Global warming-3: The science behind global warming

To understand the science behind global warming, it may be helpful to look at a simplified version of the science behind it.

Consider two objects, one that is luminous (i.e., an object that we can see without the aid of a light source) and another that is not luminous. Examples of luminous objects are the Sun (which generates energy due to nuclear reactions within it and sends a lot of that energy out as light) or a light bulb (that converts electrical energy into light energy). Examples of non-luminous objects are the Earth or a person in a room. The energy radiated by the luminous source spreads out in all directions and some of it will fall on the non-luminous object.

What is important to understand is that even what looks like a non-luminous object also radiates energy into space. In fact every object radiates energy. So in a sense, every object is ‘luminous’ in the sense that it sends out energy, but we usually reserve that term for objects that emit visible light. Not all radiated energy is visible. A human being radiates energy at a rate of about 500 watts, or the equivalent of five 100 watt bulbs, but the reason we do not “see” the radiation energy emitted by people is due to it being outside the visible range

The rate of energy emission of an object radiates depends to a large extent on its temperature (it actually goes as the fourth power of the temperature) and the nature of its surface (such as color, texture, material). So just as the Sun radiates energy into space, so does the Earth, except that the Sun’s radiation is much greater since it is at a much higher temperature.

The important thing about global warming is understanding what happens when the energy radiated by a luminous source (say the Sun) falls upon a non-luminous object (say the Earth). Part of it is immediately reflected back into space, and does not affect the temperature of the Earth. But the rest is absorbed by the Earth and, in the absence of anything else happening, will tend to cause the Earth’s temperature to rise. The relative amounts of the Sun’s energy that are absorbed and reflected by the Earth depends on the nature of the Earth’s surface. (As an example, a person in a room absorbs energy from the surroundings at a rate of about 400 watts, thus adding a person to a room is the net heat equivalent of turning on a 100 watt bulb.)

But as the temperature of the object rises due to it absorbing energy, the amount it radiates out again also increases, and at some point the object reaches equilibrium, which occurs when the energy absorbed by it from outside equals the energy it radiates away. Once an object reaches this state of thermal equilibrium, its temperature stays steady.

If for some reason we alter the ratio of energy absorbed by the Earth to the energy reflected, then the state of equilibrium is disturbed and the Earth’s temperature will shift to a new equilibrium temperature. If relatively more energy gets absorbed, then the equilibrium temperature will rise until the energy radiated again becomes equal to the energy absorbed. Conversely, if relatively more energy now gets reflected, then the equilibrium temperature will drop, i.e., the Earth will cool. The people warning of global warming argue that human activity is causing the former situation and they say that the reason for this is that we are changing the nature of the Earth’s surface, especially its atmosphere.

To understand what is happening at the Earth’s surface and atmosphere, we need to understand something about the energy radiated by the Sun. This comes largely in the form of “electromagnetic energy.” This is an umbrella term that encompasses X-rays, ultraviolet, light waves, infrared, microwaves, radio waves, etc. All these types of radiation are identical except for one single factor, which is called the wavelength of the radiation. The items in the list differ only in their wavelengths, with X-rays having the smallest wavelength and radio waves having the longest. (Similarly, all colors of visible light are also identical except for the wavelength, which increases as you go from blue to green to yellow to red.)

When this broad range of electromagnetic radiation from the Sun hits the Earth’s atmosphere, almost all of it, except the visible light portion, gets absorbed by the atoms and molecules in the atmosphere and does not reach us on the ground. Of the portion that does reach the ground, some of it gets directly reflected unchanged and escapes back into space. The remainder gets absorbed by the ground. It is the energy that is absorbed by the ground that is the source of concern.

Recall that the Earth, like any object, also radiates energy away. But since the temperature of the Earth is different from the temperature of the Sun, the distribution of the wavelengths in the energy radiated by the Earth is different from the distribution that we receive from the Sun (although the total energy involved is the same in both cases for an object in equilibrium). This affects how much is absorbed by the atmosphere as it passes through it. Some of the Earth’s radiation will get absorbed by the gases in the atmosphere (i.e., is trapped), while the rest passes through and goes off into space.

