How unusual is this? An esteemed scientist, Brian Greene, with an Opinion piece in a major paper. (I just reviewed his book UNTIL THE END OF TIME ending here.)
Washington Post, Brian Greene, 16 Sep 2024: Opinion | Decades later, string theory continues its march toward Einstein’s dream, subtitled “Why we must keep investigating physics’ most tantalizing theory — even without experimental results.”
The gist about string theory is whether it “explains” anything except mathematically, though without generating predictions that might be experimentally tested. It goes to the very nature of what science is.
Greene begins:
Forty years ago this month, the physics community was electrified by a remarkable paper that hinted at the realization of Albert Einstein’s long-held dream: a unified theory of physical reality. The new approach, called string theory, captured the attention of researchers worldwide, as its elegant mathematics offered the potential to reconcile the two most successful yet conflicting frameworks in physics: Einstein’s general theory of relativity, which governs the vast structures of the cosmos where gravity rules, and quantum mechanics, which governs particles populating the subatomic world.
Four decades and tens of thousands of research papers later, where do we stand? The answer lies not only in assessing scientific progress but also in understanding the profound influence of human nature, even in the ostensibly objective realm of science.
I’ve read a couple three books recently that challenge the conventional paradigm of how science works: hypothesis, prediction, test. Notably Strevens, and Deutsch and Kaku.
Scientists assess the validity of proposed theories by testing their predictions. The challenge for string theory is that it has yet to produce any definitive, testable predictions. This isn’t surprising. String theory diverges from conventional theories only under extreme conditions: where distances are unimaginably small and masses are extraordinarily large, such as in the core of a black hole or in the instant of the big bang. Unfortunately, exploring these realms is beyond our capabilities.
Critics argue that the situation is untenable, noting, “If you can’t test a theory, it’s not scientific.” Adherents counter, “String theory is a work in progress; it’s simply too early to pass judgment.” The critics retort, “Forty years is too early?” To which the adherents respond, “We’re developing what could be the most profound physical theory of all time — you can’t seriously cross your arms, tap your foot and suggest that time’s up.”
Deutsch explores the very nature of what an “explanation” for something means. And it’s not simply about predictions. (Infinity Chapter 1.)
Here’s where human nature stakes its ground. There’s no one-size-fits-all answer because it comes down to individual scientific taste, one’s tolerance for risk and the extent to which one is willing to defer experimental evidence in favor of mathematical progress. To be sure, I would readily abandon string theory — and I’m confident my colleagues would as well — if experimental evidence undercut it or if a mathematical inconsistency were uncovered. I’m an advocate for truth, not string theory. But so far, no such experimental insight exists, and no such mathematical flaws have surfaced.
On the contrary, string theory continues to captivate seasoned researchers and aspiring students alike because of the remarkable progress that has been made in developing its mathematical framework. …
And he ends by evoking the philosophical issue of whether mathematics is a human invention, or implicit in the real world. (I think the latter.)
The result also reflects on how mathematics has an uncanny, almost unreasonable, capacity to illuminate reality. Einstein’s math suggested the big bang, black holes, dark energy and gravitational waves — all consequences that Einstein, who was a cautious revolutionary (human nature, again) considered too exotic to be true. But over the past 100 years, each has been observationally confirmed. In a similar vein, his 1935 papers were motivated by mathematical critiques of quantum entanglement and black holes, but rather than expose theoretical flaws, the papers are now seen to refer to bona fide features of physical reality.
So, while mathematics is no substitute for experimental adjudication, mathematical progress has proved to be a crucial indicator of a theory’s potential to unlock secrets of the universe.
Will string theory follow this well-trodden path from mathematics to reality? No one can say. But its mathematical advances so far are extraordinary. And the only way to find out is to press onward. For string theorists, a community of rigorous, skeptical and ambitious scientists, the prize — revealing nature’s deepest secrets — is well worth the risk.
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This is adapted from Dawkins’ new book, The Genetic Book of the Dead: A Darwinian Reverie, published today. He knows more than I do, or you do, or most people do, about genetics and evolution and the history of the world.
Big Think, Richard Dawkins: Richard Dawkins on reverse engineering evolution’s optimal beauty, subtitled “Some biologists believe natural selection produces animals that are just good enough. Dawkins disagrees.”
Key Takeaways
• Engineers use “reverse engineering” to discern the purpose of a machine, even if that purpose had originally been lost to time. • Richard Dawkins shows how an analogous process can be used to understand the purpose of evolved characteristics in living creatures. • Even internal anatomy — bewilderingly messy and complex — will ultimately reveal its beautiful elegance to the trained eye.
Reverse engineering is the method by which scientific archaeologists reconstructed the purpose of the Antikythera mechanism, a mesh of cogwheels found in a sunken Greek ship dating from about 80 B.C. The intricate gearing was exposed by modern techniques such as X-ray tomography. Its original purpose has been reverse engineered as an ancient equivalent of an analogue computer, designed to simulate the movement of heavenly bodies according to the system of epicycles later associated with Ptolemy.
Reverse engineering assumes that the object facing us had a purpose in the mind of a competent designer, a purpose that can be guessed. The reverse engineer sets up a hypothesis as to what a sensible designer might have had in mind, then checks the mechanism to see if it fits the hypothesis. Reverse engineering works well for animal bodies as well as for man-made machines. The fact that the latter were deliberately designed by conscious engineers while the former were designed by unconscious natural selection makes surprisingly little difference: a potential for confusion readily exploited by creationists with their characteristically eager appetite for it. The grace of a tiger and of its prey could not easily, it would seem, be bettered:
What immortal hand or eye
Could frame thy fearful symmetry.
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Most mornings I reread, polish, and copy-edit my post from the evening before. If this comment is still here, I have not yet done so for this post.
