Tuesday, June 21, 2016

Michael Gove is no Einstein

Is anyone any longer in any serious doubt that the leaders of the Brexit campaign feel they can just come out with whatever fact-free, delirious twaddle jumps into their head and expect us to swallow it?

It’s getting quite surreal now. Michael Gove, faced with a question on LBC Radio about what to make of all the top economists who have warned of the dire consequences of the UK leaving the European Union, decided that there was a parallel here with the way Einstein was treated in Germany in the 1930s.

“We have to be careful about historical comparisons”, said Gove, “but Albert Einstein during the 1930s was denounced by the German authorities for being wrong and his theories were denounced and one of the reasons of course he was denounced was because he was Jewish. They got 100 German scientists in the pay of the government to say that he was wrong and Einstein said, ‘Look, if was wrong, one would have been enough’.”

So, did you get that? Michael Gove is Einstein, and the economists who have decided that Brexit would be economically bad are like Nazis in the pay of the government.

Except that he is simply peddling half-truths and fictions. Gove clearly thinks these “100 scientists” were put up to it by the Nazi authorities. But the infamous book A Hundred Authors Against Einstein was published in 1931, before the Nazis came to power and while Germany was still ruled by the Weimar government - who Einstein supported.

And as the title suggests, they weren’t “100 scientists”. They were a ragbag of academics and other “intellectuals” of various stamps, among which there was only one real physicist, an insignificant (and retired) figure called Karl Strehl. They had no expertise, and evidently had not the faintest idea what to make of relativity. The book wasn’t taken in the slightest bit seriously by the German scientific community, and the vast majority of leading physicists in Germany supported Einstein’s ideas. Of course A Hundred Authors (most of them were present in name only in the book – only a few expressed their views) was motivated in considerable part by anti-Semitism, as well as objections to Einstein’s internationalism. How that is supposed, in Gove’s mind, to bear on the reasons for the economists’ position on Brexit is anyone’s guess. Do they reach conclusions different to his because they are similarly bigoted in some fashion? The parallel is as meaningless as it is fatuous. Gove faced a very serious question here and he had nothing to say behind falsehoods and bluster. If Brexit wins, we can expect a lot more of the same.

Sunday, June 12, 2016

Best of both worlds in quantum computing

Here's an expanded version of my news story for Nature on Google's new quantum computer. It's a somewhat complicated story, so a bit more explanation might be useful.

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Combining the best of two leading approaches might be the way to make a full-scale multipurpose quantum computer.

A universal quantum computer, which can any computational problem, has been a goal of research on quantum computing since its origins three decades ago. A team in California has now made an experimental prototype of such a device. It uses nine solid-state quantum bits (qubits), which can be configured to solve a wide range of problems and has the potential to be scaled up to larger systems.

The new device was made by Rami Barends and coworkers at Google’s research laboratories in Santa Barbara, collaborating with the group of physicist John Martinis at the University of California at Santa Barbara and with a team at the University of the Basque Country in Bilbao, Spain.

“It’s terrific work in many respects, and is filled with valuable lessons for the quantum computing community”, says Daniel Lidar, a quantum-computing expert at the University of Southern California in Los Angeles.

The Google circuit combines some of the advantages of the two main approaches to quantum computing so far. One is to build the computer’s circuits from qubits in particular arrangements geared to an algorithm for solving a specific problem. This is analogous to a tailor-made digital circuit in a conventional microprocessor made from classical bits. Much of the theory of quantum computing is based on this digital approach, which includes methods for the all-important problem of error correction to avoid errors accumulating and derailing a calculation. But so far practical implementations have been possible only with a handful of qubits.

The other approach is called adiabatic quantum computing (AQC). Here, instead of encoding an algorithm in a series of digital-logic operations between qubits, the computer encodes the problem of interest in the states of a pool of qubits, gradually evolving and adjusting the interactions between them to “shape” their collective quantum state. In principle just about any problem can be encoded into the same group of qubits.

