Friday, October 19, 2012

Dyson on philosophy and the gravitational free lunch

Freeman Dyson in The NY Review of Books:
When and why did philosophy lose its bite? How did it become a toothless relic of past glories? These are the ugly questions that Jim Holt’s book compels us to ask. Philosophers became insignificant when philosophy became a separate academic discipline, distinct from science and history and literature and religion. The great philosophers of the past covered all these disciplines. Until the nineteenth century, science was called natural philosophy and officially recognized as a branch of philosophy. The word “scientist” was invented by William Whewell, a nineteenth-century Cambridge philosopher who became master of Trinity College and put his name on the building where Wittgenstein and I were living in 1946. Whewell introduced the word in the year 1833. He was waging a deliberate campaign to establish science as a professional discipline distinct from philosophy.

Whewell’s campaign succeeded. As a result, science grew to a dominant position in public life, and philosophy shrank. ...
He also tells the story of Gamow and Einstein crossing the street:
Quantum uncertainty allows the temporary creation of bubbles of energy, or pairs of particles (such as electron-positron pairs) out of nothing, provided that they disappear in a short time. The less energy is involved, the longer the bubble can exist. Curiously, the energy in a gravitational field is negative, while the energy locked up in matter is positive. If the Universe is exactly flat, then as Tryon pointed out the two numbers cancel out, and the overall energy of the Universe is precisely zero. In that case, the quantum rules allow it to last forever. If you find this mind-blowing, you are in good company. George Gamow told in his book My World Line (Viking, New York, reprinted 1970) how he was having a conversation with Albert Einstein while walking through Princeton in the 1940s. Gamow casually mentioned that one of his colleagues had pointed out to him that according to Einstein's equations a star could be created out of nothing at all, because its negative gravitational energy precisely cancels out its positive mass energy. "Einstein stopped in his tracks," says Gamow, "and, since we were crossing a street, several cars had to stop to avoid running us down".
Gamow's statement (at least as it appears above) is not quite correct. There are zero energy compact objects in general relativity, but they are quite special and not like ordinary stars. See here and also this blog post (2007):
... years ago I wrote a paper (unpublished) showing how to obtain a zero energy configuration in GR out of massive constituents. Particle theorists I discussed it with all thought I was crazy, but the referee was a very erudite relativist, who pointed out that a similar result (using different constructions) had been obtained by ADM, Novikov and Zeldovich, and others long ago.


BernardBrandt said...

As I recall, Plato had some very particular ideas about philosophy, and what it took to be a philosopher. Many of them can be found in the twelfth book of his Republic.

Basically, he thought that one should first be acquainted with grammar, so as to be able to edit one's verbal expressions to be unambiguous, then dialectic or logic, so as to be able to edit one's thoughts to be valid (or at the least, to be able to spot logically invalid statements), and then rhetoric, so as to be able to spot attempts to deceive rather than pursuade. These later became the Trivium of Grammar, Dialectic and Rhetoric.

Then the budding philosopher was to learn the rudiments of the scientific world of the time: arithmetic, geometry, astronomy (which involved both trigonometry and the Ptolomeic model of predicting the position of the planets in the sky), and music. A modern updating of such a Quadrivium would probably include (but not be limited to) number theory/algebra, geometry/topology, astrophysics/analysis, and music theory.

Of course, no one does anything like that these days. Heidegger apparently was reported to have said that the classic search for wisdom was no longer the job of the modern philosopher. More's the pity.

MtMoru said...

But isn't the question which follows The Final Theory philosophical? That is, why these laws and not some others? I can't see how it is an experimental question, but the "philosophy" involved may be theoretical computer science or mathematical logic, etc.

Contra militant atheists, a final theory would prove the idealists right. Atoms are Platonic forms.

Emil Ole William Kirkegaard said...

I agree with the conclusion "Philosophers became insignificant when philosophy became a separate
academic discipline, distinct from science and history and literature
and religion.". Many people don't like this conclusion. I think of it as obvious. Philosophers who do not concern themselves with modern information about reality are not particularly interesting.

I think the most interesting areas for modern philosophy are:

First, the area of meta-science - making breakthroughs with things like how to do good systematic reviews, how to set up good peer review systems, designing proper laws for the information society.

Second, the claiming of new ground - the establishing of new scientific fields of study. Working together with scientists to push the limits of human knowledge. Combining their broad knowledge of many fields of science to combine into new fields.

Third, research into rationality, especially instrumental rationality. Working together with logicians, AI designers and psychologists to squeeze the most out of the human brain. And how to improve our cognitive abilities through whatever means we can find.

Fourth, as policy makers, polymaths or science generalists who have a very broad knowledge of many scientific fields and can thus make good decisions about which way to take society. Politicians as they are now are notoriously bad at this.

MtMoru said...

"philosophy" when equated to the "thought" of philosophy professors IS a waste of time, but in this "age of specialization" natural scientists and business executives have even LESS to say on big issues.

When will billionaires start writing books worth reading? Never.

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