Friday, July 08, 2016 ... Deutsch/Español/Related posts from blogosphere

Medication needed against anti-physics activism

Their activity got too high in the summer

Some three decades ago, mosquitoes looked like a bigger problem in the summer. Their numbers had to drop or I am spending less time at places where they get concentrated. The haters of physics have basically hijacked the mosquitoes' Lebensraum, it seems.

The scum stinging fundamental, theoretical, gravitational, and high-energy physics became so aggressive and repetitive that it's no longer possible to even list all the incidents. A week ago, notorious Californian anti-physics instructor Richard Muller – a conman who once pretended to be a climate skeptic although he has always been a fanatical alarmist, a guy who just can't possibly understand that the event horizon is just a coordinate singularity and who thinks it's a religion to demand a physical theory to be compatible with all observations (quantum and gravitational ones), not to mention dozens of other staggering idiocies he has written in recent years – wrote another rant saying that "string theory isn't even a theory".

There's absolutely nothing new about this particular rant – it's the 5000th repetition of the anti-string delusions repeated by dozens of other mental cripples and fraudsters in the recent decade. To make things "cooler", he says that many string theorists would agree with him and to make sure what they would agree with, he promotes both Šmoits' crackpot books at the end as the "recommended reading".

Oh, sure, string theorists would agree with these Šmoitian things. Time for your pills, Mr Muller.

This particular rant has been read by more than 45,000 readers. The number of people indoctrinated with this junk is so high that one should almost start to be afraid to call the string critics vermin on the street (my fear is not this far, however). I am sure that most of them have been gullible imbeciles since the rant was upvoted a whopping 477 times. Every Quora commenter who has had something to do with high brow physics disagrees with Muller but it's only Muller's rant that is visible. Quora labels this Muller as the "most viewed writer in physics". Quora is an anti-civilization force that deserves to be liquidated.

This week, someone wrote a text about the LHC's being a disappointment, another gem from this familiar author. The LHC is a wonderful machine that has already discovered enough to justify its existence and that works perfectly. Lots of the genuine particle physics enthusiasts are excited to follow both papers by the LHC collaboration and the LHC schedules. And while naturalness may look stretched and many people (not myself!) have surely been naive about the direct way how it can imply valid predictions, it is absolutely obvious that to some extent, it will always be viewed as an argument.

It's because theories of Nature simply have to be natural in one way or another. The point is that you can always construct uncountably many unnatural theories that agree with the data. You may always say that some highly fine-tuned God created all the species just like we observe them and all the patterns (and observations that something is much smaller than something else etc.) explained by the natural theories are just coincidences. You can take any valid theory and add 50 new random interactions with very small coupling constants or particles with high masses and claim that your theory is great.

But such unnatural theories are simply no good because it's unlikely for the parameters to have at least qualitatively the right values that are needed for the theories to avoid contradictions with the empirical evidence. At some level, the Bayesian inference that indicates that dimensionless parameters shouldn't be expected to be much smaller than one kicks in. It's the quantitative reason why it's often right to use Occam's razor in our analyses. You know, the future of naturalness is basically analogous to the future of Occam's razor, a related but less specific concept. Some very specific versions of it may be incorrect but the overall paradigm simply can't ever disappear from science.

The right laws of Nature that explain why the Higgs mass is much lighter than the Planck scale may be different than the existing "sketches" of the projects but at the end, these laws are natural. They are colloquially natural which, you might object, is a different word. But in any sufficiently well-defined framework, the colloquial naturalness may be turned into some kind of technical naturalness.

To demand that naturalness is abandoned or banned altogether means to demand that people no longer think rationally. The author of that essay is just absolutely missing the point of science. His or her last paragraph says:

It’s somewhat of a mystery to me why naturalness has become so popular in theoretical high energy physics. I’m happy to see it go out of the window now. Keep your eyes open in the next couple of years and you’ll witness that turning point in the history of science when theoretical physicists stopped dictating nature what’s supposedly natural.
But naturalness isn't going "out of the window" (just look at recent papers with naturalness in the title) and physicists who complain that a theory is unnatural aren't dictating anything to Nature. Instead, they complain against the broader theory. A theory that is fine-tuned and doesn't have any explanation for the fine-tuning is either wrong or missing the explanation of an important thing – it fails to see even the sketch of it. You know, when a theory disagrees with the data "slightly" or in a "detail", something may be "slightly" wrong about the theory or a "detail" may be incorrect. But when a theory makes a parametrically wrong estimate for its parameters, something bigger must be wrong or missing about the theory. Naturalness doesn't say anything else than this trivial fact that simply can't be wrong because in its general form, it's the basis of all rational thinking. Theories in physics will always have to be natural with some interpretation of the probabilistic distributions for the parameters.

The anthropic principle is sometimes quoted as an "alternative to naturalness". Even if this principle could be considered a replacement of this kind of thinking at all, and I am confident that it's right to say that there's no version of it that could be claimed to achieve this goal at this moment, it would still imply some naturalness. The anthropic principle, if it became well-defined enough to be considered a part of physicists' thinking, would just give us different estimates for the parameters or probability distributions for them. But it would still produce some estimates or distributions and we would still distinguish natural and unnatural theories.

And it goes on and on and on. Yesterday, Ethan Siegel wrote a Forbes rant claiming that grand unification may be dead end in physics. Siegel is OK when he writes texts about Earth's being round or similar things but hey, this guy simply must realize that he is absolutely out of his league when it comes to the cutting-edge fundamental physics. Everything he has written about it has always suffered from some absolutely lethal problems and this new rant is no exception.

