Thursday, October 1, 2015

Defending logical positivism

Logical positivism is a philosophy of science that was popular in the 1930s, and largely abandoned in the following decades. It is a variant of positivism, a view that is peculiar because it is widely accepted among scientists today, but widely rejected among philosophers of science. Wikipedia says logical positivism is "dead, or as dead as a philosophical movement ever becomes". [1,2]

I defend logical positivism, based on my understanding of it, as the best way to understand math and science today.

The core of logical positivism is to classify statements based on how we can determine their truth or falsity. There are three types.

1. Math. This includes mathematical theorems, logic, tautologies, and statements that are true or false by definition.

2. Science. This includes observations, measurements, induction, approximations, hypothesis testing, and other empirical work.

3. All else - mysticism, ethics, subjective beauty, opinion, religion, metaphysics, aesthetics, etc.

Mathematical truth is the highest kind of truth, and is given by logical proofs. It goes back to Euclid and the ancient Greeks, and was not independently discovered by anyone else, as far as I know. When a theorem is proved, you can be 100% sure of it.

You might think that mathematical knowledge is empirical, but it has not been for two millennia. You might also have been told Goedel's work somehow undermined the axiomatic method. The truth is more nearly the opposite. Math means logical proof. If I say that the square root of two is irrational, that means that I have a proof.

Science arrives at somewhat less certain truths using empirical methods. A conclusion might be that the Sun will rise in the East tomorrow morning. This is backed up by many observations, as well as theory that has been tested in many independent ways. Science also makes predictions with lesser confidence. These are considered truths, even though they are not as certain as mathematical truths.

There are many other statements that are not amenable to mathematical proof or empirical verification. For example, I may be of the opinion that sunsets are beautiful. But I do not have any way of demonstrating it, either mathematically or empirically. If you tell me that you disagree, I would be indifferent because there is no true/false meaning attached to the statement. It is meaningless, in that sense.

So far, this is just a definition, and not in serious dispute. What makes logical positivists controversial is their strong emphasis on truth. They tend to be skeptical about aspects of scientific theories that have not been tested and verified, and they may even be contemptuous of metaphysical beliefs. Others don't like it when their opinions are called meaningless.

Logical positivism is part of the broader philosophy of positivism that emphasizes empirically verifying truths. Logical positivism is a kind of positivism that recognizes math as non-empirical truth. When speaking of science, positivism and logical positivism are essentially the same. [3]

Logical positivists do distinguish between logical and empirical truths. I. Kant previously drew a distinction between analytic and synthetic statements, with analytic being like logical, and synthetic being like empirical. However he classified 7+5=12 as synthetic, which makes no sense to me. So his views have little to do with logical positivism.

Some statements might be a mixture of the three types, and not so easily classified. To fully understand a statement, you have to define its terms and context, and agree on what it means for the statement to be true. For the most part, mathematical truths are the statements found in math textbooks and journals, and scientific truths are the ones found in science textbooks and journals.

Enabled by XX century progress

I might not have been a positivist before the XX century, when broad progress in many fields provided a much sharper view of the known world.

In math, the major foundational issues got settled, with the work of Goedel, Bourbaki, and many others. Nearly all mathematics, if not all, has proofs that could be formalized in some axiom system like ZFC. [4]

This opinion may surprise you, as there is a common philosophical view that the pioneering work on logicism by G. Frege, B. Russell, and others was disproved by Goedel. One encyclopedia says: "On the whole the attempt to reduce mathematics to logic was not successful." [5] Scientific American published a 1993 article on "The Death of Proof". Not many mathematicians would agree.

The math journals publish theorems with proofs. The proofs are not written in a formal language, but they build on an axiomatic foundation and could be formalizable. It is not possible to have a Turing machine to determine the truth or falsity of any mathematical statement, so math is not reducible to logic in that sense. But every math theorem is also a logical theorem of axiomatic set theory, so in that sense, math has been reduced to logic.

In physics, advances like relativity and quantum mechanics expanded the scope of science from the sub-atomic to the galaxy cluster. Also these theories went fully causal, so that physics could hope to give a complete explanation of the workings of nature. The fundamental forces have quantitative theories that are as accurate as we can measure.

Again, this opinion may surprise you, as philosophers commonly deny that fundamental physics has anything to say about causality. [6] If that were true, it would rob physics of nearly all of its explanatory and predictive power. In my opinion, incorporating causality into fundamental physics was the most important intellectual achievement in modern times. Before 1850, we did not have causal explanations for any of the four fundamental forces. Now we have fully causal theories for all four, and those theories have led to the most striking technological progress in the history of the planet.

In biology, the discovery and deciphering of DNA and the genetic code meant that life could be included in the grand reductionist scientific vision.

Medicine, statistics, economics, and other fields made so much progress that XX century knowledge is the only thing to study.

With all the advances of the last century there is hardly any need to believe in unproven ideas, as ancient people might have attributed storms to the gods being angry. Today one can stick with positive knowledge, and have a coherent and satisfactory view of how the world works.

Philosophical criticisms

Philosophers have turned against positivism, and especially logical positivism. They consider the subject dead. The most common criticism is to attack metaphysical beliefs that logical positivists supposedly have. For example, some say that logical positivists cannot prove the merits of their views.

This is a bit like criticizing atheists for being unable to prove that there is no god.

Logical positivists do not accept metaphysics as truth. No argument about metaphysics can possibly refute logical positivism.

Some say that Goedel disproved the logical part of logical positivism. That is not true, as explained above. Goedel gave a clearer view of the axiomatic method, but did not undermine it.

The argument that logical positivism is self-defeating is fallacious in the same way as the argument that Goedel's logic is self-defeating. It misses the point about what the subject matter is. It is like saying: The imaginary numbers prove that the real numbers are incomplete, and therefor real analysis is invalid. No, the imaginary numbers mere shed light on what non-real numbers might look like.

Another line of criticism comes from what I call negativism. In this view, there is no such thing as positive truth. There are only falsified theories, and theories that have not yet been falsified. In effect, they say you can only prove a negative, not a positive. [7]

This seems backwards to me. If Newtonian theory is good enough to send a man to the Moon, then obviously there is something right about it. It is a true theory, and valid where it applies. It is not wrong just because it is not perfectly suited to all tasks. Pick up any science journal, and you will find it filled with positive knowledge.

Some science historians claim that the progress of science was fueled by anti-positivists who were willing to stake out beliefs that went beyond what could be empirically demonstrated. For example, some positivists were skeptical about the existence of atoms, long after others were convinced. A later example is the 1964 discovery of quarks, which are never seen in isolation. Murray Gell-Mann got the 1969 Nobel Prize for it, but the official citation did not mention quarks, and the introduction to his Nobel lecture only mentioned the great heuristic value of quarks. His lecture said that existence was immaterial, and that "quark is just a notion so far. It is a useful notion, but actual quarks may not exist at all." [8] His original paper only called it a "schematic model". Today quarks are commonly considered elementary particles.

Gell-Mann and the Nobel committee were being positivist, because without direct evidence for quarks, it is not necessary to believe that a quark is any more than a useful heuristic notion. Anti-positivists would say that, in retrospect, Gell-Mann was being unduly cautious.

