Tuesday, February 14, 2006

Science and Pseudo-Science

Amanda Gefter has written an article in The Philadelphia Inquirer which considers the claim that string theory is pseudo-science and that in the wake of the Dover trial scientists would do well to shun it. She thinks this is wrong-headed and that any comparisons between string theory and Intelligent Design are inapt.

Her column is interesting, but in the end she fails to make her case. Excerpts from her essay are set off in block quotes followed by my comments:

The recent ruling in Dover, Pa., against the mention of intelligent design in biology textbooks was a small cultural victory for science - not because intelligent design posed a genuine threat to the theory of evolution, but because the decision showed the public that there is an important difference between science and pseudoscience.

In the wake of the trial, scientists are being criticized, even by their own colleagues, for working on anything that might be construed as pseudoscience - and string theory is drawing most of the heat. An intense controversy has erupted regarding the status of this potential "theory of everything," which aims to describe the whole universe in one fell swoop: space, time, and everything in it.

According to string theory, the fundamental building blocks of matter are not dimensionless point particles but tiny, one-dimensional strings. What appear to us as different kinds of particles are actually different vibrations of the same string. String theory might be able to reconcile Einstein's general relativity (the theory of gravity) with quantum mechanics (the theory of matter), but that's because in the theory, gravity turns out to be just another string vibration.

String theory requires extra dimensions of space that have never been detected, and it describes not one universe but a near infinity of them. Parallel universes, invisible dimensions... these fantastic concepts are not directly observable, so the critics cry: "It's not science!" They appeal to the philosopher Karl Popper, who said that what distinguishes science from pseudoscience is that science can be falsified through experiment. In Popper's scheme, string theory and intelligent design can be lumped into the same category of untestable claims, and critics can make allegations that string theory is no better than religion.

There they go again. Repeat after me, Amanda, ID is not religion - unless religion is defined in so broad a way as to include almost everything, including naturalistic materialism, within its scope. ID holds that some aspects of the universe and life bear the marks of intentional, purposeful agency. It makes no claims about the agent itself much less what our responsibilities and relationship to that agent may be.

ID does not claim that the agent is the ultimate reality or that it is the ultimate source of all that is, or that it is independent of all else. These are standard divinity claims, the sorts of claims that make any belief system religious, and they are simply absent from Intelligent Design theory. Parenthetically, we might note that they are not absent from materialism which does make such assertions about the material universe. Thus materialism is more of a religious belief system than is Intelligent Design.

Case Western physicist Lawrence Krauss, whose latest book, Hiding in the Mirror, has stirred the controversy, feels that science's current struggle against political and religious agendas makes string theory a dangerous liability. As he writes in the journal Nature, the scientific status afforded to string theory "opens us up to otherwise avoidable attacks, particularly from those who would include religious ideas in high school science curricula."

But the real danger is not string theory's lack of experiments - it is the misrepresentation of what scientific theories are all about. Sure, falsifiability is a key component of the scientific method. But there is something that matters more: the power of explanation. History reveals that the structure of a theory itself - its internal mathematical consistency, its scope, and its beauty - often determines whether it is accepted as science.

This is misleading. These qualities are not used to decide whether or not a theory is genuine science but rather to arbitrate between competing scientific explanations. It's ironic that when some ID advocates argue that their theory is appropriate in a science class it's objected that ID is pseudo-science because it can't be tested. When, however, other hypotheses that are welcomed in science classes are challenged as being non-science the criteria of what constitutes genuine science are shifted to aesthetic appeal or elegance.

For instance, it is commonly said that the 1919 observation of the bending of starlight around the sun was fantastic confirmation of Einstein's theory of general relativity. And in the public eye, it was. But in reality the results were far from conclusive - perhaps only 30 percent. Still, no one would have rejected the theory based on the outcome of that experiment. When Einstein was asked what he would have done had the experiment falsified his prediction, he replied, "I would feel sorry for the dear Lord. The theory is correct."

Ms Gefter is now getting confused. She's jumping from talking about whether a theory is legitimate science to how scientists decide whether a theory is superior to its competitors. These are two completely different matters, and nothing she says about Einsteinian relativity here helps us to answer the question of how we can tell whether a theory is scientific. That relativity was a scientific theory was never questioned because it was testable and, indeed, Gefter describes one such test. The question the bending of starlight raises for relativity has nothing to do with whether its valid science but rather whether or not it's a better explanation than the classical Newtonian model.

Why this confidence? Because the theory is breathtakingly beautiful. It takes phenomena once thought to be separate and unifies them to simplify the world, to pare it down, to inch closer to the core of reality. It enlightens and it explains. General relativity might eventually fail a test, but it will be replaced only by a better explanation.

