Fake fights are not helping climate science

• 20 March 2007
• Exclusive from New Scientist Print Edition. Subscribe and get 4 free issues
• Alan Thorpe

Few areas of science have implications as momentous as those of climate change. Much is riding not only on ensuring that the science is as accurate as possible but also on getting the political and social response right. Given the high stakes, it is hardly surprising that scientists' methods and conclusions are coming under considerable scrutiny. This is as it should be. After all, scepticism is fundamental to the scientific method.

Scepticism is one thing; cynicism and conspiracy-theorising are quite another. These are the hallmarks of a recent attempt to discredit the widely accepted theory that human-made carbon dioxide emissions are causing global warming. A loose affiliation of scientists and writers is pushing the alternative idea that fluctuations in solar activity provide a better explanation for the rise and fall in the temperature of Earth's atmosphere over the past few centuries.

Their basic argument goes something like this. When the cosmic rays that constantly bombard Earth from outer space hit water vapour rising from the oceans, they cause clouds to form in the atmosphere which shield the planet from solar radiation and cause it to cool. The sun's magnetic field dampens the effect of cosmic rays, so reducing cloud cover and causing Earth to heat up. Thus an active sun makes for a warmer planet - a correlation these scientists claim is borne out by the records.

Readers in the UK may have seen the most recent incarnation of this theory in the Channel 4 television programme The Great Global Warming Swindle, broadcast last week. The programme questioned not only the mainstream of global warming science but also the integrity of the researchers involved in it. As I am the head of the major funder of climate science in the UK, the Natural Environment Research Council (NERC), such accusations of bias, lying and prejudice were bound to catch my attention.

First, let's deal with the main thesis: that the presence or absence of cosmic rays in Earth's atmosphere is a better explanation for temperature variation than the concentration of CO₂ and other gases. This is not a new assertion and it is patently wrong: there is no credible evidence that cosmic rays play a significant role. The climate system is complex and it is likely that many factors affect it, cosmic rays among them. But to claim they are a major influence is disingenuous. There is far greater evidence suggesting CO₂ is the major cause of warming.

"To claim that cosmic rays are a major influence is disingenuous"

Another claim made by the sceptics relates to the observation that in the long-term history of Earth's climate, variations in atmospheric concentrations of CO₂ have lagged behind variations in the temperature of the atmosphere. Therefore, they say, the theory that human-produced greenhouse gases are the cause of current warming must be wrong.

Not so. True, the historical rhythm of major ice ages and interglacial periods is set by Earth's orbital variations, known as Milankovitch cycles, not by levels of greenhouse gases. However, these cycles in turn trigger feedback effects - such as increases or decreases in levels of CO₂ in the atmosphere - which amplify the change in temperature.

There is no question that the more CO₂ there is in the atmosphere, the warmer the planet becomes. It is not the only mechanism for warming, but it is a prominent one. We are adding CO₂ and other greenhouse gases to the atmosphere in a way that has never happened before. The physics of how these gases cause warming by trapping the sun's radiation within the lower atmosphere - the greenhouse effect - is well established and it is no surprise that temperatures have been rising over the past 40 years. What's more, from the comprehensive models that climate scientists have built up, it is clear that only human-made greenhouse gases can explain this warming. Other factors, such as solar variations, have been found to be insignificant in comparison.

This debate is not just about science. Implicit in the sceptics' message is the suggestion that scientists are lying about the role of CO₂ in climate change. The impression given is that this is a conspiracy; that climate scientists are deliberately trying to mislead the public, either to affect policy because of their private political motivations or to be more successful in attracting research funding.

Again, this is not backed up by any evidence. In my experience the climate science community operates at the highest ethical level and sticks to the scientific evidence.

The problem with debating the science of something like climate change is that it is hard for the public to assess the arguments across the whole spectrum of scientific opinion. It is partly in recognition of this that the Intergovernmental Panel on Climate Change periodically publishes its scientific assessments that draw together the full body of knowledge on the subject. That is not a political process. It is a scientific one. Let scepticism reign, but let's not play games with the evidence.

From issue 2595 of New Scientist magazine, 20 March 2007, page 24
reposted from: New Scientist
my: highlights / emphasis / key points / comments

Right Reason & the Scientific Method

Right Reason

Robert McHenry - February 12th, 2007

I’ve written occasionally on the results, sometimes ludicrous and sometimes dangerous, that can follow from the unbridled, ungrounded application of “reason,” so called, to the problems of human life. (See here in particular.) Let me be more pointed.

We’re not quite sure what “reason” is, to begin with. Humans have the capacity for disciplined and systematic thought along certain lines. The Greeks are usually credited with making the most, earliest, of this fact. Mathematics and logic are our inheritance from them, along with some practical applications thereof. Aristotle, of course, gets the credit for instituting the study of formal logic, in part by systematizing kinds of syllogisms and exploring their implications. It is thus that we recognize that

All men are mortal.
Socrates is a man.
Therefore, Socrates is mortal.

is a valid argument, while

All men are mortal.
Socrates is mortal.
Therefore, Socrates is a man.

is not valid, even though the conclusion happens to be true.

As regards the quantifiable, mathematics does wonderfully well. And as regards certain types of well constructed sentences, logic does, too. But understanding the limits implied by “certain types of well constructed sentences” took some time. No one could blame the Greek thinkers and their early successors for their exuberance in the application of their shiny new tool. Over time it began to be said that this “reason” was a gift of the gods, or a spark of the divine within us, or – secularly speaking – a sort of mental Swiss army knife, useful in any situation.

Because we are talking about human beings, it is no surprise that over the centuries many errors of logical deduction have been committed, sometimes because of carelessness, sometimes because premises were ill founded, sometimes because the desired conclusion was in mind from the outset and logic was overcome by the determination to arrive at it.

(A charming example of this last mode of intellection can be found in the article “Government” that James Mill, father of the more famous John Stuart, wrote for an early edition of the Encyclopædia Britannica. In it he began from first principles and, step by painstaking step, deduced the ideal form of government, which – what were the odds? – turned out to be a constitutional monarchy with a bicameral legislature, part elected and part hereditary!)

And sometimes errors have arisen from the fact that not everything in human life is quantifiable or narrowly logical.

By the time of René Descartes, a certain caution might have been expected, but no. Descartes was, among other things, a mathematician, and he persuaded himself that the same kind of axiomatic reasoning that worked in geometry would work in any subject matter. Thus it was that he reasoned himself into an inescapable trap called solipsism (Solipsism is the philosophical idea that "My mind is the only thing that exists". Solipsism (Latin: solus, alone + ipse, self) is an epistemological or metaphysical position that knowledge of anything outside the mind is unjustified. The external world and other minds cannot be known and might not exist), whence – having rested for a time on the famous “Cogito ergo sum” thing – he couldn’t reason himself out again without an ad hoc appeal to the existence and good will of a god.

The successes of the scientific method, to say nothing of our everyday experience, ought to have taught us all by now that this faculty called reason only works well when it is fed a carefully prepared diet of quantifiable, verifiable data from the outer world. And even then it is apt to go wrong, so the results we get must always be held lightly, as current best estimates, rather than tightly, as eternal truths. Eternal truths too often begin to look like weapons, and weapons tightly held are too often used.

reposted from: Britannica
my: highlights / emphasis / key points / comments

Thomas Paine, Deism & Rationalism

David Warden will give a talk on "Thomas Paine: Rationalist Hero" on 10th March 2007 at the Dorset Humanist Association.

Rationalism

In epistemology and in its broadest sense, rationalism is "any view appealing to reason as a source of knowledge or justification" (Lacey, 286). In more technical terms it is a method or a theory "in which the criterion of truth is not sensory but intellectual and deductive" (Bourke, 263). Different degrees of emphasis on this method or theory lead to a range of rationalist standpoints, from the moderate position "that reason has precedence over other ways of acquiring knowledge" to the radical position that reason is "the unique path to knowledge" (Audi, 771).

In various contexts, the appeal to reason is contrasted with revelation, as in religion, or with emotion and feeling, as in ethics. In philosophy, however, reason is more often contrasted with the senses, including introspection but not intuition (Lacey, 286).