It is not necessary to believe quarks are real particles, as there is barely any benefit to thinking of light as photons. Planck's original 1900 idea was that light was absorbed and emitted as discrete quanta, and that idea is still good today. You have to face some tricky paradoxes if you think of light always being particles.

A more recent example of positivism is the 2011 Nobel Prize for the discovery of the dark energy that permeates the universe. The recipients and most other astrophysicists refuse to say what it is, except that the phrase is a shorthand for the supernovae evidence for the accelerating expansion of the universe. When asked to speculate, one of them says "Reality is the set of ideas that predicts what you see." [9] Again, a positivist view prevails.

It is hard to find examples where positivist views have held back scientific progress, or where anti-positivist views have enabled progress. Weinberg claims to have a couple of examples, [10] such as J.J. Thomson getting credit (and the 1906 Nobel prize) for the discovery of the electron, even though a positivist did better work. Supposedly Thomson's non-positivism allowed him to see the electron as a true particle, and investigate its particle-like properties. Of course we now know that the electron is not truly a particle, and his son later got the Nobel prize for showing that it was a wave. Or a wave-like particle, or a particle-like wave, or a quantized electric field, or a renormalized bare charge, or whatever you want to call it. The positivist would say that the electron is defined by its empirical properties and our well-accepted quantum mechanical theories, and words like particle and wave are just verbal shortcuts for describing what we know about electrons.

Weinberg's larger point is that modern philosophy has become irrelevant and possibly detrimental to science. I would trace the problem to the rejection of logical positivism. That is when philosophers decided that they were no longer interested in truth, as understood by mathematicians and scientists.

Criticism of positivism also comes from the followers of T.S. Kuhn's paradigm shift theory. He denied that science was making progress towards truth, and portrayed the great scientific revolutions as irrational leaps to a theory with no measurable advantages. His favorite example was the /Copernican revolution, where a 1543 belief in the Earth's revolution around the Sun had no empirical advantages. [11]

Kuhn was influenced by the anti-positivist Michael Polanyi, who also drew anti-positivist lessons from Copernicus, and who claimed that relativity was discovered from pure speculation, intuition, and gedanken (thought) experiment, rather than from empiricism or real experiment. [12]

Polanyi's argument is as absurd as it sounds. The early papers on relativity had many startling consequences, including length contraction, time distortion, and mass increase, and every paper on these developments described them as consequences of the Michelson-Morley experiment. So do most of the textbooks, both now and a century ago. That was the crucial experiment. The sole support for Polanyi was Einstein's reluctance to credit others, but even some of Einstein's papers described the experiment as being crucial to relativity. Also, the prediction of mass increase with velocity was tested before Einstein wrote his first paper on the subject.

A positivist is likely to agree that the Ptolemy and Copernicus systems had little empirical difference. Indeed, general relativity teaches that geocentric and heliocentric coordinates are equally valid, as the physical equations can be written in any choice of coordinates.

Kuhn's paradigm shift theory really only applies to ancient debates over unobservables. XX century advances like relativity and quantum mechanics do not match his description at all, as they offered measurable advantages that a rational objective observer could appreciate.

Positivism has also become unpopular among some modern theoretical physicists who promote string theory, multiverses, and other ideas with no empirical support. A recent Nature article explains how "attempts to exempt speculative theories of the Universe from experimental verification undermine science". [13]

Logical positivist ideas have succeeded

Relativity and quantum mechanics are regarded as great theoretical advances in physics, and positivist ideas were essential in both. Relativity discards preconceptions about space, time, and mass, and replaced them with ideas more closely connected with what is measurable, and then relied heavily on experiment. The aether became a metaphysical idea whose existence was meaningless unless some way of measuring it were found.

Quantum mechanics, in the Copenhagen interpretation, made the observables the heart of the theory and openly declared the non-empirical questions to be meaningless. There is a long history of physicists and philosophers being unhappy with the positivism of this, and endorsing other interpretations that are supposedly more realist. Einstein famously denounced quantum mechanics, and others have also sought theories with hidden variables, pilot waves, and parallel universes. What they have in common is to assert the reality of unobservables, and to fail to provide an empirical test. No good has come from any of this anti-positivist work.

Nearly all good work in quantum mechanics follows the R.P. Feynman (misattributed) dictum "Shut up and calculate" [14] as well as "Unperformed experiments have no results." These slogans represent the positivist view that science is all about explaining and predicting what is observable, and avoiding speculation about what is not. The famous quantum paradoxes are all derived from anti-positivist and unnecessarily realist interpretations. [15]

Feynman did explain the virtues in having multiple theories to explain the same phenomenon, and those theories might have unobservable details. If those theories disagree about unobservables and agree about observable consequences, then they give a richer view of nature to the positivist, and not a disturbing contradiction. [16]

The verified theories are not falsified

Hypotheses are falsified all the time, and the possibility of falsification is an important way to analyze assertions of any kind. But well-accepted theories are almost never falsified. There are vast bodies of knowledge that the logical positivist can accept as verified. I consider some examples.

Euclid was not falsified by non-Euclidean geometry. Different postulates give different geometries. That is how geometry works.

The Ptolemy Almagest was a masterpiece of positivist scientific reasoning. It modeled the sky, as seen from Earth, and has not been proven wrong. His model was about as good as could be expected from the available data. His more speculative Planetary Hypotheses and his astrology treatise have not held up so well, but the Almagest was a scientific authority for a millennium.

The Almagest was geocentric in the same way that a modern personal computer planetarium program is geometric. It showed you what you see without modeling unobservables like distance from the Earth. Ptolemy also published a geography treatise. Complaining that his sky was geocentrist is like complaining that his Earth maps were flat. It should be obvious that he map is not the same as the territory.

Newton's theory of gravity has also held up remarkably well, and it still used today. If he were still alive, I think that he would be very surprised that anyone would argue that his theory was proved wrong. Instead, he might say that his theory turned out to be several orders of magnitude more accurate than he expected. After 300 years, there was a barely detectable anomaly in Mercury's orbit that was explained by relativity.

You might argue that the gravitational force is described differently in general relativity, but Newton would probably say that he was always unhappy with the action-at-a-distance aspect of his theory, and that relativity merely fills in a missing detail, thereby allowing greater accuracy under extreme conditions that he did not even consider. As a methodology for estimating trajectories and orbits, Newton's theory is as good as it ever was.

Concepts such as the aether and the epicycle are often said to have been proved wrong, but it is more accurate to say that they were refined with additional knowledge, just as the ancient concept of atoms has been refined. The main difference is that we have retained the word atom, and other terms have been replaced.

Even Aristotle's physics holds up pretty well. There is a widespread believe that he said stupid things like heavier objects falling faster than light ones, and that nobody dared question his treatise by doing the experiment. But he never said that, and there was no great reluctance to improve on his work. [17]

And modern science holds up even better. Sometimes scientists are wrong, such as those who denied continental drift, and there are lots of scientific controversies. But once something gets figured out and widely accepted, it is usually right. I do not agree with the negativists who say that all theories are either wrong, or not yet proven wrong.


