Friday, May 30, 2014

Bogus quantum teleportation claims

John Markoff reports in the NY Times:
Scientists in the Netherlands have moved a step closer to overriding one of Albert Einstein’s most famous objections to the implications of quantum mechanics, which he described as “spooky action at a distance.”

In a paper published on Thursday in the journal Science, physicists at the Kavli Institute of Nanoscience at the Delft University of Technology reported that they were able to reliably teleport information between two quantum bits separated by three meters, or about 10 feet.
This just means that an electron state was copied 10 feet away.
Classical bits, the basic units of information in computing, can have only one of two values — either 0 or 1. But quantum bits, or qubits, can simultaneously describe many values. They hold out both the possibility of a new generation of faster computing systems and the ability to create completely secure communication networks.

Moreover, the scientists are now closer to definitively proving Einstein wrong in his early disbelief in the notion of entanglement, in which particles separated by light-years can still appear to remain connected, with the state of one particle instantaneously affecting the state of another. ...

Succeeding at greater distances will offer an affirmative solution to a thought experiment known as Bell’s theorem, proposed in 1964 by the Irish physicist John Stewart Bell as a method for determining whether particles connected via quantum entanglement communicate information faster than the speed of light.

“There is a big race going on between five or six groups to prove Einstein wrong,” said Ronald Hanson, a physicist who leads the group at Delft. “There is one very big fish.” ...

To date, practical quantum computers, which could solve certain classes of problems far more quickly than even the most powerful computers now in use, remain a distant goal. A functional quantum computer would need to entangle a large number of qubits and maintain that entangled state for relatively long periods, something that has so far not been achieved.

A distributed quantum network might also offer new forms of privacy, Dr. Hanson suggested. Such a network would make it possible for a remote user to perform a quantum calculation on a server, while at the same time making it impossible for the operator of the server to determine the nature of the calculation.
This is craziness. Proving Einstein wrong is not a big deal, as all of the textbooks have said that he was wrong about quantum mechanics for 80 years.

Bell's theorem has been affirmed many times.

No faster computing or secure communication is going to come out of this work. This is just replicating an electron state. That's all.

Update: Lubos Motl has a rant about Brian Greene and other physicists and philosophers spreading confusion about quantum mechanics, and comments on the above experiment.

Thursday, May 29, 2014

Andromeda to collide with us

Dennis Overbye writes in the NY Times:
The Milky Way and Andromeda are the dominant members of a small family of galaxies known as the Local Group. Whereas the universe is expanding and galaxies are generally getting farther and farther away from one another with time, the galaxies in the Local Group are bound together by family ties in the form of their mutual gravity. Our relatives aren’t going anywhere.

And there is the problem. Andromeda and the Milky Way are actually heading toward each other in the do-si-do that constitutes life in a galaxy cluster. Recent measurements with the Hubble Space Telescope have confirmed that they will hit head on in about two billion years. Since galaxies, like atoms, are mostly empty space, they will pass through each other like ghosts, but gravity will disrupt the stars and strew them across space in gigantic spectacular streamers. Eventually they will merge into a single giant galaxy.
Does this make any sense to you? Atoms are not mostly empty space. Solids certainly do not pass thru other solids like ghosts.

If Andromeda passes thru us like a ghost, then it would not merge with us. It would continue for at least another 2 billion years, and maybe 20B years. If Andromeda is really gravitationally bound to the Milky Way, then it would eventually slow down, reverse, and collide with us again. But then it would just pass thru like a ghost again. That could continue millions of times, unless dark energy drives the galaxies permanently apart.

I am guessing that the galaxies will not really pass as ghosts, and maybe millions of stars get knocked out of position. That could dissipate some energy and make is possible for the galaxies to merge, but surely the merger would take many billions of years, and most of the stars would probably burn out first.

Overbye probably called some expert who has all this figured out. We should have gotten a better explanation.

Wednesday, May 28, 2014

The Myth of Einstein’s Brain

From a new paper on the myth of Einstein's brain:
In summary the three histological studies of Einstein’s brain have, in spite of claims to the contrary, found essentially no differences between his brain and that of controls. This should not come as any great surprise. The brain is obviously an extremely complex structure… to believe that the analyses of one or a few tiny slices of a single brain could reveal anything related to the specific cognitive abilities of that brain is naïve.
Einstein was smart, but not unusually so compared to his colleagues. It would be more interesting to study the brains of those with objectively superior mental skills, such as memorizing a million digits of pi or being able to solve hard math problems.