This is an analog rather than a digital approach, and is limited by the effects of random noise, which introduces errors that can’t be corrected as systematically as in digital circuits. What’s more, there’s no guarantee that all problems can be solved efficiently this way, says Barends.

While most research on quantum computing uses the digital approach, adiabatic quantum computing has furnished the first commercial devices, made by D-Wave Systems in Burnaby, Canada, for about $15 million apiece. Google owns a D-Wave device, but its own researchers are searching for ways to improve the method.

In particular, they wanted to find some way of implementing error correction. Without it, scaling up AQC to more qubits will be difficult, since errors will accumulate more quickly in larger systems. With that in mind, Barends and colleagues decided to combine the AQC method with the digital approach, which has a well developed theory of error correction [1].

“Implementing adiabatic optimization on a universal quantum computer is not a new idea”, explains Andrew Childs of the University of Maryland. “But now the Google group has actually carried this out, which makes for a nice test of their system.”

To do that, the Google team uses a row of nine qubits, fashioned from cross-shaped films of aluminium about 400 micrometres across from tip to tip, deposited on a sapphire surface. The aluminium becomes superconducting when cooled to 1.1 degrees Kelvin, in which state its electrical resistance falls to zero. (The Google team actually operates the device at just 0.02 K to reduce the thermal noise.) . This is state-of-the-art technology for qubits, Lidar says.

Superconductivity is a quantum-mechanical effect, and a bit of information – a 1 or 0 – can be encoded in different states of the superconducting current. Crucially, these quantum bits can be placed in superposition states, simultaneously encoding a 1 and 0 – the key to the power of quantum computing.

The interactions between neighbouring qubits are controlled by linking them via logic gates. Using these gates, the nine qubits can be steered step by step into a state that encodes the solutions to a problem. As a demonstration, the researchers let their array simulate a system of coupled magnetic “spins”, like a row of magnetic atoms – a problem well explored in condensed-matter physics. They can then interrogate the states of the qubits to determine the lowest-energy state of the spins they represent.

That’s a fairly simple problem to solve on a classical computer too. But the researchers show that their device is also able to handle so-called “non-stoquastic” problems, which aren’t tractable on classical computers. These include simulations of the interactions between many electrons, needed to make exact calculations in quantum chemistry. The ability to simulate molecules and materials at the quantum level could be one of the most valuable applications of quantum computing.

A great advantage of this new approach is that it allows for the incorporation of quantum error correction, says Lidar. Although the researchers didn’t demonstrate that in this work, the Google team has previously shown how error correction might be achieved on their nine-qubit device [2].

“Quantum error correction is needed to allow for addressing really large problems, otherwise with each qubit and coupler you add a source of noise”, says Barends’ co-author Alireza Shabani at Google. “With error correction, our approach becomes a general-purpose algorithm that is in principle scalable to an arbitrarily large quantum computer.”

The Google device is still very much a prototype. “With early small-scale devices like this one, it’s not yet possible to tackle problems that cannot be solved on traditional classical hardware”, says Lidar.

But “in a couple of years it may be possible to work with devices having more than 40 qubits”, he adds. “At that point it will become possible to simulate quantum dynamics that is inaccessible on classical hardware, which will mark the advent of ‘quantum supremacy’.”

1. Barends, R. et al., Nature doi:10.1038/nature17658 (2016) here.
2 . Kelly, J. et al., Nature 519, 66-69 (2015) here.

Tuesday, May 31, 2016

Is music brain food?

The latest issue of the Italian science magazine Sapere is all about food. So this seemed a fitting theme for my column on music cognition.

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‘If music be the food of love, play on, give me excess of it”, says Duke Orsino in Shakespeare’s Twelfth Night. The nineteenth-century German music critic Eduard Hanslick wasn’t impressed by that sentiment. It doesn’t matter what music it is, the Duke implies; I just want a load of it, like a big slice of cheesecake, to make me feel good.

