Archive for the ‘Physics’ Category


No little thing is to small for grandiose words chiseled by some marketing war machine.

Seen on a Lampe Berger anti-mosquito product this morning:

Parfum “Absolu de vanille”

Vanilla Gourmet Scent

Not only is this ridiculously hyperlative, but they also have a different “tint” for the Engish and French version. English reader will notice that the French version sounds more like “Absolute Vanilla”, because that’s basically what it means. Who on Earth paid people to tell their customers that their anti-mosquito drug had a “Vanilla Gourmet scent?”

Let’s not get used to this kind of marketing hyperbole…

Hyperbole in science

In despair, I turned to a slightly more serious text, the first page of this month’s issue of Science et Vie. And here is what I read there about faster than light neutrinos:

Incroyable? Alors là oui, totalement! Et même pis. Que la vitesse de la lumière puisse être dépassée, ne serait-ce que de très peu, n’est pas seulement incroyable, mais totalement impensable. Absolument inconcevable. [...] c’en serait fini d’un siècle de physique. Mais, et ce serait infiniment plus grave, c’en serait aussi fini avec l’idée selon laquelle la matière qui compose notre univers possède des propriétés, obéit à des lois. Autant dire que la quête de connaissance de notre monde deviendrait totalement vaine.

Incredible? Absolutely! And even worse. That the speed of light can be exceeded, even a little, is not only unbelievable, but totally unthinkable. Absolutely inconceivable. [...] This would end a century of physics. Even more serious, we would be done with the the idea that matter making up our universe has properties, obeys laws. This would mean that the quest for knowledge in our world would become totally hopeless.

Whaaaaat? I really don’t like this kind of pseudo-science wrapped in dogma so pungent to be the envy of the most religious zealots. How can anybody who understood anything about Einstein’s work write something like that? Let’s backpedal a little bit and remember where the speed of light limit comes from.

Where does the speed of light limit come from?

At the beginning was Maxwell’s work on the propagation of electromagnetic waves, light being such a wave. These equations predicted a propagation of light at a constant speed, c, that could be computed from other values that were believed at the time to be physical constants (the “epsilon-0″ and “mu-0″ values in the equations). The problems is that we had a physical speed constant, in other words a speed that did not obey the usual law of speed composition. If you walk at 5 km/h in a train that runs at 200 km/h, your speed relative to the ground is 205 km/h or 195 km/h depending on whether you walk in the same direction as the train or in the opposite direction. We talk about an additive composition rule for speed. That doesn’t work with a constant speed: if I measure the speed of light from my train, I won’t see c-200 km/h, since c is constant. The Michelson-Morley experiment proved that this was indeed the case. Uh oh, trouble.

For one particular speed to be constant, we need to change the law of composition. Instead of adding speeds, we need a composition law that preserves the value of c. It’s the Lorentz transformation. What Einstein acknowledged with his special relativity theory is that this also implied a change in how we consider space and time. Basically, Lorentz transformation can be understood as a rotation between space and time. And in this kind of rotation, the speed of light becomes a limit in a way similar to 90 degrees being the “most perpendicular direction you can take”. Nothing more, nothing less. Of note, that “c” value can also be interpreted as the speed at which we travel along time when we don’t move along any spatial dimension.

There are limits to limits

Once you understand that, you realize how hyperbolic what Science et Vie wrote is.

First, the value of c was computed as a speed of light, for equations designed for electromagnetism. It was never intended to say anything about neutrinos. We don’t know how to measure space and time without electromagnetic interactions somewhere. So the speed of light limit is a bit like the speed of sound limit for bats who would measure their world using only echo-location. It doesn’t necessarily mean nothing can travel faster than light, it only means that no measurement or interaction based on electro-magnetic interactions can ever measure it. I have tried to elaborate a bit on this in the past.

Second, Einstein revised his initial view to include gravity, and this made the world much more complex. Now space-time could be seen as modified locally by gravity. Now imagine how solid your “90 degrees is the most perpendicular direction” argument is if you look at a crumpled sheet of paper. The reasoning doesn’t mean much beyond very small surfaces. Remember that in the neutrinos experiments, we are in a very complex gravitational environment (mountains, …) and you’ll see that this “crumpled sheet of paper” analogy may not be so far off.

In short, it we find conditions where something appears to travel faster than light, it is exciting, it is interesting, it is worth investigating, but it’s certainly not the End of Science as Science et Vie claimed. Let’s not get used to this kind of crap.

Dark matter as a proof of E.T. intelligence?

Here is a random thought… What if dark matter was a sign of intelligent extra-terrestrial life?

The idea is simply that a Type III civilization on the Kardashev scale would control the flows of energy escaping their galaxy. Many solar systems (the inhabitable or useful ones) would end up with mechanisms such as Dyson spheres, therefore lowering the amount of energy escaping these system, to the point where we would no longer be able to identify such systems as stars.

