Saturday, August 13, 2005

Common sense and science

Not all New York Times contributors read The Reference Frame or other blogs about physics. One of those who apparently don't is John Horgan, the author of the controversial book The End of Science - as Peter Woit pointed out - and whom I originally confused with the enlightened professor of pure consciousness John Hagelin who has worked for Maharishi Mahesh Yogi. (Did you know that in Cincinnati, Ohio, a vedic approach to military defense based on Hagelin's insights about consciousness may earn you a PhD?)

Thanks to a reader for explaining me the difference between Horgan and Hagelin and please accept my apologies for this error.

In his book The End of Science, Horgan argued that all important discoveries in science had been made and science had switched to a postmodern speculative mode - something that Horgan called "ironic science". Even if there were something true about this general, vague, slightly arrogant, and discouraging thesis, it cannot justify the absurd details; and Horgan offers many crazy details, indeed.

In his new op-ed piece
he argues that science is compatible with the common sense and those who argue that they are incompatible are misled. Much like others, I would say that the validity of this assertion depends on your particular definition of "common sense". My definition of "common sense" is such that Horgan's statement is incorrect. Any "sense" that is supposed to be called "common sense" should be "common" which means that many (or most) people should have it.

It is obvious that most people have lived in the world where relativity, quantum mechanics, or even quantum gravity play no material role. This fact implies that most people's intuition is based on the ideas and expectations that were later mathematically embodied in classical, non-relativistic physics. In other words, quantum physics and relativity are not parts of the natural instincts of the majority of the world's population. Most of us "feel" neither relativity nor quantum mechanics. The more we work with these concepts and the relevant theories and experiments, the more natural and essential they look to us. Quantum mechanics and relativity have been included in the instincts of most theoretical physicists (and many experimental physicists) - and those intelligent people who have been exposed to theoretical physics for a sufficient amount of time.

One of the criteria to measure the depth of ideas is their ability to challenge the beliefs and intuition of most people, including the smartest ones; in particular, deep ideas often challenge common sense. No doubt, both relativity and quantum mechanics satisfy this criterion. We have emphasized many times that even thousands of philosophers working for thousands of years would not be able to invent a valid theory of the Universe that is as weird as quantum mechanics by pure thought; that's essentially a statement by Sidney Coleman whose original author may be Richard Feynman, as David Goss has pointed out to me.

The neverending inflow of silly books such as The Final Theory is a testament of the striking incompatibility between common sense on one side and relativity or quantum mechanics on the other side (or, in the case of the author of that book, it's even the incompatibility of Newton's theory of gravity with common sense). The strength of the belief of a person that relativity or quantum theory is correct is a sharply increasing function of the number of physics degrees.

Even if you believe that John Horgan internally "feels" what quantum mechanics and relativity are all about - which I doubt - his op-ed shows quite clearly that his common sense is incompatible with some newer insights. For example, he says that he believes that the critical dimension of string theory is determined by the ZIP code of a physicist. Let me assure you that the correct calculations look a bit different. Even if you don't believe that string theory has anything to say about the dimensions of this actual Universe, it does not change the fact that Horgan's statement about the critical dimension is rubbish mathematically.

Note that Peter Woit is so eager to support any kind of attack against string theory that he even seems to agree with this stupidity by Horgan.

Horgan offers many other examples of scientific theories (as well as myths; I don't claim that all ideas that Horgan finds strange must be correct) that contradict his common sense, and therefore they must be wrong, he says. Of course, his opinions about particular theories of physics or biology are not supported by rational arguments. It's all about feelings.

Because I originally confused Horgan and Hagelin, let me add a story about the latter.

A story about Maharishi Mahesh Yogi: right after the Velvet Revolution in 1989, a group of Maharishi's disciples visited our high school; many similar unusual spiritual trends were penetrating into the former communist countries of Europe, too. They did not look particularly smart when they were proposing their amazing methods of meditation, but let me admit that I was really impressed by their brochures claiming that the Einsteinian dream about the unified field theory had finally come true. I needed a week to decide that despite their reasonable choice of the words, these guys could not know anything about unification in physics. Several more years were needed to learn that the former physicist John Hagelin was behind these brochures.


  1. Lubos said:

    "We have emphasized many times that even thousands of philosophers working for thousands of years would not be able to invent a valid theory of the Universe that is as weird as quantum mechanics by pure thought;"

    I have said that philosopher can't develope physics directly because they don't do experiments. Physicists can't develope physics either if they don't have the guidence of experiments.

    However note that many great philosphers are also great physicists, and many great physicists are also great philosophers. There is not a clear cutting line between the two. If you try to cut that line, Lubos, I assume you that your highest degree received is just a D, slightly better than a F. You do not get an F only on the condition that you do know that Ph. does not stands for physicics, do you? Or maybe you really deserve a Ph. "F" :-)

    Now, your statemetn is wrong. The concept of "atom", for example, were invented by philosophers thousands of years ago, before being discovered by physicists. And for thousands of years, the Chinese claimed that only a single day had passed in the heaven, when thousands of years had passed in the human world. So that's a concept that different reference frames carry different clocks. Although only Einstein tried to figure the exact way how that's possible.


  2. The strength of the belief of a person that relativity or quantum theory...

    If you put the word "belief" into play, it is not rare to get this kind of books back in answer. You can not believe that 2+2=4; at most, you can tocheck it or to failure in the check, but belief is not involved.

  3. Now, about the "End of Science", I considered time ago the paperback while looking for reading in an airport. It was not an important book, but afterwards it seems it pressed the right buttons to provoke answers from the academy. I was more puzzled by this phenomena that by the book itseld.

    Weinberg "Efective Theory" view of QFT was promising a future of perpetual discoveries, the academia being happy about it, and poor Hogan unknowlingly attacking it.

  4. I happened to read In Defence of Common Sense following Peter Woit's link. I must admit that it was certainly well written piece and

  5. Hogan says"
    "In the midst of all this hoopla, I feel compelled to deplore one aspect of Einstein's legacy: the widespread belief that science and common sense are incompatible."

    Its preposterous to claim that this was Einstein's legacy. Horgan uses common sense to justify his argument while my common sense tells me that common sense is a term that doesnt have any definite meaning. If common sense is what is generally and appropriately called intelligence, it is the most important virtue of a scientist and no rational person can defy that in their study of nature. Nonetheless, one can acquire higher understanding and profound insight after persistence. If John Horgan is claiming that to be a bad thing then I must say that that he cannot really distinguish between science journalism and evolution of scientific ideas.

  6. How many times in the past has science been 'complete?' But it seems Nature always throws in something new, and in many cases this corresponds to technologies that allow us to probe new size scales.

    We now are capable of probing size scales through an unbelievable number of orders of magnitude (~10^-19 meters to billions of light years), and new discoveries are being made each day at all of these scales. Unprobed and poorly probed scales remain (i.e. is superstring/M-theory correct at the 10^-35 meter scale, what is out there as we 'look' closer to the big bang). But what we must not forget is the next great challenge appears to be understanding how all our basic physical rules (have we finished discovering 'basic' principles? Perhaps, perhaps not; even here we need to find out if universal constants such as c, G, h, etc., are constant over time) work when combined in complex systems. Who knows where we'll end up with studies of complexity, chaos theory, network theory, nonlinear systems, nanotech, materials science, astrobiology, and many more.

    I think scientists will have some important work to do for quite some time.