Recently, Rob Sheldon offered some thoughts on three celeb physicists, Sabine Hossenfelder, Ethan Siegel, and Chad Orzel, in relation to the current crisis in theoretical physics: Our views of the universe don’t add up. His own view is,
“We need to go back to 1950 and revisit the alternatives. Because solving today’s impasse doesn’t require any new physics, but old physics done differently.”
He offers some suggestions on that:
George Gamow’s student Robert Alpher did his Phd on a model of the Big Bang (BB) in the famous Alpher, Bethe, Gamow paper in 1948. He used a one dimensional (1D) model, with radial symmetry, isotropic and homogeneous. And why not, it was the first attempt. Then in the 1950s, John Archibald Wheeler revived the field of cosmology, eventually rewriting the textbook on Gravity (Misner, Thorne, Wheeler), again using 1D models for BB. Fred Hoyle, who didn’t believe in the Big Bang, wanted to demonstrate its limitations, and talked his colleagues into programming (in 1967 FORTRAN) a Big Bang nucleosynthesis model with a “network” of nuclear elements all built up by decays and collisions with neutrons and protons, known as the BBN–which was also 1D. This has gotten more elaborate over the years, with neutrinos, dark matter, and dark energy added as dials, but today the EU PLANCK mission’s state-of-the-art model, you guessed it, is 1D.
Now what is peculiar about this situation, is that a very, very similar model is used to describe explosions of stars, or supernovae. When supernovae observations didn’t match the models, they didn’t add dark matter and dark energy, they went to three dimensions (3D). Lo-and-behold, the 3D models worked, and more importantly, showed that 1D models could not model the new instabilities of 3D. Yet the BBN and cosmology modelers refuse to consider 3D.
Because they found a 1D solution that matched the first 30 years of observations, which means deep roots of institutional funding and tenured professors. When the next 30 years didn’t support the model, they couldn’t go back.
That is, the “self-correcting” nature of science is muzzled by federal funding through consensus committees which, no lie, put grandfather clauses in the proposals to prevent change. That is to say, no matter what noble incentivizing scheme you devise for distributing other people’s money, someone will find a way to game the system. Read Robert J. Marks on why it is so hard to reform peer review.
And that is what Sabine Hossenfelder is saying is wrong with particle physics.
About dark matter and particle physics, could one use MOND (modified nuclear dynamics) to replace dark energy? I like Stacey McGaugh’s observational arguments for MOND, but unfortunately MOND is a “new physics” answer, when the same observations can be explained with old physics—namely, active particles. My answer is to go back to 3D BBN models and insert magnetic fields, which create comets, which possess negative viscosity, and so create dark matter. No new physics required.
What about particle physics?
Here the answer is a bit grim, and this is Sabine’s main point. The Standard Model is good, in fact, it is so good that it hasn’t been updated in 39 years. But our PhD’s are not given for adding decimal points to the down quark mass, our PhD’s are given for “original research.” This provides an abnormal incentive to find “new physics”. Hence the push for higher energies, new theories, even the desperate rush into cosmology to justify WIMPs or axions or other exotic particles to explain dark matter.
The problem with that, as Sabine explains patiently, is that any theory unconstrained by experiment is just math. So our particle physicists are “Lost in Math.” And the parameter space of wrong theories is infinite. So disproving another dozen theories does not, in fact, result in progress, any more than staying up all night counting to a million gets us any closer to infinity.
The observational disagreement about the neutron half-life is a case in point. This is a real observation, and requires some hard thinking about what is different between the two experiments. What seems obvious to me, is that there is three orders of magnitude difference in the magnetic field experienced by the neutrons in the two experiments, and magnetic field is a well-known component of Fermi’s 1933 weak interaction that controls neutron decay. Yet instead of this, Oak Ridge decides to advertise the “mirror universe” theory of their experimentalist, Leah Brussard, and to waste money to see if neutrons can teleport through walls.
Let’s just suppose the experiment reports success. Will it actually have proved the theory, or simply proved that we can’t count neutrons very well? We are turning the once-esteemed skill of designing experiments into the morass of a nutrition-science diet survey, where ambiguous results are touted as support for new alchemy recipes.
What is my answer to the impasse in all such fields?
Forget “new physics”. Forget the Nobel Prize. Forget proposals and funding. Just put another three decimal points on that constant, since we now have clocks that are accurate to 1:10^19, and consider it a scientific career well-spent. Get some humility, especially us physicists, and realize that everything we possess is a gift. Show some gratitude by filling in one of the many textbook gaps.
In Feynman’s words, there’s plenty of room at the bottom.
See also: Rob Sheldon on celeb physicists Sabine Hossenfelder, Ethan Siegel, and Chad Orzel 21 July 2019“My own view is that we need to go back to 1950 and revisit the alternatives. Because solving today’s impasse doesn’t require any new physics, but old physics done differently.”