Since the rise of string theory and its derivatives (M-theory and superstring theory), physics has “stalled out” in its ability to achieve any major verified developments in our understanding of the universe. Two books published around 2006 describe the quandary it is in:
- Lee Smolin, The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next (Mariner Books, 2006)
- Peter Woit, Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law (Basic Books, 2006)
Both books describe how quantum physicists by 2006 had greatly committed themselves to pursuing the development of string theory and its derivatives as the “only game in town” for the advancement of physics. This is in spite of the fact that after over 30 years of work, the engaged physicists had not developed any predictions that experiments could verify. Also, Smolin describes how it has been unable to contribute anything significant to the three great problems of physics:
- Combining general relativity and quantum theory into a single complete theory of nature
- Resolving the problems in the foundations of quantum mechanics
- Determining whether or not the various particles and forces can be unified
Smolin also writes that any of the contribution and insights provided by string theorists are not unique.
After reading Smolin’s book and reading some reviews of Woit’s book, I wondered if anything had occurred in the last eight years to change their negatives views on string theory and its derivatives. Woit’s blog, “Not Even Wrong,”[see link at end] provided me with a place to catch up with developments: Woit writes a monthly article that captures highlights of the current state of physics, reviews new books on physics, and allows readers to comment.
In his July 2014 blog titled “String Theory and Post-Empiricism.”* Woit brings us up to date with the state of things by summarizing two presentations at the Strings2014 Conference at Princeton using highlights from a proponent of the current state of string theory and a critic. The critic, Paul Steinhardt, attacked the current practice of inflationary cosmology (based on string theory) in its inability to accommodate any experimental result; and so, on philosophical grounds, it is no longer what we have always thought of as science.
The pro string theory presentation was by physicist turned philosopher Richard Dawid. Woit summarized Dawid’s positions as “claiming that conventional ideas about theory confirmation need to be revised to accommodate new scientific practices and the increasing significance of non-empirical theory confirmation.” Nobody knows what the latter really is, though. At the end, it seems to me that the string theorists’ main argument is “there is no other game in town.” Both Woit and Smolin dispute that. (For more of details on their problems, the reader needs to go the blog article.) But I want to add a few last comments and thoughts from Smolin, Woit, and one blog commenter:
- Woit: theoretical particle physics is in a stage where empirical results are not there to keep people honest, and new and better “post-empirical” ways of evaluating progress are needed. But these must come with rigorous protections against all-too-human failings such as wishful thinking . . . and I just don’t see those anywhere in Dawid’s proposal for new kinds of theory confirmation.
- Smolin (in a comment to Woit’s blog about this article) writes: “there are several alternative programs for quantum gravity and unification and there are compelling theoretical arguments for several of them. This is why experiment is necessary for science to progress.”
- Part of a reader’s comment: “I think Woit is mostly right to argue that string theory is more mathematics than science insofar as science has reasonably firm controls in place to falsify hypotheses and more generally control and limit wrong inquiry. . . . But where I think most of the disconnect and controversy occurs in these discussions is over the subtext that science is the crown jewel of human study, and that pursuits that are not scientific are at best somehow less valuable.” This person see string theory as more of a philosophical effort “pioneering developments in conceptual space.”
My summary perspective is that physics has “stalled out” in its ability to make major advances without new concepts of reality (for example, better insights and evidence of some sort on a more expansive conceptual space). My book Frontiers of Knowledge is about these conceptual expansions and evidence for them.
Additional Update [Jan. 10, 2015]: A 2013 book by Jim Baggott also presents the same basic message as Smolin and Woit. Baggott’s book, Farewell to Reality: How Modern Physics Has Betrayed the Search for Scientific Truth, is described in a review by the Economist magazine as
- Baggott is not so confident that progress in physics is assured. In Farewell to Reality the former physicist—who left academia but still occasionally writes about science—bridles at the ubiquity of what he calls “fairytale physics”: the flights of mathematical fancy, based on nothing more than personal taste, that he feels have come to litter the theoretical landscape over the past two decades.
*Woit’s website “Not Even Wrong” link is: