The 2016 Nobel Prize in Physics | Hacker News Reader

The 2016 Nobel Prize in Physics

nobelprize.org

201 pointsokket54 comments

For those interested in the Soviet / Ukranian scientist who was part of the discovery and for whom the transition(BKT) is also named- Vadim Berezinskii

He passed away in 1980, here's his obituary: http://ufn.ru/ufn81/ufn81_3/Russian/r813k.pdf

It's all in Russian. Does it say why he died so young?

It just mentions a "lengthy serious sickness". Other sources (e.g. <https://snob.ru/selected/entry/114493>) mention him being seriously ill for at least three years before his death...

Some will be disappointed that this year's Prize was not awarded to Ronald Drever, Kip Thorne, and Rainer Weiss, in recognition of their work on LIGO. Ronald Drever is in poor health and there are some who fear that, despite being deserving of a Nobel Prize, he may never receive one.

Nobel's will actually directed that the prize to go "those who, during the preceding year, shall have conferred the greatest benefit to mankind" by a discovery or invention. The previous-year part isn't even mentioned on the Wikipedia page. (I get that it's hard to judge.)

https://www.nobelprize.org/alfred_nobel/will/

Isn't the "previous year" part usually interpreted to mean that the benefit is in the past year, rather than the work being done in the past year?

I don't know; I wondered about that too. But this proviso hardly seems to come up at all in what I read, and that's interesting -- I wonder how often unusual wills get carried out to the letter.

I believe on Wikipedia it is mentioned that the price was originally awarded soon after the discovery. However, after several occasions where a discovery awarded the Nobel price was later invalidated Kama they switch to the present practice of interpreting it as the benefits becoming clearer in the past year, rather than the discoveries.

Thanks for pointing that out -- the relevant section is the middle: https://en.wikipedia.org/wiki/Nobel_Prize#Recognition_time_l...

I believe the announcement of the Black Hole discovery came after the nominations for the Nobel had closed.

Correct. Still this was a disappointment.

From the article:

> The three Laureates’ use of topological concepts in physics was decisive for their discoveries. Topology is a branch of mathematics that describes properties that only change step-wise.

I've never heard topology characterized that way. Typically I think of it as dealing with connection properties—sort of a more abstract geometry where objects can be considered the same even if their shape changes; identity is only defined by which parts are connected to which.

Could anyone elaborate on the 'step-wise' change aspect from the article?

In the context of physics, topological phases of matter often reveal themselves by causing certain quantities that are usually continuous to change in discrete steps instead. A key example is the electrical conductivity of certain quantum Hall effect systems, which jumps in discrete steps (is "quantized" in physics jargon) as an ever stronger magnetic field is applied to the system in a transverse direction.

The connection to the donut/bagel thing more familiar in topology is that topology also deals with integers: a manifold can have 0,1,2,3... holes in it, that sort of thing.

One key mathematical quantity that comes up in the works of Thouless and Haldane is the Chern number https://en.wikipedia.org/wiki/Chern_class

The reason the physics quantities jump is that the Chern numbers of certain electron bands change, and by definition a Chern number is an integer.

That sounded odd to me also. Maybe they are referring to a tear/cut that would change an object's topology. Like taking a bite from a donut changes it from a torus to a sphere. That break is not a continuous change, more "step-wise".

Can anyone recommend a "cannonical" textbook that describes K-T transitions at an upper-year undergraduate level?

Thouless himself wrote one:

https://books.google.com/books/about/The_Quantum_Mechanics_o...

It doesn't assume graduate level physics.... but it may be a bit advanced for undergraduate. I can't recall.

Fixed link: https://goo.gl/ay9KEi

Reader needs to be familiar with non-relativistic quantum mechanics + statistical mechanics.

Fractioning the prize off to me seems silly. A half, a quarter, and a quarter. Why not just have three winners? Is this purely to deal with prize money distribution? Surely there's a more elegant solution.

It is according to Alfred Nobels' will. It can not be divided further than half and half of one half.

Not true.

Many times it's divides in thirds.

