Monday, September 22, 2014

BICEP2 just saw cosmic dust

Here is the current SciAm cover story:
How Big Bang Gravitational Waves Could Revolutionize Physics
If the recent discovery of gravitational waves emanating from the early universe holds up under scrutiny, it will illuminate a connection between gravity and quantum mechanics and perhaps, in the process, verify the existence of other universes
By Lawrence M. Krauss

In March a collaboration of scientists operating a microwave telescope at the South Pole made an announcement that stunned the scientific world. They claimed to have observed a signal emanating from almost the beginning of time. The putative signal came embedded in radiation left over from the action of gravitational waves that originated in the very early universe — just a billionth of a billionth of a billionth of a billionth of a second after the big bang.

The observation, if confirmed, would be one of the most important in decades. It would allow us to test ideas about how the universe came to be that hitherto scientists have only been able to speculate about. It would help us connect our best theories of the subatomic (quantum) world with our best theories of the massive cosmos — those based on Einstein's general theory of relativity. And it might even provide compelling (though indirect) evidence of the existence of other universes.
No, the observation has not been confirmed, and it appears that all BICEP2 saw was some polarization caused by cosmic dust.

Even if it had been confirmed, I don't see how it could have been evidence for either quantum gravity or the existence of other universes. It is widely believed that the big bang was accelerated by something called inflation, but we do not know the source, magnitude, or duration of the inflation force, or even whether it is reasonable to call it a force. So if we see echoes of the big bang, we are probably seeing inflation waves, not quantum gravity waves. And we are certainly not seeing other universes.

A clue to the over-hype is that the title says "revolutionize physics" and the first name in the article is Einstein. No, this would not have been some stupid paradigm shift. Einstein did not even believe in the big bang, gravity waves, or quantum mechanics, and probably would not have believed in the multiverse either.

SciAm also have a couple of letters about free will. A philospher writes:
In “The World without Free Will,” Azim F. Shariff and Kathleen D. Vohs assert that a survey revealed that “the more people doubt free will, the less they favor ‘retributive’ punishment” and indicate that the notion of free will is necessary to social order. What constitutes human freedom is a complex matter, fraught with ambiguities that have been debated for millennia. The authors don't clarify the survey's questions. For instance, what if it had asked respondents to rate the relative influence of several factors, such as physical laws, biological impulses, life experiences, the cultural environment, rational deliberation or a sense of self-determination? Wouldn't that have elicited a more nuanced response?
Yes, more nuanced, as those things cannot be distinguished without a lot of careful definitions. Another writes:
Shariff and Vohs ask the question “What will our society do if it finds itself without the concept of free will?” But they do little to clarify the issue.
How much can you say about what people will do if they find out that they do not have free will? If they do not have free will, then they are just robots who will follow their programming. It always seems funny to me when people who say that they do not believe in free will, and then try to convince people of various beliefs.

Thursday, September 18, 2014

Weakening scientific criteria is dangerous

Physicist George F. R. Ellis writes in SciAm:
Why the Multiverse May Be the Most Dangerous Idea in Physics
Proof of parallel universes radically different from our own may still lie beyond the domain of science

In the past decade an extraordinary claim has captivated cosmologists: that the expanding universe we see around us is not the only one; that billions of other universes are out there, too. There is not one universe—there is a multiverse. In Scientific American articles and books such as Brian Greene's The Hidden Reality, leading scientists have spoken of a super-Copernican revolution. In this view, not only is our planet one among many, but even our entire universe is insignificant on the cosmic scale of things. It is just one of countless universes, each doing its own thing. The word “multiverse” has different meanings. Astronomers are able to see out to a distance of about 42 billion light-years, our cosmic visual horizon. We have no reason to suspect the universe stops there. Beyond it could be many—even infinitely many—domains much like the one we see. Each has a different initial distribution of matter, but the same laws of physics operate in all. Nearly all cosmologists today (including me) accept this type of multiverse, which Max Tegmark calls “level 1.” Yet some go further. They suggest completely different kinds of universes, with different physics, different histories, maybe different numbers of spatial dimensions. Most will be sterile, although some will be teeming with life. A chief proponent of this “level 2” multiverse is Alexander Vilenkin, who paints a dramatic picture of an infinite set of universes with an infinite number of galaxies, an infinite number of planets and an infinite number of people with your name who are reading this article.

Similar claims have been made since antiquity by many cultures. What is new is the assertion that the multiverse is a scientific theory, with all that implies about being mathematically rigorous and experimentally testable. I am skeptical about this claim. I do not believe the existence of those other universes has been proved—or ever could be. Proponents of the multiverse, as well as greatly enlarging our conception of physical reality, are implicitly redefining what is meant by “science.”
Ellis now repudiates the title:
This just shows the dangers of having subeditors assign titles to what you write, without consulting when they do so. I do not agree with that title, and disassociate myself from it.

What is dangerous is weakening the criteria for what science is. Multiverses are only dangerous to science if they are used to motivate that move. String theory is of course another theory that has also been used to motivate that move. It is that move that is dangerous to science, not the theories that are defended in this way.
It is very sloppy of SciAm to publish this title without checking with the author. Preparation of an article like this might involve 20 different communications between the author and editors, but editors often stubbornly refuse to use one more to check the title.