Within the Western philosophical tradition, "rationalism begins with the Eleatics, Pythagoreans, and Plato, whose theory of the self-sufficiency of reason became the leitmotif of Neoplatonism and idealism" (Runes, 263). Since the Enlightenment, rationalism is usually associated with the introduction of mathematical methods into philosophy, as in Descartes, Leibniz, and Spinoza (Bourke, 263). This is commonly called continental rationalism, because it was predominant in the continental schools of Europe, whereas in Britain empiricism dominated.

Rationalism is often contrasted with empiricism. Taken very broadly these views are not mutually exclusive, since a philosopher can be both rationalist and empiricist (Lacey, 286–287). Taken to extremes the empiricist view holds that all ideas come to us through experience, either through the five external senses or through such inner sensations as pain and pleasure, and thus that knowledge is essentially based on or derived from experience. At issue is the fundamental source of human knowledge, and the proper techniques for verifying what we think we know (see Epistemology).

Proponents of some varieties of rationalism argue that, starting with foundational basic principles, like the axioms of geometry, one could deductively derive the rest of all possible knowledge. The philosophers who held this view most clearly were Baruch Spinoza and Gottfried Leibniz, whose attempts to grapple with the epistemological and metaphysical problems raised by Descartes led to a development of the fundamental approach of rationalism. Both Spinoza and Leibniz asserted that, in principle, all knowledge, including scientific knowledge, could be gained through the use of reason alone, though they both observed that this was not possible in practice for human beings except in specific areas such as mathematics.

source: http://en.wikipedia.org/wiki/Rationalist

Thomas Paine (source: Wikipedia) was a Deist.

Deism is a religious philosophy and movement that became prominent in England, France, and the United States in the 17th and 18th centuries. Deists typically reject supernatural events (prophecy, miracles) and divine revelation prominent in organized religion, along with holy books and revealed religions that assert the existence of such things. Instead, deists hold that religious beliefs must be founded on human reason and observed features of the natural world, and that these sources reveal the existence of one God or supreme being.

Beliefs about immortality of the soul

Deists held a variety of beliefs about the soul. Some, such as Lord Herbert of Cherbury and William Wollastson,^[14] held that souls exist, survive death, and in the afterlife are rewarded or punished by God for their behavior in life. Others such as Thomas Paine were agnostic about the immortality of the soul:

I trouble not myself about the manner of future existence. I content myself with believing, even to positive conviction, that the power that gave me existence is able to continue it, in any form and manner he pleases, either with or without this body; and it appears more probable to me that I shall continue to exist hereafter than that I should have had existence, as I now have, before that existence began. – Thomas Paine, The Age of Reason, Part I, Recapitulation

Still others such as Anthony Collins,^[15] Bolingbroke, Thomas Chubb, and Peter Annet were materialists and either denied or doubted the immortality of the soul.

Critical elements of deist thought included:

• Rejection of all religions based on books that claim to contain the revealed word of God.
• Rejection of reports of miracles, prophecies and religious "mysteries".
• Rejection of the Genesis story of creation and the doctrine of original sin, along with all similar stories.
• Rejection of Christianity, Islam and other religious beliefs.

Constructive elements of deist thought included:

• God exists and created the universe.
• God wants human beings to behave morally.
• Human beings have souls that survive death; that is, there is an afterlife.
• In the afterlife, God will reward moral behavior and punish immoral behavior.

Concepts of "reason"

"Reason" was the ultimate court of appeal for deists. Tindal's Lockean definitions of reason, self-evident truth, and the light of nature are especially lucid.

By the rational faculties, then, we mean the natural ability a man has to apprehend, judge, and infer: The immediate objects of which faculties are not the things themselves, but the ideas the mind conceives of them.... Knowledge [is]... nothing but the perception of the agreement or disagreement of our ideas. And any two of these, when joined together so as to be affirmed or denied of each other, make what we call a proposition... Knowledge accrues either immediately on the bare intuition of these two ideas or terms so joined, and is therefore styled intuitive knowledge or self-evident truth, or by the intervention of some other idea or ideas .... this is called demonstrative knowledge...

If there were not some propositions which need not to be proved, it would be in vain for men to argue with one another [because there would be no basis for demonstrative reasoning] ... Those propositions which need no proof, we call self-evident; because by comparing the ideas signified by the terms of such propositions, we immediately discern their agreement, or disagreement: This is, as I said before, what we call intuitive knowledge.... [Intuitive knowledge] may, I think, be called divine inspiration as being immediately from God, and not acquired by any human deduction or drawing of consequences: This, certainly, is that divine, that uniform light, which shines in the minds of all men...

– Matthew Tindal, Christianity as Old as the Creation (II)^[7]

Deists did appeal to "the light of nature" to support the self-evident nature of their positive religious claims.

By natural religion, I understand the belief of the existence of a God, and the sense and practice of those duties which result from the knowledge we, by our reason, have of him and his perfections; and of ourselves, and our own imperfections, and of the relationship we stand in to him, and to our fellow-creatures; so that the religion of nature takes in everything that is founded on the reason and nature of things.

I suppose you will allow that it is evident by the light of nature that there is a God, or in other words, a being absolutely perfect, and infinitely happy in himself, who is the source of all other beings....

– Matthew Tindal, Christianity as Old as the Creation (II)

Arguments for the existence of God

Thomas Hobbes— an early deist and important influence on subsequent deists— used the cosmological argument for the existence of God at several places in his writings.

The effects we acknowledge naturally, do include a power of their producing, before they were produced; and that power presupposeth something existent that hath such power; and the thing so existing with power to produce, if it were not eternal, must needs have been produced by somewhat before it, and that again by something else before that, till we come to an eternal, that is to say, the first power of all powers and first cause of all causes; and this is it which all men conceive by the name of God, implying eternity, incomprehensibility, and omnipotence.

– Thomas Hobbes, Works, vol. 4, pp. 59-60; quoted in John Orr, English Deism, p. 76

Source: Wikipedia - Deist

The Age of Reason is a philosophical treatise critical of the Bible written by the 18th Century British intellectual and American Founding Father Thomas Paine.

Selected Quotes

On the Old Testament

"Whenever we read the obscene stories, the voluptuous debaucheries, the cruel and torturous executions, the unrelenting vindictiveness, with which more than half the Bible [NOTE: It must be borne in mind that by the "Bible" Paine always means the Old Testament alone. -- Editor.] is filled, it would be more consistent that we called it the word of a demon, than the Word of God. It is a history of wickedness, that has served to corrupt and brutalize mankind; and, for my own part, I sincerely detest it, as I detest everything that is cruel."

-Chapter 7

On divine revelation

"No one will deny or dispute the power of the Almighty to make such a communication if he pleases. But admitting, for the sake of a case, that something has been revealed to a certain person, and not revealed to any other person, it is revelation to that person alone. When he tells it to a second person, a second to a third, a third to a fourth, and so on, it ceases to be a revelation to all those persons. It is revelation to the first person only, and hearsay to every other, and, consequently, they are not obliged to believe it.

It is a contradiction in terms and ideas to call anything a revelation that comes to us at second hand, either verbally or in writing. Revelation is necessarily limited to the first communication. After this, it is only an account of something which that person says was a revelation made to him; and though he may find himself obliged to believe it, it cannot be incumbent on me to believe it in the same manner, for it was not a revelation made to me, and I have only his word for it that it was made to him."

-Chapter 2

On Paine's personal beliefs

"As several of my colleagues, and others of my fellow-citizens of France, have given me the example of making their voluntary and individual profession of faith, I also will make mine; and I do this with all that sincerity and frankness with which the mind of man communicates with itself.

I believe in one God, and no more; and I hope for happiness beyond this life.

I believe the equality of man, and I believe that religious duties consist in doing justice, loving mercy, and endeavoring to make our fellow-creatures happy.

But, lest it should be supposed that I believe many other things in addition to these, I shall, in the progress of this work, declare the things I do not believe, and my reasons for not believing them."

-Chapter 1

source: http://en.wikipedia.org/wiki/The_Age_of_Reason

Thomas Paine described himself as a "Deist" and commented:

How different is [Christianity] to the pure and simple profession of Deism! The true Deist has but one Deity, and his religion consists in contemplating the power, wisdom, and benignity of the Deity in his works, and in endeavoring to imitate him in everything moral, scientifical, and mechanical.

source: http://en.wikipedia.org/wiki/Thomas_Paine

What put the BANG in the BIG BANG?

