Marriage Of Strings Too Loops Again?

No, give cheers you.

People ofttimes demeanour inwards funny ways – too the human chemical scientific discipline is difficult to predict. That's why the marriages may sometimes await surprising to the external world, too. Over the weekend, Rupert Murdoch engaged retired supermodel Jerry Hall,



congratulations, too the wedding ceremony is imminent. During her career, she has protested things similar the expansion of an aerodrome – it's in all probability what makes Rupert excited. Well, it's non slow to get hitched amongst dissimilar scientific theories if they're truly different. They may alone get hitched amongst if they're shown compatible and, inwards the illustration of sufficiently well-defined theories, equivalent – too that occurs rarely.




The Quanta Magazine has absolutely absurdly published a nonsensical essay yesteryear Sabine Hossenfelder titled

String Theory Meets Loop Quantum Gravity.

Why practice they practice such things? The journal was relatively OK too thus far. Won't they also reveal her recent "musings" discussed here claiming that neither the gratis volition nor whatsoever subjective experiences tin be (tell it to those of us who are subjectively aware of ourselves too the footing roughly us) too the experimenters are prevented yesteryear Nature's Big Brother from pressing buttons on their gadgets that could reveal the truth virtually Nature?

I was happy to regard that almost all of her commenters sympathize that her claims virtually the perception too decisions brand no sense. Can someone hold upwards too thus dimwitted non to regard the incoherence too incompatibility amongst the most well-known facts virtually the world?




In her "marriage" piece, she complains that the researchers of string theory too loop quantum gravity (LQG) lead maintain split conferences. The theories may hold upwards 2 sides of the same coin, she suggests as if it were mutual sense. (Her old overlord Lee Smolin was the alone other individual inwards the footing who sometimes liked to tell this stupidity.) Thankfully, she also mentions that people mostly disagree amongst the thought that the theories may hold upwards equivalent.

Moshe Rozali explains something y'all lead maintain read hither many times. If your starting betoken is a theory that violates exceptional relativity yesteryear O(100)% at the commutation level, too LQG is an example, it's pretty much guaranteed that every "intermediate too finally level" of physics derived from the theory volition violate the symmetry yesteryear O(100)%, too. That's why he doesn't innovation to piece of work on LQG anytime soon.

On the crackpot side, Carlo Rovelli defends LQG yesteryear proverb that the LHC hasn't discovered supersymmetry yet. That's neat but supersymmetry volition eventually hold upwards discovered; too the absence of supersymmetry is extremely far from beingness the alone occupation of LQG. It's really the smallest one.

OK, y'all are for sure bespeak what's Hossenfelder's show that strings too LQG may teach married. It's supposed to hold upwards a 7-page preprint yesteryear Pullin too Gambini

Emergence of string-like physics from Lorentz invariance inwards loop quantum gravity

These guys understood that "if y'all desire to brand LQG compatible amongst relativity, y'all lead maintain to add together some nonlocal interactions that be inwards [effective descriptions of] string theory into LQG". I volition get upwards the technical issues momentarily.

But when it comes to LQG or its proposed wedlock to string theory, y'all must sympathize that the "cleverness" of sure nonlocal interactions that these guys lead maintain understood has nothing whatsoever to practice amongst LQG. So what they're proposing is exactly similar the next recipe to create CocaCola from urine:

Take 2 liters of our wonderful urine.

And add together 50 liters of PEPSI, including some ingredients that are alone constitute inwards Coke. Mix it. And the termination volition sense of savor almost exactly similar CocaCola produced out of urine!

It's wonderful except that the master copy urine hasn't played whatsoever useful operate inwards the production. To tell that the skillful plenty sense of savor (and similarly positive features of sure nonlocal interactions inwards the effective theory) lead maintain anything to practice amongst urine (or LQG) is pure demagogy. It's stupidity. Everything that industrial plant inwards the mixture is taken from string theory (or PEPSI or Coke) too everything that doesn't is taken from urine (or LQG).