This is a crucial point. If the gases in the atmosphere change significantly, then you can change the relative amounts of the Earth’s radiated energy that escapes into space and the amount that is trapped by the atmosphere . The so-called ‘greenhouse gases’ (carbon dioxide, water vapor, methane, nitrous oxide, and others) are those that are very good at absorbing the energy at the wavelengths radiated by the Earth, preventing them from escaping into space.

Global warming scientists argue that human activity is increasing the concentration of greenhouse gases (especially carbon dioxide) in the atmosphere. Hence more of the energy radiated by the Earth is being absorbed and less of the energy is escaping into space. Note that the incoming visible light from the Sun is not affected much by the concentrations of greenhouse gases since they are at a different wavelength, and the greenhouse gases do not absorb them as much. As a result of this increase in the absorption levels of the outbound radiation, the equilibrium temperature of the Earth will rise.

At this point, there are various scenarios that can unfold. One is that we arrive at a new and higher but stable equilibrium temperature. If the change in equilibrium temperature is small, the consequences might not be too disastrous, although there will be some adverse effects such as some temperature-sensitive organisms (such as coral reefs) becoming destroyed or some species going extinct if they cannot evolve mechanisms to cope. If the change is large, then there could be massive floods and droughts and other catastrophes.

The worst case scenario is a kind of runaway effect, where a rise in temperature results in effects that cause an even more rapid rise in temperature and so on, in a series of cascading effects.

Some argue that we are already seeing some signs of runaway effects, and point to the melting of the polar ice caps and the general decrease in glaciers and snow coverage worldwide. Snow is white and thus reflects back unchanged into space almost all the sunlight that hits it at the Earth’s surface. When this snow melts and becomes water, not only is the amount of reflected energy decreased but water absorbs light energy. Hence the major loss of snow cover (apart from adverse environmental and ecological consequences) has a major effect on the reflection/absorption balance of the Earth, shifting it towards greater absorption. So more energy is absorbed by the Earth, resulting in even greater warming, resulting in further snow loss, and so on.

Another possible runaway factor is the amount of green cover. On balance, plants, because of photosynthesis, tend on average to be net absorbers of carbon dioxide and emitters of oxygen. Thus they reduce one of the greenhouse gases. If global warming results in less green cover of the Earth (say caused by prolonged droughts), then that would result in more greenhouse gases remaining in the atmosphere and causing yet more warming and more droughts. Human activity such as deforestation can accelerate this process.

Those are the basic elements of the science underlying global warming and the factors that go into building the models that try to predict long term climate change.

Next: The emerging scientific consensus over global warming.

POST SCRIPT: Colbert takes media apart again

As you may recall, the mainstream media did not take kindly to Stephen Colbert’s demolishing them at the White House Correspondents Association Dinner. Now he takes them apart again.

Global warming-2: Understanding the problem

Understanding global climate concerns is not easy because it is a complex issue which involves many factors and theories, is based on data that span millennia and is not easy to extract, involves sophisticated theories and computer modeling, and requires long chains of inferential reasoning to arrive at conclusions. Compared to it, evolution, that other anathema of Bush and his anti-science Christian base, is a model of clarity.

At least with evolution, the progression shows a clear pattern, with life evolving from simple single cell organisms to the wide array of complex multi-cell systems we see today. If we started discovering anomalous organisms that seem to violate that temporal ordering, that would require a major restructuring of evolutionary theory.
[Read more…]

Global warming

It is undoubtedly true that, while the increasing level of warfare in the Middle East in the immediate issue of concern, the question of global warning is the preeminent long term issue facing the planet today. It represents one of the rare situations when the health of the entire planet is at stake. The only other thing that has similar global consequences is an all-out nuclear war between major nuclear powers since that could also unleash an atmospheric catastrophe that could destroy the planet.

But while we can avoid a nuclear winter by simply doing nothing, i.e. not using the weapons, global warming is an issue where doing nothing is the problem. A strong case has been made that if we continue on the present course, the planet is going to suffer irrevocable harm, changing its climate and weather patterns in ways that will dramatically affect our lives, if not actually destroy them.