Tuesday, May 27, 2014

Lawrence Krauss book disputed

A new paper claims:
Abstract. We study some claims in Krauss’ recent book, A Universe from Nothing: Why there is something rather than nothing, that are employed to show that a universe can come from “nothing”. In this brief paper, we show that many of the claims are not supported in full by modern general relativity theory or quantum field theory in curved spacetime.

Claim 1: “General Relativity tells us unambiguously that a closed universe whose energy density is dominated by matter like starts and galaxies, and even more exotic dark matter, must one day recollapse in a process like the reverse of a Big Bang - a Big Crunch”

Claim 2: “Considering the geometry of the universe is like imagining a pencil balancing vertically on its point on a table. The slightest imbalance one way or the other and it will quickly topple. So it is for a flat universe. The slightest departure from flatness quickly grows. Thus, how could the universe be so close to being flat today if it were not exactly flat.”

Claim 3: Krauss claims on several occasions in the book that the total energy of a closed universe is zero

Claim 4: Krauss claims that “in quantum gravity, universes can, and indeed always will, spontaneously appear from nothing”

Claim 5: Krauss clams that ”the structures we can see, like stars and galaxies, were all created by quantum fluctuations from nothing”

Friday, May 23, 2014

Failing to defend philosophy for science students

Neil deGrasse Tyson advised ambitious science students to avoid the distractions of philosophy, and philospher Massimo Pigliucci responds:
Contra popular perception, philosophy makes progress, though it does so in a different sense from progress in science. You can think of philosophy as an exploration of conceptual, as opposed to empirical, space, concerning all sorts of questions ranging from ethics to politics, from epistemology to the nature of science. ...

Another popular myth is that philosophy keeps dwelling on the same questions, the implication being that, again, it doesn’t settle anything and consequently cannot move on to something else. ...

You and a number of your colleagues keep asking what philosophy (of science, in particular) has done for science, lately. ... I suggest you actually look up some technical papers in philosophy of science [12] to see how a number of philosophers, scientists and mathematicians actually do collaborate to elucidate the conceptual and theoretical aspects of research on everything from evolutionary theory and species concepts to interpretations of quantum mechanics and the structure of superstring theory. ...

A common refrain I’ve heard from you (see direct quotes above) and others, is that scientific progress cannot be achieved by “mere armchair speculation.” And yet we give a whole category of Nobels to theoretical physicists, who use the deductive power of mathematics (yes, of course, informed by previously available empirical evidence) to do just that. ...

Finally, Neil, please have some respect for your mother. I don’t mean your biological one (though that too, of course!), I am referring to the intellectual mother of all science, i.e., philosophy.
None of this addresses Tyson's point -- philosophy may be intellectually worthwhile, but modern philosophy classes are a distraction to budding scientists. Pigliucci offers no example of worthwhile philosophy, and most of those articles on quantum mechanics and string theory are crap.

The dominant philosophy of science for the last 50 years says that science in not the pursuit of truth. My FQXi essay says:
We are at the precipice of what Thomas Kuhn called a paradigm shift. The crucial defining features for such a change in view are what he called incommensurable and arational. That is, there must be no metrics for comparing the old view to the new one, and there must be no rational preference for the new view. As he described scientific revolutions, these shifts are largely cultural, as elite scientists switch to the new view and everyone follows like sheep.
A science student is better off not wasting his time being told that all the great advances in sciences were really just irrational fads.

As long as philosophers say stuff like that, they should be regarded as the enemies of science. A scientist would be better off studying theology.

I am not saying that all philosophy is worthless. I am just saying modern university philosophy of science classes are antagonistic to a career in science.

Tyson declined to respond, apparently because Pigliucci does not really rebut anything Tyson said.

Lubos Motl posted rants against recent papers by Gerard 't Hooft and Steven Weinberg that try to find more classical interpretations. These are two of our most distinguished theoretical physicists, and yet they have wandered off into the weeds of philosophical nonsense. Imagine how much worse the philosophy papers must be!

'tHooft has one of those very few Nobel prizes for theoretical physics, using the deductive power of mathematics. Pigliucci is wrong to say that there is a whole category of such prizes. They are very rare. Just look at last year's prize for the Higgs boson. The theory was done 50 years ago, and the mathematical deductions for the Standard Model a few years later. No prize for the Higgs was given then. They only gave a prize when there was a direct experimental result.

