Can we ever be certain about scientific theories?

(I am taking some time off from new blog posts. Until I begin posting again, which should not be more than a couple of weeks, I will repost some very early ones, updated if necessary. Today’s one is from February 17, 2005.)

A commenter to a previous posting raised an interesting perspective that requires a fresh posting, because it reflects a commonly held view about how the validity of scientific theories get established.

The commenter says:

A scientist cannot be certain about a theory until that theory has truly been tested, and thus far, I am unaware of our having observed the evolution of one species from another species. Perhaps, in time, we will observe this, at which point the theory will have been verified. But until then, Evolution is merely a theory and a model.

While we may have the opportunity to test Evolution as time passes, it is very highly doubtful that we will ever be able to test any of the various theories for the origins of the Universe.

I would like to address just two points: What does it mean to “test” a theory? And can scientists ever “verify” a theory and “be certain” about it?
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Evolution-21: Why evolution speeds up with time

(Please see here for previous posts in this series.)

One of interesting things about evolution is that it seems to be speeding up with time. Earth was formed about 4.7 billion years ago and it took about a billion years for the first single-celled life to appear about 3.5 billion years ago. It then took another 2.5 billion years for the first multi-cellular life form (like sponges) to appear. So everything else, all the insects, animals, and birds, came into being within the last one billion years or so.
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Petitions and politics in science

In a recent discussion on a listserv for physics teachers, someone strongly recommended the book The Politically Incorrect Guide to Science by Tom Bethell, saying that it exposed how mainstream science was suppressing some ideas for non-science reasons, in particular how the great weaknesses of evolutionary theory were being hidden.

I had not read this book myself but these kinds of arguments are familiar to me and Bethell had written an article describing his own book. It struck me as extraordinarily shallow, rehashing arguments that have long been discredited, and invoking misleading (and old) chestnuts about evolution occurring only by chance, and missing transitional forms, etc. In fact, he seemed to have drawn his arguments against evolution from the playbook of the intelligent design creationists, in particular Jonathan Wells’ book Icons of Evolution.

He even made the argument that the only thing that has been seen is ‘microevolution’ (small changes within species) and not macroevolution (change from one species to another). But the distinction drawn between micro- and macroevolution is untenable, since it has long been realized that there is a large overlap between varieties within species and between species as a whole, making the drawing of such distinctions difficult. Darwin himself pointed this out in his On the Origin of Species (chapter II), where he emphasized how difficult it was for even experts to classify whether animals were varieties within a single species or different species.

It is amazing that in this day and age people like Bethell still bring up Haeckel’s embryos. Modern biologists don’t take Haeckel’s misleading sketches seriously anymore since his theory was discredited more than a hundred years ago and only intelligent design creationists (IDC) keep bringing it up repeatedly to argue that scientists falsify things in order to buttress the case for evolution. In the documentary A Flock of Dodos IDC advocate John Calvert talks about how biology textbooks use Haeckel’s figures to mislead children but when asked to show this, thumbs through some textbooks and cannot find any examples. He had simply accepted this folklore uncritically. What use Haeckel has now is purely pedagogical.

The Haeckel case is analogous to someone finding that the Bohr model of the atom is still being taught in middle school science textbooks, “discovering” that Bohr’s model violates Maxwell’s laws of electromagnetism, and thus concluding that quantum mechanics is wrong and that children are being misled into accepting it. Quantum mechanics has come a long way since the Bohr atom and does not depend on it, just like evolutionary biology and Haeckel’s embryos. To keep bringing it up is a sign of desperation

Bethell’s argument about the fact that no one has seen half-bats and that therefore step-by-step evolution could not have occurred, reminds me of those people who say that it is absurd that an electron can go through two slits or that twins age differently based on their speeds. After all, has anyone actually SEEN an electron go through two slits? Has anyone actually SEEN twins age differently? If we haven’t seen such things directly, they must not occur, right? I have described earlier how incomplete the fossil record is, because fossilization is extremely unlikely, and how arguments that depend on the existence of gaps in the fossil record can never be satisfied because new gaps can always be created.

As I have said in this series on evolution, to really appreciate the theory one has to get beyond the simple minded rhetoric of the kind that Bethell indulges in and look at the underlying details and the mathematics. The question of whether evolution is a “fact” is a red herring. “Theory” and “fact” are fluid terms in science. What is true is that the fully developed theory of evolution, known as the neo-Darwinian synthesis, is the most productive and useful theory in biology today, and forms the basis of almost all research in that field.