One would think that global warming is one scientific question where politics would play a minor role, and where the debate would be based on purely scientific evidence and judgments. Unlike issues like stem cell research and cloning where the scientific questions have to contend with religion-based arguments, as near as I can tell the Bible, Koran, and other religious texts are pretty much agnostic (so to speak) on the issue of whether global warming is something that god has strong views on. While god has a lot to say about things like the proper ways to sacrifice animals or how sinners should be put to death, he seems to not be concerned about the weather, expect for using it as a tactical weapon, like unleashing the occasional deluge to drown everyone but Noah and his family or creating a storm to chastise his prophet Jonah.

Hence it is surprising that some people (including the Bush administration) perceive the case being made that global warming is a serious problem as some kind of ‘liberal’ plot, tarring the proponents of the idea that global warming is real and serious as political enemies, seeking to somehow destroy truth, justice, and the American way. Glenn Greenwald argues that this is the standard mode of operation of the Bush administration, saying “What excites, enlivens, and drives Bush followers is the identification of the Enemy followed by swarming, rabid attacks on it.”

Once that bugle call of politics sounded, Bush devotees dutifully fell into line. They know the script and exactly what they must do and have rallied to the cause, trying to discredit the scientific case and the scientists behind it, arguing that the whole global warming thing is a fabricated crisis, with nothing more to be worried about than if we were encountering just a warm summer’s day. Senator James Inhofe (R-OK) says “With all of the hysteria, all of the fear, all of the phony science, could it be that man-made global warming is the greatest hoax ever perpetrated on the American people? It sure sounds like it.” And this man is the Chair of the Senate’s Committee on 
Environment and Public Works.

The administration and its supporters have gone to surprisingly extreme methods to suppress alarms about climate change, such as changing the wording of reports by government scientists in order to play down the threat of global warming and muzzling government climate experts, in order to prevent information from getting to the public.

Take another example in which the administration has sought to divert government’s scientist’s focus from global warming:

From 2002 until this year, NASA’s mission statement, prominently featured in its budget and planning documents, read: “To understand and protect our home planet; to explore the universe and search for life; to inspire the next generation of explorers. . .as only NASA can.”

In early February, the statement was quietly altered, with the phrase “to understand and protect our home planet” deleted. In this year’s budget and planning documents, the agency’s mission is “to pioneer the future in space exploration, scientific discovery and aeronautics research.”

David E. Steitz, a spokesman for the National Aeronautics and Space Administration, said the aim was to square the statement with President Bush’s goal of pursuing human spaceflight to the Moon and Mars.

But the change comes as an unwelcome surprise to many NASA scientists, who say the “understand and protect” phrase was not merely window dressing but actively influenced the shaping and execution of research priorities. Without it, these scientists say, there will be far less incentive to pursue projects to improve understanding of terrestrial problems like climate change caused by greenhouse gas emissions.

“We refer to the mission statement in all our research proposals that go out for peer review, whenever we have strategy meetings,” said Philip B. Russell, a 25-year NASA veteran who is an atmospheric chemist at the Ames Research Center in Moffett Field, Calif. “As civil servants, we’re paid to carry out NASA’s mission. When there was that very easy-to-understand statement that our job is to protect the planet, that made it much easier to justify this kind of work.”

Several NASA researchers said they were upset that the change was made at NASA headquarters without consulting the agency’s 19,000 employees or informing them ahead of time.
. . .
The “understand and protect” phrase was cited repeatedly by James E. Hansen, a climate scientist at NASA who said publicly last winter that he was being threatened by political appointees for speaking out about the dangers posed by greenhouse gas emissions.

The attempts to downplay the extent of the problem, divert attention away from actions to study and remedy it, and distort the science behind the global warming issue has been helped by the fact that although the consensus conclusions of the scientific community are pretty straightforward (that global warming is occurring, it is largely caused by human activity, and that we need to take steps to reverse it or face disastrous consequences), the actual science behind it is complicated. This enables those who wish to blur the issue to find ways to cast doubt on that scientific consensus.