Logical positivism gives a coherent view of modern math and science. It more closely resembles the views of modern successful mathematicians and scientists than the alternatives that philosophers espouse. In short, scientists believe that they are finding truth, and philosophers deny that it is possible.

(This essay was written for a philosophy site, but it has restricted to opinions from academic philosophers, and then shut down when that flopped.)



[3] A scientist argues that even math is empirical in this article: Defending scientism: mathematics is a part of science, Coel Hellier,

[4] Metamath Proof Explorer Home Page,

[5] Logicism,

[6] APA 2014-2: Against causal reductionism.

[7] Karl Popper attacked positivism, and may be considered a negativist.

[8] Great Physicists: The Life and Times of Leading Physicists from Galileo to Hawking, William H. Cropper, p.415.

[9] Brian P. Schmidt, 2014 lecture, podcast

[10] Dreams of a Final Theory, Steven Weinberg,

[11] Paradigm shift,

[12] Michael Polanyi and the History of Science,

[13] Scientific method: Defend the integrity of physics, George Ellis & Joe Silk,

[14] The Feynman dictum is actually due to Mermin.

[15] Quantum Theory Needs No ‘Interpretation’, Christopher A. Fuchs and Asher Peres,

[16] The Character of Physical Law, Richard Feynman,

[17] Aristotle's physics, Carlo Rovelli,

Monday, September 28, 2015

Logicism did not fail

Philosophers of science are always denying scientific accomplishments, and here is one also denying math. Massimo Pigliucci wrote in 2012:
Let’s set aside the goal of unifying all knowledge. How are we doing in the millennia-long quest for absolute and objective truth? Not so well, it seems, and that is largely because of the devastating contributions of a few philosophers and logicians, particularly David Hume, Bertrand Russell and Kurt Gödel. ...

What about maths and logic? At the beginning of the 20th century, a number of logicians, mathematicians and philosophers of mathematics were trying to establish firm logical foundations for mathematics and similar formal systems. The most famous such attempt was made by Bertrand Russell and Alfred North Whitehead, and it resulted in their Principia Mathematica (1910-13), one of the most impenetrable reads of all time. It failed.

A few years later the logician Kurt Gödel explained why. His two ‘incompleteness theorems’ proved — logically — that any sufficiently complex mathematical or logical system will contain truths that cannot be proven from within that system. Russell conceded this fatal blow to his enterprise, as well as the larger moral that we have to be content with unprovable truths even in mathematics. If we add to Gödel’s results the well-known fact that logical proofs and mathematical theorems have to start from assumptions (or axioms) that are themselves unprovable (or, in the case of some deductive reasoning like syllogisms, are derived from empirical observations and generalisation — ie, from induction), it seems that the quest for true and objective knowledge is revealed as a mirage.
No, it did not fail. The Russell-Whitehead system was replaced by better ones, which became more famous, with the most popular being ZFC. It is a firm logical foundation for mathematics.

There is no such thing as an unprovable truth in mathematics. It is true that a statement symbolizing the consistency of ZFC cannot be proved within ZFC, and that surprised many people at the time. In retrospect, the reverse would have been stranger. But it does not alter the ancient fact that all mathematical truths are proved from axioms. The lack of an internal consistency proof is just a surprising fact to newcomers to the field, like the irrationality of the square root of two, or the uncountability of the real numbers.

It is true that theorems are proved from axioms, and that is how math has worked for millennia. Yes, math gives us absolute and objective truth.

Goedel's most famous theorems say that statements are provable if and only if they are true in all the models, and that there is no computable algorithm for determining whether a statement is provable. His work is an affirmation of the axiomatic method, not a refutation of it. If there were such an efficient algorithm, then mindless application of it would replace the axiomatic method.

Supposedly Hilbert thought that an axiomatization of math should first prove the consistency of its axioms. If so, that was a stupid belief, because inconsistent axioms allow proof of anything. So using an axiom system to prove its own consistency is worthless because the proof would not mean that the axioms are consistent (because inconsistent axioms prove the same thing). Either Hilbert made a trivial mistake or he has been misinterpreted. I suspect the latter, as I cannot find where he clearly said that the axiomatization had to prove its own consistency.

Here is a BBC Radio 4 podcast on the Incompleteness theorem, with discussion of Hilbert's program. The scholars imply that Hilbert admitted defeat by not publicly commenting on Goedel's theorem. However Hilbert posed an assortment of other problems, and sometimes he speculated about a possible solution, but no one cares too much if his speculation differed from the later solution. I do not see any good reason to say that Hilbert was defeated.

Hilbert did say that the proof should be finitary, and worked to find such proof, but there was some disagreement at the time as to what would pass for such a proof. The nature of logic is that inconsistency has finitary proofs, but usually not consistency.

Consistency is never the main goal anyway. As was later shown, consistency allows belief in either the continuum hypothesis or its negation. Mathematicians want what is true, and consistency does not decide the issue.

Even mathematicians are too eager to concede that Hilbert was refuted. Wikipedia says:
Kurt Gödel showed ... This wipes out most of Hilbert's program as follows:

It is not possible to formalize all of mathematics, ...
... there is no complete consistent extension of even Peano arithmetic with a recursively enumerable set of axioms, ...
A theory such as Peano arithmetic cannot even prove its own consistency, ...
There is no algorithm to decide the truth (or provability) of statements in any consistent extension of Peano arithmetic. ...
But I do not think that Hilbert opposed any of these things.

It is possible to formalize math in the sense of making all the theorems provable in a system like ZFC. Systems cannot prove their own consistency, but you would not want that anyway. And there is no magic truth algorithm to replace the axiomatic method.

All that shows that Hilbert's program was essentially correct, and not wrong.

Whether or not mathematical foundations developed according to Russell's or Hilbert's expectations is an amusing historical question, but not really relevant to whether math achieves objective truth.

The essence of Hilbert's Program is to reduce infinitistic mathematics to finitistic mathematics. That is an unqualified success. All modern mathematics uses finitary proofs.

Wikipedia says:
Ludwig Wittgenstein condemned set theory. He wrote that "set theory is wrong", since it builds on the "nonsense" of fictitious symbolism, has "pernicious idioms", and that it is nonsensical to talk about "all numbers".
This is just ignorant foolishness from philosophers. Set theory is the foundation of mathematics. Logic ought to be a foundation for philosophers, but it is rare to find one with basic competence in the subject. For some reason, leftist philosophers and other academics like to deny the possibility of truth, and they hate logic. Wittgenstein is mainly famous for saying, "Whereof one cannot speak, thereof one must be silent." Maybe he should have kept quiet about set theory. So should Pigliucci and the other anti-truth philosophers.

Update: A comment links to some scholarly work. You can download a free copy of the first paper, The Scope of Gödel’s First Incompleteness Theorem, here or here.

See also Number theory and elementary arithmetic by Jeremy Avigad, Hilbert's Program Then and Now and Stanford Encyclopedia: Hilbert's Program by Richard Zach, and Hilbert's Program Revisited by Panu Raatikainen.

These articles make a good case that the essence of Hilbert's program was accomplished. They even argue that all the important theorems of modern mathematics can be proved in systems that have elementary consistency proofs.