People who dislike the theory of evolution often point to the petition that the Discovery Institute (DI), the main driver of Intelligent Design Creationism (IDC), put out signed by 700 people that says: “We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged.” Such people cite this as evidence that the theory is weak and then ask: “Why are so many scientists jumping off the evolution band wagon?”

But scientists are taught to be skeptical and to examine carefully the evidence for any theory. And if a theory (like evolution) challenges their religious beliefs, they are likely to be even more skeptical of it. That is a natural human tendency. It does not take any effort for a mathematician or physicist or philosopher to say she is skeptical of evolution, just as it does not cost any biologist anything to say that he is skeptical of the big-bang. After all, in each case, they are not personally working with that theory and are unlikely to know anything about it in any detail and thus can let other factors have a greater influence. As of the time when there were 400 people who had signed on, about 80% were not even biologists. (The story of one religious scientist who signed on to the Discovery Institute statement and only later realized what was going on can be read here.)

Another problem with the petition wording is that although Darwin proposed the mutation and natural selection mechanism, developments since then have added other mechanisms such as gene flow and genetic drift, so even a biologist who sees no problem with evolution would agree that mutation and natural selection alone are not sufficient.

I personally am skeptical of ANY theory in ANY field as being the last word (or the ‘truth’) on the subject because the history of science teaches us that scientific theories have always been provisional. So for me the DI statement itself is nothing more than a platitude. The fundamental issue is whether the biological community feels that evolution is in a crisis, and as far as I am aware, the biological science community does not think so and continues to use that theory as the foundation for their work. So these kinds of statements are just meaningless. When biologists start using alternative theories to generate predictions and start getting positive results, then we can take those other theories seriously.

It is important to realize that despite so many years of pushing intelligent design creationism, the people at the Discovery Institute have not been able to generate even one prediction, let alone do any experiments to investigate their theory. What they are doing is not science, it is lobbying and public relations.

Statements like the ones put out by the Discovery Institute on evolution are, however, useful as indicators of what people desire or yearn for.

For example, I am skeptical of the idea of dark matter as the explanation for the anomalous velocity distribution of stars on the arms of spiral galaxies. Why? Mostly for aesthetic reasons. It seems a bit contrived to me and the idea of huge amounts of matter surrounding us that we cannot detect reminds me uncomfortably of the arguments for the ether before Einstein’s theory showed that the ether was a redundant concept.

I am hoping that a nicer theory than dark matter comes along and I know I am not alone in feeling this way and that other card-carrying physicists share my view. So if someone handed me a petition saying that I was skeptical of the theory of dark matter and would like the evidence for it to be examined carefully, that statement’s content would not be objectionable to me. I would totally agree.

But I would not sign because it is pointless. I have not done any real work to support my misgivings. I have not developed an alternative theory, generated hypotheses, made predictions, or explained any existing data. Physicists who actually work on the spiral galaxy problem (even if they were completely outnumbered by the people who sign a petition dismissing dark matter theory) would be perfectly justified in ignoring me and any other physicists who sign such a petition in the absence of any substantive counter-theory.

What the DI petition on evolution tells us is that there are about 700 people who wish and hope that a theory more congenial to them than evolution comes along. That’s fair enough but hardly major news. They have every right to feel that way and to say so. But it is by no means a measure of the merits of the theory, however many people sign on to it, and it is dishonest of the Discovery Institute to make such a claim.

Bethell’s thesis that the scientific community is conspiring to suppress the truth about the weaknesses of evolution is silly. Given that the US has high levels of religiosity and public skepticism about evolution and widespread unease that evolution is undermining religious beliefs, any scientist who found good evidence for special creation would be deluged with funding from both government and private sources and receive high visibility and acclaim. Furthermore, such a discovery would open up vast new areas of research. In such a climate, why would any scientist not publish findings that provided evidence for special creation?

People like Bethell are trying to achieve by public relations what they cannot do using science. They are not the first to try to do this and will not be the last. But they will fail, just like their predecessors.

POST SCRIPT: The insanity of the employer-based health care system

This question posed at a Democratic presidential candidates forum illustrates perfectly why we need a single-payer, universal health care system.

The story of evolution-20: How selection advantage arises in evolution

In the mathematics of evolutionary change, the selection advantage is a key mathematical quantity that determines the rate at which a favorable mutation spreads through the population. The selection advantage is a quantification of the net result of advantages that a variety of a species gains by virtue of its fertility and fecundity and longevity. As we saw before, even a small selection advantage can lead to rapid spread of the mutation.
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Fun and games in the world of religion

Nation magazine journalist Max Blumenthal has developed a nice little niche in political guerilla video journalism, going to right wing meetings and asking participants awkward questions. Although he is soft-spoken, always polite, and has the credentials to attend, he usually ends up getting thrown out by the organizers.