The multiverse idea is to speculate about unobservable universes. As Greene and Tegmark explain, there are several completely different proposals for such universes. What they have in common is that assertions about them are complete untestable, and more like religion than science.

Ellis is quibbling about the title. Usually an idea is dangerous because it might be right, and I guess that is what he is objecting to. Ellis is not saying that the multiverse might be right. It is dangerous because it is an anti-science ideology that is invading physics.

Wednesday, September 17, 2014

Tyson used a bogus quote to bash Bush

I am a fan of Neil deGrasse Tyson, and I thought that he avoided that mindless Republican bashing that is common among academic liberals. But apparently he has fabricates quotes for stupid political points:
According to Tyson, in the days following the 9/11 terrorist attacks, Bush uttered the phrase, “Our God is the God who named the stars.” According to Tyson, the president made that claim as a way of segregating radical Islam from religions like Christianity or Judaism.
Of course Bush never said it, and Tyson's story is completely false.

Lots of others claim that Bush lied about WMD or had God tell him to fight a war. What they don't do is supply an accurate quote to back up they claim.

Update: Tyson responds to a one of his misquotes:
Thanks for your interest in my work. Just some background: When I am invited to give a talk, especially to an audience that is not the general public, but to a specific gathering of people within a trade, I tune the contents for that audience, for that time, and for that place. So tone and flavor and context and intent are all key elements to any message I convey — all missing to anyone who was not present at the time.
These misquotes are not allowed on Wikipedia.

I don't know what is going on here. Maybe success is going to Tyson's head.

Update: A left-wing web site is rushing to Tyson's defense, and blaming conservatives:
The Right’s War on Neil deGrasse Tyson

The Cosmos host is widely despised by conservatives. Do they have a point, or are their complaints just anti-intellectualism run amok?

Celebrity astrophysicist Neil deGrasse Tyson has long been a despised figure among conservatives—and now the right is accusing him of being a “fabulist” and making up quotes.

The conservative website The Federalist ran a story last week saying Tyson had used a nonexistent newspaper headline and a fake quote from a member of Congress in a presentation. Tyson had been trying to argue that journalists and politicians don’t understand data.

In another post, the website’s Sean Davis pointed out inconsistencies in a story that Tyson has told at varying points about jury duty. A third post by Davis then took apart an anecdote Tyson told about George W. Bush, showing it to be false.

“The more I dug into it, the more I found a history of fabrication—to make points that he didn’t need fabrication to make,” Davis told The Daily Beast. “As someone who writes and publishes for a living, I take exception to people who go out and make money based on fabrication.” ...

Perhaps the philosophical difference between left and right on the nature of knowledge is key to understanding the disdain for Tyson.

Friday, September 12, 2014

Philosophers reject scientific method

On a recent podcast, scientist-turned-philosopher Massimo Pigliucci says:
It has become clear: Among philosophers of science, it is now a given that there is no such thing as the scientific method. That science is a family resemblance concept, that it is a vague fuzzy concept. [at 20:50]
This is the same guy who complains:
It seems like my friend Neil deGrasse Tyson [1] has done it again: he has dismissed philosophy as a useless enterprise, and actually advised bright students to stay away from it. It is not the first time Neil has done this sort of thing, and he is far from being the only scientist to do so. But in his case the offense is particularly egregious, ...

Here is Neil’s reply, in full:

“Up until early 20th century philosophers had material contributions to make to the physical sciences. Pretty much after quantum mechanics, remember the philosopher is the would be scientist but without a laboratory, right? And so what happens is, the 1920s come in, we learn about the expanding universe in the same decade as we learn about quantum physics, each of which falls so far out of what you can deduce from your armchair that the whole community of philosophers that previously had added materially to the thinking of the physical scientists was rendered essentially obsolete, and that point, and I have yet to see a contribution — this will get me in trouble with all manner of philosophers — but call me later and correct me if you think I’ve missed somebody here. But, philosophy has basically parted ways from the frontier of the physical sciences, when there was a day when they were one and the same. Isaac Newton was a natural philosopher, the word physicist didn’t even exist in any important way back then. So, I’m disappointed because there is a lot of brainpower there, that might have otherwise contributed mightily, but today simply does not. It’s not that there can’t be other philosophical subjects, there is religious philosophy, and ethical philosophy, and political philosophy, plenty of stuff for the philosophers to do, but the frontier of the physical sciences does not appear to be among them.”
I criticized him for this here and here.

Tyson is right to tell bright students to stay away from modern philosophers. XX century philosophers have started a war against modern science. Sometime about mid-century they all decided that there was no such thing as the scientific method.

World is not deterministic

Quantum gravity physicist Marko Vojinovic posted on a philosophy site:
Despite all developments of modern science in the last century, a surprising number of laypeople (i.e., those who are not familiar with the inner workings of quantum mechanics) still appear to favor determinism over indeterminism. ...

By “determinism” I will refer to the statement which can be loosely formulated as follows: given the state of the Universe at some moment, one can calculate a unique state of the Universe at any other moment (both into the future and into the past). This goes along the lines of Laplace’s demon [2] and physical determinism [3], with some caveats about terminology ...

