Monday, January 30, 2017

Death is the ultimate equilibrium

Philip Ball writes in Quanta mag:
Once we regard living things as agents performing a computation — collecting and storing information about an unpredictable environment — capacities and considerations such as replication, adaptation, agency, purpose and meaning can be understood as arising not from evolutionary improvisation, but as inevitable corollaries of physical laws. In other words, there appears to be a kind of physics of things doing stuff, and evolving to do stuff. Meaning and intention — thought to be the defining characteristics of living systems — may then emerge naturally through the laws of thermodynamics and statistical mechanics.
I wonder if this inspired the current FQXi essay contest.
Biological systems don’t defy physical laws, of course — but neither do they seem to be predicted by them. In contrast, they are goal-directed: survive and reproduce. We can say that they have a purpose — or what philosophers have traditionally called a teleology — that guides their behavior.

By the same token, physics now lets us predict, starting from the state of the universe a billionth of a second after the Big Bang, what it looks like today. But no one imagines that the appearance of the first primitive cells on Earth led predictably to the human race. Laws do not, it seems, dictate the course of evolution.

The teleology and historical contingency of biology, said the evolutionary biologist Ernst Mayr, make it unique among the sciences. Both of these features stem from perhaps biology’s only general guiding principle: evolution. It depends on chance and randomness, but natural selection gives it the appearance of intention and purpose. Animals are drawn to water not by some magnetic attraction, but because of their instinct, their intention, to survive. Legs serve the purpose of, among other things, taking us to the water.

Mayr claimed that these features make biology exceptional — a law unto itself. But recent developments in nonequilibrium physics, complex systems science and information theory are challenging that view. ...

So living organisms can be regarded as entities that attune to their environment by using information to harvest energy and evade equilibrium. Sure, it’s a bit of a mouthful.
Lumo says string theory can explain everything but the purpose of life, so there cannot be any scientific theory for that. But he is intrigued by some of the quotes:
Death is the ultimate equilibrium. Life is the effort to escape this equilibrium. ...

Organisms want to maximize their distance from the equilibrium which is equivalent to maximizing their freedom in the future.
Meanwhile, I see that Peter Woit has gone full Nazi:
While the US has never seen the likes of this situation, Europe has, with Trump following a playbook familiar from the history of the 1930s. At this point the US may be one terrorist attack away from full-blown Fascism, this time with nuclear weapons. This needs to be stopped, now.

The Constitution does provide two ways to deal with something like this: either the impeachment process or removal under the Twenty-Fifth Amendment as “unable to discharge the powers and duties of his office.” Many of Trump’s recent statements are clearly the product of delusional mind that is incapable of dealing with reality, and these delusions are now reflected in his actions.
And Lumo calls out him and other Trump-haters.

I don't want to get too political here, but this Trump hatred is bizarre. Supposedly smart ppl in universities and Si Valley are ranting against him, but their arguments are at about a 5-year-old level. Surely they could find some coherent argument if Trump were only 1% as bad as they say he is.

If Trump were really Hitler, then why do so many refugees and immigrants want to come here?

Saturday, January 28, 2017

New D-Wave computer sold

ExtremeTech reports:
The D-Wave 2000Q has 2,048 qubits; a substantial increase over the 1,000-qubit D-Wave 2X. Equally important, the $15 million-dollar computer has a first customer — Temporal Defense Systems, which will use the machine “to solve some of the most critical and complex cyber security problems impacting governments and commercial enterprises.” The terms of the deal also give TDS an upgrade path to future “QPUs” (quantum processing units, natch).

“The combined power of the TDS / D-Wave quantum cyber solution will revolutionize secure communications, protect against insider threats, and assist in the identification of cyber adversaries and attack patterns,” said James Burrell, TDS Chief Technology Officer and former FBI Deputy Assistant Director. “Combining the unique computational capabilities of a quantum computer with the most advanced cyber security technologies will deliver the highest level of security, focused on both prevention and attribution of cyber attacks.”
Somebody has been conned. I don't know whether Burrell believes what he is saying, but there is no way this D-Wave machine can do what he says.