His latest visit was to the annual meeting of CUFI (Christians United For Israel) where he manages to get highly amusing but also disturbing and creepy footage. The CUFI is one of those rapture-ready groups that believe the second coming is due any day now and are strong supporters of Israel, even though they think that non-Christians have to convert on rapture day or be slaughtered. This group gets a lot of money from the true believers, enabling its leader John Hagee to live in lavish style. The group is also supported by some Jewish organizations like the Israel lobby group AIPAC. The former Israeli ambassador Dore Gold and Senator Joseph Liberman also attended the meeting, with the latter receiving a very warm welcome and reciprocating during his speech by comparing Hagee to Moses. (Of course, since there is good reason to think that Moses never existed, I am not sure of the value of this comparison but I am sure it was meant as a compliment.) It looks like these right-wing Jewish groups seem to be willing to overlook the CUFI’s nasty expectations for Jews because the CUFI supports the most extreme and reactionary policies of the Israeli government and settler groups. What seems to bind these extremists together is their hatred of Muslims.

Meanwhile, some time ago I linked to a video of protestors (see the post script) shouting during the opening prayer in the US Senate when a Hindu was invited to do the honors. The reason protestors gave for choosing the Hindu day for protesting is because Hinduism is polytheistic.

But actually, Hinduism is monotheistic and the other deities that one finds in that religion are the manifestations of the one god. You would think that Christians would understand this because their religion is very similar. The doctrine of the Trinity says the same thing: that Jesus and the Holy Spirit are also manifestations of god, and that all three should be worshipped equally.

So on the basis of their criticism of Hinduism, Christianity is also polytheistic and therefore, at the very least, in violation of the first of the ten commandments.

The doctrine of the Trinity has always been a nightmare for theologians, tying them up in knots trying to explain the mathematical impossibility of 1=3. I remember in my religion classes in school and later in theology classes for my ordination as a lay preacher, discussing this question and the clergymen never really being ably to answer it, except for saying it was one of the great mysteries of the church that could be understood only through the eyes of faith, thus conveniently taking a weakness and making it your fault. If you couldn’t understand, it was because you did not have enough faith.

I wonder what would happen if someone sued, not to get rid of ‘In God We Trust’ on the currency or ‘Under God’ in the Pledge of Allegiance, but to replace them with ‘In Gods We Trust’ and ‘Under Gods’, since the existing formulation excludes two of the three members of the Trinity.

If someone sues on these grounds, perhaps we could settle this thorny issue of what the Trinity means once and for all, with the US Supreme Court making a ruling on whether there is only one Christian god or three.

Now that would be a court case worth following.

The story of evolution-19: The-Boeing-747-in-the-Junkyard

As I have emphasized repeatedly in this series, the hardest thing to appreciate about evolution is how a cumulative sequence of very tiny changes can lead to big changes. The problem is that our senses can only detect gross differences between organisms and our minds can only comprehend short time scales and to appreciate evolution requires us to overcome those limitations. This is why skeptics need to actually study the details and convince themselves that it works.
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The story of evolution-18: Missing links

About ten years ago, a group of engineering students came into my office. They were taking part in a scavenger hunt during Engineers Week and the one item that was very hard for them to find was a ‘slide rule’. They had little idea of what it was and no idea how it worked or what one even looked like but they knew it was old technology and they figured that I was old enough to possibly own one.

They were partly right. I had once owned a slide rule as a physics undergraduate in Sri Lanka but unfortunately did not have mine anymore.

For those not familiar with slide rules, the standard type looks like a ruler with another sliding ruler attached, and you use it to do complicated calculations. It was the precursor to the handheld calculator but with the arrival of cheap electronic versions of the latter, the slide rule went extinct. I actually owned a more unusual type of slide rule that was cylindrical rather than linear and was like a collapsible telescope. It had the advantage that it was small enough to carry around in your pocket, and being able to whip out a slide rule when the occasion demanded defined the nerds of that time.
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US military bases abroad: A case study of Vicenza, Italy

In an earlier post, I highlighted Chalmers Johnson’s article that described the US global military empire that is sustained by a vast network of bases around the world, more than most Americans perhaps realize. The huge bases being currently constructed in Iraq should be viewed as the extension of this plan and creating such bases could well have been the driving force behind the decision to invade Iraq. This becomes more plausible since the various ‘official’ justifications (weapons of mass destruction, war on terror, spreading democracy) have been shown to be untenable.