I don’t know if the idea has any merit, but a quick Google search shows that I’m not the first one to have it

Categories: Dark matter, Sociology, UFOs

Dark matter, the modern aether

Today, my 16-year old son asked me what dark matter was. I was surprised that he would even have heard about dark matter, but it turns out that even junior science magazines talk about the search for dark matter these days. I must say that I’m not too happy about that. The junior science article, like many other, present dark matter practically as a fact.

The reason this makes me rather nervous is because of the rather obvious parallel with aether. Just like the luminiferous aether, dark matter is something that was postulated when no physical evidence justified it, in order to preserve existing theory.

Those of you who were already dabbling in physics during the 1850s1 may recall that luminiferous aether was hardly a ridiculous idea at the time. Aether was very simply the medium carrying light waves, much like air or water carry sound waves. It was initially postulated by Isaac Newton to explain things like refraction. According to Wikipedia, Augustin Fresnel proposed in 1818 a theory of light as a transverse wave in aether. To quote Wikipedia, from this point on, no one even seems to question its existence. In other words, the existence of aether was postulated in order to preserve the existing theory of waves. All existing waves required a medium, such as air or water, therefore it was natural to assume that light waves also needed a medium to carry them.

The key point to remember here is that the brightest minds of the time did not question aether at all. Some of them, like Newton or Fresnel invented it. Later, the vast majority of scientists were busy trying to refine the concept to make it work. Yet today, luminiferous aether is seen as the canonical example of an obsolete physics theory. Einstein’s relativity made the very notion of aether not just useless, but actually wrong. Relativity simplified things by removing the need for a system of coordinates that would be special, but this simplification meant that aether could not exist, because otherwise aether itself would have defined a system of coordinates that was unique.

Back to dark matter. We find ourselves in a similar situation today. There’s something about the universe that we very plainly, very visibly do not understand. The original problem, as identified by Fritz Zwicky, was that galaxies do not spin the way they should according to our best theory of gravitation, general relativity. They behave as if there was more matter in them than we can see.

The operational keyword here is as if. At the moment, we really have no idea whether it’s the theory of gravitation that is flawed, or whether there really is 95% of the universe’s mass that we can’t detect. Talking about “dark matter” is choosing one option over the other. It’s pretending that we know, when in reality we still lack a model that really explains all the evidence. In my humble opinion, the jury is still out on what this model will look like.

In short, I’m unhappy about references to dark matter made as if it was a settled topic, a known, validated scientific fact on a par with photons or Pluto. Maybe the problem is with the terminology. Talking about dark matter rather than, say, “gravitational anomaly in galaxies” (GAG) is a good way to preserve the illusion that we know what we are talking about. It makes it sound real. But just because we gave it a fancy name doesn’t make it more real than aether or the tooth fairy.

Let’s be humble and honestly face the simple fact that our model of mass and gravitation breaks down in face of quite a bit of physical evidence. We find ourselves in the situation of physicists in 1850 whose aether-based theories predicted phenomena like aether drag and aether wind, which experiments repeatedly didn’t find. It’s exciting, it’s fun. It’s a good thing for physics, because it means there is something new to be found.

Note 1: My editor tells me it’s considered bad taste to live past 150 on this planet. My apologies to those of my readers I might have offended…

Categories: Dark matter, Physics

It’s alive!

Every single blog or web site that vaguely talks about physics is going to tell you about the LHC today… And nobody else has found the Higgs Boson yet… As Bee noticed, this has some people frightened.

There is no reason to worry, most physicists would tell you, the LHC is orders of magnitude to puny to be really dangerous… To create a really dangerous black-hole machine, physicsists would really need a few trillion dollars more… Or whatever the unit is above trillion…

Still, if we were going into a singularity, would we even see it?

Categories: Physics

Page charges…

Part of the problem I ran into for getting a physics article published was that you have to pay to get published. This is something that physicists usually accept, because they don’t directly pay for it: their institution does. For me, this was a problem, though: I could hardly justify to my family to pay a few hundred bucks or more just for the “vanity” of getting published, even less so when Internet gives me a perfectly good outlet to reach a wider audience at no incremental cost.

But I just discovered that there is another category of people that is hurt by these page charges: retired physicists… Retired = can’t publish? That’s odd…

Categories: Physics

The Perimeter Institude hit by the Slashdot effect

The Slashdot effect is what happens to a web site when it is referenced on Slashdot. Many web sites are unable to handle the load correctly, as the very large readership of Slashdot tries to connect to the linked site.

I thought that the Slashdot effect was more or less a thing of the past, but this just happened to the Perimeter Institute (PI), following the publication of a post entitled “Lectures on the Frontier of Physics”. Currently, the PI web site only displays the following:

Thank you for visiting Perimeter Institute.