Inside inflation: after the big bang

• 03 March 2007
• From New Scientist Print Edition. Subscribe and get 4 free issues.
• Peter Coles

MASSACHUSETTS, 1981. A young physicist comes up with what seems to be an absurd idea: the universe went through a period of ultra-fast expansion just after the big bang. Alan Guth cannot prove that this "inflation" actually happened nor can he suggest a compelling physical reason why it should have, but the idea seems nevertheless to solve several major problems in cosmology.

Fast forward to today. Guth is a professor at the Massachusetts Institute of Technology and inflation is now well established as an essential component of cosmology. But should it be?

There is little direct evidence that inflation actually took place. Observations of the cosmic microwave background - "fossil" radiation from the big bang - are consistent with the idea that inflation took place, but that doesn't mean it actually happened. What's more, we still don't know what would have caused it if it did. So how confident can we be that inflation is really a part of the universe's history?

A quarter of a century ago, our understanding of the universe was much less precise than it is today. In those days it was a domain in which theoretical speculation ruled over measurement and observation. Technology simply wasn't up to the task of performing large-scale galaxy surveys or detecting the all-important details in the cosmic microwave background (see "Shadow of the big bang").

“14 billion light years = size of the observable universe today”

The lack of stringent experimental constraints made cosmology a theorists' paradise in which many imaginative and esoteric ideas blossomed. Not all survived to be included in the standard model of cosmology, but inflation has proved to be one of the hardiest, and indeed most beautiful, flowers in the cosmological garden.

Although some of the concepts involved had been formulated in the 1970s by Russian physicist Alexei Starobinsky, it was Guth's 1981 paper that first crystallised the picture of the inflationary universe. At this time cosmologists didn't know that the universe was as flat as we now believe it is, but it was still a puzzle why it was even anywhere near flat. After all, the great breakthrough of Einstein's general theory of relativity was the realisation that space could be curved. Of all the possible initial conditions, isn't it very improbable that our universe should be flat?

What's more, the distribution of stuff in our universe is also astonishingly smooth. Although it contains galaxies that cluster into immense chains more than a 100 million light years long, on scales of billions of light years it is almost uniform. This also seems surprising. Why is the celestial tablecloth so immaculately ironed?

Guth grappled with these questions and realised that they could be resolved rather elegantly if only the force of gravity could be persuaded to change from pull to push for a very short time just after the big bang. The expansion of the universe would then speed up rather than slow down. The universe could then inflate by an enormous factor (10³⁰ or more) in a fraction of a millisecond. Even if it were initially curved and wrinkled, all memory of this messy starting configuration would be wiped out. The present-day universe would be very flat and very smooth no matter how it had started out.

“>10³⁰ = factor by which the universe expanded”

So how could this bizarre period of anti-gravity be possible? Guth hit upon a simple physical mechanism by which inflation might just work in practice. It relied on the fact that in the extreme conditions just after the big bang, matter would not adhere to the classical laws describing gases and liquids but must instead be described by quantum field theory. The simplest type of quantum field is called a scalar field; such objects are associated with particles that have no spin, the quantum parallel of angular momentum. Modern particle theory involves many scalar fields that are not observed in low-energy interactions, but which may well dominate affairs at the extreme energies of the primordial fireball.

Just as classical fluids can undergo a "phase transition" if they are heated or cooled, such as the transition from steam to liquid water, a similar thing happens with scalar fields: their configuration is expected to change as the universe expands and cools. Phase transitions do not happen instantaneously, however, and sometimes a bubble of the substance involved can get trapped in an uncomfortable state in between where it was and where it wants to be, like a bubble of gas trapped in a liquid.

Guth realised that if a scalar field got stuck in such a false state, it could free up energy - in a form known as vacuum energy - to drive a small piece of the universe into accelerated expansion. In the process, the tiny bubble can inflate to the size of the entire universe. We don't know which scalar field of the many that may theoretically exist is responsible for generating inflation, but whatever it is, it is now dubbed the inflaton.

“10^-35 seconds = age of the universe when inflation kicked in”

This mechanism is an echo of a much earlier idea introduced to the world of cosmology by Einstein in 1916, although he didn't use the term vacuum energy. He called it a cosmological constant, and also considered it to be a modification of the law of gravity rather than something arising from quantum fields. Nevertheless, Einstein's idea was incorporated by Dutch mathematician Willem de Sitter into a theoretical model of an accelerating universe. This is essentially the same mathematics that is used in modern inflationary cosmology.

The connection between scalar fields and the cosmological constant may also eventually explain why our universe's expansion seems to be accelerating now - something that has been attributed to a mysterious force called dark energy. However, that would require a scalar field with a much lower energy than that required to drive inflation. Perhaps dark energy is some kind of shadow of the inflaton.

Guth wasn't the sole creator of inflation. About the same time, many others including Andy Albrecht, Paul Steinhardt, Andrei Linde and Starobinsky, produced different and in some cases more compelling variations on the basic theme. It was almost as if it was an idea whose time had come. Within just a few years inflation had become an indispensable part of cosmological theory.

“10^-27 metres = size of the observable universe before inflation”

Literally hundreds of versions appeared in the leading scientific journals: old inflation, new inflation, chaotic inflation, extended inflation, and so on. Out of this activity came the realisation that a phase transition wasn't really necessary, all that mattered was that the scalar field should find itself in a state where the vacuum energy dominated.

It also became clear that even theories that didn't involve scalar fields could behave as if they did. Modified gravity or theories with extra space-time dimensions provided ways of mimicking scalar fields with rather different physics. And if inflation could work with one scalar field, why not have inflation with two or more? The only problem was that there wasn't a shred of evidence that inflation had actually happened.

This episode provides a fascinating glimpse into the historical and sociological development of cosmology in the 1980s and 1990s. Inflation is undoubtedly a beautiful idea, but the problems it solves are theoretical, not observational. For example, the flatness of the universe only appears to require this explanation because we don't have a theory of initial conditions for the universe that might provide a better reason. Inflation turns an initially curved universe into a flat one, but the fact that the universe appears to be flat doesn't prove that inflation happened.

Certain initial conditions could lead to present-day flatness without the intervention of an inflationary epoch. One might argue that these are special cases and therefore "improbable", making it more probable that inflation happened than that it didn't. On the other hand, without a theory of the initial conditions how can we say which are more probable? Based on this kind of argument alone, we could probably never work out whether we live in an inflationary universe or not.

But there is another thread in the story that makes it a much more compelling scientific theory, because it makes direct contact with observations. Although it was not the original motivation for the idea, Guth and others realised very early on that if a scalar field were responsible for inflation then it should be governed by the usual rules of quantum fields.

One of the things that quantum physics tells us is that no quantum process evolves entirely smoothly. The famous Heisenberg uncertainty principle imposes a degree of unpredictability on the behaviour of the inflaton. The upshot of this is that although inflation smoothes away any primordial wrinkles in the fabric of space-time, in the process it lays down others of its own.

“100 micrometres = size of the universe if inflation hadn't happened”

The inflationary wrinkles are really ripples, wave-like density fluctuations vibrating through the matter of the early universe like sound waves travelling through air. Without these fluctuations the cosmos would be smooth and featureless, containing no variations in density or pressure, and therefore no sound waves. Even if it began in a fireball, such a universe would be silent. Inflation puts the "bang" in big bang.

The acoustic oscillations generated by inflation comprise a wide range of wavelengths. Most importantly of all, they are formed "coherently". That is, because inflation happens so rapidly, all of the acoustic wavelengths are excited at the same time, just as hitting a metal pipe with a hammer generates a wide range of frequencies, all starting at the same time. The result is not just random noise but something more tuneful. The big bang wasn't exactly melodic, but there is a discernible relic of the coherent nature of the sound waves in the pattern of temperature fluctuations in the cosmic microwave background as seen by NASA's Wilkinson Microwave Anisotropy Probe (WMAP). The hot and cold spots of the microwave background reflect denser or rarefied regions, and the acoustic peaks seen by WMAP offer compelling proof that whatever generated the pattern did so coherently.