Thursday, September 24, 2015

Aaronson seeks Aumann agreement on quantum computing

A recent philosophy podcast was: Scott Aaronson on "The theorem that proves rationalists can't disagree".

He mostly talked about Aumann's agreement theorem:
Aumann's agreement theorem says that two people acting rationally (in a certain precise sense) and with common knowledge of each other's beliefs cannot agree to disagree. More specifically, if two people are genuine Bayesian rationalists with common priors, and if they each have common knowledge of their individual posteriors, then their posteriors must be equal.[1]

A question arises whether such an agreement can be reached in a reasonable time and, from a mathematical perspective, whether this can be done efficiently. Scott Aaronson has shown that this is indeed the case.[2]
Then Aaronson tried to apply it to his professional disagreements:
The disagreements with which I have maybe the most real-life experience are about quantum computing. This is a proposed technology that would use quantum mechanics to solve certain problems a lot faster than we know how to today. The laws of quantum mechanics, as we understand them now, seem very unambiguously to allow this.

There are experimental groups all over the world that are actually trying to build this. Some of them are very optimistic that they may have useful devices within a decade or two decades or something, but this field has also engendered a lot of skepticism, including, some of it by physicists, some by computer scientists. Some of them will say this is all just completely a sham, this is something that can never work.

I've been very, very interested, maybe more than most of my colleagues have been, in interacting with these people and just trying to understand, where does the skepticism come from? Because my default position would be, I hope that the skeptics are right. Because if they're right, then that means that there is something wrong with our current understanding of quantum mechanics.

If there is really a deep reason why a quantum computer can't be built -- I don't mean that just it's too hard, that the money will run out or something like that, but it's really fundamentally impossible -- then there's really something that we don't understand about quantum physics itself.
Here is my Concise argument against quantum computing. I fully accept quantum mechanics. When the theory says that an electron is not truly a particle and has a particular probability of being observed as a particle in a region and time, then I support that. Experiments have confirmed such experiments over and over.

But when you say that there is a mysterious quantum nonlocality that allows an unobserved electron to be in multiple places at once in order to facilitate super-Turing computation, then that is way beyond anything that has been demonstrated, and I don't believe it.

Aaronson concedes that quantum computing is an open question. Maybe it is possible, and maybe it is not. To me, that alone justifies a skeptical view. Carl Sagan said that extraordinary claims require extraordinary evidence. Some mathematicians are skeptical about the Riemann Hypothesis. Positivists only accept what is known to be true.

But Aaronson is like the theologian who admits that he cannot prove God exists, but insists that no one should identify as an atheist unless he can prove that there is no God.

Aaronson says that if quantum computing is impossible, then there must be something we don't understand about quantum mechanics. The latter is conventional wisdom among physicists and others. Whenever people talk about interpretations of quantum mechanics, such as many-worlds (MWI), or giving a Nobel Prize for Bell test experiments, or quantum gravity, or black hole firewalls, or cosmic holograms, they are always making an argument that there is something we don't understand about quantum mechanics. So most of his colleagues are already convinced!

His book lists 11 objections to quantum computing. I do not think he does them justice, but he is now writing a new book on the subject.

Monday, September 21, 2015

Attempt to prosecute climate change deniers

Greg Laden calls himself a "biological anthropologist and science communicator" and writes:
The following is the text of a letter written by a number of scientists asking for a federal investigation of climate science denial under the RICO statute.

Letter to President Obama, Attorney General Lynch, and OSTP Director Holdren

September 1, 2015

Dear President Obama, Attorney General Lynch, and OSTP Director Holdren,

As you know, an overwhelming majority of climate scientists are convinced about the potentially serious adverse effects of human-induced climate change ...
Okay, I guess most scientists would agree that if humans were to induce climate change, then there would be a potential of serious adverse effects.
We appreciate that you are making aggressive and imaginative use of the limited tools available to you in the face of a recalcitrant Congress. One additional tool – recently proposed by Senator Sheldon Whitehouse – is a RICO (Racketeer Influenced and Corrupt Organizations Act) investigation of corporations and other organizations that have knowingly deceived the American people about the risks of climate change, as a means to forestall America’s response to climate change.
I did not know that it could be a crime to oppose the leftist climate agenda.

Pres. Obama himself has been using apocalyptic language on global warming.

This reminds me of the quote:
When you tear out a man's tongue, you are not proving him a liar, you're only telling the world that you fear what he might say.
Separately Laden promotes atheist causes, and complains that Ben Carson is violating the First Amendment by being a Christian and opposing a Muslim being elected US President, and is therefore disqualifying himself to be President.

I would think that an atheist would be happy to say that certain religious beliefs are not suited for the Presidency. But apparently his leftist egalitarianism overrides his atheism, and all religions must be hated equally.

This is somewhat off-topic for this blog, and I am not going to bother rebutting this nonsense. I just want to point out that this is a quite popular leftist-atheist-evolutionist blogger, and it shows the thinking of a lot of academic scientists, particular in the soft sciences, and social justice warriors. They are intolerant creeps who want to censor other points of view.

Friday, September 18, 2015

The world could go nuclear

SciAm reports on a new book:
In just two decades Sweden went from burning oil for generating electricity to fissioning uranium. And if the world as a whole were to follow that example, all fossil fuel–fired power plants could be replaced with nuclear facilities in a little over 30 years. That's the conclusion of a new nuclear grand plan published May 13 in PLoS One. Such a switch would drastically reduce greenhouse gas emissions, nearly achieving much-ballyhooed global goals to combat climate change. Even swelling electricity demands, concentrated in developing nations, could be met. All that's missing is the wealth, will and wherewithal to build hundreds of fission-based reactors, largely due to concerns about safety and cost.

"If we are serious about tackling emissions and climate change, no climate-neutral source should be ignored," argues Staffan Qvist, a physicist at Uppsala University, who led the effort to develop this nuclear plan. "The mantra 'nuclear can't be done quickly enough to tackle climate change' is one of the most pervasive in the debate today and mostly just taken as true, while the data prove the exact opposite."
The safety concerns are mostly fictitious. The cost concerns are mostly in dealing with political and regulatory problems. If there were the will to build the plants, they could be built cheaply.

When you hear someone who says that there is an urgent need to do something about global warming, but who is also against nuclear power, then he is just a leftist ideologue who is abusing the science for political purposes.

Some global warming alarmists, such as the most famous one, James Hansen, are in favor of building more nuclear power plants.

Thursday, September 17, 2015

Aaronson attacks local realism

I discussed the latest quantum spookiness experiment, and now MIT complexity theorist Scott Aaronson explains it as Bell inequality violation finally done right. He says this could get a Nobel Prize.

My position is that it just confirmed what everyone thought since 1930, except for Einstein, Bohm, Bell, and a few others, so it is not that big a deal.