The website is under heavy load at present due to the popularity of announcements regarding the appointment of Neil Turok as Executive Director of PI, as well as awareness of PI’s online public lecture series – as reported on Slashdot and other sources.

Please visit again when traffic is back to normal.

Thank you.

Hopefully, traffic will soon return to normal, because the agenda looked quite promising. The Slashdot story cites:

Presentations include Neil Turok’s ‘What Banged?,’ John Ellis with ‘The Large Hadron Collider,’ Nima Arkani-Hamed with ‘Fundamental Physics in 2010,’ Paul Steinhardt with ‘Impossible Crystals,’ Edward Witten with ‘The Quest for Supersymmetry,’ Seth Lloyd with ‘Programming the Universe,’ Anton Zeilinger with ‘From Einstein to Quantum Information,’ Raymond Laflamme with ‘Harnessing the Quantum World,’ and many other talks. The presentations feature a split-screen presentation with the guest speaker in one frame and their full-frame graphics in the other.

Can we improve HTTP?

This kind of experience is a reminder that HTTP is a really simple protocol, one where no attempt whatsoever is made to offer some kind of proximity caching. I wonder if it’s possible to retrofit P2P proximity caching technologies into the more bare-bones HTTP? Does anybody know of any such research? The idea, obviously, would be to have nodes that are closer to the client act as content proxies, thereby offloading the original server.

The problem, of course, is that much of the content on the Internet is dynamic and hard to cache. That’s the reason it’s an interesting question :-)

Categories: Physics, Sociology

HP TechCon 2008

TechCon 2008 in Boston
I just came back from HP TechCon 2008, Hewlett-Packard’s internal conference for technologists, which was held in Boston this year.

HP TechCon is something serious. It works like a real conference: you have to submit papers to be invited, there is a formal selection process, and technologists end up presenting their work to a wide audience.

The two differences with other conferences are what makes it very interesting:

  • it’s internal to HP, so we get to see and talk about stuff that is confidential or really far out.
  • It’s all about HP, which is a big company, so there are a lot of different topics. Most conferences are really monolithic by comparison.

Meeting great people

Obviously, there is a lot I can’t talk about. But I can at least say that it was the occasion for me to meet many amazing people. Below are some public links telling you more about some people I met there:

Phil McKinney is the VP and CTO of HP’s Personal Systems Group. He has a blog, a Facebook profile, a Wikipedia entry, publishes podcasts, has more than 500 LinkedIn connections, and even a Google Phil entry on his web pages. Recommended reading.

Exploring the web around Phil’s blog and comments, I discovered a number of things, like mscape and the HP Game On series of ads. And for serious gamers, the Blackbird 002 game system (adding “002″ to the name is, by itself, a really cool piece of serious geekery.)

Duncan Stewart is a physics researcher at HP Labs. You need to add “memristor” to Google Duncan, because there are other people with the same name. Occasional readers of my blog may know that physics is a topic I’m quite interested in. He’s one of the researchers behind the memristor, which I will talk about below.

There are a number of pages about Duncan Stewart, including this one on the HP Labs web site. I really enjoyed talking to him.

The memristor

In case you did not hear about it, the memristor is the fourth passive device, after the resistor, the capacitor and the inductor. But it would be surprising if you had not heard about it. The number of papers and articles on such a recent topic is really amazing. Here is a link at HP Labs, the article in Nature that I think started it all, or the Wikipedia entry.

To explain what the memristor is, a little hydraulic analogy is in order. As you know, a good way to think about electricity is to see “voltage” as the height of water (the pressure, really), and “current’ as the flow of water.

  • A resistor is like a grid or something that blocks the flow: to get more water to flow through (more current), you will need a higher level of water (more voltage). This is expressed as Ohm’s law , .
  • A capacitor is like a tank, where inbound current elevates the level of water, and outbound current depletes the contents of the tank and therefore the level of water. Therefore, it relates a change in voltage to a current, , which you can also write as
  • An inductor is like a heavy paddle wheel in a current, which prevents it from changing quickly. In that case, changes in current are related to the height of water: if you try to reverse the current for example, water will accumulate until the paddle wheel changes direction. This is traditionally expressed as , but you can also write it as
  • Finally, a memristor is like a gravel-filled pipe near a constriction. If flow brings the gravel towards the constriction, the gravel blocks the pipe and the resistance to flow will increase. On the other hand, if the flow brings the gravel away from the constriction, water can flow freely. This relates a change in current to a change in voltage, which you can write as .

The equations show why this is the “fourth passive element”: if you consider current and voltage, and accumulated current and voltage, there are four ways to combine them.

Fine, so… what do you do with it?

So… why does it matter, what’s the big deal? Well, very simply put, the memristor looks, among other things, like a very cheap and dense way to build memory devices. There are still a good number of questions to be addressed before this unseats Flash memory and other persistent storage, and to be honest, there is even a small chance that it never will (the hard disk is still with us, no matter how many times its death was predicted.)