But after all, mightn’t music be simply cheesecake for the ears? That is what the cognitive scientist Steven Pinker suggested in his book How the Mind Works. Music, he proposed, is simply a parasite that exploits auditory and cognitive processes which evolved for other reasons, just as cheesecake exploits a primal urge to grab fats and sugars. As he put it, “Music appears to be a pure pleasure technology, a cocktail of recreational drugs that we ingest through the ear to stimulate a mass of pleasure circuits at once.”

After all, Pinker went on, “Compared with language, vision, social reasoning, and physical know-how, music could vanish from our species and the rest of our lifestyle would be virtually unchanged.”

These claims provoked outrage. Imagine comparing Bach’s B minor Mass to an Ecstasy pill! And by suggesting that music could vanish from our species, Pinker didn’t appear much mind if it did. So his remarks were read as a challenge to prove that music has a fundamental evolutionary value, that it has somehow helped us to survive as a species. It seemed as though the very dignity and value of music itself was at stake.

Pinker might be wrong, of course. Indeed, recent research suggests that there might be neurons in our auditory cortex dedicated solely to music, suggesting that sensitivity to music could be a specific evolutionary adaptation, not a byproduct of other adaptive traits. But whether or not that’s so is rather beside the point. Music is an inevitable product of human intelligence, regardless of whether it’s genetically hard-wired. The human mind naturally possesses the mental apparatus needed for musicality, and will make use of these tools whether we intend it or not. Music isn’t something we do by choice – it’s ingrained in our auditory, cognitive, memory and motor functions, and is implicit in the way we construct a sonic landscape from the noises we hear.

So music couldn’t vanish from our species without fundamentally changing our brains. The sixth-century philosopher Boethius seemed to understand this already: music, he said, “is so naturally united with us that we cannot be free from it even if we so desired.” Cheesecake, on the other hand – I can take it or leave it.

Wednesday, May 25, 2016

Still selfish after all these years?

The 40th anniversary of the publication of Richard Dawkins’ The Selfish Gene is a cause for celebration, as I’ve said.

This anniversary has also reawakened the debate about the book’s title. Do we still think genes are “selfish”? Siddhartha Mukherjee's The Gene makes no mention of the idea, while talking about pretty much everything else. It’s no surprise that Dawkins sticks to his guns, of course. He justifies it in this fashion:

"If you ask what is this adaptation good for, why does the animal do this – have a red crest, or whatever it is - the answer is always, for the good of the genes that made it. That is the central message of The Selfish Gene and that remains true, and reinforced."

This is a statement crafted to brook no dissent. It says nothing about selfishness of genes. It says that adaptations are, well, adaptive, in that they help the organism survive and pass on its genes. But for a gene to be metaphorically selfish, it must surely promote its survival at the expense of other genes.

I’m not going to rehearse again the argument that the “selfish gene” promotes the misconception – which I suspect is now very common – that different genes, not different alleles of the same gene, compete with one another. (In the comment to my blog post above, Matt Ridley points out that there can be exceptions, but at such a stretch as to prove the rule. Still, as Matt says, we're basically on the same page.) The fact is that genes can only propagate with the help of other genes. John Maynard Smith recognized this in the 1970s, and so did Dawkins. He chose the wrong title, and the wrong metaphor, and wrote a superb book about them.

I find it curious that there’s such strong opposition to that fact. For example, I’m struck by how, when the selfish-gene trope is questioned, defenders will often point to rare circumstances in which genes really do seem to be “selfish” – which is to say, where propagation of a gene might be deleterious to the success of an organism (and thus to its other genes). It is hard to overstate how bizarre this argument is. It justifies a metaphor designed to explain the genetic basis of evolutionary adaptation by pointing to a situation in which genetic selection is non-adaptive. You might equally then say that, when genes are truly selfish, natural selection doesn’t “work”.