I do object to some of Aaronson's terminology. He has bet his whole career on quantum mechanics giving us complexity classes that are faster than Turing machines but slower than full parallelism. So he describes this experiment as confirming that:
Well, I’ve also read some of Einstein’s correspondence from around the same time. He was clearer than Bohr, but as far as I can tell, neither he, nor Bohr, nor anyone else at that time clearly recognized that you could have something intermediate between “local realist” and “spooky” — something that, on the one hand, didn’t involve any superluminal signalling, but on the other hand, would require superluminal signalling to simulate in a classical universe. That had to wait for Bell.
By spooky, he means action-at-a-distance, which most physicists rightly reject.

By “local” he means no superluminal signaling, but more generally it means that causality is confined to the light cone, as in special relativity.

The tricky term is local realism:
As I use the term, “local realism” is not a “physics definition,” it’s a math definition. And Bell’s theorem is not a “physics theorem” (whatever that means), it’s a math theorem that’s been proved and will stay proved until the end of time. If you want to argue about the theorem’s relevance to physics, you can do that, but you don’t get to negotiate the definition of “local realism,” because it’s now part of math.
This is a little sleight of hand to let him study mathematical complexity, regardless of physical relevance.

The Heisenberg uncertainty principle says that you cannot precisely measure an electron's position and momentum at the same time. Local realism is the idea that the electron really is a particle with definite positions and momenta at all times, and the uncertainty principle is just a limit on our observation abilities. The conventional quantum mechanical view (in eg the Copenhagen Interpretation) is that the electron is not really a particle, but some sort of wave-like object that does not necessarily have definite physical values unless observed.

Most physicists believe in locality (such as nothing going faster than light), and in realism, in the sense that electrons are real objects and observations are reflecting some reality. We do not live in an article simulation, or in the imagination of some super-being, or just some sort of simplified appearance for supernatural events. Physicists believe that they are studying the real world.

So it is a little jarring to hear Aaronson say that local reality has been disproved. It is even more annoying to learn that he defines realism to be some stupid non-quantum mathematical model that has been shown not to work. So when he says local realism has been disproved, he just means that some stupid mathematical model does not work.

A better conclusion is that the mathematical was unrealistic. The physical world is realistic, by definition.

For Aaronson, all of this is supposed to convince you that quantum computers will create a new super-Turing complexity that is intermediate between “local realist” and “spooky”. But there is no proof that there is any such thing.

A better view is that the world is realistic and not spooky. Bell had a clever idea for disproving quantum mechanics, but he turned out to be wrong, as everyone expected. None of this gives any reason to believe that electrons can be half-spooky or that (super-Turing) quantum computers are possible. End of story.

Wednesday, September 16, 2015

Dawkins to purge those with unjustified beliefs

In this audio interview with Neil deGrasse Tyson, the leftist-atheist-evolutionist Richard Dawkins favors firing a professional who has idiosyncratic beliefs that are irrelevant to his profession:
I don't think that he should be employed in a hospital, because what you are saying about that man -- He has the kind of mind that is so adrift with reality, that even if he is a competent eye surgeon, I don't think that he could/should be trusted. [at 20:00]
I wonder how anyone would hold a job under such a standard, and how you would ever get eye surgery done. Dawkins makes it clear that he is talking about beliefs that have no bearing on the practice of eye surgery.

His main target is organized religion and other views that he considers anti-science. But, as I often post on this blog, our most brilliant professors at our most prestigious universities hold all sorts of anti-science views. And I just focus on the hard sciences like Physics. The situation is much worse in the humanities and social sciences.

To me, believing in the multiverse, or string theory, or black hole information is just as wacky as Dawkins' examples. I am tempted to add supersymmetry and quantum computing to the list.

It is the political Left that always wants to root out people for their beliefs, and purge them somehow. I am not trying to get these professors fired. I just want to determine if what they say is right or wrong.

The great majority of the public holds religious views that are not backed up by scientific findings. Jerry Coyne argues, like Dawkins, that it is all in conflict with science. See this debate with a philosopher who says that most religious
According to a new paper by Neil Van Leeuwen, religious “credence” is nothing like mundane factual belief. It has, he claims, more in common with fictional imaginings. Religious folk do not really “believe” – in the ordinary sense of the word – what they profess to believe. Like fictional imaginings, but unlike factual beliefs, religious credences are activated only within specific settings.
That is, religious belief can be like a small child with an imaginary friend. The child sometimes acts as if the friend is real, but if pressed against some concrete factual consequence, the child obviously understands that the child is not real.

Monday, September 14, 2015

The Berenstain Bears Conspiracy

A lot of big shot physicists believe in various multiverse, many-worlds, or parallel universe theories. There is not a shred of evidence for them. But now there are claims that we might have made some sort of jump to a parallel universe:
A new conspiracy theory has taken the Internet and childhood nostalgia by storm. A popular kids book series known to most of the population as “The Berenstein Bears,” is actually called “The Berenstain Bears.”

For those who grew up reading the books and have the word “Berenstein” ingrained in their minds, the fact that the title really is “Berenstain” is quite a shock to the system. A quick Internet search of the book covers and the official PBS website reveals that “The Berenstain Bears” have been there all along.

The shock of this revelation has led some to believe in alternate or parallel universes in which “The Berenstein Bears” were created and “The Berenstain Bears” is some massive, crazy, Internet hoax.
There is more info here, where the conspiracy was noticed in 2011.

Some people say that this is an example of the Mandela Effect, where a lot of people remember Nelson Mandela having died in prison.

Here is a debunking:
According to author and paranormal researcher Fiona Broome, it all relates to the phenomenon of parallel realities. Her theory, which is outlined on her website, is that we exist in a world of parallel universes that each have their own histories and timelines. Occasionally, individuals from these universes “slide” into an alternate timestream creating a changed reality. One of those changed realities, as explained by Broome, is the death of Nelson Mandela.

Although most of us recall Mandela's passing in 2013, Broome and her followers suggest otherwise. In fact, she and the many posters on her website claim that they have distinct memories of Mandela dying in prison in the 1980's. They even go as far as describing detailed accounts of media coverage, news reports, on-air broadcasts of his funeral, and more.
Each timeline is consistent with its history, so it will not do any good to look at old books or Wikipedia. The site asks some physicists:
So that leads to the question, is any of this scientifically, or at least theoretically possible? Could Nelson Mandela actually have died in the 1980's? Could the Berenstain Bears, as also suggested by Broom's website, actually have been the Berenstein Bears?

After reading the many responses on, I became intrigued by not only the concept of the theory, but the passion behind it. So I decided to do further research.

While theories exist which support the idea of parallel universes, particularly the Many-Worlds Interpretation, I remained unsure. As a journalist with little knowledge of quantum physics, I soon discovered that it would be wise to reach out to the professionals.

Andrew S. Friedman, a National Science Foundation Science Postdoctoral Fellow at Massachusetts institute of Technology (MIT) and Visiting Research Scientist at the MIT Center for Theoretical Physics, breaks down the Many-Worlds theory.

“In certain interpretations of quantum mechanics, such as the Many Worlds Interpretation of Hugh Everett and Bryce DeWitt, the equations of the theory are taken to mean that whenever a quantum event occurs, the universe (or the observer) splits and branches into two parallel timelines.

“In most views, these timelines no longer interact, which is why they could be considered parallel.

“Needless to say, your theory would have to describe alternative timelines which are not parallel, and somehow interact with one another in order to make any sense of the fantastical claims of the Mandela story.”

