Wednesday, October 1, 2014

Quantum crypto hype on PBS Nova

I just watched PBS NOVA Rise of the Hackers
A new global geek squad is harnessing cryptography to stay a step ahead of cybercriminals.
At the heart of almost everything we do on the web is a special kind of number, a prime number. ... But what makes them so special to codes is when you combine two of them. ... If ... you've got to figure out the two original primes, the only way is trial and error. ...

This system of public and private keys is known as the RSA algorithm. That beautiful piece of mathematics has fundamentally changed the world around us.
I do not think that these explanations are very helpful. It is true that most SSL web servers use RSA, but Diffie-Hellman came first and is arguably superior for most purposes. That was the real breakthrough. And trial and error is not the only way to break RSA, as other methods are asymptotically much faster.
It has made the hunt for very very large prime numbers one of the most important quests in the field of mathematics. And here is the current largest, all 5000 pages of it.
This is nonsense. These numbers have almost no importance to either mathematics or cryptography. They are just a silly curiosity.
The mathematics of the world of the very small means that things can be in many places at the same time. ... They may be a way to crack the world's most powerful codes.
Not really. Saying that particles can be in more than one place at the same time is just an interpretation of the wave function, and has never been observed. So you can choose to believe in it or not, and no one can disprove you.

They go on to explain qubits as being 0 and 1 at the same time, so that a quantum computer can calculate both simultaneously. Scott Aaronson argues on his blog that this is a bad explanation, because it leads you to believe that quantum computers are more powerful than they really are.
It blows the doors off of RSA encryption. Right. All we need is more and more qubits, a larger quantum computer. Really all that's left to do is to scale up this particular architecture.
This is just nonsense. They have not made a scalable qubit, and there is no known way to scale up what they have. They have never achieved that quantum speedup.

Seth LLoyd says:
Quantum computers are particular fine for ... or for simulating happens when a black hole collapses, or for that matter, a recent experiment that we did to actually implement a version of time travel.
He is dreaming here.
But quantum mechanics also provides methods of communicating securely in a way that is guaranteed by the laws of physics.
More nonsense from Lloyd.
Quantum cryptography is already used by folks who want extreme security. By banks and by agencies whose job is to protect information. And nowadays there are number of commercial companies who actually build quantum cryptographic systems. For a fee, you too can communicate in communicate in complete and utter privacy guaranteed by the laws of quantum mechanics.
Before you pay that fee, you should realize: Every one of those systems has been broken. No bank or agency uses them for anything important. They cannot be used with routers or any other internet equipment. They cannot authenticate who you are communicating with. Even that supposed quantum mechanics guarantee is just a probabilistic statement that is much weaker than you can get with RSA or other methods.

Lloyd admits that these systems are susceptible to an impostor at the other end, but then implies that all crypto systems have this same problem. But that is not true. The main technical advance of RSA was actually not encryption, but authentication. When you log into Ebay or Amazon, it verifies that you are really connecting to Ebay or Amazon. In worst case, you could be connecting to someone who has hijacked the DNS servers and stolen Ebay's RSA secret key, or who built a quantum computer to factor the RSA public key. Neither has ever happened. Quantum crypto offers no such assurances, and you would be on your own to verify that a cable connects directly from your computer to the Ebay server. It can detect certain kinds of tampering, but it cannot detect some hijacking the whole line.

I don't know how respectable professors like Lloyd can shamelessly over-hype their field like this. They are charlatans. Even Aaronson is not this bad.

A better popular explanation can be found in this Wired article on the double slit experiment:
To summarize, we’ve arrived at a pattern of fringes that’s built up one particle at a time. But when you try to work out exactly how those particles got there, you find that they didn’t take the left route, they didn’t take the right route, they didn’t take both routes, and they didn’t take neither routes. As MIT professor Allan Adams puts it, that pretty much exhausts all the logical possibilities!

An electron is not like a wave of water, because unlike a wave, it hits a screen at a single location. An electron is not like a baseball, because when you throw in a bunch of them through a double slit, they interfere and create patterns of fringes. There is no satisfying analogy that anyone can give you for what an electron is.
Some people prefer to think of the electron as being two places at once, or being a wave, or even as being immune to the usual laws of logic. If one of those makes you feel better, then go ahead. But there is no perfect classical analogy of the sort sought by Einstein and Bell. Those who use these analogies to promote quantum crypto or computing are just charlatans.

Tuesday, September 30, 2014

The enemies of good science

A lot of science bloggers call themselves "skeptics", and are always on the warpath against religion (like Christianity) and pseudoscience (like homeopathy). I am more concerned with bad thinking that corrupts otherwise-intelligent scholars. Here are my main targets.