Pigliucci responds to a comment:
“if Pigliucci can’t point to anyone who’s done meaningful (in terms of expanding the boundaries of human knowledge) work in philosophy in the last hundred years, that is pretty strong evidence for saying “okay, philosophy is done, let’s move on to other things.””

Oh for crying out loud, you want names? Okay, here we go, just off the top of my head, in alphabetical order, and just in philosophy of science (notice how many were also scientists): David Albert, Alfred Ayer, Niels Bohr, Mario Bunge, Rudolf Carnap, Nancy Cartwright, Daniel Dennett, John Dewey, Pierre Duhem, John Dupré, Albert Einstein, Paul Feyerabend, Bas van Fraassen, Ronald Giere, Peter Godfrey-Smith, Ian Hacking, Werner Heisenberg, Carl Gustav Hempel, Philip Kitcher, Thomas Kuhn, Imre Lakatos, Larry Laudan, Helen Longino, Peter Medawar, Ernest Nagel, Otto Neurath, Roger Penrose, Henri Poincaré, Michael Polanyi, Karl Popper, Hilary Putnam, W.V. Quine, Frank P. Ramsey, Hans Reichenbach, Alex Rosenberg, Bertrand Russell, Wesley C. Salmon, Elliott Sober, Kim Sterelny. And these are only those I’ve read. And I bet Neil hasn’t read *any*.
Tyson has probably read Bohr, Einstein, Heisenberg, and Poincare. Ayer, Popper, and Russell said some worthwhile things, but they are mostly rejected by modern professors. The rest are mostly anti-knowledge. Pigliucci fails to name a specific work that might be useful for a science student to read.

Pigliucci recommends the British Journal for the Philosophy of Science, where its special issue on T. Kuhn starts with an argument that The Structure of Scientific Revolutions "has a strong claim to be the most significant book in the philosophy of science in the twentieth century". That is the anti-science paradigm shift book.

Tuesday, May 20, 2014

Quantum computers may never materialize

Quanta magazine has excellent articles, and reports:
The key to building a quantum computer is increasing the number of qubits that can be linked together. Despite the investment of vast resources over the past 20 years, the extreme fragility of existing qubits has so far restricted efforts to network them and has even fueled uncertainty about whether the technology will ever materialize.
Good to see someone say the obvious -- 20 years and $100M of research fails, that is reason to doubt whether it is possible.

We have also had 20 years of quantum cryptography hype, and no useful application has come out of it. Another cryptographic technology, ECC pairings, has been hyped by the well-funded Voltage Security, and even proposed as an internet standard back in 2007. It had very little practical utility, and now new attacks have killed it. The company is still in business, fooling its customers.

Saturday, May 17, 2014

Controversy about Relativity in the 1920s

A reader informs me that Einstein's Opponents: The Public Controversy about the Theory of Relativity in the 1920s, by Milena Wazeck, was recently translated into English and published.

The translator acknowledged the assistance of a software translator. At first I was surprised that a reputable translator would admit to using a dumb machine translation, but now I think that it is foolish to do it any other way.

The nearest Wikipedia article on this subject is Criticism of the theory of relativity. See also Einsteinism and Reuterdahl.

The common view is that this was some sort of anti-semitic or Nazi attack on Jewish science. That may have contributed, but I do not think that is the main story. Some of the critics were Jewish.

To your average philosopher or intellectual or layman or even non-relativity physicist, relativity must have seemed like bizarre leap from the available evidence. The Michelson-Morley experiment was just an optical diffraction pattern that did not change when the equipment was rotated. The deflection of starlight was within experimental error from a simple Newtonian model. The Mercury orbit precession was just one number, and might have other explanations. To the casual observer, it must have seemed likely that these phenomena would have less radical consequences.

From that we conclude that space and time are not what everyone thought?!

I wouldn't be too harsh on the skeptics. I think that it is amazing that relativity was so rapidly accepted. I am also surprised at how readily people accept ideas like inflation and supersymmetry today.

