Sunday, January 07, 2007

After 391 years, Galileo is dangerous again

This text is a reaction to Robert Crease's essay

In 1615, the PC police received a complaint against Dr. Galileo Galilei. Someone has noticed that some of the theories of the scholar about the motion of celestial bodies were incompatible with the conventional interpretations of the Bible. Because the PC police, officially called The Inquisition, used to be fully controlled by the Catholic Church, it turned out to be a kind of problem.

Galileo chose a pragmatic approach and allowed the bigots to say whatever they wanted and to formally win their lawsuit. After their theater, he has famously declared that the Earth is revolving around the Sun anyway: at least legend has it.

Incidentally, you might ask who were the zealots? Did they have names? You bet. Their names have been forgotten and you won't even find these people's webpages on Wikipedia but the most legally relevant bigot who denounced Galileo as not even wrong was Tommaso Caccini, a Dominican friar. I wrote "not even wrong" because Caccini was also unaware what Galileo's theories were actually saying and how they were justifying it. Caccini was also a career hunter with 3rd class & derivative published results who has also worked against Galileo behind the scenes - all these things sound way too familiar.

There have been many people named Caccini who were musicians and sculptors but Tommaso Caccini was not one of them. He was just a bigot and crackpot who has rapidly evaporated from the history textbooks much like the recent "critics of science" will evaporate but he has caused as many problems to emerging science as his disciples cause today.

At any rate, Galileo Galilei may be regarded as the co-father of science as we know it, together with Isaac Newton. Galileo was the guy who started the process of defining as accurate hypotheses as possible that are later tested quantitatively by experiments. Mechanics was the first target of his experiments in Pisa. Those theories that disagree with the observations are abandoned while those that have a chance to be true are being refined.

The following centuries have taught us that the process of extracting a correct theory from the observations is not always straightforward because the scientists must sometimes be bright to get the right answers. Quantum mechanics has taught us that only the probabilities, not particular outcomes of the experiments, can be predicted. But Galileo's general picture hasn't really changed.

Galileo's 1623 quote

Crease does a good job in explaining how revolutionary Galileo's approach to natural phenomena was. Galileo had to defend the importance of natural phenomena and their detailed properties for our appraisal of the world in comparison with the wisdom of the Bible. So he has completely redefined the meaning and status of the "book of nature". Before Galileo, this book only contained signs whose true meaning is only revealed once they're interpreted using the scripture.

Galileo has made some "subtle" modifications in this mechanism. The book of nature became primary. Moreover, it was supposed to be interpreted by mathematics as opposed to the Old Testament and the New Testament. The true essence of nature is a set of laws that can be expressed in terms of mathematics and the scientists' goal is to find as much about them as they can.

Putting mathematics to the place formerly occupied by religious dogmas and theological games with words was such a profound revolution that many people, including the author of a recent blue anti-physics tirade, are apparently going to need much more than four centuries to digest this breakthrough.

Dangerous Galileo: again

In 1623, Galileo wrote some precious words that nature was a book written in the language of mathematics. Some of the readers may know that I've been using his quote as a motto, with "mathematics" sharpened to "string theory", so you shouldn't expect me to criticize the Italian scholar. I've been explained that Galileo has become incredibly controversial once again when Bert Schroer got infuriated by my motto: I guess that his vitriolic critique would have been less hysterical if he had known that the quote came from Galileo. ;-)

Galileo has also correctly pointed out that if we cannot understand this language, we will be doomed to wander in a dark labyrinth. Very true: even though science has developed and transformed in many directions, nothing has changed about these crucial words for nearly four centuries. All physicists know very well what Galileo meant and they have many more reasons to think that he was more right than he could have imagined. Using the words of Richard Feynman, not knowing mathematics is a severe limitation in understanding the world.

Nevertheless, Robert Crease seems to think that Galileo's famous metaphor about the "book of nature" can be dangerous today. Wow. You may ask: is it as dangerous as it was in 1623 or has it become even more dangerous? :-) Is it dangerous for the same reasons? Is someone going to file the same lawsuits against Galileo and his followers as they did in 1615 because of his heliocentric models?