There are very few alternative theories capable of reproducing the WMAP results. Some interesting ideas have emerged recently from string theory. Since this theory requires more space-time dimensions than the four we are used to, something has to be done with the extra ones we don't observe. For example, in so-called braneworld cosmologies our four-dimensional universe exists as a subset (called a brane) of a more multi-dimensional space.

This idea may one day lead to a viable alternative to inflation. But it is early days and not all the calculations needed to establish this theory have yet been done. In any case, not every cosmologist feels the urge to make cosmology consistent with string theory, which has even less evidence in favour of it than inflation. So does WMAP prove inflation happened? If not, will we ever know?

It is difficult to talk sensibly about scientific proof of phenomena that are so far removed from everyday experience. At what level can we prove anything in astronomy? We all accept that the Earth goes around the sun, but do we really know for sure that the universe is expanding? I would say that the latter hypothesis has survived so many tests and is consistent with so many other aspects of cosmology that it has become, for pragmatic reasons, an indispensable part of our world view. But I would hesitate to say that it was proven beyond all reasonable doubt.

The same goes for inflation. It is a beautiful idea that fits snugly with standard cosmology and binds many parts of it together but that doesn't necessarily make it true. Many theories are beautiful, but that is not sufficient to prove them right. When generating theoretical ideas scientists should be fearlessly radical, but when it comes to interpreting evidence we should all be deeply conservative.

As for the future of cosmology, WMAP has provided a tantalising glimpse of further evidence and paved the way for even more stringent tests of the standard framework. Primordial density fluctuations produce not only a pattern of temperature variations over the sky, but also a corresponding pattern of polarisation. This is fiendishly difficult to measure, partly because it is such a weak signal (only a few per cent of the temperature signal) and partly because the microwaves are heavily polluted by polarised radiation from our own galaxy. Although WMAP did indeed detect polarisation, the published map is heavily corrupted by foreground noise.

Future generations of experiments, such as the European Space Agency's Planck Surveyor, due for launch in 2008, will have to grapple with the thorny issue of foreground subtraction if it is to make progress. But there is a crucial means of cross-checking the results that would justify these endeavours. The key is that inflation does not just produce acoustic waves, it also generates twisting deformations of space-time called gravitational waves.

Gravitational waves produce a very particular form of polarisation pattern that cannot be generated by acoustic oscillations, so hunting for this signal seems a promising way to test inflation. Even though it is a very weak signal, and the experience of WMAP suggests it might be swamped by foreground noise, it is definitely worth a go. Finding it would add considerably to the evidence in favour of inflation as an element of physical reality.

“>1 kilometre = approximate size of the universe after inflation”

Besides providing strong evidence for the standard model of cosmology, WMAP has also provided tantalising evidence that we may be missing something. Not all the properties of the microwave sky seem consistent with the model. For example, the pattern of hot and cold spots should be structureless, mirroring the random fluctuations of the primordial density perturbations. In reality, certain components of the pattern are inexplicably aligned, as in the so-called "axis of evil" discovered in 2005 by Kate Land and João Magueijo of Imperial College London (New Scientist, 22 October 2005, p 19). These anomalies could be systematic errors in the data, or perhaps residual foreground effects that need to be subtracted, but they could equally indicate the presence of things that can't be described within the standard model.

Cosmology is now a mature and respectable science. Yet there are still many gaps in our knowledge. We don't know the form of the "dark matter" responsible for unexplained extra gravity. Nor do we have any real understanding of dark energy. We don't know for sure if inflation happened, and we are certainly a long way from being able to identify the inflaton. In a way we are still as confused as ever about how the universe began. But perhaps now we are confused on a higher level and for better reasons.

Peter Coles is professor of astrophysics at the University of Nottingham, UK. His latest book is From Cosmos to Chaos: The science of unpredictability (Oxford University Press)

From issue 2593 of New Scientist magazine, 03 March 2007, page 33-37

Shadow of the big bang

Our ability to reconstruct the history of the universe, or at least to attempt this feat, depends on the fact that light travels with a finite speed. The further away we see a light source, the further back in time its light was emitted. We can now observe light emitted from stars in distant galaxies when the universe was less than a sixth of its current size. In fact we can see even further back than this using microwave radiation rather than optical light.

Our universe is bathed in a faint glow of microwaves produced when it was about one-thousandth of its current size and had a temperature of thousands of kelvin, rather than the chilly 3 K that prevails today. The existence of this cosmic background radiation is one of the key pieces of evidence in favour of the big bang model. It was discovered in 1965 by Arno Penzias and Robert Wilson, for which they subsequently won the Nobel prize.

It is not just the cosmic microwave background that has helped us construct the standard model of cosmology. Observations of distant supernovae and the pattern seen in the large-scale distribution of galaxies have also offered hints. The picture that has emerged from these disparate clues is of a universe dominated by dark energy and dark matter, in which the early stages of cosmic evolution involved an episode of accelerated expansion called inflation.

Assembling the standard model of cosmology has been a gradual process, reaching its latest form with recent results from NASA's Wilkinson Microwave Anisotropy Probe (WMAP). For several years this satellite has been mapping the properties of the cosmic microwave background and how it varies across the sky. Small variations in the temperature of the background reflect sound waves excited in the hot plasma of the primordial fireball (see Diagram). Various telltale properties of these waves allow us to probe the early universe in much the same way that solar astronomers use observations of the surface of the sun to understand its inner structure.

The detection of the primeval sound waves is one of the triumphs of modern cosmology, not least because the amplitude of the waves tells us precisely how loud the big bang really was. The fundamental tone tells us that the universe is very nearly flat, while the overtones pin down a dozen or so important cosmological parameters to unprecedented accuracy - a truly remarkable achievement.

reposted from: New Scientist
my: highlights / emphasis / key points / comments

Critical Thinking - Where to start?

“Just Some Guy” wrote today:

I recently stumbled on an excellent online article authored by yourself entitled “Teaching Critical Thinking“. I was wondering if you could take a moment of your valuable time to suggest a couple of books on the subject. I would like improve my critical thinking skills so I suppose the focus sought would be adult learner skill(s) acquisition with emphasis on techniques and (lots of) practice. I have been trying to develop said skills on my own (without much success). I would really like to have find a proven program to apply. As you know there is tons of information available online however I am getting lost trying to sort out all the wheat from chaff. Thank you in advance for your consideration.

I used to be a regular academic, and one reason for heading off in a different direction was the experience most academics know all too well, which is that you’ll slave for months on a paper, have it published, and then… nothing happens. It seems you may as well not have bothered. So it is gratifying when some paper you wrote, and which seemed to have vanished without a trace, starts to get picked up, read, and perhaps even appreciated. In the case of the paper mentioned above, in past month I’ve heard that it is the subject of a faculty discussion group at the University of Pittsburgh (where I did my PhD), and read by administrators at a startup university campus in Singapore. Now it seems to have helped Just Some Guy. Maybe it was worth the effort that went into it.

Anyway, regarding JSG’s query, in workshops I used to hand out brief annotated “further reading” list. Here it is:

There are hundreds of books on thinking and how to improve it, ranging from airport junk to turgid academic treatises. Here is a short list of some of the best, focusing on critical thinking. All are accessible, entertaining, and contain many valuable insights. Listed in alphabetical order, so don’t necessarily start at the top.

Cialdini, R. B. (1984). Influence: The Psychology of Persuasion. New York: William Morrow and Co. Classic, eye-opening description of the tricks, ruses and deceptions others use to manipulate us into doing what they want.

Giere, R. N. (1996). Understanding Scientific Reasoning (4th ed.). Fort Worth: Holt, Rinehart and Winston, Inc. Very clear overview of the fundamentals of scientific reasoning. Basic literacy in scientific methodology.

Heuer, R. J. (1999). Psychology of Intelligence Analysis. Center for the Study of Intelligence, CIA. Although intended primarily to assist intelligence analysts, there is a lot of good stuff here, on both the descriptive (how our minds work) and normative (rules for better thinking) sides. Plus, available free online!

Kepner, C. H., & Tregoe, B. B. (1997). The New Rational Manager. Princeton: Princeton Research Press. These are the people who first brought “critical thinking” to the business world and built out of it a multinational consulting firm. Very practical orientation.

