31 December, 2010

Happy New Year!

We, physicists, will never understand the logic of chemists. But, che fare - che fare, the forthcoming year is going to be yours:




Be happy, and remember that if two cesium atoms are bound together by only 0.000000004 kJ/mol - we call it "the Cs2 molecule". Because... this is a molecule.  :-P


Take care,

Misha

29 December, 2010

8-year old kids publish an article

That's so-o-o sweet: Blackawton et al. "Blackawton bees", Biol. Lett. (2010).


via1, via2


Lev Landau was used to count the age of a scientist from the year he published the first article. Landau himself published his first one at the age of 18, so these kids have at least 10 years of a head start.


Take care,

Misha

17 December, 2010

Referees' quotes

That's awesome: referees's quotes 2010 from the journal of Enviromental Biology.


"This paper is desperate. Please reject it completely and then block the author’s email ID so they can’t use the online system in future." 

"The biggest problem with this manuscript, which has nearly sucked the will to live out of me, is the terrible writing style."

"Merry X-mas! First, my recommendation was reject with new submission, because it is necessary to investigate further, but reading a well written manuscript before X-mas makes me feel like Santa Claus."


Take care,

Misha

14 October, 2010

A nice title

It's an art to write a title in such a way that no one even needs to read an article:

"In general, the less degeneracy the less transition. A principle for time‐dependent Hamiltonian systems in quantum mechanics", H. Gingold, J. Math. Phys. 28, 2400 (1987).

Misha

05 October, 2010

Physics Nobel Prize 2010

I was about to make a joke that the third part of the Nobel Prize should have been awarded to Andre Geim's hamster Tisha, but I better don't :-)

Misha

04 October, 2010

The scientist whose rudeness cost him a Nobel prize

The Nobel week began today, and The Guardian published a nice article about Fred Hoyle, the scientist who should have gotten a Nobel prize, but never did.

Misha

02 October, 2010

Ivan Pacheco's drum solo

A weekend drumming video



The snare sound isn't perfect in this video, but this "elbow thing" at 2:14 is completely sick. :-)

Misha

01 October, 2010

Google street view in Antarctica

There is no Google street view in Germany, but there is one in Antarctica.

Penguins might sue these guys for privacy violation...

Misha

A Million Random Digits Book

Back to Russia I had two favorite books: one was called "The history of the USSR in IX-XIII centuries" (yes, of the USSR!), and the second one was "Tables of prime numbers from 2 to [some 10-digit prime number I don't remember]"

Actually, there exist something more weird than that: a book called "A Million Random Digits with 100,000 Normal Deviates" published by the RAND corporation. Only $81 on amazon.com.

Don't ask me how I found it. :-)

Misha

Brian Josephson

It turned out that Brian Josephson, who received the 1973 Nobel prize in Physics for prediction of the Josephson effect, is an active protagonist of cold fusion and parapsychology.

That's funny.

Take care,

Misha

29 September, 2010

Chicken chicken

Doug Zongker from the university of Washington published a paper using only "chicken" as a word. Later he was invited to give a talk about it at the AAAS meeting, check it out:


I especially enjoyed the way he'd answered questions. That's probably how experimentalists feel attending some of theory talks.

Thanks to Peter Kupser for sending me the link.

Take care,

Misha

23 September, 2010

Benford's law

In 1881 the American astronomer Simon Newcomb noticed that in books of logarithm tables first pages (logarithms of numbers starting with 1) are much more worn than others. This means that  people look up numbers starting with 1 more often than higher ones, which is a pretty weird result.

This effect was rediscovered in 1938 by Frank Benford, who checked it for different real data sets, and it's called Benford's law since then.

The thing is that such a distribution of numbers arises if their logarithms are distributed uniformly, like it's equally probable to find a value between 10 and 100 and between 100 and 1000. This is the case for most of real world statistics, such as distributions of salaries or building heights.

Well, I'm writing about all that because in 1972 the law was proposed to detect fraud in statistics, because people who make up their data tend to distribute numbers pretty much uniformly. For instance, Benford's law was used as an evidence of falsifications in the 2009 Iranian elections.