Next: Understanding the problem

The origin of life

Darwin’s theory of evolution by natural selection deals with the question of how life evolves and does not directly address the question of the origin of life itself. The fields of cosmology and physics and chemistry have provided models of how the universe evolved and created the solar system, among other things. But those theories do not explain how organic molecules, the basic building blocks of life, came about.

An article by Gareth Cook in the August 14, 2005 issue of the Boston Globe examined this question in the light of an initiative (known as the ”Origins of Life in the Universe Initiative”) by then Harvard president Lawrence Summers to invest millions to investigate this important question, partly in an effort to have Harvard try and catch up the leaders in this field at the University of Arizona, the California Institute of Technology, and the Scripps Research Institute in La Jolla, Calif..
[Read more…]

The origin of life

Darwin’s theory of evolution by natural selection deals with the question of how life evolves and does not directly address the question of the origin of life itself. The fields of cosmology and physics and chemistry have provided models of how the universe evolved and created the solar system, among other things. But those theories do not explain how organic molecules, the basic building blocks of life, came about.

An article by Gareth Cook in the August 14, 2005 issue of the Boston Globe examined this question in the light of an initiative (known as the ”Origins of Life in the Universe Initiative”) by then Harvard president Lawrence Summers to invest millions to investigate this important question, partly in an effort to have Harvard try and catch up the leaders in this field at the University of Arizona, the California Institute of Technology, and the Scripps Research Institute in La Jolla, Calif..
[Read more…]

What the neuroscience community thinks about the mind/brain relationship

The idea that the mind is purely a product of the material in the brain has profound consequences for religious beliefs, which depend on the idea of the mind as an independent controlling force. The very concept of ‘faith’ implies an act of free will. So the person who believes in a god is pretty much forced to reject the idea that the mind is purely a creation of the brain. As the article Religion on the Brain (subscription required) in the May 26, 2006 issue of the Chronicle of Higher Education (Volume 52, Issue 38, Page A14) says:

Pope John Paul II struck a similar theme in a 1996 address focusing on science, in which he said theories of evolution that “consider the mind as emerging from the forces of living matter, or as a mere epiphenomenon of this matter, are incompatible with the truth about man. Nor are they able to ground the dignity of the person.”

As I wrote yesterday, the flagging intelligent design creationism (IDC) movement seems to be hoping for some fresh energy to emerge from the work of psychiatric researcher Dr. Schwartz. Or at the very least they may be hoping that they can persuade the public that the mind does exist independently of the brain. But they are going to have a hard time getting traction for this idea within the neurobiology community. There seems to be a greater degree of unanimity among them about the material basis of the mind than there is among biologists about the sufficiency of natural selection.

Stephen F. Heinemann, president of the Society for Neuroscience and a professor in the molecular-neurobiology lab at the Salk Institute for Biological Studies, in La Jolla, Calif., echoed many scientists’ reactions when he said in an e-mail message, “I think the concept of the mind outside the brain is absurd.”

But the ability of the neurobiology community to do their work unfettered by religious scrutiny may be coming to an end as increasing numbers of people become aware of the consequences of accepting the idea that the mind is purely a product of the brain. People might reject this idea (and be attracted to the work of Dr. Schwartz), not because they have examined and rejected the scientific evidence in support of it, but because it threatens their religious views. As I discussed in an earlier posting, people who want to preserve a belief system will accept almost any evidence, however slender or dubious, if it seems to provide them with an option of retaining it. As the article says:

Though Dr. Schwartz’s theory has not won over many scientists, some neurobiologists worry that this kind of argument might resonate with the general public, for whom the concept of a soul, free will, and God seems to require something beyond the physical brain. “The truly radical and still maturing view in the neuroscience community that the mind is entirely the product of the brain presents the ultimate challenge to nearly all religions,” wrote Kenneth S. Kosik, a professor of neuroscience research at the University of California at Santa Barbara, in a letter to the journal Nature in January.
. . .
Dr. Kosik argues that the topic of the mind has the potential to cause much more conflict between scientists and the general public than does the issue of evolution. Many people of faith can easily accept the tenets of Darwinian evolution, but it is much harder for them to swallow the assumption of a mind that arises solely from the brain, he says. That issue he calls a “potential eruption.”