If a well-known philosopher of science conjectures that one of the basic philosophical pillars of all of science as summarized in Galileo's words is dangerous, you may want to know what makes him believe these extraordinary statements. Crease explains his stunning words as follows:

  • But the image of the book of nature can haunt us today. One reason is that it implies the existence of an ultimate coherent truth – a complete text or "final theory". While many scientists may believe this, it is ultimately only a belief, and it is far likelier that we will endlessly find more in nature as our concepts and technology continue to evolve.

Galileo's words do not imply that we would find a complete theory of everything within 5 years, 50 years, or 500 years. They don't impose any deadlines because it would be foolish. But they indeed do imply that natural phenomena have a quantitative, mathematical explanation. Galileo also implicitly says that scientists should try to find an ever more complete description of natural phenomena and that this pursuit makes sense. When it is done right, they are getting closer to the complete system of formulae and rules that underlie reality. Whether the amount of work to learn "everything" is finite or infinite is a different issue and Galileo didn't say anything explicit about it. Even if the destination is infinitely far away, we can be getting closer to it.

Is there a theory of everything?

But it is true that Galileo found the answer that a complete theory is a finite distance away to be more reasonable, and so does modern physics. Crease's assertion that "it is far more likely" that the world is a matryoshka with infinitely many layers is an opinion of an unqualified outsider. Vladimir Lenin has explained that he believed the same thing but he was more concrete: Lenin imagined that the electron was a galaxy with a huge internal structure. It has many smaller electrons inside. These new electrons are again galaxies and so forth. Our predecessors could have safely falsified this vision of Lenin by the 1920s. Such a model would imply a huge entropy of the electron and it would spoil many crucial phenomena such as those implied by the Pauli exclusion principle.

We know for sure that the internal structure of the electron is uniquely well-defined by the laws of nature. The architecture of this particle - the architecture of all electrons in the world - is therefore universal and a galaxy is an extremely bad analogy for an electron.

Around 1970, effective quantum field theory became the state-of-the-art description of all known phenomena. According to this picture, new insights about new physical phenomena are associated with new, higher energy scales - or, equivalently, with new, shorter length scales. Physics at low energies is arguably well-understood. Physics at energy scales that are much higher than the Planck scale is also understood because it is dominated by "classical" black hole production. Only a finite energy window in between is left. According to the physical laws as we know them, it seems virtually impossible to design a scenario in which the number of new fundamental physical laws that wait to be uncovered is infinite.

String theory gives us the same answer to this question together with a much more detailed explanation why there is no room to adjust and re-adjust our theories indefinitely. We have many new ways to explain that there is no new physics below a certain distance scale (such as T-duality) and we have many new ways to show that no unknown continuous deformations of the theory can exist. There can be surprises but our current theories indicate that a complete theory can't be infinitely far away.

Mathematical arguments rooted in observations vs. dogmas

You can see that the character of discussions about some fundamental yet difficult scientific issues hasn't changed much since Galileo's era. There are two major approaches to all these questions: one of them, the approach pioneered by Galileo, is based on book of nature governed by the rules of physics and mathematics and on a careful analysis of the best theories and facts we have - which means quantum field theory and string theory together with the experiments that led to quantum field theory. I chose this approach.

The other approach is based on non-quantitative, blank, irrational, unjustified, yet radical assertions such as "it is far likelier that we will do something endlessly" - a dogma that is mainly supported by others who preach the same thing for the same reason i.e. no reason.

I don't know how to measure or calculate the probability that there exists a compact theory of everything which is why I will avoid radical screams such as "XY is far likelier than UV". Nevertheless, we know that certain scenarios that would imply an infinite hierarchy of knowledge seem to be incompatible with the principles of physics as we've learned them. Moreover, we have a very good first sketch of such a final theory. So I am not going to scream that the complete theory of fundamental physics will certainly be found and proven, and so forth, but I do find this guess more reasonable than the opposite guess. The answer to this question doesn't influence most of the actual research of physicists in the real world too much. If they only make partial progress in some infinite sequence of future events, it is still OK with them.

But I want to emphasize that Crease's criticism of Galileo and those who agree with Galileo is not unsimilar to the criticism by all those Caccinis in the 17th century. The unifying logic behind these attacks is always the same: some people just don't like if science makes too much progress or finds answers to exceedingly important questions because they just don't want science to mess up with these questions. They dislike if science makes such a progress with the help of mathematics, especially if they're not good at it and if they won't benefit from it. So they prefer if their local culture, religion, or consensus of several friends determine these answers.