What is meant to be implied in such arguments is that this selfishness is always there lurking in the character of genes, but that it is usually masked and only bursts free in exceptional circumstances. That, of course, underlines the peril of such an anthropomorphic metaphor in the first place. The notion that genes have any “true” character is absurd. Genetic evolution is a hugely complex process – far more complex than Dawkins could have known in 1976. And complex processes are rarely served well by simple, reductionistic metaphors.

Think of it this way. There are situations in which Darwinian natural selection favours the emergence of sub-optimal fitness (for example, here). This is no big surprise, and certainly doesn’t throw into doubt the fundamental truth of Darwin’s idea. However, we could then, in the spirit of the above, argue that the real character of natural selection is to favour the less-than-fittest, but this is usually masked by the emergence of optimal fitness.

There is an old guard of evolutionary theorists, battle-scarred from bouts with creationism and intelligent design, who are never going to accept this, and who will never see why the selfish gene has become a hindrance to understanding. They can be recognized from the emotive hysteria of their responses to any such suggestion – you will find them clearly identified in David Dobbs’ excellent response to criticisms of his Aeon article on the subject. It is a shame that they have fallen into such a polarized attitude. As the other responses to David’s piece attest, the argument has moved on.

Monday, May 09, 2016

SATs are harder than you think

How’s your classical mechanics? Mine’s a bit crap. That’s why I’m having trouble working out the following question.

You have a cylinder that rotates around a horizontal axis, like the sort used to pull up buckets from wells. Around the cylinder is wrapped a rope attached to a weight. As the weight falls and the rope unwinds, you measure the time it takes to descend a certain distance.

Now you increase the mass of the cylinder – say, it’s made from iron, not wood (but of the same size). Does the weight fall more slowly? At risk of embarrassment, I’ll say that I think it does. The torque on the cylinder is the same in both cases, but what changes is the cylinder’s moment of inertia, and thereby (via torque = moment of inertia times angular acceleration) the angular acceleration. So the weight takes longer to descend the same distance when attached to the iron cylinder because the angular acceleration is less.

Also, the greater mass of the cylinder means, via Amonton’s Law, that the friction with the axis is greater in the latter case.

Am I right? Or do I need (it is quite possible) to go back to my A-level mechanics?

The reason I ask is that I am trying to understand a question in the SATs science test (now dropped, by the way) for Year 6, i.e. 11-year-olds.

You might wonder why 11-year-olds are having to grapple with torques and so forth. So am I. But they come up in this question:





Now, I suspect that the answer the pupils are expected to give is that the bigger piece of card incurs more air resistance. That is true. But it is not the only influence at play, since the card obviously adds to the rotor’s mass. So this is a rather complicated question in mechanics.

You might think I’m overthinking the problem. But I can’t see how it is ever a good idea to choose a question for which a little more knowledge makes the problem harder. Or am I just wrong here about the answer?

Elsewhere in the SATs papers you find difficulties that seem to be the result purely of bad questioning. Take this one, from an English Reading and Comprehension test. Pupils have to read the following passage:



Then they are asked



My (10-year-old) daughter was puzzled by this reference to “burning of rocks in space”. What does it mean to burn rocks in space? For one thing, you can’t do it. I mean sure, meteorites will get hot and oxidized as they fall through the atmosphere but not in space. And the frictional heating is not really about burning. “Burning up” is something of a euphemism here, and it does not mean the same thing as “burning”. The intended answer is trivial, of course: “in a flash” just means that the “burning up” happens quickly. But this question is worded in such a way that prevents it from quite making sense.

Is anyone checking this stuff, before it is unleashed on unsuspecting and highly stressed pupils and teachers?

Wednesday, April 27, 2016

Where's the soul?

I worry much more than I should about whether embryos have souls. That’s to say, I worry about how those folks who believe that at some stage humans are granted a soul by the grace of God make sense of this question.

