To the layperson, there's something odd about physicists' search for (amongst many other things) a Grand Unified Theory, that unites the four fundamental forces into one elegant model.
Why do they think that there is such a theory? Strange as it sounds, a lot of them say it's because having one force of the four (gravitation) not accounted for by the model, and requiring its own separate equations to explain, is "messy." Or "inelegant." Or -- most tellingly -- "ugly."
So, put simply; why do physicists have the tendency to think that for a theory to be true, it has to be elegant and beautiful? Couldn't the universe just be chaotic and weird, with different facets of it obeying their own unrelated laws, with no unifying explanation to account for it all?
This is the question that physicist Sabine Hossenfelder addresses in her wonderful book Lost in Math: How Beauty Leads Physicists Astray. She makes a bold statement; that this search for beauty and elegance in the mathematical models has diverted theoretical physics into untestable, unverifiable cul-de-sacs, blinding researchers to the reality -- the experimental evidence.
Whatever you think about whether the universe should obey aesthetically pleasing rules, or whether you're okay with weirdness and messiness, Hossenfelder's book will challenge your perception of how science is done. It's a fascinating, fun, and enlightening read for anyone interested in learning about the arcane reaches of physics.
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