There are many other applications as well. One of them, “artificial intelligence”, looks a bit overhyped to me at the moment. What seems true, however, is that memristors might enable cheap neural-like circuits to be mass-produced efficiently.


This was overall a great TechCon. Still, I’m glad to be back, it was exhausting.

Categories: HP, Physics, Sociology, Technology

Book review: The trouble with physics

Until now, I had not read Lee Smolin’s famous The Trouble with Physics. Having recently written a rather negative review about a book written by someone who can’t stand Smolin, I thought that I should read both sides.

A pleasure to read

Lee Smolin writes very well, and it is clear why his book had a lot of success. He presents a simple thesis, and backs it with a well-constructed reasoning illustrated with dozens of examples. Like any good book, there are dozens of sub-plots, twists and turns, recurring themes and characters, but more importantly, what makes this book interesting is, very simply, that it has a point. Lee Smolin seems to have a single and clear objective with this book, which is to explain why physics research is no longer working as well as it should. And to be honest, I find the point pretty convincing myself. It’s hard to not have a deep sense of sadness when a researcher like Smolin begins a book with “we have failed“, but to reuse one of his expressions, this has the ring of truth…

One interesting twist and recurring theme is Smolin’s own role in this grand saga, how he views himself in the small community of hard core physicists. Clearly, Smolin is an insider, but a relatively atypical one. I would say that the reason is because he recognizes failure early, and is ready to switch horses and try something else when failure happens. Smolin also makes an interesting distinction between seers, who invent new techniques, and physicists who are more adept at applying existing techniques. It is clear that he sees himself more as a seer, and that he believes that we are at a turn where seers are what physics science needs the most. One of the key subplots is how today’s academia favors technicians much more than seers. Smolin advocates for academia to be more open to ideas that seem strange to the mainstream.

Limits of the book

However, this is also the limit of the book in my view. Reading it, one cannot escape a feeling that Smolin essentially argues in favor of himself and his own research. I do not believe that he’s being dishonest at all, but rather that it somewhat distorts his judgement and weakens his argument. For example, he argues that scientists should have an open mind and be ready to find ideas where they don’t expect it. But he immediately slashed that openness with a note at the end of the book that, naturally, you have to be serious and that you can’t extend the privilege to people without a PhD in physics and other crackpots. In that case, how is that different qualitatively from Lubos Motl’s argument that physics should be closed to anybody not doing string theory? The only difference in “open mindedness” seems to be a quantitative one, where the bar is set.

History records a number of people who contributed science simply because they loved it or had a talent for it. Education often came after their major insight. We all know that Einstein did not have an academic career when he first published his special relativity papers, but he’s hardly the exception among those that Smolin calls seers. Ramanujan, for example, did not have any high-level formal education. This is a bit of an extreme case, naturally, and I would not go as far as saying that you should avoid high-level education. But what this proves (one example being enough for this proof) is that there are people without a PhD who made major contributions, and consequently, that Smolin’s proposal to put the limit there is inconsistent with the rest of his argument about welcoming ideas in physics.

Information overload: the big missing topic

Furthermore, I believe that he fails to say anything about another major issue physicists face, the “information glut”, and which most physicists would recognize in the Sokal affair or the Bogdanov affair. The problem is that there is simply too much to read, including e-mails, books, blogs, articles, and no human being can be on top of everything nowadays. In an ideal world, Smolin would have time to make an informed opinion about everything there is out there, including ideas from people who don’t have a PhD. In an ideal world, Smolin would be able to teach those people who got it wrong why they got it wrong, and maybe to pick up the occasional gem. But this is not an ideal world. Setting the bar at the PhD level is the simplest kind of filter you can put in place to reduce the information flow to manageable levels.

Specialization, this trend in academia that Smolin dislikes because it doesn’t favor seers like him, is just another simple-minded attempt to reduce the amount of data. When Lubos Motl calls “crackpot” anybody who isn’t interested in string theory, he has, in a sense, the same objective as Smolin, which is to reduce his world view to manageable amounts of data.

What I would try if I had time…

This is the reason I think that it’s now time to put some technology in the mix. It’s time to move beyond arXiv and e-mail and newsgroups. It’s time to create some tool to help scientists find the data they need. For this to work, it has to be based on social networks (where others with similar tastes help you filter things). I’ve a pretty good idea of what it would look like, but so little time… And we are back to square one: time, bandwidth, information overload, these are the problems. PhDs aren’t.

Categories: Physics, Science, Sociology

Carlo Rovelli’s "dialogue" on LQG and strings

You may remember that I recently read L’equation Bogdanov, and did not find it very good.

So it felt refreshing to come across a more interesting discussion of these problems, namely a dialogue written by Carlo Rovelli. Carlo Rovelli is one of the leading researchers in loop quantum gravity, that Lubos Motl so incorrectly describes as trying to reinvent aether with “atoms of space”. The dialogue is not new, but it was apparently refreshed in February 2008, despite what the ArXiv web site indicates.