Indeed, but we need to remind Ms. Gefter that she's wandered off the topic. Again, the questions before us are what constitutes a genuine scientific theory, and do string theory and/or ID qualify?

In the Dover courtroom, proponents of intelligent design could be heard repeating their mantra: "Evolution is just a theory. It's not a fact." Scientists would then point out the categorical error: A theory is a framework to explain the facts. A theory is one level up from fact, so the mantra ought to go, "Evolution is not just a fact. It's a theory."

The theory of intelligent design is not only not falsifiable; there is simply no way to test it. But that is not the main reason it is not science. The main reason is, that ID does not actually explain anything. When we ask, "Why is the world the way it is?" it answers, "Because it was designed that way." The world is the way it is because it is that way. That might be the furthest from a useful, satisfactory explanation you can get.

This is incorrect. ID does not answer that question by saying "because it was designed that way." At least, I've never heard anyone give that answer. The world is the way it is because if it were much different in any of its fundamental laws, constants, or parameters, life, at least conscious life, could not exist in it.

This claim, by the way, affords us the opportunity to test ID. Scientists could simply construct computer models of possible worlds with significantly different initial conditions or physical and chemical laws and then show that such worlds would still be compatible with conscious life. If it could be demonstrated that life could indeed exist in a wide spectrum of possible worlds that would certainly undermine the ID argument that this world is fine-tuned for living things. I doubt that anyone will try this, though, because very few scientists believe that such a test would bear fruit. Most of them acknowledge that the fine-structure of our cosmos is precisely adjusted to astonishingly fine tolerances, and that if it weren't almost exactly the way it is life would have either never arisen or never survived.

String theory has problems, too. But while intelligent design is untestable in principle, string theory is just really hard. It is quite possible some clever scientist will devise a way to test it. Physicists have some ideas, but it is not going to be easy. In his new book The Cosmic Landscape: String Theory and the Illusion of Intelligent Design, string theory's inventor Leonard Susskind writes: "To divine the fundamental laws of nature that govern a world 16 orders of magnitude smaller than any microscope will ever see is a very tall order. It will take not only cleverness and perseverance, but it will also require tremendous quantities of chutzpah."

How does Ms. Gefter know that ID is in principle untestable? Aside from the fact that I just mentioned a possible test there's nothing of which we know that tells us that intelligence is undectable. One need not be able to detect the designer, after all, in order to be able to detect purposeful design. The evident design of the universe may someday turn out to be so overwhelming to anyone who examines the evidence that scientists will not even try to escape the conclusion that there is a designer, but if so they will not have to be able to detect the designer in order to come to that conclusion.

But why assume that the designer itself cannot be observed? We could only conclude that a designer cannot be observed if we knew a priori that the designer is by nature an unobservable entity, but how does Ms Gefter know that? Just because the designer is not part of this universe doesn't mean that it cannot be detected. If string theorists hold out hope that other universes will someday be detected why not hold out the same hope that we will one day muster the "cleverness, perseverance, and chutzpah" to detect intelligent agents in those other universes who are capable of designing things in ours?

As Columbia University physicist Brian Greene says, "String theory is a work in progress. It is science because in its decades of development it has always adhered to the well-established methodology of theoretical physics. So far, we have not revealed enough about string theory to extract detailed predictions that are within reach of today's technology. If, however, we believed that this latter goal of testing string theory were permanently unattainable - as it most certainly is for ID as currently presented - we would no longer work on the theory. As of now, there is no way to tell how things will pan out. But that's what theoretical physics is all about: Devise theories, analyze them with rigorous mathematical tools, do your best to extract experimental predictions, and test them. No one can predict how long each individual step in this progression will take." So be patient!

In other words, string theory does not meet the standards of real science just yet, but it will someday. How do we know this? Because we earnestly believe that it really is science. This sounds very much like a religious faith commitment or incantation rather than the words of a scientist, but in any case, why couldn't something similar be said on behalf of ID? Conducting a test for an intelligent designer is surely very hard, but maybe someday we'll figure out a way to do it.

If, for example, we could figure out a test to see if specified complex patterns with high information content could be produced purely by chance and physical processes, then ID would be disconfirmed. We don't know yet how such tests would be put together or how they will pan out, but be patient!

In the meantime, mathematical consistency could provide its own sort of falsification. Mathematics is the language science uses to describe the world, and if the equations of a theory lead to nonsensical results, the theory is mathematically falsified. Intelligent design cannot be described mathematically, so, to use physicist Wolfgang Pauli's famous phrase, "it's not even wrong."

Perhaps ID is "not even wrong," but Ms Gefter's claim certainly is. Simply because something cannot be described mathematically does not mean that it's not good science. If it did mean that then large chunks of paleontology, archeology, botany, forensic entomology and a host of other disciplines would not be real science.