Wednesday, May 14, 2014

Einstein's view of phenomenological and dynamical treatment

Special relativity has always had more than one interpretation. FitzGerald's original 1889 paper first hypothesized the length contraction as a logical consequence of the Michelson-Morley experiment. That is how textbooks often introduce it today. But he also suggested an explanation in terms of motion affecting the electromagnetic forces holding the apparatus molecules together. This "dynamical" explanation is commonly badmouthed on metaphysical grounds, even tho it is consistent with all known mathematical and physical evidence. Today it is preferred by philosopher Harvey R. Brown and no one else.

Lorentz's 1892 and 1895 reasoning was very similar to FitzGerald's, but independent as FitzGerald's letter was published in AAAS Science, which was then an obscure journal to Europeans.

Einstein has said that his famous 1905 paper presented the constructive theory only because he could not get the dynamical theory to work. He defines distances in terms of rigid measuring rods (meter sticks), ignoring the fact that the rods are really just a bunch of molecules in an electromagnetic equilibrium that is upset by motion.

Marco Giovanelli addresses these issues in a new paper:
"But One Must not Legalize the Mentioned Sin". Phenomenological vs. Dynamical Treatment of Rods and Clocks in Einstein's Thought

The paper offers a historical overview of Einstein's oscillating attitude towards a "phenomenological" and "dynamical" treatment of rods and clocks in relativity theory. ...

Einstein’s waving attitudes towards the role, indispensable or provisional, of rods and clocks in both of his theories, has been usually cast in the well-known opposition between ‘constructive’ and ‘principle’ theories, which Einstein had explicitly introduced in 1919 (Einstein, 1919b), but addressed in several occasions starting at least from 1907 (see Howard, 2005, for more details). In Einstein’s original stance toward special relativity as a ‘principle theory’, the geometry of space-time appeared to be ‘defined’ through the behavior of ‘rods’ and ‘clocks’, whose contractions and dilations were postulated, without introducing a realistic microscopic model of their material constitution. However, when a suitable ‘constructive theory’ of matter would eventually be at hand, rods and clocks will be thought as rather complicated physical systems obeying fundamental dynamical laws. Symmetry properties of space-time will turn to be nothing but a codification of the symmetries of the laws governing matter. In particular ‘length contraction’ and ‘time dilation’ in special relativity should be described in the final analysis as a consequence of the dynamical laws that govern rods and clocks. ...

Einstein’s unease towards the ‘sin’ of treating rods and clocks as simple, unstructured entities rather than as complicated dynamical systems did not intend to address the question around which the contemporary debate is centered: to establish which is the ‘cart’ and which are the ‘horses’ between abstract geometrical structure space-time and the physical laws governing material spacetime devices. It was rather an attempt to give a balanced answer to a more general philosophical question, which he did not hesitate jokingly to compare Pilate’s question: ‘what is the truth?’. More humbly, it was the question whether a theory should describe its own means of verification or whether this description should lie outside its domain.
The preferred view today is that special relativity is a non-Euclidean geometry of spacetime, as discovered by Poincare and Minkowski, so this stuff is mainly of historical interest.

Tuesday, May 13, 2014

Doubts about BICEP2 conclusions

NewScientist reports:
Has the recent discovery of gravitational waves been reduced to dust? Not so fast.

The news that ripples in space-time, called gravitational waves, had been spotted stunned the physics community earlier this year. This week, rumours began swirling that the scientists who reported the find have now admitted to making a mistake. The team missed a key detail in its analysis of galactic dust, the rumours suggest, making it more likely that the signal came from a source other than gravitational waves.

But the team's response to this claim is unequivocal: "We've done no such thing," says principal investigator John Kovac at Harvard University. The validity of the discovery won't be known until another group either supports or opposes their finding, which could happen later this year.

In March, the BICEP2 collaboration announced that it had seen an imprint on ancient cosmic light that it says was created by gravitational waves. Those waves are thought to be products of inflation, a period of rapid growth during the first sliver of a second after the big bang. The finding was hailed as a smoking gun for the theory of inflation – and as evidence that theories of a multiverse may be true.
See also Woit's blog. I have posted some skepticism about BICEP2 here and here.

I wonder why the so-called "skeptic" community isn't more skeptical about radical new announcements like the BICEP2. They are always denouncing things like homeopathy, which maybe have some slight placebo effect. I can believe that BICEP2 gives some evidence for inflation, but the talk about quantum gravity waves seems dubious to me. We should know more soon, when more results are reported.