Be careful if you're making up your experimental data :-)

Misha

11 September, 2010

It tears me apart

Some people have problems with choosing between two men or women, two job offers and things like that. They say “it tears me apart”, which always reminds me a story from my childhood.

We’ve been little kids, about 10-11 years old, waiting for our English teacher in the classroom. For some reason our teacher was late, we’ve been very noisy and the director asked one of the security guards to come by to watch us and keep us quiet. The guy was a resigned soldier, and, as many of those, he took part in the first Chechen war (I’m talking about mid-90’s). All of us, especially boys, have been asking him what war is about.

He told us a story. Once they captured a girl, a Chechenian sniper, who had eleven ticks on the butt of her rifle, which means she killed eleven Russian soldiers. They didn’t think a lot, they just tied her to two tanks and teared her apart for real. I still remember a relaxed, casual face he had talking about that.

Little everyday things don’t tear you apart. It could be worse.

Take care,

Misha

10 September, 2010

...and papers citing it

Nowadays we have around such science databases as Web of Knowledge and Scopus, monitoring all the citations a published paper gets.

I think it would be nice to use "see ref. [x] and papers citing it" along with familiar "see ref. [x] and references therein" while writing articles.

It may come in handy if you refer to a field when a good up-to-date review is not published yet. Just cite one of the "citation classics" or an old Nobel lecture, "and all papers citing it".

Misha

08 September, 2010

Harry Potter course at Durham University

That's basically it. Durham University offers a course in Harry Potter to the students. That reminds me of the Starcraft course taught at UC Berkeley.

Take care,

Misha

05 September, 2010

The most useless machine. Ever.

Well, this is not really about science, but this is brilliant!



This toy is now the first on my wish list. :-)

Misha

29 August, 2010

About the light-green color

If (for some reason) you want people to remember your talk but don't remember any of results you've presented - just perform naked.

There is another, more conservative, option - use the light-green color on your slides.

26 August, 2010

How to plot spin-up and spin-down?

Nice figure with an energy levels diagram from one of the papers:


V.H. Kurreck, B. Kirste, W. Lubitz, Angew. Chem. 96, 171 (1984)

Thanks to Stasia Gonchar for passing it on to me.

Misha

25 August, 2010

Misconduct or not?

Imagine such a hypothetical situation. Someone is working in a research institution as a PhD student or a postdoc. She/he is very lazy and hires university students to analyze her/his experimental data, paying them as low-class workers. No one knows about that including the group leader, and names of these students never appear in articles neither among the authors nor in acknowledgements.

As for me, I think that this situation would make a case of misconduct, since it goes against such basic principles of research as openness and confidence.

What do you think?

Misha 

18 August, 2010

Fritz London about BEC

A funny quote about Bose-Einstein Condensation (BEC) from Fritz London's article (Nature, 1938):


About the same time, Erwin Schrödinger explicitly said that BEC will never be realized experimentally, since required temperatures are way too low (I cannot find an exact quote, please tell me if you came across it somewhere!)

However, in 1995 BEC in dilute atomic gases was observed in a number of labs [1, 2, 3]. In 2001 Eric Cornell, Wolfgang Ketterle and Carl Wieman shared a Nobel prize for that.


Take care,

Misha

10 August, 2010

Schizophrenic Neutrinos

I had a fellow artist who was completely ignorant in sciences, but tried to make an impression that he "knows something" every now and then. Once he asked me:

- Do you know who is the greatest schizophrenic in the Universe?
- No, who?
- An electron. Know why?
- Why?
- Because he thinks that he is a wave and a particle at the same time!

Back then I found that funny, and I still would, if Igor Ivanov didn't share a link to the following preprint today:

R. Allahverdi, B. Dutta, R. N. Mohapatra "Schizophrenic Neutrinos and $\nu$-less Double Beta Decay"

The abstract starts as "We point out a novel possibility for neutrinos where all neutrino flavors can be part Dirac and part Majorana." :-)


Take care,

Misha

05 August, 2010

31 July, 2010

Equalis - another Science 2.0 tool

A few days ago I got a message from Carmine Napolitano, who is a co-founder of recently launched Equalis project. It's a kind of new "Science 2.0" social network for sharing ideas, blogging, connecting people and tackling math-related problems together. I didn't get deeply into it, but it's worth checking out.