The analysis presented in the article suggests that we have only two choices: (1) accept that Nature is not deterministic, or (2) accept superdeterminism and renounce all knowledge of physics. To each his own, but apparently I happen to be predetermined to choose nondeterminism.

It is a fantastic achievement of human knowledge when it becomes apparent that a set of experiments can conclusively resolve an ontological question. And moreover that the resolution turns out to be in sharp contrast to the intuition of most people.
I mostly agree with this. If determinism means completed defined by observables or hidden variables obeying local differential equations, then quantum mechanics and chaos theory show it to be impossible.

In the comments, some argue that some interpretations of quantum mechanics (many worlds and Bohmian) are formally deterministic. But this is mainly playing stupid word games. What good is determinism, if the outcome is only determined on some goofy parallel universe that no one can ever interact with?

Einstein had a religious belief in determinism, and so he rejected quantum mechanics. History has favored quantum mechanics.

Wednesday, September 10, 2014

Lack of interpretation consensus is embarrassing

A reader notes that Elliott Tammaro claims to explain Why Current Interpretations of Quantum Mechanics are Deficient in a new paper:
Quantum mechanics under the Copenhagen interpretation is one of the most experimentally well verified formalisms. However, it is known that the interpretation makes explicit reference to external observation or "measurement." One says that the Copenhagen interpretation suffers from the measurement problem. This deficiency of the interpretation excludes it as a viable fundamental formalism and prevents the use of standard quantum mechanics in discussions of quantum cosmology. ...

We argue, and where possible, demonstrate, that all common interpretations have unresolved deficiencies.
This so-called problem really bugs some cosmologists, but not because of any pressing scientific question. Occasionally you hear someone argue that it matters to one falling into a black hole, but that is just a stupid thought experiment.
At this point in time it appears that a stalemate has been reached with regard to the interpretation of quantum mechanics. Surprisingly, despite the roughly ninety years since its conception, there is currently no single widely accepted interpretation. The variety of interpretations has acted to divide the physics community into camps. For example, one might be a “Bohmian” or an “Everettian” or in the “I shut up and calculate” camp. There is virtually no travel between camps, but there is much in the way of campaigning for new recruits. In addition to being a mere inconvenience, we currently stand at the cusp of physics beyond the standard model and it may be that further advancement will demand a deeper understanding of 20th century physics. It is firmly established that string theory, while still the most promising attempt at unification, does not provide any deeper insight into quantum mechanics.
Cosmologist Sean M. Carroll made a similar argument, and was quoted on Why quantum mechanics is an “embarrassment” to science:
The result? Not a single one of the interpretations could even garner a simple majority vote. Ninety years after the theory was first developed, there's still no consensus on what quantum physics actually means. "I’ll go out on a limb to suggest that the results of this poll should be very embarrassing to physicists," wrote cosmologist Sean Carroll.

(On the plus side, the theory turns out to be very, very, very, very accurate in making experimental predictions. So there's that!)
I suspect that some of the excitement over string theory was that it might proved some sort of hidden variables interpretation to make quantum mechanics more philosophically acceptable. No one seems to think that is possible anymore.

Here is the core of the above objection to Copenhagen:
As a result, the collapse of the wavefunction is assumed nonphysical. We find this view untenable. The wavefunction after collapse represents a radically different physical system than before collapse.

Consider a gambler betting on a horse race. Assume she has some (incomplete) data on each horse. Her bets are distributed according to the data. If she is given new information about the horses, her bets will generically be different. Such is the case with wavefunction collapse in QBism. However, the gambler’s bets have no effect on the outcomes of the races, and as such the analogy breaks down.

Finally, the claim that the collapse is a result of the changing knowledge of the observer (agent) contradicts the well verified dictum that knowing the wavefunction of a system represents a state of complete knowledge of system.
This is a strange philosophical objection. He has some preconceptions about reality and observables, and does not like how they match up in quantum mechanics. In short, he wants an ontic wavefunction.

The argument is to say that the theory explains observations very accurately, but is somehow unsatisfying because it does not explain what is really going on. One could make similar objections to relativity, electromagnetism, gravity, and other theories.

The horse race bet is a little strange. Such bets do affect future bets by others, and maybe the race itself if the rider is crooked.

Yes, of course new info may convince us that the system is in a different state. I am not sure the wavefunction represents complete knowledge, but even if it does, a new measurement or new info can change that knowledge.

Bayesianism is a view of probability and statistics that elicits disapproval from others from similarly philosophical reasons. Yes, probability has more than one interpretation. Tammaro just doesn't like the idea of using data to update a probability.

These anti-Copenhagen attitudes are anti-science. Science is all about gaining knowledge from experiments and observations, and also recognizing the limits of what can be done. Quantum mechanics gives a way of quantifying our knowledge about a system. Nothing wrong with that. Some people want the wavefunction to do more than that. Sorry, not possible, as far as we know.

