Tuesday, October 06, 2009

Roger Penrose: physics is wrong

Discover Magazine just published a rather embarrassing interview with Roger Penrose:
Roger Penrose says physics is wrong, from string theory to quantum mechanics.
Its innocent parts discuss Penrose's childhood, his low speed in mathematics as a kid, his family of achievers, and the history of some of the famous mathematical constructions he invented (such as Penrose tiles and Escher pictures). The other part is dedicated to his critical opinions about physics.

The title sounds really dumb and you might think that it is a result of Susan Kruglinski's work: she hasn't really established herself as one of the better science journalists. In fact, she has written a very stupid interview with a crackpot in the past.

But if you read the text, you may see that it is unfortunately not just the title. Penrose says a lot of genuinely stupid remarks about physics in the very interview, by his own words. He "blames" quantum mechanics for the "wrongness" of current physics. Penrose insists that Nature must be fully deterministic, otherwise it makes no sense. He says pretty much all silly things about quantum mechanics in general and Schrödinger's cat in particular that have ever been discussed on this blog, e.g. in anti-quantum zeal.

Fashion, Faith and Fantasy in the New Physics of the Universe, Lecture 1: FASHION. 86 minutes, will become a book

Besides quantum mechanics itself, he also mentions that he has written some new critiques of cosmic inflation and string theory. See also Penrose vs holography. And he thinks that it's "almost sacrilegious" to attack these things.

Well, I, for one, don't think that it's sacrilegious to attack quantum mechanics, string theory, or quantum mechanics. Billions of people in the world who have heard about these theories are making these attacks all the time. It's not sacrilegious or unusual in any sense: it's just stupid enough for an expert.

It's simply embarrassing for one of the most famous mathematical physicists to say - and believe - these stupid things about physics, and to agree with an average, severely intellectually limited woman of Susan Kruglinski's type about advanced topics in physics.

You know, I love many things that Roger Penrose has invented. I have spent quite some time with many of them - Penrose tiles, Penrose limits of geometries, twistors, and others. His name is used in theoretical physics as well as recreational mathematics all the time. But what about Penrose as a physicist?

Well, he has found cool and catchy things in recreational mathematics and important solutions of classical equations written down by others, among related things. But not knowing quantum physics well enough is just too great a handicap. Quantum mechanics is the real "engine" of the 20th century physics: all other things are just "details".

The discovery of quantum mechanics has been the most important revolution of the 20th century physics - and probably all of 20th century science. Penrose's discoveries and inventions are really cool but none of them comes anywhere close to the quantum revolution. I know that many people love to worship the cults of personality, and Penrose is supposed to be one of them.

I just can't see the reality in this way. Penrose is saying the same stupid things about quantum mechanics as many people whose fame is lower by 15 levels ;-). But Penrose's fame and contributions simply can't change anything about the fact that what he's saying are the same stupid things as others do, so they must be given the very same appraisal. The name of Penrose can't change anything about it. Science is not about worshiping cults of personality.

So every honest and informed boy must scream: the emperor's new mind has no clothes! ;-)

Also, his choice of the word "sacrilegious" is a kind of demagogy. It's him who is acting religiously. Determinism used to be a dogma of science. But it was more than 80 years ago - especially in the 19th century. In the 1920s, people simply found phenomena and theories accounting for them that proved that the dogma was wrong. And this insight was getting much sharper with new insights, such as entanglement, and the violation of Bell's inequalities in Nature.

Because of these new insights that began in the 1920s, a modern physicist must start to learn, practice, and research physics without those old dogmas of classical physics. He or she must be a priori open-minded about the way how the Universe works, he or she can review the evidence, and he or she will a posteriori determine that the classical determinism simply doesn't work and cannot work in the world around us. So the deterministic dogma of the classical physics has shared the fate with many dogmas of the Catholic Church and others: it's just scientifically invalid.

This conclusion would be hard to understand for physicists of the 19th century. But it simply cannot be hard to understand for good physicists in the 21st century, by their very definition.

In the interview, Penrose remembers that his family was not allowed to read novels, at least not on Sundays. I think that Penrose's world is still confined by many similar regulations. He is apparently not allowed to seriously accept theories that can only predict probabilities of outcomes rather than the deterministic future, at least not on Tuesdays. ;-)

Such restrictions may be good for you or good for him if they happen to direct you or him in the right direction towards the solutions of the problems you or he wants to solve. That may have been the case of the successful inventions by Penrose but it's surely not the case of his opinions about quantum mechanics, cosmic inflation, string theory, or the philosophy of physics.

As Frank Wilczek wrote in his review of the Road to Reality, there's much to admire and profit from in Penrose's interview, but judged by the highest standards, the interview and other texts he wrote are deeply flawed.

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