30 July, 2010

A story from academia

Getting a permanent job in science is extremely tough. Even if you're superbrilliant and get a tenure-track professorship, it's still very likely that you don't get through. In this case your chances for a permanent job at one of the good universities are scarce, but on the other hand you are probably too old and not competitive enough to get a good job in industry.

Recently we heard a story about Amy Bishop who killed a few people after being denied a tenure at the University of Alabama. Yesterday I was told about a chemistry Professor at MIT, who didn't get tenured after 5 years of tenure-track (acceptance rate is about 50% there). After that he gone completely crazy and joined the US army. He is in Iraq right now.

Take care,

Misha

29 July, 2010

Here is what experimentalists do for fun

Some friendly PR for a friend of mine Stasia Gonchar. She is an experimentalist and gets bored waiting for long data scans to end. As an entertainment she makes nice little sculptures like that:



http://stasia-gonchar.deviantart.com/art/bear-172016439

(follow the link and check her other animals out)

Her deviantart page is here, some of you may like her paintings and photos as well.


Take care,

Misha

24 July, 2010

The Science article that made me speechless

In his blog post Igor Ivanov dragged attention to the following paper, that recently appeared in Science magazine:

Sinha et al. "Ruling Out Multi-Order Interference in Quantum Mechanics"

In the abstract the authors refer to unification of quantum mechanics with gravitation and such kinds of things, that somehow don't seem to be very relevant. Here is what they do.

In an optical double slit experiment two different light paths interfere with each other. That means that the resulting intensity is not given by the sum of intensities from two "one-slit" experiments, but by the square of added electromagnetic amplitudes:

I = (A1 + A2)2 = A12 + A22 + 2A1A2 = I1 + I2 + I12

In this way, in addition to one-slit amplitudes, I1 and I2, we have the interference term I12 here.

If we have three slits, all three paths will interfere with each other, and the resulting intensity will be also given by the square of the resulting amplitude:

I = (A1 + A2 + A3)2 = A12 + A22 + A32 + 2A1A2 + 2A1A3 + 2A2A3 = I1 + I2 + I3 + I12 + I13 + I23

What the authors do is they measure diffraction of light in the three-slit experiment and prove that the equation above is correct, and there is no "three-slit term" there, such as A1A2A3.

Then they explicitly state that the absence of the three-slit term means that light paths interfere with each other only in pairs, and there is no interference of three paths.

This is not correct, all three paths interfere with each other: we still sum up three amplitudes and then square them. The absence of the A1A2A3 term means that intensity is calculated as square of the amplitudes, but not cube or any higher power. However, if the intensity wasn't given by a square of the amplitude, that would be already revealed in other (even more precise) experiments with light, electrons, and atoms.

This article was highlighted in Science perspectives and Nature News, but I'm still puzzled how it passed through into the Science magazine.

20 July, 2010

Physics is useful. Even in engineering.

I'm at the Gordon conference on Atomic and Molecular interactions right now, having lots of fun. For instance, here in Colby-Sawyer College they've got "hands free towel machines" in bathrooms:


(sorry for blurry picture)

In the bottom of this thing there is an infrared trigger that rolls out the towel if you put your hand close to it.

The problem is that water absorbs infrared, and this machine works well only if your hands are already dry.

Funny.

15 July, 2010

Naming kids is hard

Last year chemistry Nobel laureate Dudley Herschbach was giving a plenary talk at the Faraday Discussions conference. After the talk he got a question somehow related to angular momentum algebra and started his answer with

"You know, I love angular momentum. I even blame my parents for not naming me 'Angular momentum'!"