I have argued that QBism is essentially the same as Copenhagen as articulated by Bohr, in spite of Mermin's protests. Tammaro agrees:
QBism shares so much in common with the Copenhagen interpretation that it cannot rightfully be called a distinct interpretation. In particular, it uses a notion of measurement that corresponds precisely to that of the Copenhagen interpretation. No refinement in understanding of the measurement process is introduced. That is, there is no attempt at describing measurement in terms of more fundamental processes.
But Mermin has a new paper arguing that QBism something different, even tho he supports QBism with quotes from Bohr, Heisenberg, and Schroedinger.
Copenhagen, as expounded by Heisenberg and Peierls, holds that quantum states encapsulate “our knowledge”. This has a QBist flavor to it. But it is subject to John Bell’s famous objection: Whose knowledge? Knowledge about what?28 QBism replaces “knowledge” with “belief”. Unlike “knowledge”, which implies something underlying it that is known, “belief” emphasizes a believer, in this case the user of quantum mechanics.

A very important difference of QBism, not only from Copenhagen, but from virtually all other ways of looking at science, is the meaning of probability 1 (or 0).31 In Copenhagen quantum mechanics, an outcome that has probability 1 is enforced by an objective mechanism. This was most succinctly put by Einstein, Podolsky and Rosen,32 though they were, notoriously, no fans of Copenhagen. Probability-1 judgments, they held, were backed up by “elements of physical reality”.
Got that? Sorry, but if that is the big difference, it is a pretty trivial philosophical difference. I think that Mermin is embarrassed that he was confused about the Copenhagen interpretation for so long, and spent much of his career saying foolish things about quantum mechanics.

After writing this, I see that Lumo has some sensible commentary on Mermin's paper:
Mermin writes several paragraphs about this alleged "difference" between QBism and Copenhagen. These paragraphs contain the (bizarre) word "user" many, many times, but he completely avoids the word "observer". But foundational discussions on Copenhagen have always contained many copies of the word "observer". Much of Copenhagen is about the "observer". Mermin has either forgotten about this fact or he is demagogically avoiding the word "observer" because he knows that most readers would then realize that Mermin's claims about the "users" and "observers" who have nothing to do with each other are completely silly. That's particularly the case of statements such as
Science is about the interface between the experience of any particular person and the subset of the world that is external to that particular user.
Holy cow, Copenhagen school's theory of quantum mechanics is all about this interface, too. Mermin has used several new words such as "users" and "agents" in order to make old ideas look new. But even when it comes to this amusing trick, he failed in the case of the word "interface". If you look at Wikipedia's entry describing the Heisenberg cut, you will see that the Heisenberg cut is defined as a "hypothetical interface", by almost exactly identical words that Mermin ascribed to QBism above. There is an observer/user who cares, there has to be an external object/world that he observes, and the theory predicts properties he cares about. ...

At any rate, this sport of spitting on the founders of quantum mechanics who got everything that matters correctly is deeply pathetic. If we lived in a scientific world, they would be celebrated and their priority and their victory in all the intellectual confrontations would be universally known. Instead, we are drowning in the mud of ambiguity and downright hostility, even when we listen to people who should know better.

This is not a scientific world.
Motl is right that the founders of quantum mechanics could be called QBist, but Bell would not be.

My only disagreement with Motl is this:
And indeed, the fundamental thesis of QBism – i.e. Copenhagen – that the probabilistic nature of the wave function is intrinsic means that one shouldn't invent any "mechanisms" that would "transform" the wave function into "what we really observe". No extra "mechanism" is needed.
I agree that no extra mechanism is needed, but not that "the probabilistic nature of the wave function is intrinsic". The wave function can be used to derive probabilities, but I am not sure it is even meaningful to say that the wave function itself is intrinsically probabilistic.

Monday, September 8, 2014

Opinions on an infinite universe

A Danish non-cosmologist writes Astrosociology: Interviews about an infinite universe
If the universe is infinite now it has always been infinite. This is the opinion of many astronomers today as can be concluded from the following series of interviews, but the opinions differ much more than I had expected. Many astronomers do not have a clear opinion on this matter. Others have a clear opinion, but very different from the majority. Detailed arguments by two experts on general relativity are also included. Observations show that the universe is flat, i.e. the curvature is zero within the small uncertainty of measurements. This implies an infinite universe, though most probably we will never know that for certain. For comparison with the recent interviews, opinions during the past 2300 years since Aristotle about the universe being finite or infinite have been collected from literature, and it appears that the scientists often had quite definite opinions.
English is probably not his native language, so I shouldn't blame him for the misspelling in the title.

I am not sure the question is meaningful. Some think that the universe is spatially infinite, but that matter only occupies a bounded portion of it. Should such people say that the universe is finite or infinite?

I say finite. We can only observe a finite portion of the universe, and our physical theories relate to finite quantities. I am not sure it makes any scientific sense to speak of an infinite universe.

The whole concept of actual infinity is dubious:
The legendary Carl Friedrich Gauss denied that anything infinite really existed, saying "Infinity is merely a way of speaking" and "I protest against the use of infinite magnitude as something completed, which is never permissible in mathematics."

