Tag Archives: Sabine Hossenfelder

Fusion and Other News – Memory Hole Rescue

Another post on D-Wave is in my blog queue, but with all this attention on quantum computing my other favorite BC based high tech start-up doesn’t get enough of my time – I haven’t written anything on energy and fusion for quite a while, despite some dramatic recent news (h/t Theo) with regards to another dark horse fusion contender.

Fortunately, there is another excellent blog out there which is solely focused on fusion technology and the various concepts in the field. The Polywell is covered in depth, but General Fusion also gets is due, for its innovative technology.

Another focus of mine, the trouble with contemporary theoretical physics also keeps falling through the cracks.  From my past posts one may get the impression that I am just yet another String apostate, but I don’t really have any trouble with String Theory as such, but rather with uncritical confirmation bias. Unfortunately, the latter cuts across all fields as nicely demonstrates in this recent post of hers.

Time for Another Blogroll Memory Hole Rescue

CRA
The Canadian Revenue Agency is the equivalent to the IRS down South. They owe me money and always make me work to get it.

Unlike the US, tax returns in Canada are due by the end of April, but because of the Heartbleed bug, Revenue Canada had to take down electronic filing for a while, so the deadline has been extended a bit.  It seems I may need the extra days as life is keeping me extraordinarily busy. Saturday morning is usually my blogging time, but this weekend I had to look after my kids (my wife Sara was performing Beethoven 9th with the Peterborough Symphony) and today my oldest daughter turned seven, filling the day with Zoo visits and birthday cakes.

At least the bug bought me some more time.

So in order to not completely abandon this blog, a couple of links to other outstanding science musing are in order. To that end I would like to highlight some posts of Sabine Hossenfelder, a blogging physicist professor of theoretical physics currently teaching in Sweden. Her most recent post discusses some of the structural problems in Academia, which in reality is nothing like the commonly held notion of a utopian ivory tower (rather, the tower stands and becomes ever more compartmentalized, but there is nothing utopian about it).

Her post on the Problem of Now makes a nice primer for a long-planned future post of mine on Julian Barbour’s End of Time, because arguably he took “Einstein’s Blunder” and ran with it as far as one can take it.  The man’s biography also ties back to the dilemma of academia, as it really doesn’t  allow much space for such deep, and out of the mainstream, research programs.

Last but not least, I really enjoyed this rant.

And I probably should mention that Sabine also knows how to sing. It obviously takes a physicist to really muster the emotional impact of the agonizing ongoing demise of SUSY.

 

 

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.

Science News that isn’t really News

Usually, I don’t blog about things that don’t particularly interest me.  But even if you are a potted plant (preferably with a physics degree), you probably have people talking to you about this ‘amazing’ new paper by Stephen Hawking.

So, I am making the rare exception of re-blogging something, because already wrote everything about this I could possibly want to say, and she did it much better and more convincingly than I would.

So, if you want to know what to make of Hawking’s latest paper head over to the backreaction blog.

Rainbow_Black_hole_by_Chriall
Stephen Hawking now thinks that there are only grey holes, which is a step up in the color scheme from black. But in honor of the Sochi Olympics, I really think the world needs rainbow colored black holes.

The Unbearable Lightness of Quantum Mechanics

Updated below.

Gravity and Quantum Mechanics don’t play nice together. Since Einstein’s time, we have two towering theories that have defied all attempts by some very smart people to be reconciled. The Standard Model, built on the foundations of quantum mechanics, has been spectacularly successful. It allows the treatment of masses acquired from the binding energies, and, if the Higgs boson confirmation pans out, accounts for the elemental rest masses – but it does not capture gravity. (The current mass generation models that involve gravity are all rather speculative at this point.)

Einstein’s General Relativity has been equally successful in explaining gravity as innate geometric attributes of space and time itself. It has survived every conceivable test and made spectacular predictions (such as gravity lenses).

On the surface this dysfunctional non-relationship between the two major generally accepted theoretical frameworks seems very puzzling. But it turns out that the nature of this conundrum can be described without recourse to higher math (or star-trek like animations with a mythical sound-track).

Much has been written about the origin of this schism: The historic struggle for the interpretation of Quantum Mechanics, with Einstein and Bohr being the figureheads of the divided physics community at the time. Mendel Sachs (who, sadly, passed away recently) drew the following distinction between the philosophies of the two fractions:

[The Copenhagen Interpretation views] Schroedinger’s matter waves as [complex] waves of probability. The probability was then tied to quantum mechanics as a theory of measurement – made by macro observers on micro-matter. This view was then in line with the positivistic philosophy, whereby the elements of matter are defined subjectively in terms of the measurements of their properties, expressed with a probability calculus. […] Einstein’s idea [was] that the formal expression of the probability calculus that is called quantum mechanics is an incomplete theory of matter that originates in a complete [unified] continuous field theory of matter wherin all of the variables of matter are ‘predetermined’.

(From Quantum Mechanics and Gravity)

These days, the Copenhagen Interpretation no longer reigns supreme, but has some serious competition: E.g. one crazy new kid on the block is the Many World Interpretation.  (For an insightful take on MWI I highly recommend this recent blog post from Scott Aaronson).

But the issue goes deeper than that. No matter what interpretation you favor, one fact remains immutable: Probabilities will always be additive, mathematically they behave in a linear fashion. This, despite its interpretative oddities, makes Quantum Mechanics fairly easy to work with.  On the other hand, general relativity is an intrinsically non-linear theory.  It describes a closed system in which the field, generated by gravitating masses, propagates with finite speed and, in a general, non-equilibrium picture, dynamically affects these masses, in turn rearranging the overall field expression.  (Little wonder Einstein’s field equations only yield to analytical solutions for drastically simplified scenarios).

There is no obvious way to fit Quantum Mechanics, this linear peg, into this decidedly non-linear hole.

Einstein considered Quantum Mechanics a theory that would prove to be an approximation of a fully unified field theory.  He spent his last years chasing after this goal, but never achieved it. Mendel Sachs claims to have succeeded where he failed, and indeed presents some impressive accomplishments, including a way to derived the quantum mechanics structure from extended General Relativity field equations.  What always struck me as odd is how little resonance this generated, although this clearly seems to be an experience shared by other theoretical physicists who work off the beaten path. For instance, Kingsley Jones approaches this same conundrum from a completely different angle in his original paper on Newtonian Quantum Gravity. Yet the citation statistic shows that there was little up-take.

One could probably dedicate an entire blog speculating on why this kind of research does not break into the mainstream, but I would rather end this with the optimistic notion that in the end, new experimental data will hopefully rectify this situation. Although the experiment on a neutral particle Bose-Einstein condensate proposed in Kingsley Jones’ paper has little chance of being performed unless there is some more attention garnered, other experiments to probe the domain where gravity and quantum mechanics intersect get a more lofty treatment: For instance this paper was featured in Nature although its premise is probably incorrect. (Sabine Hossenfelder took Nature and the authors to task on her blog – things get a bit acrimonious in the comment section).

Nevertheless, it is encouraging to see such a high profile interest in these kinds of experiments, chances are we will get it right eventually.

Update

Kingsley Jones (who’s 1995 paper paper I referenced above) has a new blog entry that reflects on the historic trajectory and current state of quantum mechanics.  I think it’s fair to say that he does not subscribe to the Many World Interpretation.