Monday, April 5, 2021

Sabine Hossenfelder Rightly Calls Out Michio Kaku's String Theory Hype

Sabine Hossenfelder rightly calls out Michio Kaku for this flat wrong statement about String Theory that he made in a newspaper interview:
There’s this avalanche of experimental numbers you have to put in by hand. But in string theory the Standard Model just pops right out. With just a few assumptions you get the entire Standard Model. 
That's just wrong. #StopHype

She goes on to note that String Theory, Supersymmetry, the Multiverse and "literally hundreds of additional fields and particles and stories for the beginning of the universe" are not used in physics for any applications because they are useless and don't predict anything.

Woit is similarly very critical:

This is just complete and unadulterated bullshit, of exactly the same sort Kaku and a host of others well-credentialed physicists have been heavily and successfully promoting for the last 35 years. I started writing about this 20 years ago, and there have been some changes since then (for one thing, we have Sabine Hossenfelder). I’m still waiting though for any of the leading figures in the physics community responsible for the string-theory hype campaign to do anything at all to try and stop Kaku and the rest of the Fake Physics onslaught that they unleashed.

String theory was supposed to precisely what Michio Kaku told the interviewer that it actually does. When string theory was first starting to come together in the 1980s, not long after the formulation of the Standard Model, it looked like it would. But time and an immense amounts of work by a regiment of many of the highest IQ people on the planet for generation has come up empty, and revealed more problems and ambiguities than solutions.

The reality is that nobody has come remotely close to reproducing the Standard Model from string theory or supersymmetry. 

Nobody has come up with equations in string theory that reproduce the Standard Model's particle content and its three forces plus gravity. It hasn't even been possible to reduce string theory to a specific "grand unified theory" or supersymmetry or supergravity theory. 

Most of the similarity between the equations of string theory that are out there and the Standard Model arise because the string theory equations deliberately imitate the Standard Model equations that describe the creation, annihilation, and propagation of fundamental particles, not the other way around.

There a vast number of possible low energy physical theories that superficially look like they might be consistent with string theory, but are not, called the swampland. And, there are a vast number of theories that are consistent with string theory called the string theory landscape, that are inconsistent with observed reality.

Nobody has used string theory to reproduce any of the physical constants of the Standard Model or to determine how they are related to each other as functions of each other. Indeed, nobody has come up with any theory that reproduces all of the physical constants of the Standard Model to a degree consistent with experimental measurements (without simply adding many more equally arbitrary physical constants). 

This blog has devoted considerable attention to formulas including Koide's rule, extensions of Koide's rule beyond the charged leptons, and the LP&C conjecture relating the masses of the fundamental particles to the Higgs vev, that attempt to reduce the number of experimentally measured degrees of freedom in the Standard Model primarily because nobody has come up with alternatives that perform any better.

Nobody has discovered any non-Standard Model particles of any kind. There might be beyond the Standard Model dark matter particles, but so far that search has been inconclusive at best, and there are credible arguments that the phenomena attributed to dark matter are actually just lower order gravitational effects. Neutrino mass is the only contribution we've seen to it since it was determined that there were exactly three generations of fermions.

Nobody has observed any evidence of dimension in excess of the Standard Model's three spatial dimensions and one dimension of time. Depending on the details of the model, string theory predicts ten or eleven dimensions. There are multiple suggestions of ways to reconcile this discrepancy, but they aren't unique.

It is really even worse than that. There is wide consensus that supergravity, the gravitational extension of supersymmetry, is the low energy effective description of string theory. But there is increasing evidence that supergravity and supersymmetry are not correct descriptions of the real world.

Michio Kaku is simply gaslighting reality based physicists.


Mrs. Watanabe said...

It's Kaku, not Katu.

andrew said...

Thank you for catching that. Fixed! My apologies to Mr. Kaku for spelling his name incorrectly.