Sunday, September 7, 2014

Nothing did not turn into something

Bill Gates is pushing Common Core on the schools, and also this course:
As Gates was working his way through the series, he stumbled upon a set of DVDs titled “Big History” — an unusual college course taught by a jovial, gesticulating professor from Australia named David Christian. Unlike the previous DVDs, “Big History” did not confine itself to any particular topic, or even to a single academic discipline. Instead, it put forward a synthesis of history, biology, chemistry, astronomy and other disparate fields, which Christian wove together into nothing less than a unifying narrative of life on earth. Standing inside a small “Mr. Rogers"-style set, flanked by an imitation ivy-covered brick wall, Christian explained to the camera that he was influenced by the Annales School, a group of early-20th-century French historians who insisted that history be explored on multiple scales of time and space. Christian had subsequently divided the history of the world into eight separate “thresholds,” beginning with the Big Bang, 13 billion years ago (Threshold 1), moving through to the origin of Homo sapiens (Threshold 6), the appearance of agriculture (Threshold 7) and, finally, the forces that gave birth to our modern world (Threshold 8).
I listened to the first 2 minutes about the Big Bang, leading up to this:
Why is this so important? Because nothing had turned into something. And that something contained everything needed to build an interesting universe. One that could eventually include you and me.

No, we really don't know that "nothing had turned into something", and we certainly don't know that there is anything important about that.

We could say that the universe is expanding as if the observable portion of it were once in a much smaller volume. The early expansion may or may not have been accelerated by inflation.

L. Krauss wrote a book on how nothing turns into something, but of course he really explains that a vacuum quantum field theory can shift from one state to another.

It also says:
After the big bang there was space, which was rapidly expanding, and there was time.
I don't see how it makes any sense to say that time existed after something else.

This sort of grand synthesis course may be worthwhile, but it seems that the people who make these courses cannot resist injecting ideological biases of various sorts.

Thursday, September 4, 2014

Google doing quantum chip

The quantum computer con continues. Yahoo reports:
Google said it is working on a super-fast "quantum" computer chip as part a vision to one day have machines think like humans.

The Internet titan on Tuesday added renowned researcher John Martinis and his team at the University of California, Santa Barbara, to the Quantum Artificial Intelligence team at Google, according to director of engineering Hartmut Neven.

The new hires are part of a "hardware initiative" to design and build chips operating on sub-atomic levels in ways making them exponentially faster than processors currently used in computers,

"With an integrated hardware group the Quantum AI team will now be able to implement and test new designs," Neven said of the quest for a transformative new chip.

Last year, Google's artificial intelligence lab partnered with US space agency NASA on quantum computing research.
I predict that 5 years from now, Google is still unable to show any quantum speedup, but the quantum computing enthusiasts are undeterred.

The FQXi August 31, 2014 Podcast has a part about the "Quantum Pigeonhole Principle". It is another little paradox showing that quantum particles cannot be treated as ordinary classical particles. But instead of admitting that there are no practical applications, the researcher went into a big story about how some Feynman comments led to quantum computers. Except that there are still no practical applications of quantum computers.

I posted on Sean M. Carroll's blog because he misquotes people he is attacking. He grudgingly corrected the Larry Summers quote, while denying that it makes any difference. The misquote is strange, because Carroll also attacks an article that explained how Summers has been misinterpreted. He also misquotes Nicholas Wade as saying “therefore Chinese people may be clever, but they’ll never really understand democracy.” I think it is a misquote, anyway. You would think that it if so important to denounce Summers and Wade, then Carroll would make some effort to accurately represent what they said.

Carroll also complains about someone losing a job for anti-Israel tweets. Apparently free speech for Israel attackers is a major dilemma for today's liberals. American professors are expected to take conventional liberal political positions. That is why Carroll is compelled to denounce Summers and Wade, even if it is a stupid straw man attack. Israel is trickier, because both sides are fighting for ethnic causes.

Update: Info about how the Palestinian Arab lost his job makes one wonder how he was ever offered the job. He has a long history of anti-Israel writings, and very little worthwhile academic scholarship:
The first thing one learns about Salaita is that very little of what he has written seems to have anything to do with the field of study in which he claims expertise and in which he was offered a job, American Indian Studies.

Update: Scott Aaronson is excited about the Google quantum computer, and wants to be able to claim that he correctly predicted the outcome whether it works or not.

Monday, September 1, 2014

Misguided uses of term quantum

The humor site Cracked has The 5 Most Misguided Uses of the Word 'Quantum' in Ads
Humanity's greatest minds know that no one fully understands quantum mechanics. Our worst minds took that as an excuse. Idiots scrabble to use quantum terms like they're living on a triple-word score, thinking that the words alone will make all their points for them. ...

#1. Deepak Chopra's Quantum Consciousness

Deepak Chopra believes that consciousness transcends reality, but you should still give him real money. He combines pseudoscience and pseudoreligion to create an alloy of assholery capable of supporting his tidal waves of bullshit. If a self-help book and a science textbook got merged in a transporter accident, it would sound like Deepak Chopra's theories on quantum consciousness. And he would still claim that the spiritual aspects were more responsible for what had happened. ...

One classic quote: "Consciousness may exist in photons, which seem to be the carrier of all information in the universe." ...

Luckily, true science is immune to such assholery. Quantum mechanics is humanity's greatest scientific achievement. It's the victory of the scientific method, revealing intellectual truths that contradict all our conceptions of common sense, because common sense was created to help a couple of meters of pork substitute have sex as often as possible and really doesn't apply to the fundamental laws of reality.
I would have listed quantum communications, cryptography, teleportation, computers, cat states, many worlds, and nonlocality.