He believes there's a more logical explanation.
So maybe Mandela was in a Schrodinger cat state, where he was alive in one universe, and dead in a parallel universe. The proponents of the many-worlds interpretation absolutely believe that is possible.
“Personally, I think the examples you mentioned tell us more about human psychology, the fallibility of human memory, and the intense desire to believe in fantastical ideas.

“In my view, these things have nothing to do with parallel timelines as discussed in physics, and instead present evidence for the amazing range of ways humans can be fooled by themselves or others.”

Fred Alan Wolf, an American theoretical physicist and National Book Award Winning author of Taking the Quantum Leap agrees.

I doubt that this had anything to do with parallel universes. It would be stretch to attempt to put these recalls in terms of quantum physics.”
These guys do not seem very sure about it. And they are low-ranking physicists. Couldn't they get any big-shots to weigh in on this issue?

It is a sad day that some crackpot delusional paranormal researcher makes as much sense as our leading theoretical physicists. I will say it: There are no parallel universes, and this has nothing to do with the concept. These are people with bad memories or bad spelling.

I suspect that mainstream physicists are reluctant to criticize the Berenstain Bears conspiracy because they are afraid of undermining the case for quantum computing, black hole holograms, and other modern ideas that are fashionable and get a lot of funding.

Sunday, September 13, 2015

Rothman on Einstein's famous equation

Tony Rothman writes a SciAm article on Was Einstein the First to Invent E = mc2?:
According to scientific folklore, Albert Einstein formulated this equation in 1905 and, in a single blow, explained how energy can be released in stars and nuclear explosions. This is a vast oversimplification. Einstein was neither the first person to consider the equivalence of mass and energy, nor did he actually prove it.
I pointed out Rothman saying similar things in 2011 and 2013. He once claimed that Einstein did everything credited to him, and changed his mind in the light of all the evidence that Einstein got his famous big ideas from others.

Robert A. Herrmann wrote a 2000 paper explaining why the equation is not Einstein's discovery.

SciAm has a whole issue on the 100th anniversary of general relativity. Not much is new. I may comment on more of it. In the meantime, you can read previous blog postings on the subject, or my book, How Einstein Ruined Physics.

Rothman also has a new paper on Cardano v Tartaglia: The Great Feud Goes Supernatural. There was a hot 16th century rivalry between two mathematicians trying to solve cubic equations. The myth is that one had the other arrested on charges of heresy for having cast a horoscope of Jesus Christ. Rothman tries to get to the bottom of it, and finds this and related stories to be improbable.

Friday, September 11, 2015

Preparing for that mythical quantum computer

SciAm and Nature magazine have today's crypto scare story:
Cryptographers Brace for Quantum Revolution
Encryption fix begins in preparation for arrival of futuristic computers

It is an inevitability that cryptographers dread: the arrival of powerful quantum computers that can break the security of the Internet. Although these devices are thought to be a decade or more away, researchers are adamant that preparations must begin now.
No, it is not inevitable. Those devices are centuries away, if ever. So what researchers are adamant?
But on the day that the first large quantum computer comes online, some widespread and crucial encryption methods will be rendered obsolete. Quantum computers exploit laws that govern subatomic particles, so they could easily defeat existing encryption methods.

“I’m genuinely worried we’re not going to be ready in time,” says Michele Mosca, co-founder of the Institute for Quantum Computing (IQC) at the University of Waterloo in Canada and chief executive of evolutionQ, a cyber-security consulting company.
Oh, someone at the Institute for Quantum Computing is worried. He is so worried that he is doing fundraising to get everyone else worried.
At the time, it was not clear whether such a machine would ever be built, says Mosca, because researchers assumed that it would need to operate flawlessly. But a theoretical discovery in 1996 showed that up to a limit, a quantum computer with some flaws could be just as effective as a perfect one.
He is talking about error-correcting qubits, when no one can make scalable qubits anyway.
Published experiments with small quantum devices are starting to approach this faultiness threshold, notes Mosca. And because secretive organizations such as the NSA are keenly interested in the technology, it is widely assumed that these published results do not represent the cutting edge of research. “We have to assume there’s going to be people that are a few years ahead of what’s available in the public literature,” says Mosca. “You can’t wait for the headlines in The New York Times to have your plan in place.”
This is one situation where the NY Times stories are way ahead of the research. By centuries.
Researchers believe that it takes existing computers a long time to factorize big numbers, partly because no one has yet discovered how to do it quickly. But quantum computers could factorize a large number exponentially faster than any conventional computer, and this nullifies RSA’s reliance on factoring being difficult.
Aaronson likes to point out that it is not really exponential faster.

This is like saying that we need to build more nuclear bomb ICBMs because Russia might be building a missile defense. Or that we must pass laws about time travel, just in can someone builds a time-travel machine. Someday books will be written about how all these smart people and money chased an impossibility.

Wednesday, September 9, 2015

Paper on pragmatic quantum mechanics

A, S. Sanz looks for a pragmatic understanding of quantum mechanics:
To date, quantum mechanics has proven to be our most successful theoretical model. However, it is still surrounded by a "mysterious halo" that can be summarized in a simple but challenging question: Why quantum phenomena are not understood under the same logic as classical ones? ...

The famous Bohr-Einstein debates 4 ended in the 1930s with the orthodox or Copenhagian view of quantum systems, which has healthfully survived to date: the quantum world is essentially probabilistic and hence it does not make any sense asking questions intended for going beyond probabilities. Actually, these probabilities are such that if we try to determine accurate (probabilistic) information about one of the variables (A) from a pair of (classical) canonically conjugate variables, we will be unable to obtain any relevant information about the other (B), and vice versa. This is the essence of Bohr’s complementarity principle, which formally translates into the well-known Heisenberg uncertainty relation, ...

Bell’s contribution not only started the revolution of quantum technologies, leading to the development of the quantum information theory, quantum computing, quantum cryptography, quantum teleportation, etc., but indirectly he also motivated a reconsideration of Bohm’s approach.
This is mostly conventional wisdom, but I disagree with a couple of details.

The quantum world is not essentially probabilistic. What does not make sense is asking about observations that have not been performed. You can think about speculation about unmeasured variables as "going beyond probabilities", but I would not put it that way.

The word "revolution" seems to be used here in the Kuhnian sense of not being a scientific advance, but enable some sort of paradigm shift. There is an industry pursuing quantum info, computing, crypto, and teleportation, but nothing has come of it.

Bohm's work is also wildly overrated, possibly because he was a Commie fellow traveler.
Chapter 2 of Feynman’s renowned Lectures on Physics starts as 13 “In this chapter we shall tackle immediately the basic element of the mysterious behavior in its most strange form. We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by “explaining” how it works. We will just tell you how it works. In telling you how it works we will have told you about the basic peculiarities of all quantum mechanics.” Effectively, the two-slit experiment summarizes the essence (“mystery”) of quantum mechanics. However, like Dirac, Feynman also thought that each individual particle self-interfered, apparently being unaware of Pozzi’s and Tonomura’s experiments on the two-slit experiment. His scientific authority reinforced the Copenhagian viewpoint, but should things have been different if Feynman would have watched Tonomura’s movie 11 of his two-slit experiment with electrons?
Everyone likes to quote R.P. Feynman saying:
I think I can safely say that nobody understands quantum mechanics.
But this was not an attack on quantum mechanics. What he meant was that he did not have an intuitive understanding of how an electron can interfere with itself inn the two-slit experiment.