What puzzles me a bit is the whole 'naming kids' business. I can understand that guys far from math don't name children using indeces or primes, although 'Anna-double-prime' or 'John-three' looks and sounds great. But if people stick with the name of the mother/father while naming their dauther/son they should use something of that sort. Vladimir-prime Vladimirovich Putin, for instance.

14 July, 2010

Math is like love

There is a famous quote by R. Drabek:

"Math is like love - a simple idea but it can get complicated."


Does anyone know who this guy Drabek was (or is)? It looks like wiki has no idea about him, I cannot figure out even his first name.

Thanks for collaborating :-)

Misha

12 July, 2010

von Neumann's words come true

Everyone heard a famous quote of John von Neumann: "with four parameters I can fit an elephant, and with five I can make him wiggle his trunk".

A friend of mine Valera Yundin sent me a link to an awesome article:

Jürgen Mayer, Khaled Khairy, Jonathon Howard, "Drawing an elephant with four complex parameters", Am. J. Phys. 78, 648 (2010)

And it works!


That is definitely something to highlight in the Max Planck Research magazine :-)


Take care,

Misha

30 June, 2010

Getting married is dangerous

Willis Lamb (discoverer of the Lamb shift) got married three times: to Ursula Schaefer when he was 26, to Bruria Kaufman when he turned 83, and to Elsie Wattson at the age of 94. He deceased the same year, soon after his last marriage. I don't believe that's a coincidence.

11 June, 2010

Boycott to Nature Publishing Group

University of California threatens Nature Publishing Group with boycott, after the publisher proposed to raise the cost of California's license for its journals by 400 percent next year.

UC faculty members wrote a letter, explicitly stating that researchers will be strongly encouraged not to contribute papers to Nature journals or review manuscripts for them, if NPG doesn't negotiate.

Seven years ago this tactics worked out with Elsevier.

09 June, 2010

Science and religion

It turns out that Georges Lemaître, who proposed the Big Bang Theory (yes, the theory itself, not the sitcom), was not only a scientist, but also a catholic priest. That's funny.

03 June, 2010

All models are wrong

My research deals a lot with different analytic models. Here are two quotes about that, a long one:

"Unfortunately, models are rarely exact. The semblance of sophistication inherent in the model and used to develop parameter estimates frequently masks their deficiencies. Models are only approximate, and their predictions when the parameter estimates are based on analysis of plant performance must be considered as approximate. Validation of the model and the parameter estimates using other operating conditions will reduce the likelihood that the conclusions have significant error."

Perry's Chemical Engineers' Handbook


But there is no need in long quotes since we have a short one that captures everything:

"Essentially all models are wrong, but some are useful."

George Box


Take care,

Misha

Pumping the journal impact factor

I found a funny last year story at the forum of Russian researchers. A guy (nicknamed ST) quotes a message that he got from the Editor of one of the physics journals after submitting a paper there:

"Editor's Final Remark
In addition to the reviewers' comments given above, I recommend the authors to address and cite the relevant articles published in "....Journal ....". Such improvement on the revised version of the manuscript would not only provide a solid background to the readers regarding the current state-of-knowledge on this topic, but also promote the awareness of the available information resources in "... Journal ....". I would appreciate authors' concern and sensitivity on this matter."

So, the Editor not even encourages, but 'recommends' citing his own journal. And such 'improvements on the revised versions of manuscripts' seem to work: in his post ST mentions that the impact factor of this journal raised from 2.7 to 3.4 within one year, which is quite a jump.

Cheating is unscientific.

Take care,

Misha

30 May, 2010

It's even shorter that the shortest article ever!

In comments to my post "The shortest article ever" EastwoodDC pointed out a paper that is even shorter than that: "The Effects of Peanut Butter on the Rotation of the Earth."

This one belongs to the Improbable research project, but still...

Take care,

Misha

Laser 50 anniversary

This year it's 50 year anniversary of laser. There is a special website about that, laserfest.org, quite a few interesting links there...

27 May, 2010

Topless models

As you've understood, I do a little literature search now, and I came across the following (Italian) article:



Is there any chance to figure out what the "topless models" are about? It looks like the Google outcome is about something different.