Monday, May 12, 2014

Philosopher searches for Poincare's mistake

University of Chicago philosophy professor Howard Stein writes Physics and Philosophy Meet: the Strange Case of Poincaré:
Poincaré is a pre-eminent figure: as one of the greatest of mathematicians; as a contributor of prime importance to the development of physical theory at a time when physics was undergoing a profound transformation; ...

Let me begin with a remark about the culminating event, Poincaré’s memoir of 1905/6 on the dynamics of the electron. I am by no means the first one to comment on that paper: there is a well known controversy over the question whether or not it deserves to be considered as containing a statement of the special theory of relativity -- and if not, why not? -- i.e., the question, how does Poincaré’s theory differ from Einstein’s? That such a controversy should be possible at all is certainly a little odd; so prima facie, the case is strange. But I have not seen it pointed out just how strange; I know of nothing like it in the entire history of physics. There have been many instances of work inadequately appreciated at first, on account of what might be called philosophical preconceptions or prejudices; but here we have to deal with a great work by a great scientist and philosopher of science whose own author failed to appreciate its true worth.
It is very strange, and that is why I wrote a book on the subject, How Einstein Ruined Physics.

Everyone likes to credit Einstein for relativity. His theory was really essentially the same as Lorentz's but they can explain away Lorentz by saying that he did not have the entire theory. Explaining away Poincare is tougher because he had all the formulas, principles, interpretations, etc. On paper, Poincare went well beyond Einstein. So the only way to explain away Poincare is to somehow argue that he did not understand what he wrote.

As Stein explains, historians such as Arthur I. Miller have refused to credit Poincare largely because he was not bold enough in claiming credit for himself. And when discussing points like the aether, Poincare makdes philosophical points that seem maddening to others. Sometimes he says the aether does not exist, and other times he says that it is a useful convenience.

Some physicists find Poincare's view hard to square with relativity, which is supposedly based on the absence of the aether. But Poincare was more of a mathematician, and clearly understood that a concept can be convenient and useful, even if it is not directly measurable. So Poincare was correct.

Even if you do not agree with Poincare'd philosophy, it is very strange not to credit him for one of the greatest advances in the history of science, just because he was modest or of an idiosyncratic philosophy.

Stein starts be quoting Poincare's famous 1905/6 relativity paper. In the introduction, Poincare explains that he is presenting a reformulation of Lorentz's theory, with two views. The Lorentz view is that "there is nothing in the world that is not of electromagnetic origin." Then relativity can be understood as originating in Maxwell's equations, and universally applicable because electromagnetism is also.

In this Lorentz view, the FitzGerald contraction of a measuring rod results from the molecules of the rod being held together by electromagnetic forces, and motion distorting those forces.

The second view is that relativity theory is "something that derives from our methods of measurement." That is, the Lorentz transformations say something about how we measure space and time, and are not just a property of electromagnetism. This is the modern view.

Poincare boldly makes an analogy to the revolution that took us from Ptolemy to Copernicus. He was boldly declaring himself to be the new Copernicus, with a revolutionary view of space and time. Einstein never said that he had a spacetime theory until well after Minkowski bodly endersed the spacetime view in 1908.

At the end of the introduction, Poincare credits Lorentz and says that it all could be disproved by experiment. For this, Miller and others argue that Poincare lacked originality and confidence, and so should not be credited. Miller is wrong.

I quote Stein's translation of Poincare, so you can decide for yourself:
We cannot content ourselves with formulas simply juxtaposed which agree only by a happy chance; it is necessary that these formulas come as it were to interpenetrate one another. The mind will not be satisfied until it believes itself to grasp the reason of this agreement, to the point of having the illusion that it could have foreseen this.

But the question can be presented from still another point of view, which a comparison will help to explain. Let us imagine an astronomer earlier than Copernicus, reflecting upon the system of Ptolemy; he will notice that one of the two circles, epicycle or deferent, of each of the planets is traversed in the same time. This cannot be by chance, there is therefore among all the planets I know not what mysterious bond.

But Copernicus, by simply changing the coordinate axes that are regarded as fixed, makes this appearance vanish; each planet describes only one circle and the times of revolution become independent ... .

There may here be something analogous; if we admit the postulate of relativity, we shall find in the law of gravitation and in the electromagnetic laws a common number which is the velocity of light; and we shall continue to find it in all the other forces, of whatever origin -- which can be explained in two ways only:

Either there is nothing in the world that is not of electromagnetic origin.