Paradigm shifters - They subscribe to T.S. Kuhn's theory that science is all a big popularity contest, with new theories winning out without any rational or measurable advantages, and never making progress towards truth.

Proof deniers - They fail to appreciate that a mathematical proof can give certain knowledge.

Goedel fools - They argue that math lacks solid foundations because of some technical logic theorems.

Einstein idolizers - They treat Einstein as a god, and learn all the wrong lessons from the history of relativity and the Bohr debates.

Thought experimenters - They endlessly speculate about a black hole interior, or universes before the big bang, or quantum gravity, or other questions outside the domain of observable science.

Falsifiers - They deny that science teaches us anything, except that older theories have been

Dreamers of imaginary worlds - They like to invent fantasy worlds, and put them out under names like the multiverse, many worlds interpretation, and strings in higher dimensions.

Hidden variable searchers - These are always telling us that quantum mechanics is incompatible with realism because it fails to identify the hidden variables that will unlock all the mysteries of the universe.

Publicity panderers - They will say whatever gets media attention, such as fantastic claims for quantum communication and computers.

Political correctness enforcers - On an assortment of topics (global warming, evolution, human biodiversity, etc), they are more interested in silencing their enemies than promoting scientific truth.

Sunday, September 28, 2014

Tyson's excuse is absence of evidence

I mentioned that Tyson used a bogus quote to bash Bush, and he replied:
I have explicit memory of those words being spoken by the President. I reacted on the spot, making note for possible later reference in my public discourse. Odd that nobody seems to be able to find the quote anywhere -- surely every word publicly uttered by a President gets logged.

FYI: There are two kinds of failures of memory. One is remembering that which has never happened and the other is forgetting that which did. In my case, from life experience, I’m vastly more likely to forget an incident than to remember an incident that never happened. So I assure you, the quote is there somewhere. When you find it, tell me. Then I can offer it to others who have taken as much time as you to explore these things.

One of our mantras in science is that the absence of evidence is not the same as evidence of absence.
That is a stupid mantra. It allows people to promote all sorts of unscientific nonsense.

Someone could say, "Sure there is no evidence for psychokinesis, but that does not mean there is evidence against psychokinesis." Or substitute astrology, parallel universes, higher dimensions, quantum computing, or whatever is your favorite belief that lacks evidence.

In this case, G.W. Bush's post-9/11 public statements were all logged. The sillier ones ended up in a Michael Moore movie. If the quote is not on the record, then Bush did not say it. In public for Tyson to hear it, anyway.

A lot of people believe that the 9/11 WTC hit was just a battle in a multi-century war between Christendom and Islam. Bush is a Christian, so it is fair to assume that he believes Christianity to be superior to Islam. He may have even used the word "crusade" by mistake. But he certainly never publicly framed this as a religious war, with the Christian God on our side.

Not only is the quote wrong, but the larger point about the President announcing a religious war is wrong also. Bush's statements were similar to what the President said last week:
At the same time, we have reaffirmed again and again that the United States is not and never will be at war with Islam. Islam teaches peace. ... So we reject any suggestion of a clash of civilizations. Belief in permanent religious war is the misguided refuge of extremists ...
The other misquotes are in support of stupid points also. I know of areas where the community would be very upset if half their schools were below average, as "average" would probably mean on the state standardized tests. There are also issues where my personal views have changed 360 degrees. There is nothing wrong with a congressman saying, “I have changed my views 360 degrees on that issue.” In some cases, their views might change 180 degrees every time a lobbyist walks in his office. Two such changes, and his view have changed 360 degrees.

Electrons have to rotate 720 degrees to get back to their original state, so maybe a clever congressman might say that his views changed 720 degrees.

I am all in favor of making fun of politicians for saying something stupid, but these things are not stupid without additional context. There are plenty of better examples. Just look at the above Obama speech to the UN, where he compares Islamic terrorists to Ferguson policemen. Or look at the dumb stuff VP Biden says all the time.

Tyson is still refusing to admit that he made up the Bush quote, that Bush's actual statements were more nearly the opposite, that Tyson was trying to score cheap political points, that those points are entirely false, and that Tyson made up the other quotes as well. I was not looking for an apology. But now I know that he has a disregard for the facts when he tells personal anecdotes.

Update: Tyson now says:
When eager scrutinizers looked for the quote they could not find it, and promptly accused me of fabricating a Presidential sentence. Lawyers are good at this. They find something that you get wrong, and use it to cast doubt on everything else you say. ...

My bad. And I here publicly apologize to the President for casting his quote in the context of contrasting religions rather than as a poetic reference to the lost souls of Columbia. ...

And I will still mention the President’s quote. But instead, I will be the one contrasting what actually happened in the world with what the Bible says: The Arabs named the stars, not Yahweh.
So he will be disproving the Bible instead of Bush? There must be a better way to credit Arab astronomy, if it really matters that some stars have Arab names.