But as I discovered while reviewing Henry Greely’s book The End of Sex, Father Tadeusz Pacholcyzk – who has a doctorate in neuroscience from Yale and writes for the National Catholic Bioethics Center in Philadelphia – has at least cleared up one thing for me. Whether or not embryos have a soul should, he says, have no bearing on our judgement about the rights and wrongs of using human embryo tissue for research into stem cells, or presumably for research into anything else. He clarifies that Catholic tradition has no unanimous verdict or tradition on the precise moment of ensoulment. However, Saint Augustine, rarely consulted for his knowledge of embryology, “seemed to shift his opinion back and forth during his lifetime between immediate and delayed ensoulment”. No wonder; it’s a tough question. Much, much tougher, indeed, than Augustine could ever have imagined, because of course we can’t expect him to have known that only about 12% of fertilized eggs in vivo will develop beyond three months of pregnancy. We had best assume, then, that ensoulment is delayed until some time after that, for otherwise heaven will be overwhelmingly filled with souls of embryos less than three months old. I don’t think any of the Christian Fathers ever imagined that heaven should be as odd a place as that.

The point, Pacholcyzk says, is irrelevant in any case, because a human embryo at any stage is destined for a soul “and should not be cannibalized for stem cell extraction”. (The use of “cannibalize” to denote dismemberment for spare parts applies, by the way, only to machines. For living organisms, it refers to the eating of one’s own species. But heck, it sounds bad, doesn’t it?) We must assume that the creation of embryos for any other purpose than procreation is also prohibited by Catholic teaching. In fact, Pacholcyzk says, it is even more immoral to destroy an embryo that had not received an immortal soul (although we don’t, remember, know if anyone actually does this, because we don’t know when ensoulment happens) than to destroy an ensouled embryo – worse than murder! – “because the immortal soul is the principle by which that person could come to an eternal destiny with God in heaven”. That person? Yes, an embryo is always a person – or rather, “the privileged sanctuary of one meant to develop as a human person.”

But evidently, the majority of human embryos are not, as Pacholcyzk insists, “meant [by God, one assumes] to develop as a human person” – they don’t get beyond three months. Or has God really made such a hash of human procreation, so that all these embryos destined for personhood keep failing to attain it?

The corollary to all this must be that the Catholic Church disapproves of IVF too, since that generally involves the creation of embryos that are not given the opportunity to grow to personhood. And as the Catholic World Report reminded us in 2012, it does indeed:

Catholic teaching prohibits in vitro fertilization, maintaining that a child has the right to be conceived in the marital embrace of his parents. Human sexuality has two components, the unitive and procreative; IVF separates these components and makes the procreative its only goal. Pope Paul VI said that there is an “inseparable connection, willed by God, and unable to be broken by man on his own initiative, between the two meanings of the conjugal act: the unitive meaning and the procreative meaning.

There are other issues involved. IVF makes the child a commodity produced in a laboratory, and makes doctors, technicians, and even business people part of the conception process. The sperm used is usually obtained by masturbation, which the Church teaches is immoral. The sperm or eggs used may not come from the couple desiring the child; because one of the spouses may be infertile, it may be necessary to use the sperm or eggs from an outsider.

That phrase, making a child conceived through IVF “a commodity produced in a laboratory”, is one of the most obscene I have ever heard from the church in modern times. God’s love is infinite – but you, Louise Brown (and four million others), are just a commodity produced in a laboratory.

Of course, Catholic countries don’t tend to feel they can be quite this hardline with their citizens, and so they cook up some crude compromise, such as Italy insisting that all embryos created in IVF (a maximum of three) must be implanted. This flouts Catholic teaching, and also flouts the right of people using IVF to the best chance of making it work. Everyone loses.