Or else this part which is as it were common to all physical phenomena is a mere appearance, something that derives from our methods of measurement. ... In this theory, two equal lengths are, by definition, two lengths that light takes the same time to traverse.

Perhaps it would suffice to renounce this definition, for the theory of Lorentz to be as completely overthrown as Ptolemy’s system was by the intervention of Copernicus. If this happens some day, it will not prove that the effort made by Lorentz was useless; for Ptolemy, whatever one thinks of him, was not useless to Copernicus.

Therefore I have not hesitated to publish these few partial results, even though at this very moment the whole theory might seem placed in danger by the discovery of the magnetocathodic rays.
I never understood the reference to "magnetocathodic rays". Stein tracks it down, and it was some sort of magnetic monopole idea that died several years later. Poincare is not expressing any opinion about these rays, except to say that new observations could disprove the theory. Miller and others have made the silly argument that this showed that Poincare lacked confidence in the theory.

As you can see, Poincare was presenting a very modern and correct view.

Stein goes on to quibble with some of Poincare's philosophy, and to claim this sheds light on the strangeness of Poincare not getting credit. Poincare's biggest mistake, according to Stein, was to not take the theory seriously enough. As a result, he was more interested in explaining the existing experimental data than in predicting new experiments.

As an example, Stein says that Poincare tried to find a relativistic gravity theory compatible with Newton while Einstein (10 years later) tried to explain the anomalies in Mercury's orbit. The example is not so convincing because Poincare first used relativity to partially explain that Mercury anomaly, and Einstein got the idea from Poincare.

If this seems like a weak and muddled conclusion, Stein admits that when presenting his this this thesis, listeners do not get the Poincare mistake. In Stein's words:
The basic mistake that I ascribe to Poincaré is that of seeing the significance of theoretical work as residing essentially and exclusively in its function in organizing knowledge (putative as well as real): that is, organizing the “real generalizations” -- which count as presently claimed knowledge, although it is always possible that they may later fail experimental test. ...

And this is the crucial difference, as I see it, between Poincaré’s relation to the special theory of relativity and Einstein’s. Both of them discovered this theory -- and did so independently. So far as its mathematical structure is concerned, Poincaré’s grasp of the theory was in some important respects superior to Einstein’s. But Einstein “took the theory seriously” in the sense that he looked to it for NEW INFORMATION about the physical world -- that is, in Poincaré’s language, he regarded it as “fertile”: as a source of new “real generalizations” -- of empirically testable consequences.
For this, Einstein is the world's greatest genius was just a misguided fool? No, Stein's analysis just makes the common view look stranger. Devising theories to explain experiments is not a mistake.

Another new philosophy paper carefully distingsuishes the Lorentz constructive view from the spacetime view. In A Case for Lorentzian Relativity, Daniel Shanahan writes:
For the student of physics, there comes a moment of intellectual pleasure as he or she realizes for the first time how changes of length, time and simultaneity conspire to preserve the observed speed of light. Yet Einstein's theory (1) provides little understanding of how Nature has contrived this apparent intermingling of space and time. The language of special relativity (SR) may leave the impression that the Lorentz transformation (the LT) describes actual physical changes of space and time. Thus we have Minkowski's confident prediction that,
Henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows and only a kind of union of the two will preserve an independent reality (2).
... Indeed the Minkowski metric should itself be seen as a kind of illusion, and as a consequence rather than the cause of this change in matter. But to entertain these thoughts is to embark upon a process of reasoning, associated primarily with Lorentz, that became unfashionable following Einstein's famous paper of 1905 (1). Lorentz had sought to explain the transformation that bears his name on the basis of changes that occur in matter as it changes velocity. This was, it is suggested, an idea before its time. ...