Update: Sean Davis concludes:
After all the strum and drang, Tyson still doesn’t seem to grasp the main issue here: this wasn’t a misquote. It was a fabrication that deliberately created the exact opposite impression of how reality actually transpired. It was the sort of thing a dishonest politician does, not the sort of behavior you’d expect from a scientist who’s allegedly devoted to studying reality.
That's right. I would not be piling on if Tyson just corrected the (mis-)quote, and skipped the argument about how the misquote was okay.

Friday, September 26, 2014

Ed Witten still believes in string theory

John Horgan has interviewed the smartest living physicist:
At a 1990 conference on cosmology, I asked attendees, who included folks like Stephen Hawking, Michael Turner, James Peebles, Alan Guth and Andrei Linde, to nominate the smartest living physicist. Edward Witten got the most votes (with Steven Weinberg the runner-up). Some considered Witten to be in the same league as Einstein and Newton. Witten was and is famous for his work on string theory, which unifies quantum mechanics and relativity and holds that all of nature’s forces—including gravity–stem from infinitesimal particles wriggling in a hyperspace consisting of many extra dimensions.

Even then, string theory — which some enthusiasts (not including Witten) called a “theory of everything” – was extremely controversial, because there seemed to be no way to confirm experimentally the existence of strings or the extra dimensions they supposedly inhabit.
Witten has somehow convinced mathematicians and physicists that he is a great genius, even tho he does not do straight math or straight physics. Some of his math ideas have been turned into legitimate proofs by others. Not sure if any of his physics ideas have panned out.
Horgan: Do you see any other rivals for a unified theory of physics?

Witten: There are not any interesting competing suggestions. One reason, as remarked in “Unravelling,” is that interesting competing ideas (twistor theory, noncommutative geometry, …) tend to be absorbed as part of a larger picture in string theory. The competing interesting ideas have been very fragmentary and have tended to gain power when absorbed in string theory. ...

Witten: Personally, I hope the landscape interpretation of the universe would turn out to be wrong, as I would like to be able to eventually calculate from first principles the ratio of the masses of the electron and muon (among other things). However, the universe wasn’t made for our convenience. Plenty of leading physicists — prominent examples being Steve Weinberg and Martin Rees – have taken the acceleration of the cosmic expansion seriously as a hint that a landscape interpretation of the universe may be correct.
This is the opinion of a true believer. Whatever he sees, he finds a way to interpret it to match his beliefs from 30 years ago.
Horgan: Do you agree with Sean Carroll that falsifiability is overrated as a criterion for distinguishing science from pseudo-science?

Witten: Scientists aim to get as reliable and precise an understanding of nature as we can. The gold standard is a precise prediction that can be tested in a precise way in a laboratory experiment. Experiments that disprove theories are an important part of the scientific process.

With that said, it is a little too narrow to claim that science consists of trying to falsify theories because a lot of science consists of trying to discover things. (Chemists who attempt a new synthesis could say they are trying to falsify the hypothesis that this new synthesis won’t work. But that isn’t what they usually say. People who search for life on Mars could say they are trying to falsify the hypothesis that there is no life on Mars. Again, people don’t usually talk that way.)
Witten attacks a straw man, as nobody ever said that science consists only of trying to falsify theories. As Horgan said, it is a criterion for distinguishing pseudoscience. Karl Popper argued that Sigmund Freud would not accept anything as falsifying his theory of dream interpretation, and hence it is unscientific (and pseudoscience). Popper was right, and falsifiability is a useful criterion.

Carroll and Witten don't like it because they promote ideas that are no more testable than Freud's dream interpretations. Like the multiverse and string theory.

Woit points out that Witten responded to Horgan in a 1996 WSJ article:
There is a high probability that supersymmetry, if it plays the role physicists suspect, will be confirmed in the next decade. The existing accelerators that have a chance of doing so are the proton collider at the Department of Energy’s Fermi Lab in Batavia, Ill., and the electron collider at the European Center for Nuclear Research (CERN) in Geneva.
Speaking of scientists being wrong, Tyson is apparently still refusing to admit that he has been making up quotes in speeches, and there is a Wikipedia edit war about it. This is pathetic. The Bush quote is almost directly opposite what Bush said. Others have been disgraced for inventing quotes. I try to verify quotes on this blog. Occasionally I'll use a quote that I cannot verify, but then I will say so.