I won’t take sides between string theory and loop quantum gravity. I’m not entirely comfortable in either approach, which may be because I don’t know enough (that’s clearly what Lubos Motl thinks), or maybe because the questions I’m interested in are not resolved by either.

Still, I feel conceptually slightly closer to LQG. For example, through a different line of reasoning, my approach also suggests that there is no “background”, i.e. some sort of fixed space-time where you play physical events. The existence of such a background (and of properties I really cannot subscribe to, like the fact that it is continuous) are, to the best of my knowledge, essential for string theory.

And obviously, on the form, I much prefer the calm, short, yet substantiated and verifiable approach to the debate that Carlo Rovelli gives us here to the endless, abusive approach Lubos Motl represents. Of course, that means that Carlo Rovelli is not as loud, and possibly is heard less. But he’s the smart guy.

Categories: Physics, Sociology

L’equation Bogdanov: The Salvador Dali school of physics

Two days ago, I stumbled across L’equation Bogdanov at the local bookstore in Grasse, France. That was a surprise, since that particular store is where I go to buy gifts or kids school books. It is generally not too strong on science books. That means that the book is intended for a rather wide distribution. Lubos Motl, writing an introductory book? About the Bogdanovs? That was sure to pique my curiosity!

Well, call me biased, but…

If you occasionally read my blog, you may know that I have reasons to not really like Motl too much, after he wrote a rather silly and inflamatory column about one of my posts. If you have some time, read my post, then Lubos’, and try to find any correlation between the two. For example, Lubos’ first point presents me as supporting the idea that “The goal of science is to wait for a “new Einstein” or a savior,” when my own text precisely criticizes Lee Smolin’s famous question Why is there no new Einstein. I’m still wondering how he could attribute me any of the ideas he seems to claim were mine in his ten bullets list…

The first pages of the book left me with the same kind of feeling, the feeling you get when looking at a picture from Salvador Dali, that some people care more about their interpretation of beauty than about mundane things like reality or truth. It sure makes for great art, impossible visions of what could almost be, stuff that is almost, but not quite, entirely unlike tea. But in science, I don’t think that it has as much value. I will illustrate this shortly.

Still, I refrained from writing this post immediately after reading the introduction (an ode to Lubos the Great that is in itself “worth its weight in peanuts”, as we say in French). Instead, I chose to remain focused and read the book to the end. Although, for the first time in years, I read a book while scribbling all over it with a pencil. Ultimately, reading it through was the right thing to do, as some parts of the book are not entirely worthless.

However, if you are interested in something else than Lubos’ passionate yet sterile debate about strings vs. the rest of the universe, I unfortunately have to recommend spending your 19€ elsewhere. And if Lubos’ point of view interests you, there isn’t much in the book that you won’t find on his blog. But since I realize I’m biased, I’ll try to support this opinion with facts. And I’ll try to keep these facts simple and verifiable, including by the “layman”.

The good

There are some relatively good things in this book if you are willing to sift through mud. The mandatory review of physics history in chapter 2 is much less intertwined with the primary topic of the book than, say, in Brian Greene’s The Fabric of the Cosmos. But it has the redeeming quality that it shows the relationships between various physicists, illustrating “standing on the shoulders of giants” better than many other “histories of physics”.

Chapter 6, “The strange adventure of the Bogdanovs“, is probably the most interesting part in the book. It appeared slightly less surrealist than the rest of the work. It essentially argue that the Bogdanovs did not deserve the attacks they received, because even if their work is hard to follow (Lubos himself grants that he had trouble following it), their efforts seem a genuine attempt to contribute to physics rather than a malicious attempt to play some elaborate hoax on physicists. I’ll refer the reader to what has been written on the subject. The Bogdanov affair, as it is now called, is a complex case of the sociology of science, and tempers certainly flared more than they should have.

Anyway, this chapter is especially good coming from Lubos, as it illustrates that he can sometimes show some balance and moderation in his writings.

The mediocre

Unfortunately, these few nuggets are hard to find in a book that is, overall, mediocre, mostly because Lubos never seems to have decided who the target audience was. Is this an introductory book intended for laymen, as seems to be indicated by multiple footnotes like on page 61, explaining what a wave is, or a very vague explanation of what complex numbers are on page 156? Actually, Lubos himself calls his book the “100th vulgarization book on supergravity” on page 165…

But then, if it’s an introductory book, the order is all wrong for this target audience. Lubos talk about topics such as black holes entropy and horizons on page 55 and 56, and again about information loss in black holes on page 89, and at several other places. And then, on page 125, a footnote finally tells us what a black hole is. Huh? Ah but wait, there’s another such explanation on page 75! Confusing enough?