Periodically, one hears of rumblings of discontent among the local population living near these US bases and demands for their removal. When this happens in countries whose governments are friendly with the US, such as in Europe, the reaction here is often one of indignation at those ungrateful people who are biting the hand that protects them.

A fascinating and detailed case study of one particular American military base is that in the town of Vincenza, Italy where in February 2007 somewhere between 70,000 and 150,000 people demonstrated against the expansion and extension of the US base in their city. The kinds of problems such bases create and the hostility they generate can be found in this article (and which has been highlighted here) by Paul Iversen, a professor of classics at Case Western Reserve University, who happens to have family connections in that town that take him there regularly.

Iversen emphasizes the deep and long-standing connections between Vincenza, a “world renowned city of art and architecture,” that influenced US government buildings through the fact that its native son architect Andrea Palladia’s work was the inspiration for many US government buildings including the Capitol dome, the White House, and Monticello. Perhaps because of these connections “Vicenza is thought by many Italians to be the most pro-American of Italian cities” and hence bitter protests over the US plans to expand its military base there cannot be dismissed as reflexive anti-Americanism.

Iversen says the extent of the public opposition was quite severe:

As for public opinion, local polls showed that 61% of the residents were against it, while a whopping 85% were in favor of settling the matter through a popular referendum. The City Council, surrounded by “unprecedented security”, had 20 representatives speak for the “yeas” and 20 speak for the “nays”, and then they voted first to reject the idea of a referendum and then to approve the expansion. The final tally for the project-vote was strictly along party lines, with 21 “yeas” (right coalition), 17 “nays” (left coalition), 2 abstentions, and 1 missing in action. The vote to reject holding a referendum was even closer, winning by only a margin of 1. After the vote, the previous mayor of Vicenza for 15 years, Achille Variati, is reported in the local paper to have said about the council’s decisions, “No, they cannot decide the future of Vicenza themselves. I will work to bring about the referendum.”

The main problem was that the plans for expansion did not take into account the already existing problems of congestion and pollution in the town and would actually aggravate them.

They would also inherit a new US air base that is a mere 25-minute leisurely walk from the Basilica Palladiana, which sits in the heart of the city.
. . .
Expanding the airport here, then, would be far worse than building a major military airbase one and half miles from the most historic piece of real estate in the US. As such it represents a serious callousness on the part of the US to local conditions and thus to justice itself.

As is usually the case, discussions over the decision to expand the US base is being done without consultation with the local populace or taking its interests into account, and involved heavy-handed arm-twisting by the US.

There was, however, one major problem with the discussions and agreement – the governments of Berlusconi, [center-right mayor] Hüllweck and the US had done all of the negotiating behind closed doors, thus keeping the people of Vicenza, including members of the city council, completely in the dark about it.
. . .
In fact, several months later Prodi’s Foreign Minister, Massimo D’Alema, would say that “Revoking the authorization would have been a hostile act on our part against the United States.” This clearly demonstrates that the US government was leaning hard on Prodi’s government and telling them that if they did not allow the base expansion, the US government would put Italy on a list of uncooperative or even “hostile” countries. This “all or nothing” approach to the relationship by the US, which amounts to extortion, is hardly what one would expect of a just and fair ally.

Iversen points out that such bases, contrary to conventional wisdom, are not an unmitigated economic boon to the local area.

Most Americans might be surprised to learn that Italian tax payers actually cover a significant share of American bases on their soil (this is called Host-Nation Support [pdf], see also here). While the exact stipulations of who pays what for each specific project are mostly kept hidden per the stipulations of the post-WWII treaty, in Italy it is widely believed that Italian tax-payers are required to pick up just over 40% of the tab, in addition to the large sums for the enormous amounts of water and electricity. This doesn’t cover time of war, when America often asks Host Nations to kick in even more ad hoc support, so a new base may also entangle Italy in paying greater costs for future conflicts. Any suggestion, therefore that somehow the Italians or the other nations where we have bases are “freeloaders” is terribly misguided. They help pay for a significant chunk of our bases on their soil. In addition, few Vicentini think that America’s help during WWII, as much as it is appreciated, obliges them to build yet another base in their overcrowded and beautiful back yard. Most are tired of America always expecting another pay back and treating them as their eternal client state.