Intelligent designers

Crease adds the following sentences to his criticism of Galileo's metaphor:

  • Furthermore, the image suggests that the "text" of the book of nature has a divine origin. The idea that the world was the oeuvre of a superhuman author was the precursor of the idea that it was the engineering project of an intelligent designer. This implication has led some contemporary sociologists of science to succumb to the temptation of characterizing scientists as behaving, and seeking to behave, in a priest-like manner.

I don't see anything false about Galileo's metaphor that would imply an incorrect statement about the creation of the Universe. Whether we call the cause of the existence of the Universe a "creator" or a "divine designer" is a matter of terminology and a psychological decision that depends on our cultural background but won't directly lead to any wrong conclusions. Today, most of us usually don't talk about a "designer" in the context of the Big Bang theory. But even if we did, Galileo would still lead us to study His properties using the tools of mathematics so this religious terminology would create no inconsistencies.

Is our Universe an engineering project of an intelligent designer? It is hard to define the meaning of all the words in this question scientifically, in order to make it an operationally testable question which is why most physicists don't like and don't appreciate similar questions. Nevertheless, I would answer "Yes" to the question if I had to answer. What I find so correct about the "Yes" answer is not religious jargon, of course, but the observation that the whole vast Universe follows some rules that become much more compact and meaningful if we look at them carefully with the tools of mathematics: it's just like if the rules were written down in advance by "someone" or "something".

Is this statement a belief or a fact? It depends how you define a belief. It is an important principle that underlies and justifies a significant portion of theoretical physics and that was becoming increasingly natural as physicists were making progress. I think that sciences such as theoretical physics couldn't exist if this weak, scientific version of an "intelligent designer" were abandoned. No scientist, or almost no scientist, would advocate an intelligent designer as promoted by William Dembski. But if someone asks whether there is wisdom, elegance (or at least ugliness, for Lenny Susskind), and cleverness visible in the laws of nature that requires a similar cleverness from the scientists who are decoding it, the answer is definitely "Yes" while the answer "No" is simply incompatible with the scientific method as we know it.

Also, Crease seems to have all the precursor arrows backwards. The correct history is the opposite one from what he wrote: the idea that the Universe was created by an intelligent designer called JHVH or God was a precursor to the modern scientific notion that the Universe was created by someone or something according to a mathematically formulated engineering project. The precursor of William Dembski's intelligent designer was the same old God who was mentioned in the previous sentence, not the creator introduced by Galileo. This should be clear to everyone. Galileo's creator was the precursor to ever more scientific notions of creation only: the scientific method doesn't really allow us to move towards more irrational beliefs.

Sociologists and priests

Needless to say, the cutest sentence by Crease is his last comment about sociologists who have recently noticed that scientists have behaved in a priest-like manner, already since the era of Galileo. ;-) That's a very cute observation. I wonder whether at least one of these "sociologists" has been brave enough to propose a conjecture that it could be the "sociologists", not the father of science, who is behaving in a silly manner and who is saying wrong things about the character of science and nature.

I suspect that it is always easier in their community to publish extraordinary statements such as that science is fundamentally flawed than to suggest that their community could be doing something wrong. That's one of the main differences of their community from a scientific one.

Someone could also try to tell them that even if they determine that they don't behave in a priest-like manner themselves, they could still be behaving in a very dumb manner. If someone's only criterion for a reasonable behavior is to behave as differently from a priest as possible, he can pretentiously call himself a contemporary sociologist but the word "moron" will be fine with me, too.

I am not entirely sure whether it is such a great idea to act in a priest-like manner or not but I am very certain that it would be very painful to act in a contemporary-sociologist-like manner. ;-)

Note that Galileo was criticized and harassed by the religious zealots for his heresy. A heresy is an alternative school of belief. The contemporary sociologists criticize Galileo and other scientists for being another school of belief. If there is supposed to be a difference between the religious zealots from the 17th century and the contemporary sociologists, what is exactly this hypothetical difference?