Arguments about interpretations continue. Carlo Rovelli gives An argument against the realistic interpretation of the wave function, and just a few days later, H. Dieter Zeh posts a rebuttal. They each have their own peculiar interpretations that they push.

Monday, September 7, 2015

Krauss attacks religion again

Lawrence Krauss has a video on the xenophobia inherent in religion. This is mostly off-topic for this blog, but he is a prominent physicists, and he is reciting nonsense. He says:
It is created by Iron Age peasants who didn't even know the Earth orbited the Sun. ...

The xenophobia ... People who don't conform are to be ostracized or killed. ...

Islam is 500 years younger than say Christianity. And 500 years ago Christianity was producing far more violence than Islam is today, from the Crusades to the Inquisition.
If Christianity were so xenophobic, then the USA and Europe would never admit the millions of Moslem immigrants and refugees. Christians do not kill people for non-conformity.

There is some opposition to the foreigners, but it appears to be mainly based on secular concerns like cost, crime, disruption, non-assimilation, etc, and not based on organized religion.

No, Christianity was never as violent as Islam. Islam spread by conquering foreign lands. The Crusades and Inquisition were defenses against Moslem invaders.

The history of Europe is one of regular warfare for millennia, but that cannot be blamed on Christianity.

The Earth-Sun motion is relative. Most professors today do not seem to understand that. He as might as well say "peasants who didn't even know about dark matter clumping in galaxies." It has little to do with the religious messages.

Krauss wrote a book about how we don't need God because the laws of physics can create a universe out of nothing. There is some logic to the core of his argument. But when he goes on these rambling anti-religion diatribes, he is way out of his expertise. The vast majority of Christians accept nearly all scientific knowledge.

Krauss also has an article in the current SciAm on What Einstein Got Wrong. Black holes, gravity waves, quantum mechanics, big bang, etc.

Update: Krauss just wrote a New Yorker article titled All Scientists Should Be Militant Atheists:
The Kim Davis controversy exists because, as a culture, we have elevated respect for religious sensibilities to an inappropriate level that makes society less free, not more. ...

In science, of course, the very word “sacred” is profane. ...

I see a direct link, in short, between the ethics that guide science and those that guide civic life. Cosmology, my specialty, may appear to be far removed from Kim Davis’s refusal to grant marriage licenses to gay couples, but in fact the same values apply in both realms. ... Five hundred years of science have liberated humanity from the shackles of enforced ignorance.
No, there is no scientific argument for same-sex marriage, and the objections to it are not necessarily religion. Krauss's cosmology does not inform us on the issue.

Even some supporters of same sex marriage say that jailing Davis was illegal and unnecessary.

A lot of people feel strongly about same-sex marriage, and even jailing Davis as a public show of subservience to LGBT ideals. But for Krauss to say that this is the reason for all scientists to become militant atheists, he is am embarrassment to science. Stick to cosmology.

Update: Atheist-nonleftist-physicist Lubos Motl piles on:
Is atheist jerk Krauss worse than religious fanatics? ...

Why is someone like Lawrence Krauss willing to write something so utterly insane, such as the claim that there exists a link between the insights of cosmology and the right attitude to Kim Davis' actions? Is it because he can't see that there exists no scientific derivation of the "right attitude to Kim Davis"? I doubt so. The actual reason is that Lawrence Krauss' attitude to cosmology is based on lots of arbitrary unjustified prejudices, too. He lacks the integrity not only as a human being but as a scientist, too.

In the context of recent controversies, this is most clearly seen on Krauss' support of the concept of the multiverse. We don't know whether this concept is relevant for a proper scientific understanding of anything, and if it is, we don't know in what form it is relevant. But folks like Krauss indeed promote this idea for the same reasons why they are against Kim Davis – because they love to promote left-wing political views. There is no valid evidence behind either of their approaches.
This is something left-wing about the multiverse. Leftists take great pleasure in arguing that humans are not special, that Western culture is not special, that Earth is not special, etc. Now they like to say that even our universe is not special, and that maybe homosexuals do all the breeding in some parallel universe.

Saturday, September 5, 2015

Intel joins search for quantum computing

ExtremeTech reports:
Intel CEO Brian Krzanich released an open letter today, pledging to dedicate $50 million to long-term research of quantum computing. The CPU giant is partnering with TU Delft, the largest and oldest Dutch public technical university, and will work with QuTech, TU Delft’s quantum research institute. Intel is also pledging to dedicate its own resources and engineers to solving the problems of quantum computing.

It might seem odd to see Intel pumping so much money into quantum computing research, given that D-Wave’s systems have been tested and largely verified to be quantum computers.
Maybe you should sell Intel stock.

In case you think Intel is always right to such technical matters, remember the Intel Itanium. For about 5 years, HP and Intel convinced the world that they had a superior computer processor architecture. Rivals were dropping out of the business because everyone was so sure that Intel's chip would dominate the market. The chip was a spectacular failure.

Someday this quantum computing research will be seen as seriously misguided. Intel will never sell a quantum computer processor.

Update: I never saw a good explanation as to why the Intel Itanium was such a failure. They certainly spent enuf billions of dollars on development, and made chips that worked as designed. But the main advantage was supposedly that long complex instruction sets were superior to reduced (and simplified) instruction sets that were popular. Intel's simulations showed huge performance advantages, but apparently they never took into account all the extra time to load those long instructions from memory. It is hard to see how so many smart people could have bet so much money on something so foolish.

John Dvorak wrote in 2009:
This continues to be one of the great fiascos of the last 50 years, and not because Intel blew too much money on its development or that the chip performed poorly and will never be widely adopted. It was the reaction and subsequent consolidation in the industry that took place once this grandiose chip was preannounced.

I witnessed this in real time, in person, and I've never seen anything like it before or since.

In 1997 Intel was the king of the hill; in that year it first announced the Itanium or IA-64 processor. That same year, research company IDC predicted that the Itanium would take over the world, racking up $38 billion in sales in 2001. Wow! Everybody paid attention. ...

The problem was that Intel wasn't the only company drinking the Kool-Aid. The entire industry took this project so seriously that the press was inundated by both a massive roll-out campaign and a press kit that had releases from all the strategic partners—which was practically everyone in the Valley…and beyond.

What we heard was that HP, IBM, Dell, and even Sun Microsystems would use these chips and discontinue anything else they were developing. This included Sun making noise about dropping the SPARC chip for this thing—sight unseen. I say "sight unseen" because it would be years before the chip was even prototyped. The entire industry just took Intel at its word that Itanium would work as advertised in a PowerPoint presentation.

Because this chip was supposed to radically change the way computers work and become the driving force behind all systems in the future, one promising project after another was dropped. The MIPS chip, the DEC Alpha (perhaps the fastest chip of its era), and anything else in the pipeline were all cancelled or deemphasized. Why? Because Itanium was the future for all computing. Why bother wasting money on good ideas that didn't include it?

