Tag Archives: Peter Woit

He Said She Said – How Blogs are Changing the Scientific Discourse

The debate about D-Wave's "quantumness" shows no signs of abating, hitting a new high note with the company being prominently featured on Time magazine's recent cover, prompting a dissection of the article on Scott Aaronson's blog. This was quickly followed by yet another scoop: A rebuttal by Umesh Vazirani to Geordie Rose who recently blogged about the Vazirani et al. paper which sheds doubt on D-Wave's claim to implement quantum annealing. In his take on the Time magazine article Scott bemoans the 'he said she said' template of journalism which gives all sides equal weight, while acknowledging that the Times author Lev Grossman quoted him correctly, and obviously tries to paint an objective picture.

If I had to pick the biggest shortcoming of the Times article, my choice would have been different. I find Grossman entirely misses Scott's role in this story by describing him as "one of the closest observers of the controversy". Scott isn't just an observer in this. For better or worse he is central to this controversy. As far as I can tell, his reporting on D-Wave's original demo is what started it to begin with. Unforgettable, his inspired comparison of the D-Wave chip to a roast beef sandwich, which he then famously retracted when he resigned as D-Wave's chief critic. The latter is something he's done with some regularity, first when D-Wave started to publish results, then after visiting the company and most recently after the Troyer et al. pre-print appeared in arxiv (although the second time doesn't seem to count, since it was just a reiteration of the first resignation).

And the say sandwiches and chips go together ...Scott's resignations never seem to last long. D-Wave has a knack for pushing his buttons. And the way he engages D-Wave and associated research is indicative of a broader trend in how blogs are changing the scientific discourse. For instance, when Catherine McGeoch gave a talk about her benchmarking of the DW2, Scott did not immediately challenge her directly but took to his blog (a decision he later regretted and apologized for). Anybody who has spent more than five minutes on a Web forum knows how the immediate, yet text only, communication removes inhibitions and leads to more forceful exchanges. In the scientific context, this has the interesting effect of colliding head on with the more lofty perception of a scientist. It used to be that arguments were only conducted via scientific publications, in person such as in scientific seminars, or the occasional letter exchange. It's interesting to contemplate how corrosive the arguments between Bohr and Einstein may have turned out, if they would have been conducted via blogs rather than in person. But it's not all bad. In the olden days, science could easily be mistaken for a bloodless intellectual game, but nobody could read through the hundreds of comments on Scott's blog that day and come away with that impression. To the contrary, the inevitable conclusion will be that science arguments are fought with no less passion than the most heated bar brawl.

During this epic blog 'fight' Scott summarized his preference for the media thusly

"... I think this episode perfectly illustrates both the disadvantages and the advantages of blogs compared to face-to-face conversation. Yes, on blogs, people misinterpret signals, act rude, and level accusations at each other that they never would face-to-face. But in the process, at least absolutely everything gets out into the open. Notice how I managed to learn orders of magnitude more from Prof. McGeoch from a few blog comments, than I did from having her in the same room ..."

it is by far not the only controversy that he courted, nor is this something unique to his blog. Peter Woit continues the heretical work he started with his 'Not Even Wrong' book, Robert R. Tucci fiercely defends his quantum algorithm work when he feels he is not credited, Sabine Hossenfelder had to ban a highly qualified String theory troll due to his nastiness (she is also a mum of twins, so you know she has practice in being patient, and it's not like she doesn't have a good sense of humor). But my second favorite science blog fight also occurred on Scott's blog when Joy Christian challenge him to a bet to promote his theory that supposedly invalidates the essential non-locality of quantum mechanics due to Bell's theorem.

It's instructive to look at the Joy Christian affair and ask how a mainstream reporter could have possibly reported it. Not knowing Clifford algebra, what could a reporter do but triangulate the expert opinions? There are some outspoken smart critics that point to mistakes in Joy Christian's reasoning, yet he claims that these are based on flawed understanding and have been repudiated. The reporter will also note that doubting Bell's theorem is very much a minority position, yet such a journalist not being able to check the math himself can only fall back on the 'he said she said' template. After all, this is not a simple straight forward fact like reporting if UN inspectors found Saddam Hussein's weapons of mass distractions or not (something that surprisingly most mainstream media outside the US accomplished just fine). One cannot expect a journalist to settle an open scientific question.

The nature of the D-Wave story isn't different, how is Lev Grossman supposed to do anything but report the various stances on each side of the controversy? A commenter at Scott's blog was dismissively pointing out that he doesn't even have a science degree. As if this were to make any difference, it's not like everybody else on each side of the story doesn't boast such degrees (non-PhDs are in the minority at D-Wave).

Mainstream media reports as they always did, but unsettled scientific questions are the exception to the rule, one of the few cases when 'he said she said' journalism is actually the best format. For everything else we fortunately now have the blogs.

When Popular Science is Neither Science nor Popular

This is a detour from my usual subject of quantum computing due to the unusual media attention that the story of faster than light neutrinos caused.

As was to be expected this brought out the special relativity detractors in droves. Usually my attitude towards this crowds is similar as depicted here in this xkcd strip:

xkcd's take on faster than light neutrinos

Yet, I think this is symptomatic for a broader problem: I am convinced that when it comes to popular science, modern physics has utterly failed the public. TV science shows with fancy CGI graphics that somehow are supposed to make string theory and dark matter plausible don’t really help.

By often presenting untested theories such as super-strings as factual they rather help to undermine trust in the entire endeavor. Then there is the obsession with not using math at all cost because it might hurt the sales of the pop science product. Thus leaving us with the overuse of vague, yet seemingly overbearing terminology and strained metaphors. Great, if meant as material for techno babble on Star Trek but a sorry excuse for supposedly “scientific truth”.