If some sociologists find the replacement of the religious dogmas and verbal games by experiments and mathematics to be an irrelevant detail, then indeed, science is just like religion or theology. It must be so. There is no other major difference between them. Both are based on certain principles that are used to divide theories to right and wrong and if these principles are not carefully followed, the structure collapses. Both create certain hierarchies in the community because some special skills are required in various contexts. Note that similar statements apply to many other human activities, too. So is science identical to religion? I, for one, think that the difference between dogmas and meticulous verbal games on one side and cold experiments and exact mathematical reasoning on the other side is a pretty important one.

It's the main difference between religion and science - two important creations of Man that can otherwise be viewed as siblings.

And that's the memo.



    Manfred Weidhorn

  2. (Prominte mi, Pane Motl, that I've written about you in the 3rd person here--and that I've taken such liberties with your name!--but I wrote the following for use elsewhere and I thought you might like to see it. Pardon my presumptuousness & my general ignorance...)

    Galileo's Book of Nature metaphor is dangerous, insofar that it has a certain truth & power about it. I've been throwing it around in very different contexts from those used by Luboš Motl and Robert Crease, but it's extraordinary how little it matters what the specific context is--the truth of the idea approaches the universal.

    Motl, (whose name, interestingly enough, is almost "motyl," which means "butterfly" in Czech--even further interestingly, one of his blogs is called Lumídkova užvatlaná zahrádka, which translates as a sort of "garden of conversations") is a self-described "conservative physicist" whose perspective is that of the "superstringy" theorist. In his Reference Frame blog he's got this excellent discussion of an article by a guy named Robert Crease who finds Galileo's Book of Nature idea "dangerous" for a number of reasons, including:

    * that it allows for some sort of intelligent design (or designer),

    * that it posits an ultimately "knowable" universe (that we'll one day refine or find a Grand Unified Field Theory), and

    * that scientists are seen by some as some sort of priest class guarding the specialized knowledge (dogma?) which only they can really understand.

    I won't go any further into the battle of the scientificos here, since you'd be better off reading it for yourself at Motl's After 391 years, Galileo is dangerous again and Crease's The book of nature, but I will say that while I much prefer Motl's position (mostly because Crease seems to be extremely defensive and reactionary--in another piece he extols the bounteous gifts that Western thought, via the engine of capitalism and science in the service thereof, has brought to an ungrateful world), I think that Motl is also open-minded enough to enjoy Bibhas De's unrelenting criticism of the business of science, even though Motl himself is a proud adherent to the superstring model which De dissects with such precision. I think Motl would also enjoy the thoughts of another science guy, Ian Yorston, whose blog, The Unreasonable Man carries such practical considerations as - Money and Politics: Illuminating the Connection (Amazing: brings together US campaign contributions and how legislators vote, providing an unprecedented window into the connections between money and politics.)

    Yorston also talks about Prof. David Singmaster's essay, The Unreasonable Utility of Recreational Mathematics, which brings us full circle back to Motl, Crease & Galileo. For some additional perspective (which is really my point in describing all these things), Einstein was famously puzzled by the strange contradiction he saw in mathematics being the language of Nature. His puzzlement centered on his belief that man had invented math, as opposed to discovering it. It's no wonder that this idea puzzled our most famous Uncle Albert, since something we invented can hardly be expected to not only "be" everywhere in the universe, but even to explain, undergird (whichever defining principle you care to use) Nature itself.

    The solution to Einstein's quandary, as well as the heated debate between the creationists and the hardcore mechanistic/materialists, seems painfully obvious to me, although that's probably due to my own faulty education. If man has merely discovered the language of Nature, then we can very neatly take our enormous ego right out of the picture with some prodigiously satisfying results.

    This means that, yes, we can (and should) safely look to the Book of Nature for lessons still unlearned: practical stuff, like how to build upon Nature's blueprints, modeling our technology and even our societal structures on the interconnected web of niche & cooperation that is the real Nature, as opposed to the self-serving tooth, nail & claw model pimped by the social Darwinists, the robber barons, the hegemonists and the eugenicists. (I left out the corporate apologists, but they're obviously in there, trumpeting this kind of propaganda from every silicon minaret.)

    Of course, in order for such a sea change among the labcoats, they'd have to engage in a bit of introspection, including an examination of how Darwin & Malthus have been yoked to a cause which is not mankind's, but it's just a matter of perspective, after all. Maybe they'll even rehabilitate Goethe one day...