Sunday, February 05, 2012

The Hoganmeter

Almost three years ago, I wrote about Craig Hogan's holographic noise. If you look up Hogan's papers on the arXiv, you'll see that he has been on the topic of holographic noise at least since 2004. His time came in 2009, when the GEO600 gravitational wave interferometer detected unexplained excess noise, just at the right frequency to be "holographic." New Scientist reported.

Unfortunately, the GEO600 noise vanished after a new readout method was employed by the collaboration. Hogan corrected his prediction for the noise by finding a factor in his calculation, so that the noise was no longer in the GEO600 range.

But that wasn't the end of the story. Craig Hogan is a man with a mission - a holographic mission. Last year, I mentioned that Hogan got a grant to follow his dreams and is now building his own experiment at Fermilab, the "Holometer," especially designed to detect the holographic noise. (Which might or might not have something to do with holographic foam. More likely not.)

In the February issue, Scientific American's cover story asks the questionn "Is Space Digital?" The article by Michael Moyer reports on Hogan's Holometer. I really like Scientific American. Look, we have a subscription to the PRINT version, do I need to say more? But this is the worst article I've ever read in this magazine.

To begin with, it is entirely uncritical, and one doesn't actually learn anything about the, in principle quite interesting, question whether space may be digital. One doesn't even learn why the question is interesting. But even worse is that the article is also factually wrong in several places. You can read there for example:
"[Hogan] begins by explaining how the two most successful theories of the 20th century - quantum mechanics and general relativity - cannot possibly be reconciled. At the smallest scales, both break down into gibberish."

Where to start? Moyer probably meant "quantum field theory" rather than "quantum mechanics." One might forgive that, since this simplification is often made in science journalism.

I am more puzzled that Hogan allegedly explained quantum field theory and general relativity cannot possibly be reconciled. Last time I looked there were literally thousands of people working on such a reconciliation; they would surely be interested to learn of Hogan's insight. Therefore, I doubt that this is what Hogan was saying, especially since his experiment is supposed to test for such a reconciliation. More likely, he was laying out the main difficulties in quantizing gravity. Which brings me to the next misleading statement: one might say indeed that gravity breaks down at small distances, which could mean all from the formation of singularities at high densities to the breakdown of the perturbative expansion. But it's news to me that quantum mechanics "breaks down to gibberish" at short scales.
"The Planckscale is not just small - it is the smallest."

Depends on whether you are talking about the Planck length or the Planck mass!
"The laws of quantum mechanics say that any black hole smaller than a Planck length must have less than a single quantum of energy."

The laws of quantum mechanics don't say anything about black holes. And probably neither Hogan nor Moyer have ever heard of monsters.

And then I came to this sentence:
"[P]hysicists mostly agree that the holographic principle is true"

Micheal Moyer's evidence comes from talking to Craig Hogan and Leonard Susskind. He also quotes Jacob Bekenstein, Raphael Bousso and Herman Verlinde.

I am always stunned how easily science writers lose perspective. The vast majority of physicists work in condensed matter physics, nuclear and atomic physics, solid state physics, plasma physics, optics or quantum optics, and astrophysics, half of them in experiment. The idea that space may be digital is a fringe idea of a fringe idea of a speculative subfield of a subfield. I'm not saying it's not interesting. I'm just saying if you'd actually go and ask a representative sample of physicists, I guess you'd find that most don't care about the holographic principle and wouldn't agree on any statement about it.

Anyway, the best part of Moyer's article is a quotation by Hogan about the motivations for his experiment:
"It's a slight cheat because I don't have a theory."

Indeed, if you look at the Holometer website, you find an extensive list of two articles, both unpublished, one of which scores with 25 revisions in 2 years.

Hogan is also quoted with saying
"Things have been stuck for a long time. How do you unstick things? Sometimes they get unstuck with an experiment."

That is true and exactly the reason why I am working on the phenomenology of quantum gravity! But normally, before investing money into an experiment, it is worthwhile to check if not the hypothesis that would lead to a signal in the experiment would also lead to other effects that we should already have seen. Unfortunately, this is difficult to tell without a theory! The criticism in my post from three years ago was essentially that Hogan's scenario breaks Lorentz invariance, and we know that Lorentz-invariance violation is very tightly constrained already. Maybe there is a way to avoid the already existing constraints, but I'd really like to know how.

