Learn #4 – Week 118 of PhD *Late

♪♫ It’s the most wonderful time of the year…♪♫

Oc(Ink)tober is just finished, Christmas lights start covering the city and I finally get sometime to go back on track with my duty to communicate science to friends (as well as keeping a diary of notions I learn so I feel like I value my time).

It was the beginning of October the last time we met, and what happened next was a week plenty of exciting science: Nobel!!! Let’s learn (briefly) who won, plus (to make up for the delay), a list of associated curiosities.

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Medicine Nobel Price to Y. Ohsumi for his discoveries about autophagy! *clapping hands*

The importance of autophagy wasn’t never undestood before Prof. Ohsumi decided to dedicate his life to the subject; now we know that not only is a crucial mechanism the cells employ in case of stress, above all when starving, in order to recycle material, but that it’s going on continuously at basal level, being the only mechanism capable to degrade certain type of organelles in the cells, keeping the cell, unlike my desk, clean and tidy.

Since autophagy can refers to organisms eating part of their own body, I want you to know that Octopus can sometime devote themself to the practice. Since they are quite intelligent creatures, we humans decided to attribute the reason to human-society-related problems, like stress (always the first reason for autophagy apparently despite the scale) or boredom, just to later discover that most likely the major cause is actually an infectious disease!

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Physics Nobel Price to D. J. Thouless (1/2), J. M. Kosterlitz (1/4) and F. D. M. Handane (1/4) for their theoretical discoveries of topological phase transitions and topological phases of matter! *take-breath-again-after-long-title*clapping hands*

To make my life difficult, the Nobel committee decided to attribute the price for theoretical discoveries (not my strong side). Nevertheless, as a material scientist I am in a good position to appreciate the importance of this trio discoveries, and I’ll do my best to transfer this to you! The moment I heard the news, my first thought flew to the Quantum Hall Effect. The Hall effect describes the production of a Voltage across a conductor transverse to an applied current when a magnetic field is applied perpendicularly to the plane. When you reduce the dimensionality of the system, and you go to a perfectly 2D material, then the conductance of the material takes values that are integer multiples of the squared charge of an electron divided by the Plank constant. This discovery was worth of a Nobel prize (Klitzing) well before its understanding. In fact, it was accepted that the experimental plateaus observed at the quantizised value of the conductance were reflective of the Landau levels in a the material. But, observed the level of accuracy of the quantum Hall values, this argument should be valid only for very pure materials, since defects would spread the width of such levels. So what make the conductance value so precise, despite using real materials? Well, apparently topology. I did no go through all the math, but visually you can think at the electron moving in the 2D lattice, or you can think in terms of its momentum that in this case would lie on the surface of a torus. Using the right math at this point, you my dear smart reader will find out that conductance is multiplied by a topological invariant (Chern Numbers), that just depends on the geometrical properties of the system.

While looking for good ways to explain this, and to be honest looking for good ways to understand this myself, I found out that a must-be-relative of Sheldon Cooper bestie, Prof. D. Hofstadter (yes! the son of the Nobel Laureate Hofstadter) has introduced a stunning representation of the electron states in a magnetic potential, where each color indicates a quantum Hall integer  (pictured). I am mentioning this because, beyond the fact that the butterfly makes a beautiful header for the day, I also found out that his inventor is also the author of Gödel, Escher, Bach: An Eternal Golden Braid, a book I left dusting on my shelves since my husband had bought it, sure it was one of the essay on productivity and successful stories he buys for personal development. Now I know is a book about consciousness and cognitive processes (ignorant me – I should have known already!), written by someone with a PhD in Physics. Guess what? It rapidly escalated my reading list.

Back to this year Physics Nobel, I mentioned maybe one of the most boring example to talk about topology, but if picking some other example of the universality of topology I would have ended mimicking some of the beautifully written material I came across in the last days, that I would recommend you to have a look at:

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Chemistry Nobel Price to J. P. Sauvage (1/3), J. F. Stoddart (1/3) and B. L. Feringa (1/3) for the design and synthesis of molecular machines! *more clapping hands*

I am not the sport-kind, but I do love to watch car races. Best if nano-cars races! While, I am sure, the world is in palpitation for this event to occur next spring and chances are the internet will fail because of the traffic during the live broadcasting of this grand-prix (jokes aside, I am probably going to be tuned in with a cheering t-shirt once I have figured which team to cheer for), we have to thank these new Nobel Laurates if we can have this race at all.