The D-Wave machine may be able to solve certain problems, but it does not really have 2048 qubits. Nobody has been able to make true qubits yet.

Thursday, January 26, 2017

Philosophy professors hate Trump

Philosopher Massimo Pigliucci likes to write about pseudoscience, but also tells us:
I’ve been giving a lot of thought about the rise of Trump, and even though I rarely write about explicitly political matters on this blog, this will be one of the exceptions. I think it is necessary. WARNING: unusually strong language ahead, ...

The guy is not a political ideologue, ... He is simply a narcissistic and pampered bully, ignorant to the point of ridiculousness. ... Republican takeover ... is an unqualified disaster. ...

Please, don’t tell me I’m “biased.” If by that you mean I have reasoned, empirically informed opinions about values and politics that are different from yours, sure, I’m biased. And proud of it.
Then what follows is a lot of name-calling and obscenities.

No, I would not say he has reasoned, empirically informed opinions on Trump. I could not find any.

He is from another country, and does not appear to know much about American politics or Trump. He has probably never even met a Trump supporter, so I do not expect much from him.

Nevertheless he writes with the same over-opinionated certainty with which he writes about the philosophy of science.

Just think about that when you read philosophers of science like him. I don't say that he has to agree with Trump, but if he understands Trump less than 50 million voters and still has extremely strong opinions, then he is someone whose opinions should be disregarded.

I have criticized Pigliucci before for having anti-science and leftist-biased opinions. He is worse than I thought.

Here is an ex-philosopher ranting against Trump. I am sure that there are many others.

Update: Texas professor Scott Aaronson also suggests that Trump is another Hitler, and complains:
Today, we learned that Trump is suspending the issuance of US visas to people from seven majority-Islamic countries, including Iran ...

To the Trump regime, I make one request: if you ever decide that it’s the policy of the US government to deport my PhD students, then deport me first. I’m practically begging you: come to my house, arrest me, revoke my citizenship, and tear up the awards I’ve accepted at the White House and the State Department. I’d consider that to be the greatest honor of my career.
He is an American citizen, married to an Israeli. No one is threatening him or his students. He and Pigliucci do not have much loyalty to the USA.

Aaronson is essentially arguing that the USA should let in any quantum complexity theorist who wants to come here and pursue his useless research program. The comments are moderated, and they are all Trump-haters praising Aaronson.

Update: I am informed that Aaronson deleted this comment:
Quantum complexity is an almost entirely useless field. It would have some minor theoretical interest if quantum supremacy were demonstrated, but that is speculative and we do not need very many people in the field. We train too many students for the available jobs.

Trump was elected President of the USA. Every postdoc job given to an Iranian takes one away from an American. Trump's policies favor Americans, not countries that breed terrorism. We do not need any more Iranians in the USA.

Scott, you are pursuing your personal interests, against those of American students, against those of Amerian voters, and against those who are trying to limit the expansion of Islamic terrorism.
That must have hit a sensitive spot.

Where are the professors who are willing to stick up for the Americans who have their careers derailed by these anti-American leftists like Pigliucci and Aaronson?

Update: LuMo has a more detailed criticism of Aaronson:
Most importantly, there just isn't any "universal human right" to work as a postdoc in the U.S. – for anyone, even members of nations that are much more friendly towards America than Iran. Whoever is acting as if he were assuming that such a right exists may get rightfully burned because his assumption is idiotic. The inability to get the postdoc visa may be a personal inconvenience for the Iranian student – and indirectly for his adviser Aaronson – but it's just complete rubbish when this personal inconvenience is presented as a flaw in the new system of policies. Aaronson is pretending that he is defending some deep values but in reality, he's only defending his personal interests.

And the problem isn't really serious, anyway. There are other places outside the U.S. where one may be hired as a postdoc in similar fields.
Motl himself is an ex American postdoc who now lives in Czechia, I think.