The failure of this chip to do anything more than exist as a niche processor sealed the fate of Intel — and perhaps the entire industry, since from 1997 to 2001 everyone waited for the messiah of chips to take us all to the next level.

It did that all right. It took us to the next level. But we didn't know that the next level was below us, not above. The next level was the basement, in fact. Hopefully Intel won't come up with any more bright ideas like the Itanium. We can't afford to excavate another level down.
It is going to be the same thing with quantum computers. Everyone is going to wonder how so many smart people with convinced by a slide show, when no one had any real results to show.

Thursday, September 3, 2015

Belief in farfetched physics ideas

I mentioned Lubos Motl and the quantum gravity religion, and now he elaborates on his beliefs:
We haven't visited a black hole – no one will ever return alive from the black hole interior. We haven't directly and/or clearly observed the Hawking radiation, the Unruh radiation, a singularity in general relativity, gravitational waves let alone gravitons, excited strings, additional compactified spatial dimensions, superpartners, quanta of the inflaton field, regions with a different value of the inflaton field, regions with differently compactified extra dimensions than our way, and many other things.

Nevertheless, theoretical physicists generally assume that all those things – or at least most of them – exist. They do so most of the time. They say that they "believe" that those things are needed. Is the word "believe" another proof that their activity has evolved into a religion?

Not at all. The words "I believe X" simply means "my opinion is that X is probably right". Both religious and irreligious people have the right to "believe". The churches have no monopoly over the word. And religious and irreligious people may become convinced about something equally staunchly and feel the same psychological certainty about something. Where the churches differ from the scientists is in the methods to arrive to a "belief".
This is a fair comment. There are atheist-evolutionists who get very upset at the notion that scientists have beliefs, but they clearly do. The beliefs preferably have some evidentiary support, but that is almost nonexistent in his examples.

He skips some other common physicist beliefs: many-worlds, other forms of the multiverse, proton decay, holographic universe, quantum nonlocality, super-Turing quantum computing, and Barack Obama Hope and Change. Okay, I am just joking about the last one.
A person who is viscerally hostile towards physics may call the opinion that gravitational waves exist "religion". A physicist knows that the person from the previous sentence is an ignoramus. After all, a Nobel prize in physics has already been given primarily for the indirect detection of gravitational waves. ...

OK, I obviously consider those who disagree with the existence of gravitational waves to be close to the "deniers of high school science" who also reject the existence of ice ages or heliocentrism. If you're one of them, please try to adjust your comments to the fact that I basically consider you a wild animal, a skunk of a sort. This is not meant to be insulting. It's meant to be as accurate an appraisal of the intellectual depth of two mammals as I am capable of producing.
Just about everything shows wave behavior at some scale, so I can believe in gravity waves.

I have beliefs against many of the above things. I am skeptical about superpartners (SUSY particles), proton decay, and quantum computing partially because these are farfetched and dubious theories, but mostly because experimental attempts have been such failures.

My skepticism in extra compactified dimensions and extra universes is a little different. These are ideas that are not testable and do not really explain anything either. I am not even what there is to believe in, because their ideas do not have much to do with observational science, as it has always been understood. I certainly do not believe in that nonsense, but I am not sure it makes any sense to disbelieve it either.

If you tell me that you have a spiritual connection with your grandmother, and then ask me my opinion, I would not have any opinion. I do not know how I would ever be able to come to a conclusion that your belief is true or false. It does not have any objective meaning that can be analyzed by the tools that I have.

Likewise, you are free to believe in other universes with different inflaton fields, if you wish. Motl is right that irreligious people have the right to have their own beliefs, even if there is no way to test or demonstrate them. I only raise objections when you claim to have some sort of scientific backing for them.

Tuesday, September 1, 2015

The quantum gravity religion

I have agreed with physicist Lubos Motl a couple of times recently, but he is back off the rails with his latest rant. He complains that this is a dumb question:
Why do physicists believe that a mathematically consistent model that unites quantum mechanics and general relativity exists?

If mathematics breaks down when applied to black holes, why do scientists believe that mathematics can describe black holes? Perhaps the search for the mathematics that unites quantum mechanics and general relativity is pointless. Mathematics is a useful tool for modelling the universe in many ways, but maybe black holes are exceptional entities that can't be modeled by mathematics. Is it possible that the interior of black holes are so alien to our known universe and so different that current mathematical models/abstractions simply do not apply.
It is a good question, and obviously hit a nerve. I have written a FQXi essay on this topic, and many blog postings. Today's theoretical physicists are preoccupied with the belief that there is some inconsistency between quantum mechanics and relativity that must be resolved, especially for black holes.

In fact there is no inconsistency as a physical problem. Quantum mechanics has been made fully consistent with relativity and gravity for all observable scales. To get a problem, you have to assume that all the mass of an electron is concentrated in a point, reject QFT renormalization, and look for the electron's event horizon. Of course, the electron is not really a point particle.

What annoys Motl is that well-known Berkeley professor Richard Muller does not subscribe to the string theory religion on this question:
It is almost a physics religion to believe that relativity can ultimately be combined with quantum physics. There is no evidence for this other than the fact that all the other forces of physics have been "unified". It is possible that relativity is different; that it is geometric and not quantum mechanical. But most physicists think that will not be the case, in large part because quantum physics has been so successful in the past. That's why they are looking to unify them. But it is worthwhile to recognize that this is based on hope, not on any firm physics or mathematics reason. ...

Much of the enthusiasm for string theory is that it addresses this [renormalization] problem, while introducing many more (extra dimensions, huge numbers of parameters, etc). Personally, given the problems of string theory, I am not optimistic that it will be with us 20 years from now.
He is right. Motl answers:
Well, the person who wrote this question is a layman who obviously doesn't understand what the words "mathematics" and "science" mean. Mathematics can't "fail" as a description of Nature because mathematics is, pretty much by definition, the language of the most accurate and reliable description of anything. ...

Dr Muller clearly stands next to the most insane pro-religion nuts who say that theoretical physics is just another religion – one that only tries to compete with The Church of Jesus Christ of Latter-day Saints.
Math is all about deducing consequences from axioms. Physics is all about explaining the natural world. The study of quantum gravity is neither.

When our leading theoretical physicists focus on questions with no possible observable consequences, then it is like discussion of theological issues.

Physicist Sabine Hossenfelder attempts to answer these questions:
1. Why do some physicists think our universe may be a hologram?

2. Why is it interesting that our universe might be a hologram?

3. Where are we in the holographic universe?

4. How well does this duality work?

5. Does this have something to do with Stephen Hawking's recent proposal for how to solve the black hole information loss problem?
To summarize, our physics elites believe we are in a hologram, but there is no rigorous math for this, and no observable consquences.

Sometimes physics is determined by a boundary value problem, and the boundary to the universe can be considered the set of black hole event horizons. So maybe we are all determined by black hole boundaries. Sound profound? No, it is just a stupid idea to use some mathematical trickery to confuse you.

Update: Motl attacks another Muller answer on black holes.