I admit that I admire Hogan for his passion, perseverance, and also his honesty to admit that he doesn't exactly know what he's doing or why, just that he feels like it has to be done. He is the archetypal American with a hands-on, high-risk, high-gain attitude. He also looks good on the photo in the Scientific American article, is director of the Fermilab Center for Particle Astrophysics, and probably doesn't care a lot about peer review.

Of course I hope he succeeds, because I really want to see some positive evidence for quantum gravity phenomenology in my lifetime!

And hey, you know, I too have an idea for an experiment that can revolutionize our understanding of the world. And mine did even get published.

18 comments:

Steven Colyer said...

Ha! What did Roger Penrose say who is also not fond of the Holographic Principle? Something to the effect of "Who decided that a conjecture be promoted to a principle without proof?" Something like that. :-)

I'm not surprised however whenever Dr. Susskind is consulted that principle gets promoted to fact. Same for the Multiverse. Both of which may be true.

QFT v QM is a bit of a nitpick but technically correct. I get that the target audience is the general intelligent lay public though, and most wouldn't know even had they taken 4 semesters of college level calculus ending in differential equations, what quantum field theory is, and I don't believe The Dirac Equation is taught to any field other than Physics majors. whijact

Zephir said...

/* At the smallest scales, both break down into gibberish..*/

I dunno about smallest scales, but at the human observer scale they both break down to the mainstream theories, developed and residing inside of human brains.

Zephir said...

The frequency range of Hogan interferometer is limited by audiofrequencies from bottom (no gravity waves were found there) and with TV frequencies from top. Why just TV frequencies? Because these frequencies are interfering with omnipresent CMBR noise. And this is the actually the stuff, which Hogan is supposed to measure - a gravitational waves. It's just another example of phenomena, where the physicists avoid the measurement of just the effect, which they're expecting to detect. Why the physicists simply will not consider the CMBR noise as a gravity waves and stop with building of detectors worth of billion dollars? Anyway, Hogan's machine is just a huge waste of money. He tries to find holographic noise at the moment, we have the vacuum full of CMBR noise, which everyone can detect with his TV set.

Plato said...
This comment has been removed by the author.
Plato said...

Hi Bee,

I guess in a sense I am a romantic fool too:)

See:Holometer

Best,

Plato said...
This comment has been removed by the author.
Robert L. Oldershaw said...

Very nice comment on some trends that are all too common in today's version of theoretical physics.

Empirical evidence will eventually provide the necessary course corrections, but observations are the tortoise and pseudo-physics is the hare.

Bee said...

Hi Plato,

I've freed one of your comments from the spam queue. (Now it seems there are several!) Best,

B.

Uncle Al said...

Hogan offers tinsel for a dead Christmas tree. Cosmesis is grant fundable. Dark Star (1974): Commander Powell "Teach it phenomenology." Thermostellar Bomb #20 instead exercised Cartesian doubt.

Fermionic mass is not wholly described by photon vacuum symmetries postulated in gravitation and particle theory. There is testably more (if said tests support the Party line by failing).

Plato said...

Hi Bee,

“People trying to tie reality together don’t have any data, just a lot of beautiful math,” said Hogan. “The hope is that this gives them something to work with.” See:Hogan’s holometer: Testing the hypothesis of a holographic universe

I am not sure if they should give up being progressive in what was not detected before.....so, naturally one refines their experiment or raise questions about the process itself.

If you can advance predictions before hand as to what might be seen then what said the basis of one's argument will not have some foundational value as to insight into what will materialize?

So credibility is given, on sound oppositional arguments as to why this experiment is no good?

Your at the front line now?;)

Best,

Unknown said...

Hogan's observation of the "graininess" of space-time argues perfectly for my theory of a spacetime subatomic wormhole geometry. I believe that space-time is in fact a constantly shifting mass of closely packed subatomic wormholes (which are stretchable and spring-like). IF one accepts this theory, and it's corollary that gravity is not a true field force (i.e., universal force), but rather the observed interaction of matter with the subatomic wormhole geometry of space-time, than you can explain quantum effects with Newtonian and Relativity physics alone. It also explains the recent neutrino anomalies reported at CERN. If low mass, or no mass, subatomic particles, like neutrinos can use the subatomic wormhole geometry of space-time, than they can take shortcuts in traveling through space-time, which would give the appearance of greater than light speed. Additionally, the subatomic wormhole theory explains the double-slit experiment, Feynmann diagrams, the Heisenberg Uncertainty Principle, and other probabilistic concepts of quantum theory based on which particular moving subatomic wormholes certain subatomic particles enter and exit. Prof. E. Sergio Santini wrote a paper in 2007 that postulated a subatomic wormhole connection with protons in order to explain the strength of the Strong Nuclear Force, too.