Monday, January 23, 2017

History of general relativity

A new paper summarizes the history of general relativity:
This short exposition starts with a brief discussion of situation before the completion of special relativity (Le Verrier's discovery of the Mercury perihelion advance anomaly, Michelson-Morley experiment, Eotvos experiment, Newcomb's improved observation of Mercury perihelion advance, the proposals of various new gravity theories and the development of tensor analysis and differential geometry) and accounts for the main conceptual developments leading to the completion of the general relativity: gravity has finite velocity of propagation; energy also gravitates; Einstein proposed his equivalence principle and deduced the gravitational redshift; Minkowski formulated the special relativity in 4-dimantional spacetime and derived the 4-dimensional electromagnetic stress-energy tensor; Einstein derived the gravitational deflection from his equivalence principle; Laue extended the Minkowski's method of constructing electromagnetic stress-energy tensor to stressed bodies, dust and relativistic fluids; Abraham, Einstein, and Nordstrom proposed their versions of scalar theories of gravity in 1911-13; Einstein and Grossmann first used metric as the basic gravitational entity and proposed a "tensor" theory of gravity (the "Entwurf" theory, 1913); Einstein proposed a theory of gravity with Ricci tensor proportional to stress-energy tensor (1915); Einstein, based on 1913 Besso-Einstein collaboration, correctly derived the relativistic perihelion advance formula of his new theory which agreed with observation (1915); Hilbert discovered the Lagrangian for electromagnetic stress-energy tensor and the Lagrangian for the gravitational field (1915), and stated the Hilbert variational principle; Einstein equation of general relativity was proposed (1915); Einstein published his foundation paper (1916).
This is a good balanced view, and informative for anyone who thinks that Einstein did it all. He made some key contributions, but a lot of the crucial work was done by others.

Wednesday, January 18, 2017

Finding solace in the Multiverse

A string theorist writes:

In physics we’re not supposed to talk about how we feel. We are a hard-nosed, quantitative, and empirical science. But even the best of our dispassionate analysis begins only after we have decided which avenue to pursue. When a field is nascent, there tend to be a range of options to consider, all of which have some merit, and often we are just instinctively drawn to one. This choice is guided by an emotional reasoning that transcends logic. Which position you choose to align yourself with is, as Stanford University physicist Leonard Susskind says, “about more than scientific facts and philosophical principles. It is about what constitutes good taste in science. And like all arguments about taste, it involves people’s aesthetic sensibilities.” ...

Quarks are permanently bound together into protons, neutrons, and other composite particles. “They are, so to speak, hidden behind a … veil,” Susskind says, “but by now, although no single quark has ever been seen in isolation, there is no one who seriously questions the correctness of the quark theory. It is part of the bedrock foundation of modern physics.”
Notice the verbal trickery here. He does not say that no one questions single quark particles.

Susskind wants you to thing: "No one has ever seen an isolated quark but everyone believes in them anyway."

But that is not right. Lots of physicists do not even believe in particles at all. A quark is a useful fiction that helps to understand the SU(3) theory, but that's all. There is no need to believe that quark particles are real, or that they have colors.

My own research is in string theory, and one of its features is that there exist many logically consistent versions of the universe other than our own. The same process that created our universe can also bring those other possibilities to life, creating an infinity of other universes where everything that can occur, does. ...

The multiverse explains how the constants in our equations acquire the values they do, without invoking either randomness or conscious design. If there are vast numbers of universes, embodying all possible laws of physics, we measure the values we do because that’s where our universe lies on the landscape. There’s no deeper explanation. That’s it. That’s the answer.

But as much as the multiverse frees us from the old dichotomy, it leaves a profound unease. The questions we have spent so long pondering might have no deeper answer than just this: that it is the way it is. That might be the best we can do, but it’s not the kind of answer we’re used to. It doesn’t pull back the covers and explain how something works. What’s more, it dashes the theorists’ dream, with the claim that no unique solution will ever be found because no unique solution exists.