Similarly, Lie groups are introduced by a footnote on page 29 that finds it useful to illustrate this with “the Lorentz group SO(3,1)” and “SU(2)”… How can the layman have any idea what SO(3,1) or SU(2) might be? If at least there was a forward-reference to the page 165, where Lubos attempts to explain the importance of symmetries and Noether’s theorem, but nope… One last example: why explain complex numbers on page 156 if the introduction insists on “imaginary time measured by imaginary numbers” and the lack of total order on the complex plane on… page 14!?!

And if the book is for a wide audience, some topics are pretty advanced for someone who would not know what waves or complex number are. For instance, how can such a person feel about the argument given on page 102, that there’s a problem in LQG because spectra of surface operators are not gauge invariant? Seriously?

The book also does not do a very good job at explaining anything. I invite the interested readers to contrast Lubos’ explanation of the importance of correlated systems and (even if the name is not given) the EPR paradox on page 67 with that given by Brian Greene around pages 107-109 of “The Fabric of the Cosmos”, and you will understand what I mean.

The bad

So in general, the book does a very poor job addressing the layman. For someone with a little bit more knowledge, it’s irritating to see various comments that are either overly simplistic or just plain wrong. For instance, on page 157, another footnote argues that you need imaginary numbers to build a circuit breaker!

All too often, a moderately educated person like myself might expect to learn something, only to realize that he’s been fooled once more. For example, on page 156, there is a footnote on Hopf algebra, that doesn’t even begin to explain what they are, but basically tells us that Hopf played music with Einstein! Similarly, on page 103, the footnote about the hamiltonian constraint only vaguely tells us what the Hamiltonian is, but nothing about the constraint which seems to be the heart of the discussion. Fooled again!

And then, there are way too many plain errors. There’s one I can’t help but laugh about, because of Motl’s insistence on calling me a “French programmer” in his blog, apparently with the intent to ridicule my ability to say anything about physics. On page 103, in a discussion about separable and non-separable Hilbert spaces, Lubos states that a bit can hold 256 values. Well, “everyone” knows that a bit contains 2 values, usually represented as 0 and 1, and that it takes 8 bits to make a byte, which does indeed represent 28=256 values. But then, being able to work on computers is apparently a bad thing for Motl, who describes Peter Woit as being merely “in charge of computer systems” at Columbia University, on page 33…

That’s not the only such major error. On page 55, he writes that if you ever see a cup of cold coffee warm up while the table cools down, you can immediately call the French Academy of Science. Well, maybe I should, because that’s exactly what happens whenever the table is hotter than the coffee cup. I did not add the word “cold” before “coffee”, Lubos did, but I strongly suspect he intended to write “hot coffee”. On page 72, Lubos states that Einstein should in no way be held responsible for nuclear weapons. This is simply not true: Einstein’s letters were highly influential on the decision to develop the first A-bomb, irrespective of Einstein’s later regrets (he called this his “greatest mistake”). There is a mention of “the european GPS and Galileo” on page 77 (Galileo is the european GPS). On page 157, Lubos apparently attributes the invention of complex numbers to Hero of Alexandria, which is stretching the truth, to say the least.

This leaves the impression of a book that was barely proofread, an impression in stark contrast with the surprising self-promoting tidbit Lubos gives us on page 122, that for his greatest pleasure, he had reported 120 errors in a book by Joe Polchinski, who he essentially describes as a failed perfectionist. Instead of embarassing Polchinski, Lubos might have wanted to spend a little more time improving the quality of his own writings!

The ugly

But the worst aspect of the book is, without a doubt, that it seems to be a barely disguised excuse to attack other physicists and indulge in more of the sterile debate that opposes Lubos Motl and people like Peter Woit or Lee Smolin. Living in France, I hoped I might have a chance to evade that dispute. Too bad. Most of chapter 4, for example, is dedicated to this. This would be legitimate if it was on topic. But it’s not, and Motl instead resorts to sneak tactics, name calling, all techniques that made him a persona non grata in so many places.

Let me put it this way: I like the Bogdanov brothers, not for their self-promotion or for their theories, but because I loved their TV shows. And I feel almost sorry for them that Lubos Motl used their names and pictures. With the Bogdanovs on the front cover, the book is almost guaranteed to sell at least a little in France, since the Bogdanov entertained so many of today’s adults back when they were kids.

But for what? A book in which Lubos Motl talks less about the Bogdanovs than about the alleged damage that Lee Smolin or Peter Woit made to physics, and why all these folks are (in Motl’s view) idiots. I mean: who cares? If a book was ever going to restore the scientific credit of the Bogdanovs, that’s certainly not it, and it’s too bad, because on that point, Lubos might be right. But if he wanted to support to the Bogdanovs, he would have been well inspired to focus on their work and very temporarily put aside his personal griefs, at least for the time it took him to write the book. But even that was apparently too much to ask!