Wednesday, September 24, 2014

Aaronson writing quantum computing book

MIT complexity theorist Scott Aaronson announces:
A few months ago, I signed a contract with MIT Press to publish a new book: an edited anthology of selected posts from this blog, along with all-new updates and commentary.  The book’s tentative title (open to better suggestions) is Speaking Truth to Parallelism: Dispatches from the Frontier of Quantum Computing Theory.
His book will surely include his post with the most hits:
For better or worse, I’m now offering a US$100,000 award for a demonstration, convincing to me, that scalable quantum computing is impossible in the physical world. This award has no time limit other than my death, and is entirely at my discretion (though if you want to convince me, a good approach would be to convince most of the physics community first).
He explains that he was driven to make this offer by skepticism from me and others about the possibility of quantum computers. He has been active in throwing cold water on the over-hyped claims about quantum computers, but he is also stung by criticisms that he is devoting his life to analyzing something that may not even be physically possible. He has confessed his envy because other scientists can point to the intrinsic worth of the field, but quantum computer theorists have to rely on bogus claims about practical applications.

If I collect my quantum mechanics posts for a book, I'll be sure to mention his offer.

Among physicists, the common views on quantum computing, in order of decreasing popularity, are: (1) quantum computers have already been built, and they will eventually have enough qubits to be useful; (2) scalable quantum computing has not been demonstrated but is a logical consequence of quantum mechanics and advanced engineering should eventually make it possible; and (3) achieving super-Turing computing is like building a perpetual motion machine, and is unlikely to ever be achieved.

The popular press would lead you to believe opinion (1). Aaronson stands for opinion (2), and I agree with him that (1) is wrong. I believe in opinion (3), for reasons explained here. I could be proved wrong, of course.

In addition to those reasons, I have some philosophical differences with him that contribute to our divergent views.

I subscribe to an epistemic, rather than ontic, interpretation of quantum mechanics. That is, I accept the Copenhagen interpretation that was promoted by Bohr and generally accepted since the 1930s, and what Mermin now calls QBism. Aaronson paints a picture of our universe as weirdly intermediate between local and nonlocal. The psi-ontic physicists are the ones who are forever saying that quantum mechanics does not make sense, and that philosophical principles require an unobservable multiverse.

I subscribe to logical positivism, so I am very skeptical about what cannot be demonstrated. My preference is for a more positivist interpretation than even what Bohr proposed.

My slogan is Natura non facit saltus. Leibniz used this phrase to attack the "occult qualities" of an action-at-a-distance theory.

Here is Lumo and Gell-Mann sensibly dismissing many-worlds and nonlocality:
Gell-Mann spends several minutes by arguing that the feature of Everett's ideology that there are "many worlds that are equally real" is operationally meaningless. The comment may only mean that the theory treats the possible alternative histories on equal footing, except for their generally different probabilities. But only one of those actually takes place in the "real", experience-based sense of the word "actually". ...

However, that changes totally after 11:50 when Gell-Mann starts to talk about the "foolishness" often associated with the entanglement ("Einstein-Podolsky-Rosen-Bohm effect", using his words). He treats this issue at some length in his book; I hope he meant The Quark and the Jaguar.

OK, where did the "foolishness" come from? Gell-Mann says that the bulk of John Bell's work was right but he introduced words that were prejudicial such as "nonlocal". People often say that there is something nonlocal about the EPR phenomena but the only correct similar statement that they could mean, Gell-Mann emphasizes (and I often do, too) is that a classical interpretation of what is happening would require nonlocality (or negative probabilities). But the world is not classical, and no nonlocality is needed because the world is quantum mechanical. As far as Gell-Mann can tell, it's like giving a bad name to a dog and sticking with it.
Many of the quantum computing enthusiasts subscribe to many-worlds, as some of them argument that the mysterious speedup is going to come from computation in parallel universes. Guru David Deutsch says that, and Brian Cox just said something similar on the UK BBC. Aaronson does not go that far, but he does stress that the key to understanding quantum mechanics is negative probability. Gell-Mann has a much more sensible view.

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.

Update: Lumo is a believer:
There is a scientific substance. Everyone who is interested in cosmology would love to know whether the imprints of the primordial gravitational waves have been seen. I agree with those who say that this discovery, if true, is the greatest discovery in many years if not decades or a century. I would probably place it above the Higgs boson discovery because unlike the Higgs boson, it wasn't really guaranteed.

However, we must ask: is the discovery real?

Of course that I am not 100.00000% sure. But I still think it's significantly more likely than not that the BICEP2 discovery is genuine and the pattern they see is simply not dust. Why? Because it clearly doesn't look like dust.
And it looks like primordial quantum gravity waves? I don't think so.

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.
Update: As of Sept. 27, Tyson is still refusing to admit that he made up the Bush quote, that Bush's actual statements were more nearly the opposite, that Tyson was trying to score cheap political points, that those points are entirely false, and that Tyson made up the other quotes as well. I was not looking for an apology. But now I know that he has a disregard for the facts when he tells personal anecdotes.

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.