There are some who don’t like that answer, others who don’t think it even qualifies to be called an answer, and some who accept it. ...

Tasneem Zehra Husain is a theoretical physicist and the author of Only The Longest Threads. She is the first Pakistani woman string theorist.
This is the crazy world view of a string theorist. Their god is the elusive mathematical equation that is going to unify all of physics, even if it explains nothing. They believe so much that they will accept the possibility of essentially infinitely many equations driving infinitely many unobservable universes.

Gian Giudice, head of CERN’s theory group, speaks for most physicists when he says that one look at the sky sets us straight. We already know our scale. If the multiverse turns out to be real, he says, “the problem of me versus the vastness of the universe won’t change.” In fact, many find comfort in the cosmic perspective. Framed against the universe, all our troubles, all the drama of daily life, diminishes so dramatically that “anything that happens here is irrelevant,” says physicist and author Lawrence Krauss. “I find great solace in that.”
Great solace?

Even without the multiverse or even anything cosmological, our lives on the surface of the Earth are infinitesimal compared to just the interior of the Earth. That is already enuf to overwhelm his psychological sense of well-being, and I don't believe that anyone really finds any solace in the multiverse.

Monday, January 16, 2017

Quantum gravity from philosophy

From a new paper on Kant and Quantum Gravity:
In quantum gravity space and time lose their status as fundamental parts of the physical reality. However, according to Kant, space and time are the a priori conditions of our experience. Does Kantian characterization of these notions give constraints to quantum gravity, or does quantum gravity make Kantian characterization of space and time an invalid approach? This paper provides answers to these questions with a philosophical approach to quantum gravity.
You are probably going to say that this is self-evidently ridiculous, because physics is about the observable world, not the the prejudices of some silly German philosopher. Kant said a lot of stupid stuff about space and time before relativity, and there is no agreement over whether it can be reconciled with relativity.

But all quantum gravity is just philosophy. There is no data or experiment to guide the theory. Researchers are just looking for "a priori conditions of our experience", whatever that means.

Speaking of philosophy, Stanford philosophy professor Helen Longino said:
Sokal has this very sort of old-fashioned idea about science — that the sciences are not only aiming at discovering truths about the natural world but that their methods succeed in doing so.
Outside the hard sciences, I suspect that it is very common for academics to deny that science discovers truths.

Philosophers complain that they get no respect from the hard sciences. Of course they do not. Philosophers will never get respect as long as they deny the discovery of truths.

SciAm blogger John Horgan writes that the point of philosophy is not to discover truth or even to make progress:
What is philosophy? What is its purpose? Its point? The traditional answer is that philosophy seeks truth. But several prominent scientists, notably Stephen Hawking, have contended that philosophy has no point, because science, a far more competent truth-seeking method, has rendered it obsolete. ...

[David Chalmers] concedes that whereas scientists do converge on certain answers, “there has not been large collective convergence to the truth on the big questions of philosophy.” A survey of philosophers carried out by Chalmers and a colleague revealed divisions on big questions: What is the relationship between mind and body? How do we know about the external world? Does God exist? Do we have free will?

Philosophers’ attempts to answer such questions, Chalmers remarks, “typically lead not to agreement but to sophisticated disagreement.” That is, progress consists less in defending truth claims than in casting doubt on them. Chalmers calls this “negative progress.”
It appears that philosophers making negative progress are jealous of other fields that make positive progress.

Saturday, January 14, 2017

Top modern philosophy books

Want to know what passes as a great modern philosophy book? Here are the top ones with some relation to science (and a couple of others):
Most-cited Anglophone philosophy books published since WWII (according to Google Scholar)

These are rounded to the nearest 100. I tried to find all post-WWII philosophy books with at least 5,000 citations. ...