Minto, B. (1995). The Pyramid Principle: Logic in Writing and Thinking. Edinburgh Gate: Pearson Education. Barbara Minto was a McKinsey in-house trainer; this book is now the “Bible” in this area for major consulting firms. Some simple but profound truths about good thinking and communication, cast in a way which makes sense for folks in the business community.

Myers, D. G. (2002). Intuition: Its Powers and Perils. New Haven: Yale University Press. “Europe in ten days” tour of the ways intuitive thinking can go wrong, according to serious psychologists. Pretty exhaustive coverage, but most of it will just wash over you.

Paul, R. W., & Elder, L. (2002). Critical Thinking: Tools for Taking Charge of Your Professional and Personal Life. Upper Saddle River, New Jersey: Financial Times Prentice Hall. Paul and Elder are prominent critical thinking instructors. This book packages their insights as practical tools for personal and professional life. Stresses psychological and ethical issues, though often becomes a bit too “pop psychology”.

Piatelli-Palmarini, M. (1994). Inevitable Illusions: How Mistakes of Reason Rule our Minds. New York: Wiley. Very readable introduction to some of the most famous cognitive biases and blindspots. More diagnosis than therapy.

Salmon, M. (1989). Introduction to Logic and Critical Thinking (2nd ed.). San Diego: Harcourt Brace Jovanovich. The best of the standard undergraduate textbooks. A bit dull, but very sound.

Spence, G. (1995). How to Argue and Win Every Time. New York: St. Martin’s Press. Written by a criminal attorney who (according to the dust jacket) never lost a case. If you can look beyond the very “American” style, there is much wisdom here. It is a treatise in the art of rhetoric, but it is principled rhetoric rather than mendacious sophistry.

Whyte, J. (2004) Crimes Against Logic. McGraw-Hill. A short introduction to “fallacies,” i.e., common patterns of bad reasoning. Whyte runs through about a dozen, but there are dozens of others. Witty, fast-moving and brief.

February 24th, 2007 - Posted by Tim van Gelder

Most of the books are on Critical Thinking - I've highlighted the books specifically on Scientific Method.

reposted from: rtnl.wordpress.com via clipped by Djiezes
my highlights / emphasis / comments

What scientists believe and what they can prove (with a flowchart for Sir Karl Popper) - Janet D. Stemwedel

Posted on: February 26, 2007 1:12 PM, by Janet D. Stemwedel

On the post in which I resorted to flowcharts to try to unpack people's claims about the process involved in building scientific knowledge, Torbjörn Larsson raised a number of concerns:

The first problem I have was with "belief". I have seen, and forgotten, that it is used in two senses in english - for trust, and for conviction. Rather like for theory, the weaker term isn't appropriate here. I would say that theories gives us trust in repeatability of predicted observations, and that kind of trust counts as knowledge. In fact, already the trust repeated observations gives count as knowledge.

The second problem I have is with "the problem of induction". Science has a set of procedures that observably generates robust knowledge, and the alleged problem is seldom seen. When the terrain and the map doesn't agree, junk the map.

The third problem I have is with the specific diagrams. Real scientific knowledge production will not yield to any one diagram. So for the philosopher that raises a hypothetical "problem of induction" we could turn around the question and ask why the obvious "problem of description" (which ironically is a real problem of induction :-) isn't bothersome. The scientist answer would probably be as above: "e puor si muove".

... Without feeling like testability is the end-all of science the diagram is slanted away from testing towards a weaker and in the end nonfunctional descriptive science. Whether we call tested knowledge "a conclusion" or "a tentative conclusion" is irrelevant IMHO, it is a conclusion we will (have to) trust in.

The fourth (oy!) problem I have is with the conflated description the diagram alludes to. In the text there is a distinction between individual scientists and the scientific enterprise. Different entities will obviously use different approaches to knowledge, and if the individual doesn't need to trust her findings the enterprise relies on such a trust.

These are reasonable concerns, so let me say a few words to address them.

I'll start with the fourth concern, the relation between what's going on with the individual scientist and the larger community of scientists working together to build knowledge. While some thinkers have framed the problem of building objective knowledge as one that depends on each individual scientist being highly objective and switching off his or her own biases, others (including Frederick Grinnell and Helen E. Longino) have put theburden of objectivity primarily with the community -- bias is stripped out of what ends up being identified as scientific knowledge when the community "checks the work" of individual scientists within it.

Myself, I'm inclined to think that the community has an easier time being more objective when each of the individuals within that community is doing his or her best to be aware of, and unmoved by, his or her own biases. This may be psychologically challenging, but it's not impossible. Certainly, the process of trying to persuade other scientists that you've found something interesting puts you in touch with the idea that others in your community may not share your hunches.

So, it might be advisable to have different flowcharts for what the individual scientist is doing and what the scientific community is doing. But given that each individual scientist is (or might be) striving to be as hardheadedly objective as the community of individual scientists working in concert, we might be able to get away with using the community-level process as an idealized model of the individual-level process.

Torbjörn Larsson's third concern is also related to the worry that a lot is being idealized in these charts -- that the actual process of building scientific knowledge "on the ground" is messy and can't be properly captured in a single road map. I agree. It's best to think of the flowcharts as trying to capture the process of justifying scientific claims, not the process by which you come up with them or get the experiment to work or what have you.

And justification is the issue at the heart of the problem of induction, which seems to be the sticking point in Torbjörn Larsson's second and first concerns. What is it that make a claim count as scientific knowledge? There is an operational kind of answer to this question: here are the steps you need to take to support your claim in order for scientists to regard it as playing a particular role in the scientific discourse (whether you want to identify the claim thus supported as "credible" or "convincing" or "the best available explanation of the phenomena" or something else).

But there's also a bare-knuckles logical warrant sort of answer to this question, and this is where the problem of induction comes in. The problem of induction is a worry if you think knowledge ought to come down to claims about which you need entertain no doubts. If you want your claim to be unsinkable before you call it knowledge, then you can't laugh the problem of induction off as a mere philosophical trifle.

The observations we've gathered so far don't provide empirical evidence about the observations we haven't yet made. As regular as the phenomena in the universe seem to be, we've only observed a fraction of all the things we could observe, and no one set of inferences we could draw from the data now in evidence is the only set of inferences that fit these data.

Sir Karl Popper didn't see the problem of induction -- that inductive inferences drawn from limited data could go wrong -- as something that could be "solved". However, he thought that the methodology of science avoided the problem by not identifying conclusions arrived at through inductive inference as "knowledge" in the strong sense of "there is no way this could fail to be true". Here's Popper's picture of the process of building scientific knowledge:

Notice that Popper doesn't think it matters all that much where your hypothesis P comes from. Maybe it comes from lots of poking around and observing your phenomena. Maybe it comes from that recurring nightmare of the snake biting his own tail. It's not important. The thing that can make P a respectable scientific claim is that it is tested in the right kind of way.

How it is tested, for Popper, comes down to working out the observable consequences that would follow if P were true and especially the things we should not be able to observe if P is false. With these predictions in hand, you make your observations. If your observations don't match with your predictions from P, they let you deduce that P cannot be true, and you achieve as much certainty as you can hope for. Since your conclusion that not-P is the conclusion of a deductive argument, you can bet the farm on it.

If, on the other hand, the observations match your predictions from P, Popper says that you haven't established P with certainty (since you come to P at the conclusion of an inductive argument, and new evidence might undermine that conclusion). So, you go through the whole process again. You can't, as far as Popper is concerned, conclude on the basis of all manner of successful observations (and an utter lack of observations that contradict P) that P is true -- just that it has (so far) survived all attempts at falsifying it.

Does taking Popper seriously mean that scientists can't ever draw positive conclusions? I don't think so. The fact that scientists acknowledge that their conclusions are tentative and could be updated in the face of future data strikes me as an acknowledgment that they recognize that inductive inference doesn't come with a guarantee. This recognition doesn't mean you're not allowed to use inductive inference, but rather that you have to be at least a little cautious about the weight you place on the conclusions derawn with it.