In what follows, the distinction drawn will be between Einstein's SR (ESR) and what we will call Lorentzian SR (LSR). This is not to diminish the contributions of others, but it was Lorentz in particular who sought to explain SR from underlying physical processes, as will be the objective below. Once the form of the LT was known, all else in SR then followed, including the composition of velocities, the group theoretic properties of the transformation, and the invariance of Maxwell's equations. It may be argued that with these refinements (largely due to Einstein and Poincaré), ESR and LSR are essentially equivalent. They cannot be distinguished, mathematically or empirically, through the privileged frame that was supposed by Lorentz, but declared "superfluous" by Einstein (1). It would seem that any such frame is rendered undetectable by the covariance of the LT. Nor can ESR and LSR be distinguished by supposing that in ESR, though not in LSR, the LT describes a transformation of spacetime. As we have seen, the LT must be explained in either case by changes occurring in matter as it is accelerated from one inertial frame to another. Historically, the two approaches are distinguished by the assumptions made by Einstein in justifying the LT. His confident assertion of these "postulates" gave impetus to the recognition and development of SR.
This is mostly accurate, but it makes more sense to distinguish LSR from Minkowskian SR. Poincare was the first to formulate the spacetime view, as an alternative to LSR, and Minkowski was the first to unequivocally adopt it. After Minkowski, the leading European physicists also adopted it, and eventually Einstein did also.

Einstein's reasoning in his famous 1905 paper was essentiallly the same as Lorentz's original reasoning, but expressed differently. Whereas FitzGerald, Lorentz, Larmor, Poincare, and Minkowski directly appealed to the Michelson-Morley experiment to deduce the relativity principle and the constant observed speed of light, Einstein said that he was elevated these principles to the status of postulates. Either way, they were deducing the LT from the relativity principle and the constant speed of light.

Lorentz went deeper and provided and electromagnetic explanation. Einstein did not comment on that explanation, as Poincare did.

Here is Shanahan's version of the history:
Briefly first some history. The problem addressed by Lorentz and subsequently Einstein was the speed of light. This emerged as a constant in Maxwell's equations, but if as was generally supposed, light is wave-like, it seemed reasonable to assume that it must be carried by some medium (the "luminiferous aether") at a velocity characteristic of that medium. Thus its velocity relative to an observer should have varied with the motion of the observer through the medium. Experiments of increasing sophistication failed to reveal any trace of that variation.

Several explanations were put forward. It was proposed that the Earth must carry the local aether with it, but a more fruitful suggestion made independently by Fitzgerald (10) and Lorentz (11) was that objects moving through the aether must be somehow shortened along their direction of travel, thereby disguising relative changes in the velocity of light. It was supposed that intermolecular forces must be transmitted at the same velocity as electromagnetic waves, so that movement through the aether would influence the degree of attraction between molecules and thus the separation of those molecules. ...

The LT was already reasonably well known by 1905. There had been significant contributions to its development, not only from Lorentz and Fitzgerald, but also by (among others) Heaviside, Larmor and Poincaré. It was Heaviside's analysis of the disposition of fields accompanying a charged particle (the "Heaviside ellipsoid") that had suggested to FitzGerald the idea of length contraction (12). Larmor had described an early form of the LT and discussed the necessity of time dilation (13). Poincaré had recognized the relativity of simultaneity and had studied the group theoretic properties that form the basis for the covariance of the transformation (14).

But these "trailblazers" (Brown (6), Ch. 4 ) appear to have missed in varying degrees the full significance of the transformation3. It is not only particular phenomena, but all of Nature that changes for the accelerated observer. Lorentz struggled to explain how all aspects of matter could became transformed in equal measure, being discouraged by experimental reports that seemed to show that particles do not contract in the direction of travel (see Brown (6), p. 86). A wider view seems to have been noticed by Poincaré (14), who has been regarded by some as codiscoverer of SR (see, for instance, Zahar (15), and Reignier (16)). But it is not apparent that these earlier investigators saw the changes described by the LT as anything more than mathematical constructs. In his paper of 1905 (1), Einstein simply asserted that the velocity of light, and other properties of Nature, must appear the same for all uniformly moving observers, thereby effecting an immediate reconciliation between Maxwell's equations and classical mechanics.

In 1905, Einstein's approach may have been the only way forward.
Again, this is pretty accurate, but a couple of comments are bizarre. Some historians do claim that Lorentz and Poincare saw the LT as nothing more than mathematical constructs. But this is clearly false, as the Lorentz and Poincare papers are concerned with explaining the Michelson-Morley and other experiments, and directly say that the LT is necessary for those observations.

This is another example of a scholar acknowledging that Poincare had the entire SR theory, but then trying to devalue him by saying that he did not understand what he was doing.

The last claim that Einstein's 1905 paper was the "only way forward" is another common misconception. It is a historical fact that his paper had very little influence in 1905, and papers on SR did not mushroom until after publication of the famous 1908 Minkowski paper, quoted above. The chain of development went from Maxwell to Michelson to Lorentz to Poincare to Minkowski to widespread acceptance to textbooks.