1. Thomas Kuhn, The Structure of Scientific Revolutions (1962) (89,500)

2. John Rawls, A Theory of Justice (1971) (65,000)

8. Karl Popper, Conjectures and Refutations: The Growth of Scientific Knowledge (1963) (15,700)

14. Jerry Fodor, The Modularity of Mind (1983) (12,800)

16. Daniel Dennett, Consciousness Explained (1991) (11,100)

20. Karl Popper, Objective Knowledge:  An Evolutionary Approach (1972) (10,100)

21. Paul Feyerabend, Against Method (1975) (9,900)
Karl Popper, The Open Society and Its Enemies (1945) (9,500)
John Searle, The Construction of Social Reality (1995) (8,400)
Derek Parfit, Reasons and Persons (1984) (8,200)
David Chalmers, The Conscious Mind (1996) (7,400)
Jerry Fodor, The Language of Thought (1975) (7,300)
Daniel Dennett, Darwin's Dangerous Idea (1995) (7,000)
Martha Nussbaum, Women and Human Development:  The Capabilities Approach (2001) (6,900)
Hubert Dreyfus, Stuart Dreyfus & T. Athanasiou, Mind over Machine (2000) (6.800)
John Searle, Intentionality (1983) (6,500)
Popper occasionally said sensible things, but those are disavowed by modern philosphers.

Where are the philosophers who have contributed to modern scientific understanding? These books have hurt the cause of science more than they are helped.

Monday, January 9, 2017

Isosceles triangles and common sense

Geography professor and popular anthropology writer Jared Diamond writes:
In fact, common sense should be invoked more often in scientific discussions, where it is sometimes deficient and scorned. Scientists may string out a detailed argument that reaches an implausible conclusion contra ...

The proof purported to demonstrate that all triangles are isosceles, i.e. have two equal sides. Of course that conclusion is wrong: most triangles have unequal sides, and only a tiny fraction has two equal sides. ...

The proof tacitly assumed that that perpendicular bisector did intersect the triangle’s base, as is true for isosceles and nearly-isosceles triangles. ...

Conclusion: don’t get bogged down in following the details of a proof, if it leads to an implausible conclusion.
He apparently never understood the flaw, as his reasoning would imply that a nearly-isosceles triange must be isosceles.

Mathematics is all about understanding what is a valid proof, and what is not. Diamond did not get the point.

It figures, as his books are filled with illogical arguments that he takes to be conclusive.

Here is his second example:
This discovery became explained only two decades later by Albert Einstein’s theory of relativity, for which the Michelson-Morley experiment offered crucial support.

Another two decades later, though, another physicist carried out a complicated re-analysis of Michelson’s and Morley’s experiment. He concluded that their conclusion had been wrong. If so, that would have shaken the validity of Einstein’s formulation of relativity. Of course Einstein was asked his assessment of the re-analysis. His answer, in effect, was: “I don’t have to waste my time studying the details of that complex re-analysis to figure out what’s wrong with it. Its conclusion is obviously wrong.” That is, Einstein was relying on his common sense. Eventually, other physicists did waste their time on studying the re-analysis, and did discover where it had made a mistake.
This is a funny one, because the textbooks agree that Michelson-Morley was crucial for the development and demonstration of relativity, but Einstein himself regarded it as unimportant for his contribution. That is because Einstein's work was largely a reformulation of Lorentz's, and Einstein relied on Lorentz's analysis of Michelson-Morley.

The experiment was re-done many times. If Einstein did not care much about the first experiment, why would he bother with the subsequent ones? This is a story of indifference, not common sense.

Diamond ends up arguing that the Clovis ppl were the first settlers of the Americas. I have no idea about that.

Saturday, January 7, 2017

Predicting quantum supremacy for 2017

SciAm reports:
Quantum computing has long seemed like one of those technologies that are 20 years away, and always will be. But 2017 could be the year that the field sheds its research-only image.

Computing giants Google and Microsoft recently hired a host of leading lights, and have set challenging goals for this year. Their ambition reflects a broader transition taking place at start-ups and academic research labs alike: to move from pure science towards engineering.