When researchers study the nature of consciousness, they find nothing that persuades them that the mind is anything but a product of the brain.

The reigning paradigm among researchers reduces every mental experience to the level of cross talk between neurons in our brains. From the perspective of mainstream science, the electrical and chemical communication among nerve cells gives rise to every thought, whether we are savoring a cup of coffee or contemplating the ineffable.
. . .
Mr. [Christof] Koch [a professor of cognitive and behavioral biology at the California Institute of Technology] collaborated for nearly two decades with the late Francis Crick, the co-discoverer of DNA’s structure, to produce a framework for understanding consciousness. The key, he says, is to look for the neural correlates of consciousness – the specific patterns of brain activity that correspond to particular conscious perceptions. Like Crick, Mr. Koch follows a strictly materialist paradigm that nerve interactions are responsible for mental states. In other words, he says, “no matter, never mind.”

Crick summed up the materialist theory in The Astonishing Hypothesis: The Scientific Search for the Soul (Scribner, 1994). He described that hypothesis as the idea that “your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules.”

What many people may find ‘astonishing’ about Crick’s hypothesis is that among neurobiologists it is anything but astonishing. It is simply taken for granted as the way things are. Is it surprising that religious believers find such a conclusion unsettling?

Next: What does “free will” mean at a microscopic level?

POST SCRIPT: Why invading Iraq was morally and legally wrong

Jacob G. Hornberger, founder and president of The Future of Freedom Foundation has written a powerful essay that lays out very clearly the case of why the US invasion and occupation of Iraq is morally and legally indefensible, and why it has inevitably led to the atrocities that we are seeing there now, where reports are increasingly emerging of civilians being killed by US forces. Hornberger writes “I do know one thing: killing Iraqi children and other such “collateral damage” has long been acceptable and even “worth it” to U.S. officials as part of their long-time foreign policy toward Iraq.”

The article is well worth reading.

IDC gets on board the brain train

An article titled Religion on the Brain (subscription required) in the May 26, 2006 issue of the Chronicle of Higher Education (Volume 52, Issue 38, Page A14) examined what neuroscientists are discovering about religion and the brain. It is a curious article. The author (Richard Monastersky) seems to be trying very hard to find evidence in support of the idea that brain research is pointing to the independent existence of a soul/mind, but it is clear on reading it that he comes up short and that there is no such evidence, only the hopes of a very small minority of scientists.
[Read more…]

Religion’s last stand-2: The role of Descartes

In the previous posting, I discussed two competing models of the mind/brain relationship.

It seems to me that the first model, where the physical brain is all there is and the mind is simply the creation of the brain, is the most persuasive one since it is the simplest and accepting it involves no further complications. In this model, our bodies are purely material things, with the brain’s workings enabling us to think, speak, reason, act, and so forth. The idea of ‘free will’ is an illusion due to the brain being an enormously complicated system whose processes and end results cannot be predicted. (A good analogy would be classically chaotic systems like the weather. Because of the specific non-linearity of the equations governing weather, we cannot predict long-term weather even though the system is a deterministic and materialistic.)

The second model, that of an independently existing non-material mind/soul, separate from the brain and directing the brain, immediately raises all kinds of problems, which have long been recognized. The scientist-philosopher Rene Descartes (1596-1650) of “I think, therefore I am” fame was perhaps the first person to formulate this mind-body dualism (or at least he is the person most closely associated with the idea) and it is clear that he felt that it was necessary to adopt this second model if one was to retain a belief in god.

But he realized immediately that it raises the problem of how the non-material mind/soul can interact with the material brain/body to get it to do things. Princess Elizabeth of Bohemia, with whom Descartes had an extended correspondence, was unable to understand Descartes’ explanation of this interaction and kept prodding him on this very question. Descartes had no adequate answer for her, even though both clearly wanted to believe in the existence of god and the soul. In the introduction to his translation of Descartes’ Meditations and other Metaphysical Writings (which contains extended segments of the Elizabeth-Descartes correspondence), Desmond Clarke writes:

After repeated attempts to answer the question, how is it possible for something which is not physical to interact with something else which, by definition is not physical?, Descartes concedes that he cannot explain how it is possible.