In fact it is thanks to Sauvage if we have the first building blocks that have opened the field to new exciting ideas: catenanes, molecular chains obtained by mechanical links between molecules rings – the mechanical part is the exciting part that results in independent moving parts of more complex molecules. Funny digression, catenes have been used to explore the area of topological chemistry (hurrah for thematic Nobels!), with molecular version of trefoil knots, Solomon’s knot and Borromean rings. Stoddart did not let the idea slip his mind, and jumped on the next step towards nano-cars: rotaxanes, molecules in which one part is able to slide on another part of the molecule in a controlled way. We have independent parts, we have movement: the only thing we miss to have our nanocars is directionality. But Feringa designed a molecules that could rotate only in one direction when activated with UV light because of ratchet snipping of its part (preventing the other direction motion). Put 4 of those to a tiny molecular chassis and you have the first nano-cars!

*disclaimer: catenanes and rotaxanes weren’t invented by Sauvage and Stoddart, but they were the first to synthesis them with high yields.

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The random facts about (Physics)-Nobel Prizes                

Or everything you always wanted to know about  sex  Physics Nobel Prize* (*But were afraid to ask)

  • The section of the history of Nobel Prize in Physics starts with “What is Physics?” (it is also a nice tale on the evolution of physics!)
  • If I fail to get my name on the Nobel prizes pages as a physicist, I can still make it with my B career plan: every Nobel diploma has a unique artwork. — In the picture, left to right, top to bottom, are the following Nobel Diplomas artworks: Cohen-Tannoudji’s (Nobel 1997: Atoms cooling and trapping – shared with Chu and Phillips); Cornell’s (Nobel 2001: Bose-Einstein condensation – shared with Ketterle and Wieman); Higgs’ (Nobel 2013: Higgs particle – shared with Englert); Kajita’s (Nobel 2015: Neutrinos Oscillations – shared with McDonald); Kilby’s (Nobel 2000: heterostructures and integrated circuits – shared with Alferov and Kroemer); Novoselov’s (Nobel 2010: Graphene – shared with Geim); Gross’ (Nobel 2004: Strong Interaction – shared with Politzer and Wilczek); Smith’s (Nobel 2009: Optical fibers and CCD – shared with Kao and Boyle); Haroche’s (Nobel 2012: Ions trap and quantum optics – shared with Wineland); Laughlin’s (Nobel 1998: quantum fluid with fractionally charged excitation [fraction quantum Hall effect] – shared with Stormer and Tsui); Ginzburg’s (Nobel 2003: superconductors and superfluids – shared with Abrikosov and Leggett); Giacconi’s (Nobel 2002: cosmic neutrinos and cosmic X-ray sources – shared with Davis and Koshiba); Kobayashi’s (Nobel 2008: families of quarks – shared with Nambu and Maskawa); Hooft’s (Nobel 1999: Electroweak interactions – shared with Veltman); Nakamura’s (Nobel 2014: Blue LED – shared with Akasaki and Amano); Riess’ (Nobel 2011: Universe expansion – shared with Perlmutter and Schmidt).
  • Latin makes everything sounds more important. But jokes asides, the inscription on the medal, taken from Virgilio’s Eneide, is really beautiful:

Inventas vitam iuvat excoluisse per artes – And they who bettered life on earth by their newly found mastery

  • Particles physics rocks! With the highest number of Nobel Laureates – followed by a tied second place for Atomic Physics and Condensed Matter (\m/), with their 28 Nobels each, and Instrumentations that takes a third place with 21. No Nobel prizes for biophysics, to mock me and remind me that what I do does not probably exist.
  • There are only 6 people/organisation that have been awarded the Nobel prizes multiple time. The only one with a double in Physics is Bardeen, famous for its contribution to transistor and to superconductivity (Yeah!! more phase transitions!)
  • Physics is a family matter! There are 5 couples of family related members that have both received the Nobel prize for physics: the highest number among the family laureates (14 couples in total, but just few of them have been awarded the prize for the same field).
  • lasergameLeast, but not the last, the Nobel Prizes website is plenty of surprises, like the multitude of flash games provided. And although same could have been more relevant to this year Nobel prize (like the ones about liquid crystals), my favourite by far is the laser challenge game, and not only because I work with lasers, but mainly because the aim of the game is to organize a party!

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Although Friday should be a joyful day, the 7th of October was that just partially. That day the Peace Nobel prize was awarded to Juan Manuel Santos, president of Colombia (pictured: Cartagena, Colombia) for his effort to restore the peace between the government and the guerrilla forces that have being fighting each others for more than 50 years. The bitterness of the award comes from the fact that despite the fact that an agreement was obtained in June 2016, on the 2nd of October the people of Columbia decided not to ratify the peace accord, voting against 50.2% to 49.8% in the agreement referendum.

I don’t know what are the reasons behind voting in favor of a war, what are the priorities of citizens that would not mind more people killed, what are the feelings that grave on people that have to take such a thorny matter, nevertheless I feel sad for the outcome and for that nearly half of the population that wanted to end the civil war. Because my personal opinion is that if there is a decision that would spare life and another that could results in more killing, then there should be no choice.

Sorry for the bitter ending of the post, but LEARNing sometimes can be a painful process.. and those occasions are often the most important!

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