To the extent that using induction has generated pictures of the world that hold up to scientific scrutiny, inductive inference is a useful tool. Success to date is not, of course, a guarantee that inductive inference will always work, any more than the fact that the phenomena in our world seem reassuringly regular is a guarantee that they will remain so.

"Conviction" for a scientist, then, is not: "From this day forward, I am committed to P and nothing you could show me will ever shake my commitment to P." Instead, we have something like: "Given the data amassed, and the stringent tests which P has passed, and the current lack of other claims that fit the phenomena as well and have held up as well to our testing, I'm committed to P. I'd be surprised if the situation were to change, but it could, in which case, I may update my view."

For a belief to become a scientific conviction seems to require certain kinds of justification (from empirical data, theories, etc.). A belief without that kind of justification behind it is just a belief -- nothing wrong with that, but it has no special status in scientific discussions. The problem of induction is concerned with what we can prove. It's a matter of logic. To the extent that scientists find it fruitful to draw inductive inferences, they can, so long as they recognize (as they generally do) that the careful justifications that they offer don't quite meet the level of deductive proof. Still, they are good justifications, and a claim backed by these will be on better scientific footing than a claim without such justifications.

reposted from: http://scienceblogs.com/ethicsandscience
my highlights / emphasis / comments

Scientific and unscientific conclusions: now with pictures! - Janet D. Stemwedel

Posted on: February 24, 2007 9:21 PM, by Janet D. Stemwedel

This is another attempt to get to the bottom of what's bugging people about the case of Marcus Ross, Ph.D. in geosciences and Young Earth Creationist. Here, I've tried to distill the main hypotheticals from my last post on the issue into flowcharts*, in the hopes that this will make it easier for folks to figure out just what they want to say about the proper way to build scientific knowledge..

First, here's the process that no one thinks is a good description of how to come to a scientific conclusion:

Believing something doesn't make it so. Science is an endeavor that is not concerned with what a person believes about the world but instead with what one can establish about the world, usually on the basis of emprical evidence.

The worrisome thing about the Marcus Ross case was that his YEC committed him to views (e.g., the Earth is at most 10,000 years old) that directly conflict with claims made in his disseration about the abundance and spread of marine reptiles which disappeared about 65 million years ago. He seems to be claiming not-P while believing P, and that seems a lot like lying. This is why I labored through the doppelganger-Ross post to try to work out whether it's even possible to build good scientific knowledge while believing (for completely non-scientific reasons) the opposite.

My commenters seemed divided on this. In the "unlikely it's possible" column, we have Brian:

... as a scientist, you're committed to the idea that the most parsimonious explanation is likely the truth.

and Larry Moran:

The Earth is billions of years old. That's not a theory, it's a fact. (Where fact is defined in the Gouldian sense of something that's so well established that it's not worth questioning any more.) Yes, of course there's some place deep in our brains where we retain a smidgen of doubt, but the practice of good science demands that it stay down deep unless some contrary evidence comes along. We'll only dredge it up when we're playing with philosophers.

and possibly David Harmon:

A basic part of being a scientist is being able to suspend your beliefs. Not your disbelief -- that's easy -- but your beliefs, and especially the ones you actually like!

since I take it the suggestion here is that a serious scientist ought to be able to set the YEC aside. These responses seem to fit with a picture of scientific knowledge production that looks like this:

For the record, if you'd rather switch the order of "Believe that P" and "Conclude P" boxes (and similarly with the corresponding not-P boxes), that's OK with me. The important feature here is that the empirical evidence, theories, and inferences lead to something you think is properly identified as a belief -- and that believing the opposite of what the data/theory/inference process directs you to believe would be an astoundingly bad thing to do.

Other commenters seemed willing to say that even if the real Marcus Ross is not someone they'd want to call a good scientist, doppelganger-Ross might be able to do good science despite his YEC beliefs. This group included Paul Schofield:

... what does a belief matter to the work done? Surely what goes on inside your own head only becomes a problem if it goes beyond that and influences your work and writings. ...

In the case of the hypothetical here, the belief is kept entirely detached from the work produced (otherwise there would have been no way any PhD, or science fair sticker for that matter, could have been awarded). It would be no different to an atheist making an argument to Christians that referred to the bible. You may not believe it is true, but that doesn't stop you understanding the others viewpoint and using it to make arguments.

and Janne:

What he "actually" believes is of course rather unrelated to how his work should be evaluated. ...

What matters is the quality of the work and the evidence he brings forth in it. The rest is really irrelevant.

and Lab Lemming:

A person who can solve problems is a scientist. ... Science is an outcome-based activity. If it works, it works. Whether or not he is delusional is irrelevant, as long as his work is transparent and reproducible.

These responses suggest a picture of scientific knowledge production that looks like this:

The only difference between this picture and the last one is that there are no boxes that have to do with whether you believe P or not-P. In other words, what you conclude in this process is determined by the data/theory/inference process -- not by whay you believe. If this is a good picture of how scientists arrive at their conclusions, then it's at least possible for a scientist to conclude P (on the basis of the data/theory/inference process) while believing (for entirely separate reasons that he himself recognizes as non-scientific) not-P. Because "Believe not-P" isn't part of this process, it's not going to bring you to a scientific conclusion of not-P.

If you're a serious Popperian you might worry about those conclusion boxes, given the possibility of new data or updates in our theories or the persistence of the problem of induction. A real Popperian keeps riding the data/theory/inference merry-go-round. That's fine; read "Conclude P" as "TENTATIVELY conclude P" and, in the case of new information that could undermine that conclusion (and we promise, Sir Karl, that we'll keep looking for that information!), revisit the available data and theories to draw the best available inference. This is the kind of thing Larry Moran is pointing to with the possibility of "contrary evidence" above. However, he's acknowledging that actual scientists don't keep beating that (tentatively) dead horse as long as Popper makes it sound like they should.

Scientists, of course, are human. As such, they have beliefs, and there's nothing wrong with that. The question is whether there is, or ought to be, a certain kind of relationship between their beliefs and their scientific conclusions.

The sense I'm getting from some of the comments is that people are deeply suspicious that a person could come to the scientific conclusion that P if that person holds a belief that not-P. There are all sorts of efforts scientists take to remove bias from their scientific work, to shift the burden of proof so that they won't give an unfair advantage in their interpretation of the data to the view they're predisposed to believe. Sure, it's hard to completely remove your own individual biases, but that's why scientists build knowledge in communities. It doesn't become knowledge until you can persuade the others in that community of your conclusions, and how you do that is by displaying the data/theory/inference used to arrive at those conclusions.

Maybe whether a particular scientist working within the community can be sufficiently unbiased to contribute to the building of good knowledge is an empirical question. How the community would judge whether his conclusions were biased or unbiased, though, would probably come down to the data/theory/inference displayed to back up the conclusions. This is not to say that a belief that not-P couldn't be the relevant cause of the biased conclusions, but rather that that belief is not the thing the community needs to trip over to identify that the conclusions are biased.

But perhaps the worry is really something like this: A real scientist ought only to believe conclusions reached through an appropriate data/theory/inference process. This would mean that scientific conclusions ought properly to smash any beliefs you have that contradict them. It would not be acceptable, on this view, to say, "I know my belief that P is not scientifically supported! I understand that there's no reason for anyone in the scientific community to take my belief that P as a scientific conclusion, and I have no intention of asserting it as such, whether to other scientists or to non-scientists. Yet, in my heart of hearts, I believe that P."

Again, there's probably an empirical question about whether it's really possible for humans to hold contradictory beliefs. But, must all of a scientist's beliefs be on solid empirical footing? Can any human actually live up to this standard (without simplifying the problem by believing very few things)?

Believe me, I understand the consternation around the actual Marcus Ross. I will be the first one to decry any arguments-from-the-authority-of-having-a-geosciences-Ph.D. offered to defend YEC, as well as any silly claims that his being a scientist and his believing YEC means that YEC constitutes a set of scientific beliefs.

But, it seems to me that the aim of the scientific enterprise is to find ways to draw inferences that move beyond the beliefs of any individual scientist. Leaving the "belief" boxes out of the flowchart doesn't seem to remove any of the steps required for building sound scientific conclusions. Scientific conclusions may well affect the belief structures of individual scientists, but that's a matter of their own personal growth, not required step in the construction of the shared body scientific knowledge.