“People are really building things,” says Christopher Monroe, a physicist at the University of Maryland in College Park who co-founded the start-up IonQ in 2015. “I’ve never seen anything like that. It’s no longer just research.”

Google started working on a form of quantum computing that harnesses superconductivity in 2014. It hopes this year, or shortly after, to perform a computation that is beyond even the most powerful ‘classical’ supercomputers — an elusive milestone known as quantum supremacy. Its rival, Microsoft, is betting on an intriguing but unproven concept, topological quantum computing, and hopes to perform a first demonstration of the technology.

The quantum-computing start-up scene is also heating up. ...

Academic labs are at a similar point.
I am predicting that none of these groups achieve quantum supremacy in 2017, but the year will end with everyone predicting it for 2018. And that pattern will repeat for a few years.
Whereas classical computers encode information as bits that can be in one of two states, 0 or 1, the ‘qubits’ that comprise quantum computers can be in ‘superpositions’ of both at once. This, together with qubits’ ability to share a quantum state called entanglement, should enable the computers to essentially perform many calculations at once. And the number of such calculations should, in principle, double for each additional qubit, leading to an exponential speed-up.
Scott Aaronson likes to say that this explanation is wrong, because quantum computers do not necessarily get an exponential speedup.

These articles do not even cite any skeptics anymore. There is a consensus. They are so far committed that I expect them to refuse to admit that they have been proven wrong for about ten years after they have been proven wrong. And I predict that they will be proven wrong.

Friday, January 6, 2017

The Trouble with Quantum Mechanics

Steven Weinberg writes The Trouble with Quantum Mechanics in the NY Review of Books:
The development of quantum mechanics in the first decades of the twentieth century came as a shock to many physicists. Today, despite the great successes of quantum mechanics, arguments continue about its meaning, and its future. ...

Probability enters Newtonian physics only when our knowledge is imperfect, ...

Many physicists came to think that the reaction of Einstein and Feynman and others to the unfamiliar aspects of quantum mechanics had been overblown. This used to be my view. After all, Newton’s theories too had been unpalatable to many of his contemporaries. ...

It is a bad sign that those physicists today who are most comfortable with quantum mechanics do not agree with one another about what it all means. The dispute arises chiefly regarding the nature of measurement in quantum mechanics. ...

The introduction of probability into the principles of physics was disturbing to past physicists, but the trouble with quantum mechanics is not that it involves probabilities. We can live with that. The trouble is that in quantum mechanics the way that wave functions change with time is governed by an equation, the Schrödinger equation, that does not involve probabilities. It is just as deterministic as Newton’s equations of motion and gravitation. That is, given the wave function at any moment, the Schrödinger equation will tell you precisely what the wave function will be at any future time. There is not even the possibility of chaos, the extreme sensitivity to initial conditions that is possible in Newtonian mechanics. So if we regard the whole process of measurement as being governed by the equations of quantum mechanics, and these equations are perfectly deterministic, how do probabilities get into quantum mechanics? ...

What then must be done about the shortcomings of quantum mechanics? One reasonable response is contained in the legendary advice to inquiring students: “Shut up and calculate!” There is no argument about how to use quantum mechanics, only how to describe what it means, so perhaps the problem is merely one of words.
This is a very strange complaint. Obviously he understands perfectly well how probability, measurement, and chaos get into quantum mechanics, because there is wide agreement on how to do the calculations that predict experiments.

So his problem is purely philosophical. If this is a problem, then I think that most theories have problems if you take them too literally and ask too many philosophical questions.