Chopra seems like just a buffoon who parrots the goofy stuff that real physicists say. Here is his latest idea:
What forces such a radical change is reality itself, which science is obliged to follow. Reality has led us to the point where reductionism, a “bottom up” approach that seeks to build reality up from its smallest constituents, must give way to holism, a “top down” approach that accepts an undeniable fact: Reality is one thing. Up to now, reductionism has been successful in disguising the dualism that is threatening to become a fatal flaw. There is no credible bridge between classical and quantum physics, brain and mind, physiology and psychology. In effect, the march of science through theory and technology has yet to explain how atoms and molecules took the leap that produced human experience, our mental participation in the reality science is trying to explain. Science has relegated personal experience to the sidelines and at times even rejected that consciousness is a valid subject of study. The reason is obvious, because the scientific quest has been for objective findings, not subjective impressions. The split between objective and subjective lies at the bottom of every other duality. But without a top down, holistic framework, there will never be an adequate explanation of reality. The two big questions facing science (What is the universe made of? What is the biological basis of consciousness?) needs to be reframed. What’s at stake is actually “What is existence?” and “How is existence known?”
We do not even have a good definition of consciousness.

Here is a recent Dilbert cartoon on use of buzzwords.

Thursday, August 28, 2014

Quantum computer joke

I like intellectual geek jokes, like this one:
There are only 10 types of people in the world: those who understand binary, and those who don't.
Here is an high-brow joke:
“Werner Heisenberg, Kurt Gödel, and Noam Chomsky walk into a bar. Heisenberg turns to the other two and says, ‘Clearly this is a joke, but how can we figure out if it's funny or not?’ Gödel replies, ‘We can't know that because we're inside the joke.’ Chomsky says, ‘Of course it's funny. You're just telling it wrong.’ ”
Just the idea of Heisenberg, Gödel, and Noam Chomsky having to talk to each other is funny already. I am not sure if this is a reference to Chomsky being a expert on language and human nature, or his goofy politics, or his combative demeanor, or what.

Scott Aaronson just told a good one:
Let me start with a story that John Preskill told me years ago.  In the far future, humans have solved not only the problem of building scalable quantum computers, but also the problem of human-level AI.  They’ve built a Turing-Test-passing quantum computer.  The first thing they do, to make sure this is actually a quantum computer, is ask it to use Shor’s algorithm to factor a 10,000-digit number.  So the quantum computer factors the number.  Then they ask it, “while you were factoring that number, what did it feel like?  did you feel yourself branching into lots of parallel copies, which then recohered?  or did you remain a single consciousness — a ‘unitary’ consciousness, as it were?  can you tell us from introspection which interpretation of quantum mechanics is the true one?”  The quantum computer ponders this for a while and then finally says, “you know, I might’ve known before, but now I just … can’t remember.”
I don't get it, but I am probably not smart enuf. This story has all the appearances of being both profound and funny. Maybe someone will explain it to me.

Update: Here is a joke Chomsky story:
Professor of linguistics and political campaigner Noam Chomsky has been confirmed as the new judge on TV talent show The X Factor. ‘Cheryl Cole was still recovering from malaria and we needed someone who could fill the intellectual void,’ said programme creator Simon Cowell, ‘Professor Chomsky is perfect and the audience just loves him.’

In his first outing as judge, Chomsky quickly made his mark. ‘Your act is part of a propaganda state promoting a culture-ideology of comforting illusion’, he told one hopeful young girl, before adding, ‘I’m saying yes.’

Chomsky then set about a teenage boy-band, describing them as ‘yet another example of pre-packaged ideological oppression whose lyrics systematically fail to demonstrate even a basic understanding of what happened to East Timor in 1975,’ he paused for effect, ‘But, I’m giving you a second chance … You’re through to the next round.’

Not satisfied with attacking the acts, Professor Chomsky then turned his critique on The X Factor audience. ‘You are all complicit in a hegemonic construct designed primarily to keep you from questioning what is really going on in the world,’ he told them, ‘You must learn to think critically and reject the pernicious cult of celebrity.’ It was at this point that the audience went wild, whooping, cheering and chanting his name. ‘We love you Chomsky!’ they screamed as the 81 year-old professor sat at the table with his head in his hands.

Wednesday, August 27, 2014

SUSY particles predicted for LHC

Gordon Kane writes in SciAm:
In “Supersymmetry and the Crisis in Physics,” Joseph Lykken and Maria Spiropulu discuss hopes that evidence of supersymmetry, which proposes that all known particles have hidden superpartners, will be found at CERN's Large Hadron Collider within a year's time — and the effects on physics as a whole if it is not. ...

Predictions based on such theories should be taken seriously. I would like to bet that some superpartners will be found at the LHC, but I have trouble finding people who will bet against that prediction.
That article was in the May issue, so it will be proved wrong on May 1, 2015. Make your bets now, before Kane changes his mind.