Some people later decided that Einstein's approach had some pedagogical advantages because it allows deriving the LT without discussing actual experiments. But that is not how SR was originally proposed and accepted.

Friday, May 9, 2014

Neil deGrasse Tyson is a philistine

Damon Linker writes:
Why Neil deGrasse Tyson is a philistine
The popular television host says he has no time for deep, philosophical questions. That's a horrible message to send to young scientists.

Neil deGrasse Tyson may be a gifted popularizer of science, but when it comes to humanistic learning more generally, he is a philistine. Some of us suspected this on the basis of the historically and theologically inept portrayal of Giordano Bruno in the opening episode of Tyson's reboot of Carl Sagan's Cosmos.

But now it's been definitively demonstrated by a recent interview in which Tyson sweepingly dismisses the entire history of philosophy. Actually, he doesn't just dismiss it. He goes much further — to argue that undergraduates should actively avoid studying philosophy at all. Because, apparently, asking too many questions "can really mess you up."

Yes, he really did say that. Go ahead, listen for yourself, beginning at 20:19 — and behold the spectacle of an otherwise intelligent man and gifted teacher sounding every bit as anti-intellectual as a corporate middle manager or used-car salesman. He proudly proclaims his irritation with "asking deep questions" that lead to a "pointless delay in your progress" in tackling "this whole big world of unknowns out there." When a scientist encounters someone inclined to think philosophically, his response should be to say, "I'm moving on, I'm leaving you behind, and you can't even cross the street because you're distracted by deep questions you've asked of yourself. I don't have time for that."

"I don't have time for that."
The article goes on to say how some philosophers had some good ideas 2500 years ago.

I am inclined to agree with Tyson. If a student wants to be a scientist, he is better off not studying philosophy. The philosophy of today is taught by professors who seems to misunderstand 20th century physics. Much of it is wrong and confusing.

Tuesday, May 6, 2014

My FQXi essay is posted

FQXi is running its annual essay context on "
How Should Humanity Steer the Future?
". I have submitted an essay, and it is posted online for FQXi community and public voting. The links to this and previous essays are here.

I had a hard time taking this essay seriously. These contests attract a lot of crackpot essays pushing ideas that have little to do with the official topic. Judging from my past scores, I have been downrated by people who think that I am wrong about something. But they do not say in the online discussions what is wrong. If I had submitted to a peer-reviewed journal, then the referee would have to say what is wrong or trivial or otherwise deficient in the paper.

You can read, comment, and rate my essay on the FQXi site. If you follow this blog, then you will recognize my opinions about time. For the most part, I mock the views of mainstream scientists. I quote them in detail so that it is clear that I am not just attacking a straw man.

Friday, May 2, 2014

Theorists don't need to be consistent

NPR Radio reports:
The Standard Model encapsulates all we know so far of the material world: that there are 12 matter particles (the electron being the most familiar) and 12 kinds of particles that transmit the forces between these matter particles (the photon being the most familiar). To these, we must add the most recent particle celebrity, the Higgs boson, found in 2012, and the hypothetical graviton, the particle that supposedly transmits the gravitational force. ...

Lykken and Spiropulu give an excellent illustration of the struggle, quoting noted physicist , from the Institute for Advanced Study:

"What if supersymmetry is not found at the LHC?" he asked, before answering his own question. "Then we will make new supersymmetric models that put superpartners just beyond the reach of the experiments. But wouldn't that mean that we would be changing our story? That's OK; theorists don't need to be consistent; only their theories do."

The question, though, is how long can you keep on changing your story before you realize the story is just wrong? This is the hardship (and the excitement) of research; we don't have a path ahead, we need to forge one. And we are not sure of which direction to take, having only inklings that it could go this or that way.
SUSY would more than double the number of particles.

I think the Standard Model count is already high. There are 3 families of fermion particles, but maybe they are just different states of 1 family. Maybe the electron is just a charged neutrino. Maybe the up and down quarks just differ by charge. They have different masses, but that might be attributable to charge.

There are 8 strong bosons, but there is an SU3 symmetry that relates them all. And a SU2 symmetry relating the 3 weak bosons.

So maybe there are only 6 elementary particles: the down quark, neutrino, photon, strong boson, weak boson, and Higgs boson. There are also anti-particles.