This leaves the lay person very vulnerable when it comes to assessing any claims about physics.  Rather than trying to sell the public on the latest scientific pet theory I wished the media would go a bit meta and facilitate a better understanding of what actually makes good science.  For instance by exploring the question what criteria a physics theory should fulfill.

Most people are quite familiar with the concept of falsifiability by experiment, but few contemplate where the power of a good theory comes from: Reduction to plausible first principles that drives a drastic increase of the domain of applicability. Or to state it like Kurt Lewin, in a much more straightforward and less abstruse manner: There is really nothing as practical as a good theory.

And it better be good. Way back, when I was a full-time physics student, I was struck by how much more experimental physicists seem to be satisfied with their lot in life. I only met a single career theoretical physicist who appeared genuinely happy and content (he was one of the great ones and close to retirement). He explained it to me like this: "As an experimentalist chances are you can constantly make some incremental progress. Fixing hardware, eliminating some systematic errors, coming up with some new creative ideas of how to probe for a specific effect. Chances are as an experimentalist you will experience positive feedback from your work quite regularly. It also helps that you often get to work hands-on. A theoretical physicist on the other hand can count himself lucky if he has just one eureka moment in his life. And even then it might turn out your insight was plainly wrong. Experimental physicist win any which way – any result is a good result.”

Einstein once said "Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction." And moving it in the opposite direction is exactly the hallmark of a good theory.  But this reduced complexity doesn’t necessarily make understanding nature any easier. To illustrate this, let’s pick an example that pre-dates modern physics:

Newtonian physics requires several not immediately obvious first principles (axioms) i.e. his famous three laws:

  1. Inertia
  2. Force is proportional to acceleration
  3. Action equals reaction

These principles are anything but obvious in everyday live. They had to be distilled from carefully conducted and idealized experiments (after all Newton didn’t have access to a perfect vacuum).

Now consider that these principles can be replaces by far more immediately plausible first principles:

  1. Time and space are homogeneous and the latter also isotropic. This is just a fancy way of saying that experiments behave the same if we move them to a different place and time. For instance a pendulum on the moon would have swung the same way thousands of years ago as it does today.
  2. The principle of least action – in colloquial terms: The system follows the path of least resistance or to be more precise it gets from point A to B with the least amount of reshuffling of energy. For instance from kinetic to potential energy in the case of a pendulum.

So why did Newton not start with these simpler and more self-explanatory principles? No doubt he was a genius, and he invented Calculus to present his theory of mechanics, but he inconveniently didn’t get around to the Calculus of Variations. So he didn’t have the mathematical tools required to derive classical mechanics from these more fundamental first principles.

I turned out that this superior Hamiltonian approach to mechanics was so immensely successful and elegant in its mathematical execution that after it ran its course a young Max Planck was told he’d be silly to want to pursue a career in physics – obviously everything was already known.

A good physics theory works a bit like a good lossless compression algorithm. You have to remember much less to derive all physics laws but you have to work harder to get there the more advanced the theory is.

This is our first important criteria to judge the merits of a theory.

It not the only one though. Another important one is nicely laid out by David Deutsch in this TED talk:

In a good theory every piece and part is needed - it cannot be easily varied to accommodate different outcomes.

So let’s see how some theories fare against these criteria.

For instance Special Relativity can be derived from the same principles as Hamiltonian mechanics when adding group properties for the allowed spatial transformations i.e. reversibility and requiring that applying several transformations result in the same class of transformation. It can then be mathematically shown that only the Galilean and the Lorentz transformations satisfy these axioms. A great paper demonstrating this, while only requiring high school level math, was published in 1976.

Yet, more than thirty years later Special Relativity is still mostly taught in the same convoluted way that Einstein originally established the theory. (Very doubtful that Einstein would still teach it that way if he was still around).

To get to General Relativity requires just one more axiom: The equivalence principle that states that effects of acceleration and gravity are locally indistinguishable. Following this through with mathematical rigor is beyond the scope of high-school math, but contrary to popular believe it is really not that complicated. After all it’s the same math that underlies our ability to produce reasonably accurate maps of our curved planet.

General Relativity therefore satisfies my quality criteria: It can be derived from first principles.

How about the David Deutsch criteria? It satisfies that as well, what follows from the axioms doesn’t allow for any wiggle room. Einstein stumbled over this himself when he introduced the unmotivated cosmological constant to his field equations, because he just couldn’t believe that an expanding universe made any sense.

In summary:

  1. It is well tested
  2. Follows from first principles
  3. Can’t be easily varied to accommodate different results.

Now, let’s contrast this with what is considered to be the leading contender for a unifying theory: After decades of research super-string theory produced not a single testable prediction, there is no known approach that’ll allow super-string theory to be derived from first principles and the theory is notorious for being tweakable to accommodate for different results.

Thankfully, there has been an entire book written about this colossal failure on all counts.

Nevertheless, this hasn’t really reached the public sphere where super-string theory is still often presented as the current factual understanding of the universe rather than the Standard Model.

This growing befuddlement of the public with regards to the state of contemporary physics theories comes at an inopportune time. Long gone are the days of the cold war when particle physics was always funded - no questions asked.

With the Higgs Boson hunt sold to the public as the main motivation for CERN's supercollider I fear that physics may be confronted with a major credibility crisis if this search comes up empty.  A crisis fully self-inflicted by selling untested theories as factual.