Update: For the french readers who would be tempted to believe the arguments of Lubos Motl that loop quantum gravity is reintroducing aether, there’s an excellent answer to this very question from Prof. Rovelli (in French) in this conference. The question is asked from the audience at 1h08m15s into the video.

All kinds of invalid proofs

Another thing that I find particularly ugly is the vast collection of invalid techniques of proof Professor Lubos managed to accumulate in a single book. This is particularly annoying for someone who, to do his job well, is supposed to be capable of some seriously solid reasoning. But even the average “layman” is going to be annoyed by all the bogus arguments. Here are a few examples:

  • On page 28, we have a pretty long proof by eminent authority, citing names like André Lichnerowicz (and, as if this was not enough, Élie Cartan and Sophus Lie) to give credit to the Bogdanovs. I do not dispute that having a guy like Lichnerowicz recommend the Bogdanovs to their advisor, Moshe Flato, is probably a good sign for them. But you have to remember that this is not enough, in particular in a French context where both Lichnerowicz and the Bogdanovs were celebrities. This reverence to names is spread throughout, including in the way he calls the everyday scale of things the “Planck-Einstein scale”, by averaging the “Planck scale” of very small things with the “Einstein scale” of very big stuff.
  • On page 94, a proof by partial enumeration, namely that candidate theories fall into the theories that have not been proven and the theories that have been proven false. This eliminates the most important category, theories where people are still debating. And whether Lubos likes it or not, both string theory and the “atoms of space theories” (to use his bizarre terminology) fall into that category more than in others.
  • On page 97, we have both a proof by mutual reference (since Lubos cites his own blog to make a point), and a good case of proof by vehement assertion (quoted directly from the blog, rather than translated back from French):

    First of all, Lee reveals his intense hostility against all of modern physics, not just string theory. He believes that quantum mechanics must be wrong at some fundamental level and many people should try to prove it. He also believes that the attempts to falsify the theory of relativity are among the most important topics to work on.

    This attack is all the more surprising because Motl himself writes on page 83, about general relativity: “the existence of infinities reminds us that we may not have learned our lesson well, and then suggests that either we asked the wrong question, or our theory is wrong. He then follows on to point similar problems in quantum mechanics. So how is that different from this bad attitude Lee Smolin allegedly has towards “modern physics“? Are the two guys in violent agreement here or what?

  • On page 111, we have a proof by appeal to intuition, where we are supposed to believe that LQG is an invention, as opposed to a discovery, making the LQG researchers roughly comparable to a Thomas Edison, complete with a footnote about who Thomas Edison is, in case anybody on Earth doesn’t know! So… LQG is much like Thomas Edison’s inventions? Says who? Why? How?

These are only examples. Finding more is left as an exercise for the reader…

True lies

If this was not enough to completely bury that book, there is more, unfortunately. There are various statements in the book that cannot be mere errors, but can only be considered willful lies. The best illustration is a quote on page 151. In the context, the quote, from a referees, is clearly intended to give some credence to the Bogdanov’s idea that a topological field theory is just the thing to describe the early universe. Here is Lubos Motl’s version:

I can accept that in the limit of infinite temperature,
contact can be made with a topological phase of some field theory

Doesn’t this sound as if the guy agreed with the Bogdanovs? Well, fortunately, I have a relatively good memory, and even if the quote is in French in the book, I remembered reading that sentence, so it was just a matter of tracking it down. You can find the complete referee report, helpfully not provided by Lubos Motl, here. And here is the non-truncated version, which you probably would agree sounds much less supportive of the Bogdanovs:

(5) I can accept that in the limit of infinite temperature,
contact can be made with a topological phase of some field theory
(the type of field theory needs to be elaborated on however). The
crucial question, however, is how does the initial topological phase
break down to a universe we see today. It would be of great interest
if the authors’ could at least worry about this issue.

And the little things

Is there more? Well, I think that the rest goes without saying, knowing Motl. There are insults, for example on page 134, where Motl says that he spoke with Lee Smolin numerous times, and that they always had “interesting and peaceful discussions” (sic!), but that “each time we were getting close to the answer to a crucial question, his spirit evaporated in the clouds”. Uh oh! I picked up this one because I thought it was funny, but there are others.

There’s also a rather usual dose of self-promotion (and Lubos is in good company with the Bogdanovs here, if I may give a personal opinion). On page 105, Lubos calls himself a messiah. On page 134, he compares himself to Einstein, specifically referring to himself as another guy from the patent office. On page 143, he mentions the IQ of the “Zweistein”, which they allege is about 210, in a sentence where he presents himself as the new Max Planck. Literally, it reads: By the way, if you bought this book in the hope that a new Max Planck – me in that case – would present the two new Einsteins (the “Zweistein” if you will), well, too bad“. So much modesty in so little space!