But he tried, using the best scientific knowledge available to him at that time. He argued that the location of the soul’s interaction with the body occurred in the pineal gland.

As is well known, Descartes chose the pineal gland because it appeared to him to be the only organ in the brain that was not bilaterally duplicated and because he believed, erroneously, that it was uniquely human. . . By localizing the soul’s contact with body in the pineal gland, Descartes had raised the question of the relationship of mind to the brain and nervous system. Yet at the same time, by drawing a radical ontological distinction between body as extended and mind as pure thought, Descartes, in search of certitude, had paradoxically created intellectual chaos.

Although Descartes failed in his efforts to convincingly demonstrate the independent existence of the soul, research into the relationship of religious beliefs to the central nervous system of the brain has continued.

Descartes is an interesting character. Much of his scientific work, and even his temperament, seem to indicate a materialistic outlook. But at the same time, he took great pains to try and find proofs of god’s existence. One gets the sense that he was a person trying to convince himself of something he did not quite believe in, and had he lived in a different time might have rejected god with some relief. The article on Descartes in Encyclopaedia Britannica Online, 13 June 2006 says:

Even during Descartes’s lifetime there were questions about whether he was a Catholic apologist, primarily concerned with supporting Christian doctrine, or an atheist, concerned only with protecting himself with pious sentiments while establishing a deterministic, mechanistic, and materialistic physics.

The article points to reasons for the ambiguousness of his views, which could be due to the fact that there was, at that time, considerable fear of the power of the Catholic Church and this may have guided the way he presented his work.

In 1633, just as he was about to publish The World (1664), Descartes learned that the Italian astronomer Galileo Galilei (1564–1642) had been condemned in Rome for publishing the view that the Earth revolves around the Sun. Because this Copernican position is central to his cosmology and physics, Descartes suppressed The World, hoping that eventually the church would retract its condemnation. Although Descartes feared the church, he also hoped that his physics would one day replace that of Aristotle in church doctrine and be taught in Catholic schools.

Descartes definitely comes across as somewhat less than pious, and non-traditional in his religious beliefs.

Descartes himself said that good sense is destroyed when one thinks too much of God. He once told a German protégée, Anna Maria van Schurman (1607–78), who was known as a painter and a poet, that she was wasting her intellect studying Hebrew and theology. He also was perfectly aware of – though he tried to conceal – the atheistic potential of his materialist physics and physiology. Descartes seemed indifferent to the emotional depths of religion. Whereas Pascal trembled when he looked into the infinite universe and perceived the puniness and misery of man, Descartes exulted in the power of human reason to understand the cosmos and to promote happiness, and he rejected the view that human beings are essentially miserable and sinful. He held that it is impertinent to pray to God to change things. Instead, when we cannot change the world, we must change ourselves.

Clearly he was not orthodox in his thinking. Although he tried to believe in god, it was his emphasis on applying the materialistic principles that he used in his scientific work to try and identify the mechanism by which the mind interacts with the brain that has the potential to create the big problem for religion.

To sum up Descartes’ argument, following sound scientific (methodological naturalistic) principles, he felt that if the mind interacted with the brain, then there had to be (1) some mechanism by which the non-material mind could influence the material brain, and (2) some place where this interaction took place. Although he could not satisfactorily answer the first question, he at least postulated a location for the interaction, the pineal gland. We know now that that is wrong, but the questions he raised are still valid and interesting ones that go to the heart of religion.

Next: What current researchers are finding about the brain and religion.

POST SCRIPT: Documentary on Rajini Rajasingham-Thiranagama

I have written before about the murder of my friend Rajini Rajasingham-Thiranagama, who had been an active and outspoken campaigner for human rights in Sri Lanka. I have learned that a documentary about her life called No More Tears Sister is the opening program in the 2006 PBS series P.O.V.