Pullin too Gambini may permute their restroom too their kitchen inwards many chaotic ways too thus that some readers volition lose their might to distinguish these 2 rooms too the liquids inwards them. But smarter readers won't lose this ability.

And y'all may easily cheque that afterwards 1.5 years, the newspaper has three citations. An fifty-fifty crazier appear of this fact is that 1 of the followups was written yesteryear Hossenfelder herself. That as illogical followup is a (valid but absolutely non new) no-go theorem claiming that y'all can't teach the Lorentz invariance from sure discrete starting points. So it's a preprint that contradicts the basic destination of the Pullin-Gambini article as good as her Quanta Magazine review. She contradicts herself.

The content of her skull may hold upwards classified as an absolutely, hopelessly unfixable, mess.

Just to get upwards something virtually the technical content: Because strings are extended objects, if y'all rewrite the interactions of the massless fields as if they were interactions of fields creating point-like particles, y'all volition unavoidably obtain some nonlocal interactions as well. The point-like particle is "actually" an extended object too thus it influences physics (and particles) at other points than exactly the center-of-mass where y'all imagined the particle to hold upwards located (although it's an extended string). And that's why nonlocal interactions occur if y'all write string theory inwards this way.

However, the actual underlying string dynamics is Lorentz-invariant too is, inwards some sense, perfectly local. The string interactions are local on the footing sheet of the strings, too because the footing canvas is smoothly embedded inwards the spacetime, the interactions are local inwards the spacetime, too. At to the lowest degree inwards some sense. It doesn't contradict the fact that the theory may await nonlocal inwards the spacetime if y'all rewrite this dynamics (or its effective approximation) inwards a sure way.

These nonlocalities are of a exceptional form. They yet know virtually the perfectly consistent, Lorentz-invariant underlying theory. The amount theory could hold upwards reconstructed from the amount listing of the nonlocal interactions betwixt all the fields. But different, generic types of nonlocal interactions stay deadly – generic nonlocality for sure contradicts the Lorentz symmetry. Comments similar that, amongst some equations, appear at the commencement of some introductory texts to string theory. Pullin too Gambini lead maintain finally understood these sentences. (They lead maintain thousands of other basic things they demand to sympathize inwards front end of them.) They got a chip excited too rhetorically complained that their urinated theory, LQG, doesn't lead maintain whatsoever of these things. It should have. Let's import them, they recommended.

However, LQG is intrinsically incompatible amongst the Lorentz symmetry. It's also incompatible amongst the nonlocality of this sort or whatsoever similar kind. String theory is perfectly Lorentz-invariant despite the fact that some of its formulations await nonlocal. From that perspective, string theory is a victory despite a bad starting point. On the other hand, due to the discreteness etc., LQG is Lorentz-violating despite the fact that its interactions are yesteryear structure "local" (in the discretized spacetime). It's a failure despite a neat starting position.

This whole thought yesteryear Hossenfelder is exactly a demagogic betoken meant to pretend that the LQG folks are basically doing something similar similar string theorists. Except that they don't. LQG folks lead maintain never written a skillful newspaper too they don't lead maintain to write whatsoever skillful papers to teach LQG jobs – because no 1 else inwards LQG has e'er done anything of the sort, either. They're hired only inwards companionship to hold upwards inwards "opposition" too to fill upwards the affirmative activity quotas (including the quota proverb that ignorant, stupid, too lazy people lead maintain to hold upwards as widespread inwards the scientific community as the educated, brilliant, too hard-working ones). It's alone string theorists who are really contributing to physics. So how tin someone claim that those are "peers" or theories to teach married?

String theory conferences don't demand to hold upwards flooded yesteryear hectoliters of urine who lead maintain understood at most the initiatory of all pages of an introductory string theory textbook – too commonly much less than that – too who only lead maintain null interesting or coherent to say. I am exactly absolutely disgusted that these fraudulent tricks are tolerated if non encouraged inwards the Academia too that the Quanta Magazine that has been mostly OK too thus far is willing to transform itself into some other cesspool that publishes indefensible nonsense similar the nonsense from Ms Hossenfelder.