Actually, there is a form of IVF that the Catholic church will sanction. It is called gamete intra-Fallopian transfer, or (cutely) GIFT. Here’s how I described it in my book Unnatural. The woman’s eggs are collected as in IVF and mixed with sperm in vitro. This mixture is then immediately transferred back to the woman’s Fallopian tubes, so that fertilization can occur inside the body. One claimed benefit of GIFT is that the embryo can begin its earliest development in ‘natural surroundings’ rather than in an ‘artificial environment’. It’s not clear that a developing embryo cares in the slightest about this distinction, and indeed GIFT both is more invasive than standard IVF and makes it impossible to select the embryo of best apparent quality from several prepared in vitro. But it’s OK with the church, provided that the sperm is collected using a condom (a perforated, leaky one, mind) in sexual intercourse and not by masturbation – because everything then seems to be happening in its ‘natural’ place, with just a momentary sleight-of-hand involving a Petri dish. This obsession with the ‘proper’ mechanics, notwithstanding the lengths that are necessary here to achieve it, speaks of a deeply strange attitude towards the relation between sex and procreation, not to mention the bizarre and, I should have thought, highly disrespectful notion of a God who watches as if with clipboard in hand (but ready to avert his eyes at the crucial point) to tick off each step when it happens as it ‘ought’.

Generally I want to find ways to respect what people believe. But the Catholic position on IVF is on a par, in its inhumanity, with its position on condom use. If I sound sarcastic about it, please don’t read that as flippancy. It is fury. If these folks could content themselves with expressing their prejudices as blind faith and dogma, I would find it more palatable than if they tried to justify them with idiotic attempts at rational argument. I’m told that “Father Tad... studied in Rome, where he did advanced studies in theology and in bioethics.” I don’t find a shred of ethical reasoning in his comments on embryo research. It is unreason of the most retrograde kind.

Wednesday, March 23, 2016

On the attack

One of the easiest ways to bring humour to music is with timbre. It’s cheap (literally) but still funny to play Led Zeppelin’s “Whole Lotta Love” or Richard Strauss’s “Also Sprach Zarathustra” on kazoo, as the Temple City Kazoo Orchestra did in the 1970s. Most things played on kazoo are funny. It just has a comical timbre.

Such performances inadvertently make a serious point about timbre, which is that it can matter more than the notes. This is overlooked when music is considered as notes on paper. Yet musicologists have largely neglected it, for the simple reason that we don’t really know what it is. One definition amounts to a negative: if two sound signals differ while being identical in pitch and loudness, the difference is down to timbre.

One feature of timbre is the spectrum of pitches in a note: the amplitudes of the various overtones. These are quite different, for example, for a trumpet and a violin both the same note. But our sense of timbre depends also on how this spectrum, and the overall volume, changes over time, particularly in the initial “attack” period of the first few fractions of a second. These are acoustic properties, though, and it might be more relevant to ask what are the perceptual qualities by which we distinguish timbre. Some music psychologists claim that these are things like “brightness” and attack, others argue that we interpret timbre in terms of the physical processes we imagine causing the sound: blowing, plucking, striking and so on. It’s significant too that we often talk of the “colour” of the sound.

Arnold Schoenberg thought it should be possible to write music based on changes of timbre rather than pitch. It’s because we don’t know enough about how the brain organizes timbre that this notion didn’t really work. All the same, Schoenberg and his pupils created a style called Klangfarbenmelodie (sound colour melody) in which melodies were parceled out between instruments of different timbre, producing a mesmeric, shimmering effect. Anton Webern’s arrangement of a part of Bach “The Musical Offering” is the most renowned example.

There’s one thing for sure: timbre is central to our appreciation of music, and if we relegate it below more readily definable qualities like pitch and rhythm then we miss out on a huge part of what conditions our emotional response. It would be fair to say that critical opinion on the music of heavy-metal band Motörhead, led by the late bass guitarist Lemmy Kilmister, was divided. But if ever there was a music defined by timbre, this was it.