Monday, August 25, 2014

No need for quantum interpretation

I just found this sensible March 2000 Physics Today article, Quantum Theory Needs No ‘Interpretation’, by Christopher A. Fuchs and Asher Peres:
Recently there has been a spate of articles, reviews, and letters in PHYSICS TODAY promoting various “interpretations” of quantum theory (see March 1998, page 42; April 1998, page 38; February 1999, page 11; July 1999, page 51; and August 1999, page 26). Their running theme is that from the time of quantum theory’s emergence until the discovery of a particular interpretation, the theory was in a crisis because its foundations were unsatisfactory or even inconsistent. We are seriously concerned that the airing of these opinions may lead some readers to a distorted view of the validity of standard quantum mechanics. If quantum theory had been in a crisis, experimenters would have informed us long ago!

Our purpose here is to explain the internal consistency of an “interpretation without interpretation” for quantum mechanics. Nothing more is needed for using the theory and understanding its nature. ...

The thread common to all the non-standard “interpretations” is the desire to create a new theory with features that correspond to some reality independent of our potential experiments. But, trying to fulfill a classical worldview by encumbering quantum mechanics with hidden variables, multiple worlds, consistency rules, or spontaneous collapse, without any improvement in its predictive power, only gives the illusion of a better understanding. Contrary to those desires, quantum theory does not describe physical reality. What it does is provide an algorithm for computing probabilities for the macroscopic events (“detector clicks”) that are the consequences of our experimental interventions. This strict definition of the scope of quantum theory is the only interpretation ever needed, whether by experimenters or theorists.
Fuchs now promotes Quantum Bayesianism, which is essentially the same as the original Copenhagen interpretation.

I go even farther, and say that probability is just an interpretation, and is not necessary for quantum mechanics. Probability is a mathematical convenience for evaluating experiments in quantum mechanics or any other branch of science, but it is not an observable physical thing.

Quantum mechanics without interpretation has been called the Instrumentalist interpretation
Any modern scientific theory requires at the very least an instrumentalist description that relates the mathematical formalism to experimental practice and prediction. In the case of quantum mechanics, the most common instrumentalist description is an assertion of statistical regularity between state preparation processes and measurement processes. ...

By abuse of language, a bare instrumentalist description could be referred to as an interpretation, although this usage is somewhat misleading since instrumentalism explicitly avoids any explanatory role; that is, it does not attempt to answer the question why.
This article applies it to the Stern-Gerlach experiment. Sometimes the Ensemble interpretation is said to be the minimalist one, but that does not predict individual outcomes.

Sunday, August 24, 2014

Three arguments for string theory

This is summarized from a David Gross lecture:
String theory is a framework, not a specific theory making specific down-to-earth predictions about realistically doable or ongoing experiments that could decide about its fate, ...

The three arguments that either instinctively or knowingly contribute to the competent physicists' faith and growing confidence in string theory are:

UEA: unexpected explanatory coherence argument. If the theory weren't worth studying, it would probably almost never lead to unexpected answers, explanations, and ways to solve problems previously thought to be independent
NAA: no alternative argument. There's no other game in town. The argument has existed in the case of the Standard Model – in recent decades, NAA was getting increasingly important.
MIA: meta inductive argument. String theory is a part of the same research program that includes theories whose success has already been established.
Are you kidding me? Theologians make better arguments.

Here is another opinion, that string theory resulted from physics being trapped in a wrong philosophy:
Horgan: Do you ever think it’s time for physicists to abandon the quest for a unified theory?

Rovelli: The “quest for a unified theory” is a misconception. Physicists never really searched for it. They stumbled upon string theory, which to some appeared as a possible unification of everything, and, for lack of imagination, put too much energy into strings. When the enthusiasm for strings begun to fade, many felt lost. Now that supersymmetry is not showing up where string theorists expected it, it is a disarray. ...

Here is an example: theoretical physics has not done great in the last decades. Why? Well, one of the reasons, I think, is that it got trapped in a wrong philosophy: the idea that you can make progress by guessing new theory and disregarding the qualitative content of previous theories. This is the physics of the “why not?” Why not studying this theory, or the other? Why not another dimension, another field, another universe? Science has never advanced in this manner in the past. Science does not advance by guessing. It advances by new data or by a deep investigation of the content and the apparent contradictions of previous empirically successful theories. Quite remarkably, the best piece of physics done by the three people you mention is Hawking’s black-hole radiation, which is exactly this. But most of current theoretical physics is not of this sort. Why? Largely because of the philosophical superficiality of the current bunch of scientists.
It is not just the string theorists who suffer from a unified theory delusion. Einstein suffered from that since about 1925, and so have nearly all of the leading theoretical physicists of the last 40 years.

Leftist-atheist-evolutionist Jerry Coyne is upset that the Rovelli interview is not sufficiently atheistic, and writes:
Well, if you see compatibility as the ability of human minds to do science and believe in fairy tales, then Rovelli’s right. ...

Most of the rest of the first paragraph is good; it’s useful to realize that religious people dislike science because it forces us to live with doubt, and many believers aren’t comfortable with that. (Richard Feynman particularly emphasized that difference, as in the video below)
The Feynman video does not say anything about religion.

Coyne's blog attacks religious people all the time. But Coyne always writes with great certainty while the religious people express doubt. So Coyne seems to have missed Feynman's point, and is attacking a straw man.