Here it wasn't because someone (in my opinion correctly) decided Kosterlitz and Thouless deserved less money.

Sometimes it's divided in thirds. Here it was decided to go the other route 1/2 + 1/4 + 1/4

I still remember my condensed matter professor saying "The Kosterlitz-Thouless transition is the most important discovery in physics in the second half of the 20th century". Surely partly motivated by professional bias, no doubt, but there's still merit to the claim. If you believe that "all physics is either harmonic oscillators or phase transitions", the Kosterlitz-Thouless is the first example (I believe) of a phase transition that does not contain a local order parameter. Because of that certain materials proved illusive to all mathematical models of the time.

Related: Onsager received the 2000 Nobel Prize in Physics, also for 2D phase transitions. Trivia: Onsager was a Chemist! :D

EDIT: I believe this is the original paper: http://iopscience.iop.org/article/10.1088/0022-3719/6/7/010/...

FYI, Wikipedia page about the Kosterlitz–Thouless transition:

https://en.wikipedia.org/wiki/Kosterlitz%E2%80%93Thouless_tr...

I expect that article will see lots of improvement in the coming weeks/months.

Good. It's one of those bloody articles that requires a layman to read all of the attached articles, two or three links deep, to have any chance of understanding just the parts without mathematical formulae.

And before anyone accuses me of wanting to dumb down Wikipedia: yes, that's exactly what I want. Wikipedia should be written to a generalist audience, not by specialists for specialists.

edit: I can't say it any better than this article: https://scholarlykitchen.sspnet.org/2012/09/24/wikipedias-wr...

> Wikipedia should be written to a generalist audience, not by specialists for specialists.

Until this has been done (feel free to help), I prefer that the specialists view is in place, rather than nothing. Or worse, a tabloid one sentence placeholder.

Exactly. And furthermore, the more niche and complex a topic is, the smaller the pool of people qualified to massage a specialist topic into a generalist audience.

I disagree. With anything technical, there's going to be many ways to explain it, and the best way depends on the audience. I don't think every article should be written for the same audience. Some pages will likely be visited by all sorts of people, and some only by experts. If you're writing for experts and don't assume they already know a bunch of things, it's going to be many times less concise and clear than it should be. You would have to repeat fundamental math and physics education on every page like this one if you wanted to explain to a general audience.

An article like "Kosterlitz–Thouless transition" is not even being seen by a general audience anyways, except for when some news-worthy event like this happens, so why write like it's being read by someone it's not? It's not like writing this stuff is easy.

>It's one of those bloody articles that requires a layman to read all of the attached articles

I don't see why this is a bad thing. I often do this for fun, and when I do it's never information I need to get on in my day to day life. These are extremely complex topics. If you don't want to understand them in their complete complexity, do you really want to understand them at all? What's the point of dumbing down a subject for the layman if the subject can't really be understood at that dumbness level?

The problem is that there's no way to know whether your search process is going to terminate in a path from what you understand to what you don't understand, or if it's just going to wander around in specialist subjects, each referencing each other, with no obvious way back down to non-specialist topics. Or, potentially, no way at all. For all you know the "explanatory links" on a given specialist topic actually point to topics that are yet more specialist.

My dream someday is to see these things organized into a "lattice", where links are clearly labeled as going "down" or "up" the lattice and you can have a clue what's going on.

Something not entirely quite unlike this http://matpalm.com/blog/2011/08/13/wikipedia-philosophy/

Not every topic can practically be reduced to a layman-friendly explanation.

Physics is complex man, what did you expect. If you know nothing, you need to learn a lot in order to even understand their starting point.

And regarding wikipedia articles, there's two big design alternatives: for each article you either write into it all the necessary background, or instead link to the necessary background in different articles. I suspect that the modus operandi that wikipedia has chosen is that you should do the former for mainstream topics and the latter for niche topics.

Here's a complex biology article that contains a lot of technical terms and links, yet still manages to be readable to a general audience: https://en.wikipedia.org/wiki/Leaf

I get the feeling that most math-involving Wikipedia pages are simply compound regurgitations of various textbooks.

