawsuit, or a major disaster. It is imperative that engineers steadfastly hold paramount their duty to protect the public. Engineers who violate their ethical code and managers who override the engineer’s decisions on safety should be financially and criminally liable for the disasters they cause.

(1) http://www.nspe.org/Ethics/CodeofEthics/index.html

(2) http://ethics.tamu.edu/ethics/shuttle/shuttle1.htm

Doubling Time: Interest and Population Growth.

Mon ,15/02/2010

It is easy to calculate the approximate doubling time for compound interest, credit card debt, or population growth. A simple rule of thumb to get doubling time is to divide the growth rate into 70. For example, an investment at 7% compound interest would double in 70/7 = 10 years. After 10 years, a $100 investment would double to $200, in another 10 years it would double again to $400, and in 10 more years to $800. Not bad. This will also work for credit card debt. If your interest rate is 20% and you only make the minimum payment, your debt will double after 70/20 = 3½ years. You might think again about buying an expensive item on your credit card if you realize that a $1000 purchase, unless paid off, will cost you $2000 after 3 ½ years and $4000 after 7 seven years. Everyone with a credit card should know this simple rule of thumb.

The rule also works for population growth. The world now has about 6 ½ billion people and the rate of growth is about 2%. That means that the Earth’s population will double in about 70/2 = 35 years to 13 billion people. It will then double again in 35 more years to 26 billion people. If you think the roads are crowded now, just wait until 2080. Unlimited growth is considered good for business as the number of consumers just keeps going up. However, we should realize that the current growth rate is unsustainable, as at some point we will begin to run out of resources. Economists say the law of supply and demand insures we will never actually run out of resources. As the supply decreases, the resources will just become increasingly expensive. Nevertheless, those who have little money will soon run out of resources. Then what, wars over resources? Also, our contribution to air and water pollution increases with our population growth. Studies of populations in nature show that when a population exhausts its resources or strangles in its pollution, the population doesn’t just reach equilibrium and stop. There is a massive die off.

In the past, population growth was considered a good thing. More people meant more workers, more soldiers, and more offspring to carry on our values and our genetics. Times have changed, but the old thinking remains. Some countries that have reduced their population’s growth have been criticized as being “weak”. Other countries have claimed efforts to help them with population control are an attempt at “genocide”. Many religions have prohibitions against certain birth control practices. And, many businesses see an increasing number of consumers as more profit. Nevertheless, the path we are on is unsustainable and we must control our population growth. How to do that is the problem.

Certainly, it must be done through education. We firmly believe in our right to choose how many children we have and our right to act in ways consistent with our religious beliefs. Perhaps if people realized that we are on an unsustainable path, they would make personal decisions to help ensure the survival of their descendants. Perhaps people would not bring more children into the world than they can feed and care for if they had the knowledge and methods to avoid doing so. There is a method of birth control acceptable to most every religious belief and the world’s religious organizations must help to educate people in those practices and the necessity of using them wisely. Finally, those who profit from increasing population growth should realize that developing a sustainable economy is in their best interest. What is the point of amassing wealth for your descendants if they cannot live comfortably on the Earth?

Climate Change and the Greenhouse Effect

Wed ,12/08/2009

Most gardeners know how greenhouses work.  In the daytime, the sun’s radiation (visible and UV) comes in through the glass and warms the plants and soil.  The glass stops the heat radiation ( infrared ) from passing back through and the greenhouse stays warm enough to keep the plants from freezing, even at night. The Earth works pretty much the same way except there is no glass. Greenhouse gases, primarily water and  carbon dioxide, play the role of the glass and trap some of the radiation. Winter nights on Earth would be very cold without greenhouse gases.

Of the Sun’s energy coming to Earth, 30% is reflected immediately back into space by particles in the air, by clouds, and by the surface. Another 20% is absorbed by the atmosphere where it runs the weather cycle. The remaining 50% heats the land and oceans. All the absorbed heat is eventually radiated back into space as infrared radiation. It’s a balanced energy budget, 100% in and 100% back out. Anything that reflects more light back into space, such as an increase in particulate matter in the air, would cause the Earth to cool. Anything that delays the energy’s trip back to space, such as an increase in greenhouse gases, would cause the Earth to warm.

The best data we have clearly shows the Earth is getting warmer. NASA has compiled the Earth’s average temperature for each year since 1880 by using ships logs, weather stations, and satellite measurements. In the graph below , each square dot shows how far that year’s average temperature was above or below the 1970 value. The solid red line is the moving average, which makes the trend easier to follow.  Although the data varies widely from year to year, the trend is clearly upward.

NASA Data

http://data.giss.nasa.gov/gistemp/2007/ Credit: NASA/JPL/MSSS

The greenhouse effect links the temperature increase to man’s activities. The trend starts upward in about 1920. That was when the automobile, industrialization, and energy production began increasing the carbon dioxide concentration in the air. . The processes that remove carbon dioxide from the air take decades, so as the carbon dioxide concentration slowly built up, the Earth became a better greenhouse. The concentration of carbon dioxide in the air is now 50% higher than in 1920 and the Earth’s temperature is about 0.8°C (or 1.3 °F) higher. No natural occurrences such as volcanoes, sunspots, fires, or dust storms can account for the major trend in the data.

Aristotle's Lessons from the Past

Tue ,11/08/2009

“Aristotle gave us a universe whose laws are invariant and capable of being discovered by observation and reason.” 

In ancient times, nature had been explained as the actions of the gods. The early Greek philosophers questioned the role of the gods as the cause of events and by the fifth century B.C. the Greek philosophers, such as Socrates, had separated philosophy from theology.

But, if the gods were not the cause of events, what was?  Aristotle (384 BC – 322 BC) thought the principles governing nature could be found within nature and could be discovered using careful observation and reasoning.  His reasoning followed a pattern familiar to students today as the scientific method: a statement of the problem, the definition of terms, a review of what he and other scholars thought, a comparison of the ideas to  observations , and finally what could be concluded.

Aristotle thought all things should be open to examination and subject to reason and he applied his methods to many areas of human knowledge. Aristotle made major contributions to biology, physics, philosophy, ethics, logic, poetics, education, and citizenship that are still valuable today. (Durant and Ross, 1949) Most importantly, Aristotle gave us a universe whose laws are invariant and capable of being discovered by observation and reason. May posts on this site honor Aristotle and his method.

1. Durant, Will. The Story of Philosophy: The Lives and Opinions of the Great Philosophers of the Western World. 5th ed. New York: Simon and Schuster, 1949

2. Ross, W. D. Aristotle. 5th ed. London: Methuen & Co. LTD. 1949