He uses Garrett Lisi's childish picture to "visualize" the Georgi-Glashow grand unified \(SU(5)\) model (projection of some weights of the fermion reps on a 2D subspace of the Cartan subalgebra). I don't think that this unusual picture is useful for anything (perhaps to incorrectly claim that some \(\ZZ_6\) symmetry is what grand unification is all about) but yes, there are much more severe problems with Siegel's text.

When he starts to enumerate "problems" of grand unified theories, he turns into a full-fledged zombie crackpot:
But there are some big problems with these ideas, too. For one, the new particles that were predicted were of hopelessly high energies: around \(10^{15}\) to \(10^{16}\GeV\), or trillions of times the energies the LHC produces.
What? How can someone call it a "problem" in the sense of "bad news"? The scale at which the couplings unify is whatever it is. If it is \(10^{16}\GeV\), then it is a fact, not a "problem". A person who calls one number a "problem" unmasks that he is a prejudiced man or woman. He simply prefers one number over another without any evidence that would discriminate the possibilities – something that an honest scientist simply cannot ever do.
For another, almost all of the GUTs you can design lead to particles undergoing flavor-changing-neutral-currents, which are certain types of decays forbidden in the Standard Model and never observed in nature.
Great. But it's true for any generic enough theory of new physics, too. Clearly, Nature isn't generic in this sense. But there exist grand unified theories in which all these unwanted effects are suppressed in a technically natural way and that's everything that's needed to say that "everything is fine with the broader GUT paradigm at this moment". Similarly, the proton decay is acceptably slow in some classes of grand unified theories that are as fine as the Georgi-Glashow model.

But the most staggering technical stupidity on grand unified theories that Siegel wrote was one about the unification of the couplings:
The single “point” that the three forces almost meet at only looks like a point on a logarithmic scale, when you zoom out. But so do any three mutually non-parallel lines; you can try it for yourself by drawing three line segments, extending them in both directions until they all intersect and then zooming out.
What? Every three straight lines intersect in one point? Are you joking or are you high?

If you draw three generic straight lines A,B,C in a plane, the pairs intersect at points AB, BC, CA, but there is no intersection of all three lines ABC. Instead, there is a triangle inside. That's the left picture. On the other hand, for a special slope of the third line C – one real number has to be adjusted – the intersection BC may happen to coincide with the intersection AB, and when it's so, the intersection of CA coincides with this point, too: all three lines intersect at one point. That's the right picture. The triangle shrinks to zero area, to a point.

This outcome is in no way guaranteed. It's infinitely unlikely for three lines in a plane to intersect at one point. The small likelihood of this small miracle is roughly equal to the ratio of the actual precision (i.e. the longest side of the triangle) we get over the characteristic precision (the size of the triangle) we expected. The fact that the unification (intersection at a point) happens in a large subset of "morally simple enough" grand unified theories with a certain precision is a nontrivial successful test of these theories' viability. It doesn't prove that the 3 forces get unified (because the precision we can prove isn't "overwhelming") but it's not something that may be denied, either.

How can Ethan Siegel misunderstand the difference between 3 lines intersecting and non-intersecting? I think that every layman who has failed to understand this simple point after reading a popular book on particle physics has failed miserably. Siegel just doesn't make it even to an average reader of popular physics books.

And the incredible statements are added all the time:
The small-but-nonzero masses for neutrinos can be explained by any see-saw mechanism and/or by the MNS matrix; there’s nothing special about the one arising from GUTs.
One can get neutrino masses of a reasonable magnitude from any physics at the right scale but the scale has to be near the GUT scale. Funnily enough, it's the scale \(10^{15}\) to \(10^{16}\GeV\) that Siegel previously called a "problem". Except that this value disfavored by Siegel is favored by the neutrino masses. It's the scale where one expects the new physics responsible for the neutrino masses and nontrivially, it's approximately the same scale as the scale where the unification of the couplings demonstrably takes place (according to a calculation).

So that's another piece of evidence for the picture – that something is taking place at the scale and the something is rather likely to include the unification of non-gravitational forces. Moreover, it's somewhat beneath the Planck scale where gravity is added to the complete unification and it's arguably a good thing: the non-gravitational forces shouldn't split "unnaturally too low" beneath the truly fundamental, Planck scale.

It's the conventional picture which is still arguably most convincing and likely: the true unification of 4 forces occurs close enough to the Planck scale as calculated by Planck and at energies lower by some 2-3 orders of magnitude, the GUT force splits to the electroweak and the strong one. The electroweak force splits to the electromagnetic and weak force at the LHC Higgs scale. This old picture isn't "a demonstrated scientific fact" but it sounds very convincing and as long as we live in a civilized society, you can't just "ban" it or try to harass the people who think that it's the most persuasive scenario – which includes most of the top particle physicists, I am pretty sure about it.

This person just fails to understand all these basic things and he sells this embarrassing ignorance as if it were a virtue. At the very end, we read:
There’s no compelling reason to think grand unification is anything other than a theoretical curiosity and a physical dead-end.
A more accurate formulation is that Mr Siegel doesn't want to see any arguments in favor of grand unification because he is a dishonest and/or totally stupid prejudiced and demagogic crackpot. But I guess that Siegel's own formulation, while totally untrue, sounds fancier to his brainwashed readers.

The number of individuals just like him has grown astronomical and they produce their lies on a daily basis without facing almost any genuine enemies.

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