In the Cleveland area, the program is being shown on Friday, June 30, 2006 at 10:00pm on WVIZ 25. Airing dates vary by location, with some PBS stations showing it as early as June 27. The link above gives program listings for other cities. The synopsis on the website says:

If love is the first inspiration of a social revolutionary, as has sometimes been said, no one better exemplified that idea than Dr. Rajani Thiranagama. Love for her people and her newly independent nation, and empathy for the oppressed of Sri Lanka – including women and the poor – led her to risk her middle-class life to join the struggle for equality and justice for all. Love led her to marry across ethnic and class lines. In the face of a brutal government crackdown on her Tamil people, love led her to help the guerrilla Tamil Tigers, the only force seemingly able to defend the people. When she realized the Tigers were more a murderous gang than a revolutionary force, love led her to break with them, publicly and dangerously. Love then led her from a fulfilling professional life in exile back to her hometown of Jaffna and to civil war, during which her human-rights advocacy made her a target for everyone with a gun. She was killed on September 21, 1989 at the age of 35.

As beautifully portrayed in Canadian filmmaker Helene Klodawsky’s “No More Tears Sister,” kicking off the 19th season of public television’s P.O.V. series, Rajani Thiranagama’s life is emblematic of generations of postcolonial leftist revolutionaries whose hopes for a future that combined national sovereignty with progressive ideas of equality and justice have been dashed by civil war – often between religious and ethnic groups, and often between repressive governments and criminal rebel gangs. Speaking out for the first time in the 15 years since Rajani Thiranagama’s assassination, those who knew her best talk about the person she was and the sequence of events that led to her murder. Especially moving are the memories of Rajani’s older sister, Nirmala Rajasingam, with whom she shared a happy childhood, a political awakening and a lifelong dedication to fighting injustice; and her husband, Dayapala Thiranagama, who was everything a middle-class Tamil family might reject – a Sinhalese radical student from an impoverished rural background. Also included are the recollections of Rajani’s younger sisters, Vasuki and Sumathy; her parents; her daughters, Narmada and Sharika; and fellow human-rights activists who came out of hiding to tell her story. The film rounds out its portrayal with rare archival footage, personal photographs and re-enactments in which Rajani is portrayed by daughter Sharika Thiranagama. The film is narrated by Michael Ondaatje, esteemed author of The English Patient and Anil’s Ghost.

I knew Rajini well. We were active members of the Student Christian Movement in Sri Lanka when we were both undergraduates at the University of Colombo. It does not surprise me in the least that she threw herself with passion into the struggle for justice. She was brave and spoke the truth, even when it was unpalatable to those in power and with guns, and backed up her words with actions, thus putting her life on the line for her beliefs. Such people are rare. I am proud to have known her.

The desire for belief preservation.

In the previous post we saw how human beings are believed to not be natural critical thinkers, preferring instead to believe in the first plausible explanation for anything that comes along, not seeing these initial explanations as merely hypotheses to be evaluated against competing hypotheses.

But one might think that when we are exposed to alternative hypotheses, we might then shift gears into a critical mode. But Tim van Gelder, writing in the article Teaching Critical Thinking: Some Lessons from Cognitive Science (College Teaching, Winter 2005, vol. 53, No. 1, p. 41-46) argues that what foils this is the human desire for belief preservation.

He quotes seventeenth century philosopher Francis Bacon who said:

The mind of man is far from the nature of a clear and equal glass, wherein the beams of things should reflect according to their true incidence; nay, it is rather like an enchanted glass, full of superstition and imposture, if it be not delivered and reduced.

In other words, van Gelder says, “the mind has intrinsic tendencies toward illusion, distortion, and error.” These arise from a combination of being hard-wired in our brains (because of evolution), natural growth of our brains as we grow up in the Earth’s environment, and the influence of our societies and cultures. “Yet, whatever their origin, they are universal and ineradicable features of our cognitive machinery, usually operating quite invisibly to corrupt our thinking and contaminate our beliefs.”

