The author has an axe to grind with modern physics. On television and in books about contemporary
physics intended for general audiences, established knowledge is seamlessly
presented along with speculation and theories (like string theory) which do
not, and possibly cannot, have experimental or observational support. Baggott makes a distinction between what he
calls the “authorized version” (theories of physics with well-established
empirical support) and “fairy-tale physics” (theories that lack such support). Moreover, according to him, some physicists
have advocated a “post-empirical” re-defining of the scientific method, which
would cut science loose from its empirical grounding.
The book begins with a chapter on some amateur philosophy
of science, where Baggott sets out the six principles that he thinks demarcate
science from metaphysics. The first is
the “reality principle” which is a statement of metaphysical realism – the real
world is “out there” independent of our perception of it – tempered by
acknowledging that we only have access to “things as they are measured”, not “things
in themselves”. Moreover, “reality is
rational, predictable and accessible to human reason.” Second is the “fact principle” which states
that facts are not theory-neutral: “Observation
and experiment are simply not possible without reference to a supporting theory
of some kind.” Third is the “theory
principle” which states that any creative process used to develop a theory is
acceptable as long as the resulting theory works. How we define whether a theory works leads to
the fourth principle, the “testability principle”, which states that scientific
theories must be empirically testable, and for this to be possible auxiliary assumptions
are required. Moreover, no single test
is decisive, since either the theory or an auxiliary assumption may be
responsible for any discrepancy. The
fifth principle is the “veracity principle” which states that theories can at
best be tentatively accepted, while absolute certainty is beyond reach. The final principle is the “Copernican
principle” which states that we are not privileged observers (discussed in a
different context by Adams and Laughlin, 1999).
The rest of the book is divided into two parts. The first is an exposition of the “authorized
version”, and the second is titled “The Grand Delusion”, where he outlines “fairy-tale
physics” and his problems with it.
Part One begins with a chapter on quantum theory,
including the foundational questions.
This is followed by a chapter on quantum field theory and the standard
model of particle physics, up to and including the discovery of the Higgs
boson. The next chapter tackles special
and general relativity. Then follows a
chapter on the standard model of big bang cosmology, including the inflation
model and the unknown nature of dark matter and dark energy. The final chapter of Part One is about the
gaps and flaws of the authorized version.
These include puzzles about quantum measurement, difficulties with the
standard models of particle physics and cosmology, and the lack of a theory of
quantum gravity. Efforts to address
these issues, such as dark matter searches, are discussed. Finally, the “fine-tuning problem” is
introduced: this states that the free
parameters of the universe seem unusually fine-tuned to allow for the existence
of life forms to observe it.
Part Two begins with a chapter on supersymmetry
(SUSY). Baggott feels that SUSY is at
least a testable theory and that we can expect experimental elucidation in the
next few years. On the other hand, he is
a skeptic of SUSY because he thinks it creates just as many problems as the
ones it solves. He also points to the
lack of experimental or observational evidence for supersymmetry thus far,
although in my view this judgment is premature.
The next chapter takes on the numerous flaws of string theory (including
superstrings and M-theory), ground previously trodden most famously by Smolin
(2006) and Woit (2007). The next chapter
tackles various versions of the multiverse concept, from the “many worlds”
interpretation of quantum theory, to the inflationary multiverse. All of these are dangerous, in Baggott’s
view, as they violate the testability principle. The next chapter, “Source Code of the Cosmos,”
tackles a hodge podge of ideas. The
first is Max Tegmark’s claim that the universe is a mathematical structure. Next, he presents quantum information theory
and quantum computing, in a more non-committal way. (I assume he believes these fields do fall
into the legitimate side of science, though not yet part of the authorized
version, since much remains to be worked out in those fields.) He then discusses the “black hole war” (involving
ideas from general relativity, quantum theory, thermodynamics, and quantum
information) which was resolved by Juan Maldacena’s holographic principle. The fact that the “black hole war” between
Stephen Hawking and Leonard Susskind was finally resolved shows that progress
can be made here, but it is not the kind of progress Baggott would prefer. The resolution of the “war” was based
entirely on theoretical developments, without grounding in observational or
experimental data.
The book’s penultimate chapter takes on the anthropic
cosmological principle, which directly contradicts the Copernican principle
that Baggott develops at the start of the book.
He also takes a swipe at the John Templeton Foundation in this
chapter. In the concluding chapter,
Baggott tries to answer six questions. First,
“If fairy-tale physics isn’t science, what is it?” Baggott’s answer is that the stuff isn’t even
metaphysics, but rather “nothing but sophistry and illusion” (quoting
philosopher David Hume). Second, “But
aren’t theoretical physicists supposed to be really smart people?” He answers affirmative but gives an analogy
with the financial crisis of 2008, which was partly the result of very
intelligent financial engineers who nonetheless fell under a “grand delusion”. Third, “Okay, but in the grand scheme of
things is there any real harm done?”
Baggott’s answer is that the “integrity of the scientific enterprise” is
being harmed. This is where he trots out
Brian Greene and Leonard Susskind apparently defending a post-empirical
redefinition of the scientific method.
Fourth, “What do the philosophers have to say about it?” Baggott cites only a commentary by philosophers
Cartwright and Frigg (2007), but otherwise would like to hear more from philosophers. Baggott states that “the guardianship of
science and the scientific method should not be left solely in the hands of
scientists, particularly those scientists with intellectual agendas of their
own.” Fifth, “Are we witnessing the end
of physics?” Baggott cites Horgan (1996)
but offers that the list of unanswered questions in physics is still quite
lengthy. The real problem is impatience,
which Baggott feels is a factor driving the development of fairy-tale
physics. The final question is “So, what
do you want me to do about it?” Baggott’s
answer is to maintain a healthy skepticism when reading about contemporary
physics.
So, what to make of the book? Baggott focuses on particle physics,
cosmology, and quantum information theory.
He makes no reference at all to the largest field in physics, condensed
matter, not to mention all the other subfields of physics. Smolin (2006) does the same but at least
explains that he does; Baggott never explains that there are vast areas of
physics untouched by the “fairy tale” issue he rants about. Baggott also fails to explore the
sociological reasons why “fairy tale” physics persists, an issue that Smolin
(2006) does address in some detail. Thus
in comparing the two books, Baggott tackles a broader set of issues (whereas
Smolin is mainly concerned about string theory) but Smolin gives a much more
thorough account of his topic.
Personally I think Baggott is mostly right (though his
dismissal of SUSY due to lack of evidence is far too premature). However I think Smolin does a better job of
convincing us that fairy-tale physics is actually damaging—how funding and
hiring is being dominated by less than worthy theoretical efforts. Baggott is clearly ticked off, but is not articulate
enough about the damage and why we should care.
I am not as prepared to completely dismiss string theory as Baggott and
Smolin are, but I certainly agree that in their current form they offer little
in the way of scientific progress.
Nonetheless, it’s about time someone wrote a book like Baggott’s.
References
Fred Adams and Greg Laughlin, 1999: The Five Ages of the Universe: Inside the Physics of Eternity. Free Press.
Nancy Cartwright and Roman Frigg, 2007: String theory under scrutiny. Physics World, Sept. 2007, p. 15.
John Horgan, 1997:
The End of Science: Facing the
Limits of Knowledge in the Twilight of the Scientific Age. Little, Brown.
Lee Smolin, 2006:
The Trouble with Physics: The
Rise of String Theory, the Fall of a Science and What Comes Next. Penguin.
Peter Woit, 2007:
Not Even Wrong: The Failure of
String Theory and the Continuing Challenge to Unify the Laws of Physics. Vintage.
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