Bee said...

Hi Plato,

What I am saying is that over the centuries the scientific community has developed ways to efficiently channel investment of time and money. One way to prevent wasting effort is to make sure you're not fooling yourself (and others) and write down the equations, and follow the conclusions, if you like them or not. More often than not you'll find that your idea, nice as it is, is actually not compatible with some feature of the world that we have a lot of evidence for. Every credible scientists who works on phenomenology does that, and everybody knows how easy it is to fool yourself if you're not doing the math.

That having been said, it doesn't mean that Hogan's idea is wrong or that he won't find anything. I am just saying, in lack of a solid theoretical basis, the risk is very high he is, unintentionally, fooling himself and those who have funded the experiment. Basically, he has omitted one of the most important instances of quality control in his community and replaced it with intuition. It's interesting to some extend, but I hope that's not becoming a trend for science in the USA. Best,

B.

Jason said...

Dear Unknown, Your ideas are intriguing to me, and I wish to subscribe to your newsletter.

Zephir said...

/* One way to prevent wasting effort is to make sure you're not fooling yourself (and others) and write down the equations..*/

I'm afraid, the future physics will be more difficult for formally thinking theorists, because they should be required to understand their formal model first. Contemporary theorists are often mixing equations from various dual/plural models without bothering if these equations are consistent mutually.

At the case of Mr. Hogan, in some aspects he understands the physics better, than everyone else here. If CMBR noise is real, than the holographic noise must be present too. In other hand he does the very same mistake, like others if he ignores the CMBR noise, because it's the most tangible evidence of holographic model.

Please note that the holographic model considers the superluminal waves spreading - or its projective model couldn't work at all. It is therefore consistent with aether model of CMBR noise as a manifestation of superluminal gravitational waves. But you cannot get these connections just from equations, face it. You should understand the problem at its nonformal, intuitive level (water surface model, whatever). It's because the formal equations don't provide reliable clue at the case of singular conditions.

For example, the location in space-time is defined in relativity in the same way, like the reference frame for gravitational wave spreading. The gravitational wave is behaving like the sequence of space-time curvatures and location in space-time is defined with these space-time curvatures as well. It means, the reference frame of gravitational waves is not defined in relativity and such waves would therefore propagate like the noise. The point is, you're trying to describe hyperdimensional situation with low-dimensional equations, which are becoming poorly conditioned in this case. You cannot derive such singular situation just with mathematical analysis, because its equations are becoming singular as well. You should have it in your head - no matter, how much you believe into unlimited power of formal math or not.

Zephir said...

So that one way to prevent wasting effort is to make sure you're not fooling yourself (and others) and compose the nonformal model first, before you starting to combine the existing equations blindly. In some case the intuitive model is more predicative, than the singular combinations of existing equations, in some cases not - but the intuitive logics should always come first.

After all, in formal math all theorems must be proven first at the level of predicate logic, before they can be used in subsequant derivations. So that the formal physics should work in the same way - it's actually more rigorous approach, not less rigorous one. Without it every theorem becomes a conjecture only, no mater how carefully it is derived from existing equations.

Bee said...

I've tried to explain Zephir a dozen times or so that what he believes is noise that requires his ingenuity for explanation are the temperature fluctuations in the Cosmic Microwave Background. They are very well understood, and do neither require his "theory" nor holography for understanding.

I have given up the hope that Zephir is able to overcome his ignorance, and just want to add this to avoid other readers get confused.

Plato said...

Thanks Bee

Zephir said...

/*..what he believes is noise that requires his ingenuity for explanation are the temperature fluctuations in the Cosmic Microwave Background..*/

The photons cannot be the temperature fluctuations of itself. But being photons is not their only meaning in mainstream physics. Can you imagine the situation, you're a physicist and a mother at the same moment? So do these photons.