Posts in category Other funny things
Lesbos
is where I came from after a week of vacation with my yongest son. I’m positively charmed with the island that is still pretty wild and hardly inhabitant just in a mile or two from standard touristic places. Swinning is unpleasant and may be dangerous: yet the beaches are natural. We tramped dusty paths in hills, soaked in hot springs, broke shoes in narrow streets of traditional and less traditional villages, went to barren part of the island to venerate petrified trees and Sappho birth place…
All usual, yet natural.
Hans Schumacher
from Physikalisch-Technische Bundesanstalt Braunschweig, German metrology center, gave a talk today. The main direction of his research is to make a practical electric-current standard that uses electron counting in Coulomb blockade regime. Many teams, including that in Delft, have attempted this 20-15 years ago but have to stop. Hans Schumacher boldly took the road that has considered to be a dead end and has demonstrated to us a significant progress as well as a hope for even further progress. I like his strive very much and wish him best sucsess.
That was positive and encouraging part of the talk. There was also a negative and dissapoinig part. It appears that the physical factor that stopped the research 15 years ago – undesired co-tunneling processes – has been completely forgotten today. At least the speaker could not give correct esimations of the precision limitations owing to this factor, and I suspect that people helping him did not think about it too. Find this outrageous since the factor has been discussed in the literature in quite some detail and presents common knowledge in quantum transport. I suggest that the authors, invoved editors and especially anonymous referees of
Phys. Rev. Lett. 104, 186805 (2010)should immediately attend my master course in quantum transport. This seems the only way to restore the continuity of scientific progress:)
Exam Quantum Transport: results
I will leave for vacations soon. In order not to dissappoint the sudents with the delay of the marks, I had to check the exam papers of quantum transport quickly. I’ve worked over the weekend and finally done the job today.
The exam consisted of two parts: the problem and multiple-choice questions (mcq). Roughly, problem checks the attendance of problem-solving sessions, while mcq check if a student has re-read the lecture material before the exam:) The mcq are very accurate tool: in many cases, I can see at which lecture a student stopped re-reading of the lecture material.
The distribution of the answers to mcq was rather standart, perhaps with the maximum slightly larger than expected. However, there was a problem with the problem.
Let me explain the problem without formulas. There are two ways to solve scattering problems considered in the course. Way 1 employes summation of elementary scattering trajectories, is easy and constructive for elementary setups, but is too complicated for just a bit more complex situations. Way 2 is more formal: it requires to make a system of linear equations for amplitudes of reflected and transmitted waves that has to be solved subsequently. Both ways, the difference between them and their formal mathematical similarity have been explicitly explained in course of the lectures and problem sessions. The formulation of the exam problem clearly suggested: do it in way 2.
Oh. Vast majority of the students did it in way 1. The success to follow the way has been varying while the suffering remained rather invariant. Now I understand why the students looked so gloomy. Now it’s my turn to look so: I’ve so carefully paved way 2 to lead to examination sucsess, and almost nobody took it.
Besides a point in the problem that we regarded as ultimately trivial appeared to be an almost universal stumbling block for both strong and weak. Oh. These apparent misunderstandings made the evaluation a complicated and painful procedure. The results could be better, but, after all, they are not so bad.
No Coulomb Blockade of Majorana Fermions
you, dear reader, and all modern society will have to live without spectacular achievements in this research direction.
My research proposal described in this post has been rejected in the course of our national competition, FOM Projectruimte. In comparison with the last year competition I invested more time to the writting, have brought more original and more experimentally relevant ideas, have discussed proposal with many and incorporated their feedback.
The result of these actions was evident and imminent: the proposal has been rejected faster and with worse mark. A modern referee does not have time to read the proposal, and expects to see the things expected. Any unexpected creativity is punished immediately, at the level of instinct.
Yet the creativity was certainly present in the marks I get. The referees suppose to give three marks: “scientific quality”, “risky character”, “total assesment” that supposed to summarize the two. Only the third one counts, while the first two are given for fun. In that case, the fun was all mine: 3.0 “scientific quality”, 3.2 “risky character”, 3.5 “total assesment”. Surprised, I asked the FOM functioneers for a comment. Got nothing except “such things happen”. They happen indeed!
Exam Advanced Statistical Mechanics: as an event
has taken place today in one of the rooms of nearly-infinite building of Civil Engineering. Me and Alina made two levels upstairs and two hunderd meters in horizonal direction to reach the room. The latter appeared closed, the students confusingly flocking around. Being a responsible person, I marched the way back, got the key and marched forth. So I was already tired to start with. Fortunately, Alina has performed most of exam supervision.
Seven students have shown up. Most of them made presentation and got a bit easier version of the exam. Only one international student has decided to do a fuller version.
The impression is the exam was doable for most students. I still have to check the results and their responses on the questionaire.
Wedding in Leiden
(Posting back in time)
Frans Goldschalk, my phd student, and Denise have married today. What a perfect young couple they stroke! Having seen all these academics who do not marry before finding a “proper place” in social structure, I really admire their decision and wish them very best luck and Lord’s blessing in all the ways.
Me and my wife been to the service and marrige blessing in neat Herengrachtkerk in Leiden. Very good, detailed, everything was carefully explained. The church appreared a bit far from the station, and for the party we had to make that walk back so we did not stay long.
Getting sick of being busy
(Posting back again)
I can’t believe that: the semester, that was so difficult, time-consuming and seemingly everlasting, is over, but instead of rejoycing I am confronted with a heap of things that I’ve wisely postponed till the end of the semester. Like seven referee reports (with the deadline end of the week). Like preparing talks and promises to review the texts of articles I involed, checking calculations, thinking of running projects…
Unfair it is. Why a prominent scientist like me could not spend time in leisure, playing with thoughts about things eternal? Recall I was able to do it in a younger age. Will have to think about post doc position…
April 12, 1961
the date of the first manned space flight. When I was a kid, news about advances in space research came about almost every month: that created an athmosphere of a development, adventure, and a hope for more interesting and content-rich adventures. And my kids read about majour advances of international terrorism, and spectacular school shootings…
What can we do to keep the dream and hope alive?
Any suggestions?
Phase slip devices accepted
On the last day of the year past, Alina has heroically submitted a long article about charge-sensitive phase-slip devices. We got soon the referee reports that contain many remarks, suggestions and requests. This is hardly surprising given the fact that we were really in a hurry to submit the article. To give a detail, we have omitted the author’s list: not for the sake of brevity, neither from extensive modesty, just so happened that our attention has been adsorbed by more important details…
So we had to work hard and long to implement all the remarks. Alina has submitted the revised version only yesterday evening. Today in the morning she got the acceptance note. That you cannot read in fairy tales, since fairy tales are meant to be trustworthy. Very special decision speed. This, of course, stresses the urgency and importance of our article.
On a more serios note, we have taken the referee remarks very seriously. We have added a two-page appendix that summarizes advances in the field of phase slips from stone age up to know. Let me advertize this: I think it will be usefull for everybody. Please find it here in the version number 3 that will be available soon.
Phase-slip oscillator
a marvelous device Alina and me have proposed in december 2009, have finally made it to the pages of Physical Review Letters. At least, the manuscript has been accepted for publication under a tricky title: “Model of a proposed superconducting phase-slip oscillator: A method for obtaining few-photon nonlinearities”. In less than 13 months, wow.