LuMo explains:
When it comes to well-defined laws governing the evolution of probabilities in time, it's just a plain stupidity to suggest that these laws are "troubling" in any sense. Quantum mechanics doesn't change anything about the meaning of probabilities, their relationship to imperfect knowledge, the existence of well-defined equations by which these probabilities evolve as well as discontinuous Bayesian/collapse changes by which the probabilities jump after an observation. The only thing that is new in quantum mechanics is the uncertainty principle (due to the nonzero commutators) which, among other things, forbids any perspective in which two generic observables are perfectly known at the same moment. The nonzero commutators make it unavoidable to talk about probabilities between 0% and 100% i.e. about imperfect knowledge. But what the "knowledge", "imperfect", "probability" etc. mean is exactly the same as it always was. ...

At any rate, I consider Weinberg to be a 100% anti-quantum zealot ... at this point. It's sad.
Weinberg's hangup about probabilities is especially strange. He says that probabilities enter classical mechanics "when our knowledge is imperfect", and enters quantum mechanics because "not everything can be simultaneously measured." Okay, I can accept that, but why is it a problem? Our knowledge is always imperfect in the classical case because of observation errors, and always imperfect in the quantum case for the additional reason that it is impossible to predict the measurement of variables that cannot be simultaneously measured. So yes, probabilities are appropriate in either case.

I can only infer that Weinberg has some conceptual misunderstanding of probability, but I don't see what it is.

He favorably describes the many-worlds interpretation, but does not endorse it.

Physics professor Frank Tipler does endorse the many worlds:
Most physicists, at least most physicists who apply quantum mechanics to cosmology, accept Everett’s argument. So obvious is Everett’s proof for the existence of these parallel universes, that Steve Hawking once told me that he considered the existence of these parallel universes “trivially true.” Everett’s insight is the greatest expansion of reality since Copernicus showed us that our star was just one of many. Yet few people have even heard of the parallel universes, or thought about the philosophical and ethical implications of their existence.
Quantum mechanics is a theory of physics on an atomic scale, so only crackpots apply quantum mechanics to cosmology. Maybe most of them believe in many-worlds, I don't know, but I really don't think that most physicists do.

Thursday, January 5, 2017

Blaming Einstein for the name Relativity

Jim Holt writes:
In physics, as Emmy Noether showed us with her beautiful theorem, invariance turns out to entail the conservation of energy and other bedrock conservation principles — "a fact," noted Richard Feynman, "that most physicists still find somewhat staggering."    

And in the mind of Albert Einstein, the idea of invariance led first to e = mc2, and then to the geometrization of gravity.   

So why aren't we hearing constantly about Einstein's theory of invariance? Well, "invariant theory" is what he later said he wished he had called it. And that's what it should have been called, since invariance is its very essence. The speed of light, the laws of physics are the same for all observers. They're objective, absolute — invariant. Simultaneity is relative, unreal.  

But no. Einstein had to go and talk about the "principle of relativity." So "relativity"—and not its opposite, "invariance"—is what his revolutionary theory ended up getting labeled.
No, Einstein did not conceive the geometrization of gravity. As a recent paper noted:
It is generally believed that Einstein identified gravitation with the non-Euclidean geometry of spacetime. However, contrary to common belief, as Lehmkuhl showed [7], Einstein himself did not believe that general relativity geometrized gravitation: "I do not agree with the idea that the general theory of relativity is geometrizing Physics or the gravitational field" [8].

[7] D. Lehmkuhl, Why Einstein did not believe that General Relativity geometrizes gravity. Studies in History and Philosophy of Physics, Volume 46, May 2014, pp. 316-326.
[8] A letter from Einstein to Lincoln Barnett from June 19, 1948; quoted in [7].
Einstein also did not originate the terms "relativity" or "principle of relativity". As well as I can determine, Maxwell invented the term "relativity", and Poincare popularized the "principle of relativity", long before Einstein ever wrote anything on the subject.

In short, relativity was named by those who invented it, not Einstein.

Holt likes "invariance" because it suggests a group action, but Einstein missed that. The group is called the "Lorentz group", because that is what Poincare called it in a 1905 paper that was published before Einstein submitted his famous relativity paper. Poincare named it after Lorentz, who did pioneering work on it ten years earlier.