All these things lead us to have cognitive biases and blind spots that prevent us from seeing things more clearly, and one of the major blind spots is that of belief preservation. van Gelder says that “At root, belief preservation is the tendency to make evidence subservient to belief, rather than the other way around. Put another way, it is the tendency to use evidence to preserve our opinions rather than guide them.”

van Gelder says that when we strongly believe some thing or desire it to be true, we tend to do three things: “1. We seek evidence that supports what we believe and do not seek and avoid or ignore evidence that goes against it. . . 2. We rate evidence as good or bad depending on whether it supports or conflicts with our belief. That is, the belief dictates our evaluation of the evidence, rather than our evaluation of the evidence determining what we should believe. . . 3. We stick with our beliefs even in the face of overwhelming contrary evidence as long as we can find at least some support, no matter how slender.”

This would explain why (as vividly demonstrated in the popular video A Private Universe) people hold on to their erroneous explanations about the phases of the moon even after they have been formally instructed in school about the correct explanation.

This would also explain the question that started these musings: Why for so long had I not applied the same kinds of questioning to my religious beliefs concerning god, heaven, etc. that I routinely applied to other areas of my life? The answer is that since I grew up in a religious environment and accepted the existence of god as plausible, I did not seek other explanations. Any evidence in favor of belief (the sense of emotional upliftment that sometimes occurs during religious services or private prayer, or some event that could be interpreted to indicate god’s action in my life or in the world, or scientific evidence that supported a statement in the Bible) was seized on, while counter evidence (such a massive death and destruction caused by human or natural events, personal misfortunes or tragedies, or scientific discoveries that contradicted Biblical texts) was either ignored or explained away. It was only after I had abandoned my belief in god’s existence that I was able to ask the kinds of questions that I had hitherto avoided.

Did I give up my belief because I could not satisfactorily answer the difficult questions concerning god? Or did I start asking those questions only after I had given up belief in god? In some sense this is a chicken-and-egg problem. Looking back, it is hard to say. Probably it was a little of both. Once I started taking some doubts seriously and started questioning, this probably led to more doubts, more questions, until finally the religious edifice that I had hitherto believed in just collapsed.

In the series of posts dealing with the burden of proof concerning the existence of god, I suggested that if we use the common yardsticks of law or science, then that would require that the burden of proof lies with the person postulating the existence of any entity (whether it be god or a neutrino or whatever), and that in the absence of positive evidence in favor of existence, the default assumption is to assume the non-existence of the entity.

In a comment to one of those postings, Paul Jarc suggested that the burden of proof actually lay with the person trying to convince the other person to change his views. It may be that we are both right. What I was describing was the way that I thought things should be, while Paul was describing the way things are in actual life, due to the tendency of human beings to believe the first thing that sounds right and makes intuitive sense, coupled with the desire to preserve strong beliefs once formed.

van Gelder ends up his article with some good advice:

Belief preservation strikes right at the heart of our general processes of rational deliberation. The ideal critical thinker is aware of the phenomenon, actively monitors her thinking to detect its pernicious influence, and deploys compensatory strategies.

Thus, the ideal critical thinker
• puts extra effort into searching for and attending to evidence that contradicts what she currently believes;
• when “weighing up” the arguments for and against, gives some “extra credit” for those arguments that go against her position; and
• cultivates a willingness to change her mind when the evidence starts mounting against her.

Activities like these do not come easily. Indeed, following these strategies often feels quite perverse. However, they are there for self-protection; they can help you protect your own beliefs against your tendency to self-deception, a bias that is your automatic inheritance as a human being. As Richard Feynman said, “The first principle is that you must not fool yourself – and you are the easiest person to fool.”

The practice of science requires us to routinely think this way. But it is not easy to do and even scientists find it hard to give up their cherished theories in the face of contrary evidence. But because scientific practice requires this kind of thinking, this may also be why science is perceived as ‘hard’ by the general public. Not because of its technical difficulties, but because you are constantly being asked to give up beliefs that seem so naturally true and intuitively obvious.

POST SCRIPT: The people who pay the cost of war

I have nothing to add to this powerful short video, set to the tune of Johnny Cash singing Hurt. Just watch. (Thanks to Jesus’ General.)