> you need to learn a lot in order to even understand their starting point

This is kind of a cop-out. In the coming days there will be reams written on these laureates in the scientific press, much of which will be more enlightening, informative and contextually relevant than the dedicated encyclopaedia article.

Although even that Leaf article highlights some unfortunate Wikipedia tendencies such as the tendency to unnecessarily insert pseudo-academic jargon. Take the third sentence: "Foliage is a mass noun that refers to leaves collectively." With two footnotes even. This could easily have been worded as something along the lines of "Leaves are collectively referred to as foliage, as in "autumn foliage."

Except the former shows that "mass noun" is a thing. And indeed the phrase was a hyperlink to a fascinating page discussing the concept. Unfortunately, somebody took your criticism to heart and changed the page to your formulation

  https://en.wikipedia.org/w/index.php?title=Leaf&type=revision&diff=742673936&oldid=741796479

excising the hyperlink in the process.

Your phrasing would be better were Wikipedia not a hyperlinked encyclopedia. Because Wikipedia is a hyperlinked encyclopedia, it's perfectly acceptable and even preferable to use stilted phrasing when it benefits the concise exposition of related concepts.

In law school we were taught that it's preferable to use simple English phrasing--so-called plain language--in legal writing, and to avoid terms of art. But look at what that has wrought in reality--legal instruments that are dozens of page longer than necessary, more often than not with dictionaries prepended. They're more inscrutable than ever, and arguably more difficult to approach for both layman and jurist.

Archaic legal writing relied heavily on terms of art. Terms of art, IMHO, provided many benefits, including 1) concision, 2) consistency, and 3) signaling. Concision because terms of art are a way to reference more complex concepts that you don't need to spell out. Consistency because widespread use of terms of art meant that there was only one way to say something; if you used other phrasing it was presumed you meant something different than what was meant by a related term of art. And signaling because using a term of art made it clear and obvious you were referring to some concrete legal concept, even if the reader wasn't familiar with it.

Notably the shift to "plain language" legal writing did not in the least change expectations in the legal community regarding the consistency and signaling aspects of legal language. Today, instead of using terms of art, lawyers literally copy+paste whole blocks of long-winded clauses.

IMO, all three of those aspects--concision, consistency, and signaling--should likewise be emphasized in an encyclopedic text, _especially_ in the context of hyperlinked text.

Different contexts require using language differently. You wouldn't criticize a musician for using a different style of prose, right? It's not just the medium that dictates how we phrase things, but the context and function of the communication.

>In the coming days there will be reams written on these laureates in the scientific press, much of which will be more enlightening, informative and contextually relevant than the dedicated encyclopaedia article.

In my experience, the scientific press usually does not know what they are talking about, and relying on them for enlightenment or information is dangerous.

> I get the feeling that most math-involving Wikipedia pages are simply compound regurgitations of various textbooks.

You are absolutely right, because writing quality original work takes effort, and writing quality original maths work takes 100x more effort.

> This is kind of a cop-out

Call it whatever you want, but the fact remains that some subjects are more complex than others. Complex matters take more effort to write about, and there's fewer people qualified to write about them. When these two factors come together, you see regurgitated stuff. If you think that everything is equally simple if you explain it the right way, you're sorely mistaken about the nature of reality.

All this reminds me that I shouldn't be spending my own effort on HN :D

He didn't really say nor imply it'd take an equal amount of effort.

I 100% agree about wikipedia and math/physics topics. They give the distinct impression that either 1) The person writing them does not understand the topic or 2) The people working on the topic are not doing anything connected to reality.

However, I must disagree with your claim that the scientific press will do better. As part of their coverage of the physiology prize they made up a new term "cell recycling" that will waste the readers time when they try to look up what it is about. As long as they are technically correct, the math wikipedia pages are at most useless.

I think the main issue here is not so much in choosing between including every prerequisite in every page or not, but in adding a meta-level of information that allows people to consume the prerequisites more easily.

When you open a Wikipedia article about a complex subject, it's expected that you're going to do a lot of background reading.