And always in the background is the fact that the disastrous Iraq war and other actions by the US has squandered any goodwill on the part of people around the world towards US government policies. Iversen continues:

There is no doubt that in Italy and most of the world there is a widespread and growing conviction that Bush’s America is no longer the same America that reluctantly fought to end a horrific war sixty years ago; rather, she is going out of her way to pick unnecessary fights, thus displaying obvious signs of fascist, militaristic and imperial behavior herself – things the Italians have quite a bit of experience with, can easily recognize, and for which they now have a term that recalls the Fascismo of yester-year: Bushismo. It also hasn’t helped that the Bush administration has thumbed its nose at the UN, IAEA, the Kyoto Protocols, the Geneva Conventions, Habeas Corpus, and is responsible for Abu Gharib, Guantanamo, the recent probable involvement of CIA agents in an illegal case of extraordinary rendition in Milan, and that the US military cleared of all wrongdoing the American soldiers who in Iraq killed an Italian Secret Service agent named Nicola Calipari while he was rescuing an Italian journalist. Naturally the Italian public would prefer the US to change its policies and behavior, but if the US doesn’t, even traditionally pro-American cities like Vicenza would rather risk future Vandals, Visigoths and Huns rather than be complicit enablers of US imperial hubris by hosting another American base.

Iversen has written a wonderful article. You should read the full thing.

POST SCRIPT: Hubris

It is great fun talking to classics scholars. They are a font of interesting information about the ancient origins of words and ideas, and Iversen’s article had an interesting digression on the origins of the word ‘hubris.’

The noun hybris is derived from the Greek preposition hyper meaning “above” (which is cognate with the Latin preposition super from which is derived the Latin noun superbia). Hubris to the ancient Greek, however, was not just a matter of “pride”, as the word is usually poorly translated in English. Hubris was the condition of having a haughtiness so high that it led to a feeling of impunity, which in turn led to a wanton act of violence. That is why the Athenians prosecuted crimes such as rape under the rubric of hybris. For the Greeks, then, the pride of hubris was one that produced a wanton act of violence that caused great ruin, even death (which is why hubris was later listed amongst the Seven Deadly Sins). That death, however, was not limited to the victim, as any one who has read Greek literature can tell you, but the ruin of hubris eventually doubled back upon the perpetrator’s own head.

While many people have used the word hubris to describe the Bush administration, Iversen’s clarification of its full meaning makes that description even more apt.

The story of evolution-17: How species diverge

When my daughter was quite young, about five or so, the question of where people came from came up in a mealtime conversation. Naturally we told her that human beings had evolved from ancestors who were monkey-like and then became human-like. She sat there for a while silently digesting this interesting bit of new information and mulling it over in her mind. It seemed clear that she was not at all disgusted or even bothered by the thought that we were related to the monkey family. That kind of revulsion seems to be something that has to be acquired, often nurtured by religions.

But something was bothering her and she finally articulated it, asking “But when that happened, wouldn’t the mother monkey notice that her child looked different?”

She had hit upon an issue that many skeptics of evolution raise. They argue that there is a contradiction if we assume that we had evolved from an ancestor species that was so different from us that we could not interbreed with that species. Surely, the argument goes, doesn’t evolution imply that if species A slowly evolves into species B, then there must be a time when the parent is of species A while the child is of species B? Isn’t it a ridiculous notion for parent and child to belong to different species?
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The dangerous consequences of a militarized foreign policy

Chalmers Johnson is a former CIA consultant and a professor of Asian studies at Berkeley, and was an avowed cold-war warrior during the Vietnam war era. He has written a very interesting article titled Evil Empire: Is Imperial Liquidation Possible for America? He points out the Iraq war as an unmitigated disaster on many levels and the failure of the media as culpable.

The people of the United States became mere spectators as an array of ideological extremists, vested interests, and foreign operatives — including domestic neoconservatives, Ahmed Chalabi and his Iraqi exiles, the Israeli Lobby, the petroleum and automobile industries, warmongers and profiteers allied with the military-industrial complex, and the entrenched interests of the professional military establishment — essentially hijacked the government.
. . .
One subject that the government, the military, and the news media try to avoid like the plague is the racist and murderous culture of rank-and-file American troops when operating abroad. Partly as a result of the background racism that is embedded in many Americans’ mental make-up and the propaganda of American imperialism that is drummed into recruits during military training, they do not see assaults on unarmed “rag heads” or “hajis” as murder. . . Some militarists will reply that such inhumanity to the defenseless is always inculcated into the properly trained soldier.
. . .
Imperialism and militarism have thus begun to imperil both the financial and social well-being of our republic. What the country desperately needs is a popular movement to rebuild the Constitutional system and subject the government once again to the discipline of checks and balances. Neither the replacement of one political party by the other, nor protectionist economic policies aimed at rescuing what’s left of our manufacturing economy will correct what has gone wrong. Both of these solutions fail to address the root cause of our national decline.

I believe that there is only one solution to the crisis we face. The American people must make the decision to dismantle both the empire that has been created in their name and the huge (still growing) military establishment that undergirds it.

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