Update: Now Coyne says that he does not want to diss philosophy, and disagrees with those who do, but he cannot find any example of where philosophy helped science.

Saturday, August 23, 2014

Bad argument that math is science

Astrophysicist and exoplanet searcher Coel Hellier writes A scientism defence of Logical Positivism:
Like everyone else I read Ayer’s Language, Truth and Logic as a teenager and, like many people of a scientific bent, I loved it. The Logical Positivism that it espoused can be summarised as the claim that knowledge is of two types: (1) logical reasoning from axioms, such as used by mathematics; and (2) claims about the universe that can (in principle) be verified empirically. Anything else — such as metaphysics — is literally meaningless.
That is correct up to the word "meaningless". There might be some meaning to metaphysics, but it is not the sort of knowledge that comes with a demonstration that it is true or false.

He also writes Defending scientism: mathematics is a part of science on his blog, and tries to defend these views on the Scientia philosophy blog:
I will take one statement as standing proxy for the whole of mathematics (and indeed logic). That statement is: 1 + 1 = 2

Do you accept that statement as true? If so (and here I presume that you answered yes), then why?

I argue that we accept that statement as true because it works in the real world. All of our experience of the universe tells us that if you have one apple in a bag and add a second apple then you have two apples in the bag. Not three, not six and a half, not zero, but two. 1 + 1 = 2 is thus a very basic empirical fact about the world [3]. ...

I have argued that all human knowledge is empirical and that there are no “other ways of knowing.” Further, our knowledge is a unified and seamless sphere, reflecting (as best we can discern) the unified and seamless nature of reality. ... I thus see no good reason for the claim that mathematics is a fundamentally different domain to science, with a clear epistemological demarcation between them.
I also defend logical positivism, but not this. He has abandoned the "logical" part of logical positivism. Logic and math are forms of knowledge that need no empirical verification, and usually do not get any.

Here are comments I left:
Coel, the flaw in your argument is in the triviality of your math examples. "1+1=2" is not much of a theorem, and is more accurately the definition of "2". Try applying your argument to a real theorem, such as the infinity of primes, as someone suggested.

There certainly is a sharp qualitative difference between the work of Riemann and Einstein. The mathematical theory of general relativity was worked out by Minkowski, Grossmann, Levi-Civita, and Hilbert -- all mathematicians. Einstein did not prove any theorems and rarely even made any mathematically precise statements.

Your comments about Godel's theorem are about like saying that the irrationality of the square root of 2 shattered hopes for geometry, or that comets shattered hope for astronomy. And it surely does not help your argument, unless you can explain how the theorem can be empirically understood or validated.

Your lesson from this is that "scientific results are always provisional". Maybe so, but mathematical results are not. Godel's theorem is not provisional.

You can, of course, define "science" any way you please, but you have failed to give a definition that includes mathematics. To you, science is empirical and provisional, but you do not give a single mathematical result with these properties. Do you really want to argue that "1+1=2" is a provisional result subject to empirical acceptance or rejection? Will you please tell us how this equation might be rejected?

You deny a "clear epistemological demarcation", but you do not give an example on the boundary of math and science. Your closest example is string theory, but you must realize that most of that subject is viewed by outsiders as neither science nor mathematics.

Coel, you say that it is " epistemologically identical", except that one uses empiricism and plausibility arguments and the other uses axioms and logic. In other words, not similar at all.

Part of the problem here is that what mathematicians mean by math is quite a bit different from what most scientists mean. I have heard science and engineering professors tell their students not to take math classes for math majors, because they have proofs in them. The professors act as if a proof is some sort of mysticism or voodoo with no applicability. Most of them do not understand what a proof is.

Coel argues that knowledge is science, and science is provisional, but that is just not true about mathematical knowledge. Mathematical truths are not provisional or subject to any empirical tests. He suggests that "1+1=2" can be tested by looking to see if alternate definitions can be used to predict eclipses. But there are lots of alternative number systems that are completely mathematically valid, even if they are not used to predict eclipses.

I could test "1+1=2" by laying 2 1-foot pieces of string together, and measuring the length. If so, I am likely to get 2.01 or something else not exactly 2. The mathematician says that 1+1 is exactly 2. So what have you tested? You certainly have not validated the mathematical truth that 1+1 is exactly 2. You have an empirical result about the usefulness of the equation, and that's all.

So when Coel says that math is epistemologically identical to science, he is not talking about how mathematicians do math.

SciSal is correct that most math has nothing to do with modeling the real world.

String theory is an odd beast. There are some mathematicians who prove theorems about string models, and physicists who look for empirical tests. But the vast majority of string theorists are not concerned with either of these pursuits. They are more like people playing Dungeons & Dragons in their own imaginary universe.

Coel, you say that math axioms are codified regularities of nature. The most common axiom system for math is ZFC (Zermelo-Frankel). Can you explain how those axioms relate to nature?

Coel, you repeatedly deny any distinction between a definition, a theorem, and an equation that empirically seems approximately valid. So I would lump you in with those other science and engineering professors who do not recognize the value of a proof.
I believe that my comments and other comments refute his position.