Getting physics out of the hole

Let me finish this review on a slightly less negative note. On page 188, there is a nice long note about the right processes to follow to identify truly innovative ideas in physics. It’s actually not from Motl, he simply quotes Dr Osher Doctorow, but there are interesting things in there. One I found particularly interesting, is that true creativity is identified by looking at folks who do not just follow, but go one step ahead of the pack. OK, I realize it sounds obvious, but the point being made is really that it’s hard for the pack to judge those who are already ahead. This is one reason why I advocate a more “open-source” approach to peer reviews.

This question interests me. Readers of this blog, if there is any, may know that I have my own pet theory, and that even if I believe it’s dead simple compared to the kind of ideas the Bogdanovs are working on, I still seem to have an extraordinarily hard time getting the point across to any physicist. For example, if Lubos seems to have no problem with the idea that near the singularity, the description of space-time is entirely topological (i.e. there is no “distance”), or even that space-time reduces to “pure information”, whatever that means (page 25), or that there is a lower physical limit to distance (the Planck scale), he still insists that any theory where space-time is not continuous is absurd, for instance on page 102. In my experience, that kind of “historical” position is frequent among physicists.

I hold the exactly opposite view. If there is a minimum length in physics, and if all our physical measurements give results that are not even countable, but actually finite, don’t we need to build that into physics? Isn’t there a clear contradiction between “continuous” and “smallest physical distance”? In other words, if it’s truly a continuum, shouldn’t we be able to find a physical meaning for a distance of 10-250m? That question is essentially the foundation of my “theory“.

A non-local theory of creativity

But since I’m an outsider, I keep asking myself the question: do my ideas make sense, or am I just delusional. In other words, do I have problems getting the point across because I’m ahead of the pack, or because I’m lost in the woods? As Lubos points out, it’s easy to tell in retrospect, but when you are in the middle, it’s much harder. Related question: assuming my ideas do make sense, do I stand a chance of getting the point across someday? Lubos argues on pages 197 and 198 that being an outsider is not necessarily a bad thing. He also reminds us, on pages 177-179, that big guys like Einstein or Heisenberg, had to fight initially. Of course, it would be better if this call for an open-minded approach to physics was not so clearly contradicted by Lubos’ attitude…

Anyway, Lubos and I share at least two things: the same birthdate, and a desire to contribute something to physics. Of course, it’s obvious that just thinking you have something to say is not enough. To paraphrase the Calvin cartoon characters, “You know Einstein had bad grades in math? Well, mine are even worse!” So it’s entirely possible, and not even improbable, that my ideas about physics are simply bogus. However, for the moment, I’m still waiting for any solid rebuttal of what I already wrote. From what I can tell, it looks more like I’m in the “nobody cares” category rather than in the “patently idiotic” category. Ah, delusion… That’s what keeps me alive.

Actually, another thing that gives me hope is that, in my own field, I think it is fair to say that I have shown some creativity, both when I was young and more recently. Maybe, just maybe, having shown some creativity in one field means you might be able to show the same creativity at another place. And if I have beaten someone like John Carmack in the race to the first 3D videogame, maybe I can beat someone like Lubos Motl in the race to the next big idea in physics…

The KISS principle (Keep It Simple, Stupid!)

But the key thing in my ideas which, I think, is in sharp contrast with Lubos’ approach to physics, the key thing that differentiates the Salvador Dali school of physics in which Lubos excels from the Thomas Edison school of physics that I’d much rather belong to, it’s the clarity of the questions and answers.

As Einstein once said: Make everything as simple as possible, but not simpler. A good test is: do your questions and answers make sense to the layman? Einstein or Feynman were really good at that game. It’s a point I already made earlier on this blog. In the present case, I think it strongly speaks in my favor:

  • Lubos asks questions like “can the signature of the metric fluctuate around the Planck scale”, or “are homology cycles in the moduli space of gravitational instantons the right way to represent observables at the beginning of the universe”. He answers things like: “who can say this won’t be the right answer in 2030″ (page 144), and he calls that “research”. I’m really tempted to call that a proof by obfuscation.
  • At least from my own biased point of view, my own questions seem much simpler. Things like: “why would an invert square law like gravitation or electromagnetism remain an inverse square law when we change the definition of distance” (specifically, from measuring it with solid rods to measuring it with light waves). And my answer is: “because we calibrate the two definitions to match”, which raises another question: “does that calibration hold for all values, at all scales”. No part of these questions or answers is something that the laymen can’t understand. I’m not trying to obscure things behind layers and layers of jargon.

Now, I believe that my questions and answers may hold a key to putting physics back in shape in the coming century. And I believe that Lubos’ questions and answers only confuse things a little further. Again, that’s the difference between the Salvator Dali and the Thomas Edison schools of physics. Of course, I may be wrong, but I’m afraid you’ll have to prove it.

Categories: Physics, Science, Sociology

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