I don't see why "invariance" is a better name anyway. The theory's origin was with attempts to understand the motion of the Earth, with a key observation being that the motion we see is relative to the Earth's frame of reference. The theory shed new light on an ancient and easy-to-understand question. Getting to invariants is a little more obscure.

Tuesday, January 3, 2017

The future is uncertain

Professor Anthony Sudbery writes in Aeon mag, as an intro to his forthcoming book:
Aristotle formulated the openness of the future in the language of logic. Living in Athens at a time when invasion from the sea was always a possibility, he made his argument using the following sentence: ‘There will be a sea-battle tomorrow.’ One of the classical laws of logic is the ‘law of the excluded middle’ which states that every sentence is either true or false: either the sentence is true or its negation is true. But Aristotle argued that neither ‘There will be a sea-battle tomorrow’ nor ‘There will not be a sea-battle tomorrow’ is definitely true, for both possibilities lead to fatalism; if the first statement is true, for example, there would be nothing anybody could do to avert the sea-battle. Therefore, these statements belong to a third logical category, neither true nor false. In modern times, this conclusion has been realised in the development of many-valued logic. ...

Aristotle formulated the openness of the future in the language of logic. Living in Athens at a time when invasion from the sea was always a possibility, he made his argument using the following sentence: ‘There will be a sea-battle tomorrow.’ One of the classical laws of logic is the ‘law of the excluded middle’ which states that every sentence is either true or false: either the sentence is true or its negation is true. But Aristotle argued that neither ‘There will be a sea-battle tomorrow’ nor ‘There will not be a sea-battle tomorrow’ is definitely true, for both possibilities lead to fatalism; if the first statement is true, for example, there would be nothing anybody could do to avert the sea-battle. Therefore, these statements belong to a third logical category, neither true nor false. In modern times, this conclusion has been realised in the development of many-valued logic. ...

Knowledge of the future, therefore, is limited in a fundamental way. It is not that there are true facts about the future, but the knowledge of them is not accessible to us; there are no facts out there, and there is simply no certain knowledge to be had. Nevertheless, there are facts about the future with partial degrees of truth. We can attain knowledge of the future, but that knowledge will always be uncertain.
His explanation is sensible enuf, but it is funny how he has to dive into quantum mechanics to reach the same conclusions that Aristotle reached 2.5 millennia earlier.

Yes, Laplace mentioned a deterministic fantasy in 1814, but he also had a very probabilistic view of the world.

Monday, January 2, 2017

Awe for the Second Law of thermo

Harvard psychology professor (and popular Jewish atheist science writer) Steven Pinker writes:
Why the awe for the Second Law? The Second Law defines the ultimate purpose of life, mind, and human striving: to deploy energy and information to fight back the tide of entropy and carve out refuges of beneficial order. ...

The biggest breakthrough of the scientific revolution was to nullify the intuition that the universe is saturated with purpose: that everything happens for a reason. In this primitive understanding, when bad things happen — accidents, disease, famine — someone or something must have wanted them to happen.
So science eliminated all these diverse purposes for bad things, and unified them into one central purpose that explains them all?

This is like ancient Judaism discovering that river gods, weather gods, and all the other gods could be combined into one true God. Or early scientists discovering that all known energy sources could be trace to the one Sun.

Scott Aaronson endorses Pinker's essay and adds:
Again and again, people imagine that, if their local pocket of order isn’t working how they want, then they should smash it to pieces, since while admittedly that might make things even worse, there’s also at least 50% odds that they’ll magically improve.  In reasoning thus, people fail to appreciate just how exponentially more numerous are the paths downhill, into barbarism and chaos, than are the few paths further up.  So thrashing about randomly, with no knowledge or understanding, is statistically certain to make things worse: on this point thermodynamics, common sense, and human history are all in total agreement.
He doesn't realize it, but he is making an argument for political conservatism. The policies of Barack Obama and Hillary Clinton have led us downhill into barbarism and chaos. We need a government that is willing to go back to what has worked before, and make America great again.