___________
*"You're using hand drawn flowcharts?!" exclaims my better half. Yes, I am. Now you all know what a Luddite I am. Please excuse me while I churn some butter.

reposted from: http://scienceblogs.com/ethicsandscience
my highlights / emphasis / comments

Knowledge, belief, and what counts as good science: More thoughts on Marcus Ross - by Janet D. Stemwedel

I reposted the original debate here.

Posted on: February 22, 2007 5:56 PM, by Janet D. Stemwedel

Following up on my query about what it would take for a Young Earth Creationist "to write a doctoral dissertation in geosciences that is both 'impeccable' in the scientific case it presents and intellectually honest," I'm going to say something about the place of belief in the production of scientific knowledge. Indeed, this is an issue I've dealt with before (and it's at least part of the subtext of the demarcation problem), but for some reason the Marcus Ross case is one where drawing the lines seems trickier.

reposted from: Adventures in Ethics and Science
my highlights / emphasis / comments

First, for the sake of argument, I want to set aside all questions of Marcus Ross's actual motivations in pursuing a Ph.D. in geosciences and plans for using that Ph.D. now that he has it. To get to the issue I'm after here, I'm going to assume a Ross-doppelganger who is not just "trying to get through" the process of satisfying a thesis committee, and who is committed to arguing in good faith. (I do not know what the case is with the actual Marcus Ross, but we're going to set it aside as irrelevant to my question, so please don't email me with personal testimonials on either side.) Also, let's stipulate that this Ross-doppelganger has made no special effort to conceal his religious beliefs (which include a belief that the Earth is no older than 10,000 years), but that he may not have felt any particular need to bring his religious beliefs up in the context of his scientific studies or research. (Whether intellectual honesty would require that he call attention to particular of his religious beliefs in a scientific context is something we'll get to.)

Are we clear on the character in my thought experiment? Good.

Our Ross-doppelganger wants to study geoscience. He is interested in the sorts of phenomena geoscientists study, the features of these phenomena they observe, the theories they construct to explain the phenomena, the tests to which they subject these theories -- the whole ball of wax. He applies himself to learning how to make good observations, how to use instrumentation and analytic methods of various sorts to generate further data, how to do good calculations, how to use statistical methods to get good measures of the statistical power of the results and the sized of the error bars. He has a thorough acquaintance with the geosciences literature and a firm grasp of the theories guiding research in his field (as well as keeping up to date with the new approaches described in the current literature).

His efforts make him someone who can make excellent observations in the field, work up data exactingly, and develop explanations that stand up to rigorous testing (which he can also perform well to evaluate his own explanations and the explanations of others).

It seems reasonable that this level of competence in a field requires mastery of a number of empirical and analytic techniques, a thorough understanding of the theoretical structure of the field, and a good grasp of how scientists draw inferences from data and justify those inferences.

Does it also require that he believe the theories of his field are true? Does it require that he believe that the patterns of inference at work in building geoscientific accounts of the world necessarily result in true claims?

The answer to the second question is pretty clearly "no". Scientists are well aware that their reasonable inferences can go wrong. Sometimes this is a matter of drawing inferences from a necessarily incomplete set of data (what with the problem of induction and all that). And sometimes it's because the theoretical structure within which the inferences are being drawn is not precisely right -- possibly because it's missing some important feature, or a little off on another. Of course, this means that scientists can draw perfectly good scientific inferences without having full faith in the truth of their theories.

Rob Knop has an excellent post about using theories that can't all be true in physics. In it, Rob writes:

All the time in science we have to behave as if we believe something is true, even though deep down we don't believe it really is true. Here's a concrete example: in Physics, we have two very excellent, very well-tested fundamental theories. For gravity, there is General Relativity (GR). For everything else, there is Quantum Mechanics (QM). Unfortunately, the two are inconsistent; if you try to do quantum mechanics where gravity is significant, you get nonsensical results.

This means that GR and QM can't both be right. And, yet, we soldier on, using GR every day to do gravity calculations, even though it probably isn't completely correct. We learn the rules and play the game so that we can get the results out. ...

[A]lthough we know that either GR or QM isn't the most fundamental description of reality-- most physicists assume it will be GR, rather than QM, that needs to get modified-- we do believe, and indeed know, that GR is an excellent approximation to what is going on for a wide range of situations. GR may not be "The Truth," but it does work for predicting the orbit of Mercury or the gravitational lensing of light around a cluster of galaxies. ... GR may not be the fundamental truth, but we really believe that there is mass there when gravitational lensing measurements tell us that it is there.

(I should note that Rob uses this example to set up a contrast with the real Marcus Ross. We're considering what to say about my Ross-doppelganger, so we'll have to see whather it's possible for him to avoid the pitfall into which Rob sees the actual Marcus Ross falling.)

In the current state of affairs, you can't simultaneously believe that GM gives a true account of the physical world and that QM gives a true account of the physical world. At most, only one of these theories can be true. And, it's possible that neither is true. Nonetheless, good physicists can work with both of them to make sense of data, to explain various phenomena, etc. This would seem to say that, strictly speaking, belief in the truth of a theory is not a requirement for use of that theory to generate good science. Philosopher Larry Laudan points out (in his book Progress and Its Problems) the useful distinction between accepting a theory and pursuing a theory.* Scientists can pursue all manner of theories that they take to be pretty far out, even unlikely to be true -- to see whether anything useful could come from working with that theory. Arguably, the willingness of scientists to explore theories that they don't accept (at least at the outset) can be very productive for science. Isaac Newton was not inclined to think action-at-a-distance was a good way to model reality, but pursuing what seemed like a nutty idea got us to a theory of gravity (whatever we mean by theory) that made sense out of Kepler's laws.

Here's another consideration: If scientists are serious about testing their theories, belief in those theories could be an impediment. This is part of why people like at least the spirit of Karl Popper's picture of the scientific attitude: scientific testing is looking for evidence against our theories, not evidence for them. We may love those theories to bits, but we cannot let our acceptance of them be unconditional -- they must prove themselves worthy of our love by standing up to a barage of tests. (Imagine an adaptation of Mr. Jealousy in which Annabella Sciorra plays the theory of Quantum Mechanics.)

Put another way, what makes scientific knowledge scientific is that believing in the truth of your claim contributes exactly nothing to whether other scientists will accept your claim. Scientific claims are supported with evidence of a certain sort (including empirical evidence, possibly fit with theories that are well-supported by empirical evidence, etc.). The insistence on testable claims is not just a step away from arguments from authority ("It's true beacuse I say it's true!") but also a step away from relying on your gut-feelings to make the judgment. Empirical science elevates the evidence of our senses over the deliverance of our gut. In a sense, this means that, as a matter of methodology, scientists have good reason to be cautious in their regard for what they're inclined to believe. That they believe it surely doesn't win the argument.

Now, back up a step. Our Ross-doppelganger has showed his skill in the pursuit of theories that other scientists in his field accept. Perhaps the Ross-doppelganger even accepts these theories in a Laudanian way -- he recognizes their problem-solving prowess compared to all the alternatives currently in use or development. But, he doesn't believe these theories. What he believes is what his religious instruction has taught him on this matter.

Assume for the sake of argument that the Ross-doppelganger knows his religious beliefs on things like the age of the Earth have no scientific credibility -- that they don't have empirical support, don't fit into the inferential structure in the right way, etc. Thus, he's not going to hold up his religious conviction as persuasive evidence that the science must be wrong. Let's also assume that the Ross-doppelganger will happily allow that the account of things that fits best with the empirical evidence is the account from the geosciences. In other words, from the point of view of offering natural explanations for natural phenomena, the geosciences are doing a good job.

Are you inclined to view the Ross-doppelganger as a good scientist? Can we trust the scientific knowledge he builds?

You might object, "How can he call what he's producing 'knowledge' if he doesn't believe it's true?" But if you're going to challenge the Ross-doppelganger on these grounds, you may have to challenge the physicists as well.

Here, return to Rob's analysis. When Rob writes,

GR may not be "The Truth," but it does work for predicting the orbit of Mercury or the gravitational lensing of light around a cluster of galaxies. ... GR may not be the fundamental truth, but we really believe that there is mass there when gravitational lensing measurements tell us that it is there.