The problem is that you start surfing Wikipedia with a BFS/DFS approach, when it would be a lot more efficient if the articles were organized more systematically to lead to a gradual understanding of the subject.

I'm intrigued by your quote "all physics is either harmonic oscillators or phase transitions". Could you please elaborate on that? Just looked up online sources but can't seem to find this quote anywhere.

Consider a system that is slightly perturbed from its resting place. If it returns to its previous resting place it's a (damped) harmonic oscillator (or an infinite collection of them = a free field). If it doesn't, and it looks different than before, then it underwent a phase transition described by Landau-Ginzburg theory.

Obviously this is not exhaustive. But it gets you further than you naively think it should. Let's look at the harmonic oscillator, why is the thing probably a harmonic oscillator? Well the potential is typically an analytic function, and we are near a resting point, so the linear order in the Taylor expansion vanishes and the potential is approximately V(x) ~ x^2. Harmonic oscillator.

Say you want to look at a quantum field theory. Well actually defining one is hard. The only case where we know how to is for a free field theory. And a free field theory is actually a collection of harmonic oscillators.

Now interacting QFT, which underlies all of observed matter, is built by gluing together harmonic oscillators in a clever way. You know Feynman diagrams? The lines in a Feynman diagram represent the particle behaving as if it was made up of independent harmonic oscillators (free field). At the vertices we just bump the harmonic oscillators around a bit. So standard QFT is a very clever shuffling around of harmonic oscillators (lots of group representation theory organises the shuffling, and several Nobel prizes worth of physics are contained in the details).

Obviously there is plenty of physics that does not fit into either of these paradigms (GR, non-linear dynamical systems, atomic and molecular physics). But they both are utterly fundamental and enormously powerful tools in two very prominent branches in physics: High energy and condensed matter.

Another way to put it would be that "all physics is either perturbative or non-perturbative", although this one doesn't sound as catchy since it is transparently a tautology ;-)

Nitpick: Onsager died in 1976 [1]. Also, his Nobel citation credits his work on reciprocity relations [2] and, I suppose, by extension regression hypothesis and what we would now call fluctuation-dissipation theorem. His solution of the 2d Ising model was not mentioned (though to be sure a tour de force).

[1] https://en.wikipedia.org/wiki/Lars_Onsager

[2] http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1...

Sorry, I must've gotten confused at some point.

I actually always thought the same, and finally checked one time. Of course Onsager did many great things, it's hard to say what he should have gotten a Nobel for.

It would be an exaggeration, but not by much, to say I was crying tears of joy at my desk this morning.

Onsager wasn't alive in 2000.

If you want to get a start on understanding this, try considering the problem of BEC in 2D. The same logarithmic (algebraic, that is to say not exponential) divergence in that integral is at the heart of the BKT transition.

http://mecklenburg.bol.ucla.edu/kosterlitz%20and%20thouless%...

full text

I'm curious, who was your professor?

Professor at a third-world country University, you wouldn't know him.

For the lazy:

> British trio win Nobel prize in physics 2016 for work on exotic states of matter

> Prize to be shared by David Thouless, Duncan Haldane and Michael Kosterlitz...

> ...in the field of condensed matter physics. They discovered totally unexpected behaviours of solid materials - and came up with a mathematical framework (in the field of topology) to explain these weird properties. The discoveries have paved the way for designing new materials with all sorts of novel properties.

> Topology, which was central to this year’s discoveries, explains why electrical conductivity inside thin layers changes in integer steps. Kosterlitz and Thouless studied the electrical behaviour of surfaces or inside extremely thin layers (physicists call these two-dimensional materials). Haldane studied matter that forms threads so thin they can be considered one-dimensional.

https://www.theguardian.com/science/live/2016/oct/04/nobel-p...

Perhaps this will open up new ways to build microprocessors and other semiconductor electronics?

There's a live stream here: https://www.youtube.com/watch?v=9qpoBG5hy-A

8 minute Interview with a Nobel Committee member (Thors Hans Hansson) about the prize and the science behind it:

https://twitter.com/NobelPrize/status/783253434044600320

Reply on news.ycombinator.com