Moreover, just because something can be described in mathematical terms does not mean that it is science. With no empirical content or basis for testable predictions it's hard to see how string theory could be anything other than theoretical mathematics. If it's objected that it should nevertheless be studied in physics departments because it may offer a true explanation for the universe then it could be replied that we should also study intelligent design in science classes since intelligence may well turn out be the true ultimate explanation for the universe.

It may be that the claim that the universe and life did not arise solely through natural forces cannot be analyzed mathematically, but even if that's true what follows? Can the claim that life arose from non-life be described mathematically? Can the proposition that purely physical processes sufficiently explain the origin and subsequent diversification of life be described mathematically? Ms. Gefter wants to set the bar high enough that IDers can't leap over it, but in so doing she inadvertantly eliminates from the science department of many universities a lot of people whose work is regularly published in scientific journals.

But the fate of string theory is unlikely to be decided by experiment. It will be decided when a physicist wakes up one day and slaps his forehead and yells, "Aha! Now it all makes sense!" If string theory can stitch together the facts of the world that do not quite fit, if it can explain why the universe is the way it is, no one will conjure the ghost of Popper. Yes, string theory is lacking in testable predictions, but more important, it is lacking some underlying principle to give it deep explanatory power. Still, scientists pursue it because they see paths of unification, shards of beauty, glimmers of ultimate reality. And that determination to explain the mysteries of the universe no matter how difficult the task, and the refusal to accept easy pseudo-explanations in place of truth, is a telltale sign of genuine science.

So, the telltale sign of genuine science is that it offers simplicity of explanation, elegance, and insight into ultimate reality. In other words, Ms. Gefter assures us, genuine science is thoroughly metaphysical. This being so, we wonder what it is about the assertion that the cosmos and life display evidence of having been purposefully designed and do not appear to have been produced solely by chance and blind forces that disqualifies that assertion as a genuinely scientific claim?

According to Amanda Gefter's reasoning, nothing at all.

The Lesser Evil

This might be an intentional leak to concentrate the minds of the mullahs in Tehran, or it might mean that Iran is in for a couple of rough nights sometime in the next year or so:

Strategists at the Pentagon are drawing up plans for devastating bombing raids backed by submarine-launched ballistic missile attacks against Iran's nuclear sites as a "last resort" to block Teheran's efforts to develop an atomic bomb. Central Command and Strategic Command planners are identifying targets, assessing weapon-loads and working on logistics for an operation, the Sunday Telegraph has learnt.

They are reporting to the office of Donald Rumsfeld, the defence secretary, as America updates plans for action if the diplomatic offensive fails to thwart the Islamic republic's nuclear bomb ambitions. Teheran claims that it is developing only a civilian energy programme. "This is more than just the standard military contingency assessment," said a senior Pentagon adviser. "This has taken on much greater urgency in recent months."

The prospect of military action could put Washington at odds with Britain which fears that an attack would spark violence across the Middle East, reprisals in the West and may not cripple Teheran's nuclear programme. But the steady flow of disclosures about Iran's secret nuclear operations and the virulent anti-Israeli threats of President Mahmoud Ahmadinejad has prompted the fresh assessment of military options by Washington. The most likely strategy would involve aerial bombardment by long-distance B2 bombers, each armed with up to 40,000lb of precision weapons, including the latest bunker-busting devices. They would fly from bases in Missouri with mid-air refuelling.

The Bush administration has recently announced plans to add conventional ballistic missiles to the armoury of its nuclear Trident submarines within the next two years. If ready in time, they would also form part of the plan of attack. Teheran has dispersed its nuclear plants, burying some deep underground, and has recently increased its air defences, but Pentagon planners believe that the raids could seriously set back Iran's nuclear programme.

We are deeply concerned about the consequences of a military strike on Iran. If a dozen simple drawings can throw the Muslim world into an apoplectic rage imagine what a massive bombing of Iran's nuclear facilities would do. Oil shipments from the region will probably be stopped and suicide terrorism will skyrocket. Worse, if it's just a bombing mission with no invasion and regime change then the problem will just be deferred, not solved, but if there is an invasion it would doubtless become an extremely ugly affair.

Nevertheless, John McCain is correct when he says that as bad as a last-resort military strike might be, a nuclear-armed Iran would be far worse.

Slogan Contest

Bookworm Room has a slogan contest going on in which readers can vote for their favorite conservative slogans in a number of different categories. Some of them are really clever and funny. One of our favorites is in the slogan about Democrats category:

Democrats: A 40 year war on poverty and still no exit strategy.

Clever. There are many more at the link.