I take it what he's getting at is that science involves a certain commitment to the reality of the observational data -- that there is a planet Mercury, that it does have an orbit, that there is light, there is gravity. Without some kind of acceptance that empirical data are real -- that we get them through certain kinds of interaction with the physical world -- there would be absolutely no reason to think it problematic to just make up data.

What seems less clear cut is what kind of commitment science requires to the causes behind the empirical data. There are some (Bas van Fraassen comes to mind**) who suggest that the task of science is accounting for the empirical data with empirically adequate theories, but that the "hidden causes" you might infer lay beyond those data are not the kinds of things you can establish with certainty. In other words, there are some scientific claims you can support with empirical data, and other scientific claims that fit really well with the data -- maybe better than any of the competing claims we've cooked up to date -- but about which it is possible, or even proper, to maintain a healthy agnosticism.

If the Ross-doppelganger acknowledges that the empirical data are what they are -- that this is what the world presents to our senses (and to the instrumentation we use to extend our senses) -- is he on solid scientific footing? Remember that he knows what to do with those data to draw proper scientific inferences, that he knows how to test his inferences against possible scientific objections, and so on.

Does the fact that he entertains as a possibility, albeit one that he acknowledges as scientifically untestable, that the empirical data are produced by a God who also made the world within the last 10,000 years -- even if this possibility plays no role at all in his scientific work -- disqualify him as a proper scientist and disqualify his work as properly constructed scientific knowledge?

If so, why?

________
*Acceptance in Laudan's account is similar to belief, but it's worth noting that, in contrast to some other kinds of belief we might have in everyday life, acceptance of a scientific theory is something for which Laudan thinks we can have rational grounds (on the basis of the theory's current overall level of problem-solving power compared to the available alternatives). Note also that as other theories are developed, it's perfectly possible that we will be presented with rational grounds for accepting a different theory over the one we had accepted.

**The full articulation of van Fraassen's view is given in his book The Scientific Image.

Comments

The only flaw with the GR/QM scenerio and the YEC/current-geological-science scenerio is that BOTH the GR and the QM are scientifically valid and mathematically accurate to within acceptable degrees of certainty.

Neither are "believed" in so much as supported by the evidence available at the time at which they are applicable. That they contradict at certain points is not, in itself, a problem of belief. Physicists who's fields reflect one or the other continue on as if the contradiction didn't exist, because at acceptable levels of certainty it doesn't. They're both science, and extremely accurate sciences in spite of the contradictions and funnyness that goes on when the very small works around the very big.

However,

YEC is not only NOT VERIFIABLE by any standard at all (unlike, say, "angels" or supernatural gods), it CONTRADICTS all evidence utterly.

This is not a case of believing in one while ignoring the other merely because at acceptable scientific levels of accuracy, "it works". This is believing something that totally contradicts ALL evidence at hand, even without the philosophical hand-waving of "God made it *look* like it was 4 billion years old, but its really young".

The comparison is inapplicable.

Posted by: Joe Shelby | February 22, 2007 06:34 PM

Joe, the point wasn't to suggest that YEC is like either GR or QM. Rather, the point was to ask whether using geological theories (which deep down, one doesn't believe) might be like working with GR (which deep down, one doesn't really believe).

I take it there's no case to be made here that YEC can be construed as scientifically supported belief. The worry is whether "good science" requires that you have a certain level of belief in the scientific theory you're using.

Posted by: Janet D. Stemwedel | February 22, 2007 06:50 PM

Does one really "not believe" in GR, or does one merely accept that GR is the best available explanation for the phenomena THAT ACTUALLY WORKS within that acceptable certainty. One can accept that GR is not "right" while at the same time accept that the better explanation eludes us, "but we're working on it" (which we are).

That's totally different from suggesting that one can accept that GR is not right by *believing* that "planets and stars spin on crystal spheres", the astronomical equivalent to YEC.

When a scientist says "I don't believe in GR" its completely different from when some "faithful" chap says "I don't believe in everything anybody has ever said about modern cosmology". They really are two different meanings to "believe" and the context remains key. The comparison has not resolved that contextual difference that changes the weight behind "believe".

Posted by: Joe Shelby | February 22, 2007 07:13 PM

Well, Janet, you're a philosopher, so you know that there are all kinds of tenable possibilities for empirical observations. The only thing that you can prove to exist is your own mind. Aside from that, there are all kinds of completely logical, if not incredibly likely, possibilities. The world could have been created 10 seconds ago. There is absolutely no way to disprove this hypothesis.

But as a scientist, you're committed to the idea that the most parsimonious explanation is likely the truth. There's all kinds of evidence that the world has been around a very long time. I can look at a sample of uranium and see that, on average, one atom decays into thorium about every ten seconds (and then through all the chains to lead). Then I can look at a piece of rock that should be all uranium, but 50% of it is lead. The most parsimonious explanation is that this piece of rock is billions of years old.

That's how scientists decide how the world works. Looking for empirical evidence to explain how things are the why they are. If I honestly believed that the world was created 10 seconds ago, and I would continue to do so no matter how many radiodating studies I did, I'm not being a scientist. I'm not actually looking for evidence about how the world really works. And as such, I have no motivation to be truthful about what I find, because it's all just a game anyway.

I think that's the real problem here. Science really relies on people being utterly open about their observations. That means being personally motivated to report the truth.

Posted by: Brian | February 22, 2007 07:31 PM

Joe, what does a belief matter to the work done? Surely what goes on inside your own head only becomes a problem if it goes beyond that and influences your work and writings. If I was to deny GR because I honestly accepted the Crystal Spheres hypothesis (don't worry, I have never even heard of this one before) would it really, honestly matter, so long as I didn't allow that prejudice into my work?

Lets be honest with ourselves, all scientists will have some prejudices. The whole point of peer review and standards of ethical conduct (including intellectual honesty in all its forms) is to minimise the impact of those prejudices.

In the case of the hypothetical here, the belief is kept entirely detached from the work produced (otherwise there would have been no way any PhD, or science fair sticker for that matter, could have been awarded). It would be no different to an atheist making an argument to Christians that referred to the bible. You may not believe it is true, but that doesn't stop you understanding the others viewpoint and using it to make arguments.

In this case you can see the paper written as almost a thought experiment. The same sort of view taken by the church with Galileo when his model made beautiful predictions but didn't fit with dogma. While such a stance is in no way scientific, it doesn't make the science done any less viable to those who do accept it.

There were no grounds to deny the PhD on the work done or the general religious beliefs held by this man. There may have been other reasons, such as straight up dishonesty in presenting data that he believes is false. But if he believes the data is real and his reading of it is the best that exists materially, then there is no real way to avoid admitting he did as much as any other PhD student in the way of science.

Posted by: Paul Schofield | February 22, 2007 07:39 PM

One thing I haven't seen brought up in any of these discussions is "Last Thursdayism". Last Thursdayism is the recognition that God could have created the world last Thursday with all of the historical elements required to make the Earth (and Universe) look like it is 13 billion years old.

It is entirely possible that Ross could believe that the Earth really was created by God 6000 (or so) years ago, but with all the attributes to make it look like 13 billion years. In that case, accepting that 13 billion year age "for scientific purposes" would be a necessary part of learning more about the mind of God.

Posted by: Ahcuah | February 22, 2007 07:53 PM

1) A basic part of being a scientist is being able to suspend your beliefs. Not your disbelief -- that's easy -- but your beliefs, and especially the ones you actually like!

2) The GR/QM confict is vastly overhyped. It applies solely under conditions which are not directly observable (even in principle, AFAIK), and in which one or the other theory may reasonably "forced out" by new findings or boundary conditions.

3) In the same vein, the ultimate test of a physical theory is technology -- that is, given the theory, can you use it to create devices or conditions which did not previously exist? Both GR and QM pass this test with flying colors. Besides the astronomical observations, relativistic effects become directly relevant when, say, building a GPS system. The system we're using explicitly accounts for those effects, and it works. QM becomes directly relevant when building very small electronic devices, such as those in the computer you're using to read this comment. That works too. QED.

Posted by: David Harmon | February 22, 2007 07:54 PM