Hm, probably 50 years ago even Italian prime minister was interested in these topless models... :-)

26 May, 2010

The shortest article ever

I'm pretty sure I've posted it somewhere about 3-4 years ago, but anyway. This is the shortest article I've ever seen, it was published in Physical Review:


Guys involved in the 'variation of fundamental constants' business always show it in the talks. But I wonder whether it was a joke or not...

Phys. Rev. Lett. half a century ago

Imagine, that you publish an article in Physical Review, then find a mistake and a misprint in it, and decide to submit the correction to Physical Review Letters. Sounds crazy?

This was somehow possible fifty years ago:



(by that time Phys. Rev. Lett. was a section of Phys. Rev.)

But anyway, later there was another, real erratum to this letter to the editor...


Take care,

Misha

25 May, 2010

How would you know?

Here is a quote from the popular article of Nissan Zeldes "Giulio Racah and theoretical physics in Jerusalem":

"Tensor algebra is the natural mathematical tool for treating angular correlations of successive nuclear radiations, as shown first in [Racah, Rhys. Rev. 84, 910 (1951)] and independently in [Lloyd, Phys. Rev. 85, 904 (1952)]".

Well, that sounds fine. Two scientists were involved in the same kind of business and came up with similar theories about the same time - we see that everywhere in science.

The only problem is that in 1951-52 both Giulio Racah and Stuart Lloyd were working at the same place, Institute for Advanced Study in Princeton. Can one really be sure that the theories were developed independently in such a case?

24 May, 2010

Stravinsky in jail


In 1940 Igor Sravinsky was arrested in Boston for playing his arrangement of the American National Anthem, which was considered a 'national property' by Massachusetts law (it was forbidden to tamper with any national property). He was released the same day after convincing authorities of his good intentions.

via undernews

10 May, 2010

Nice quote from the past

"Every attempt to employ mathematical methods in the study of chemical questions must be considered profoundly irrational and contrary to the spirit of chemistry... if mathematical analysis should ever hold a prominent place in chemistry – an aberration which is happily almost impossible – it would occasion a rapid and widespread degeneration of that science."

Auguste Comte, Cours de philosophie positive, 1830

27 April, 2010

Do you still use Comic Sans in your presentations?

Here is what Vincent Connare, creator of the Comic Sans font thinks about it:

"You know, I just have to ask, like, why? Why the hell do people choose Comic Sans? It boggles the mind. There are more than 200 fonts in Mac OS X and Windows Vista, meaning there are much better fonts out there for most everything. But people still choose Comic Sans for the most retarded, improper uses. I made Comic Sans to fill a dog’s speech bubble in Microsoft Bob. Then the marketing department got ahold of it, and they included it in the OEM version of Windows 95. And that is when my problems began. I don’t know if you can really understand what it is like to have your life defined by the most improperly used font in history. I am introduced as ‘the guy who created Comic Sans,’ and I think people have a viscerally negative reaction to that."

Here is his presentation I Hate Comic Sans.

Take care,

Misha

14 March, 2010

13 March, 2010

When theorists are forced to do experiments

It is well known that Nobel laureate Ernest Rutherford was a brilliant but very authoritarian type of scientist. He was a head of the Cavendish lab in Cambridge and many well known scientists passed through it, such as Piotr Kapitza (Nobel Prize`78), Patrick Blackett (Nobel Prize`48), and Robert Oppenheimer (later chief of the Manhattan Project).

These three were increasingly at odds, due to their different relationships with Rutherford. While Kapitza shamelessly flattered and courted his boss, who in return gave him favours and even friendship, Blackett, who admired Rutherford's creative running of the lab, never had time for such things.

Also, Blackett was tutoring Oppenheimer by teaching him the art of experiments, for which Oppenheimer had little aptitude, and Blackett knew well about that. The tension between the two became so strong that one day Oppenheimer left on Blackett's desk an apple poisoned with chemicals from the lab (!).

Hopefully, Blacket survived, and Oppenheimer didn't lose his job only because his parents persuaded the university to put him on probation, on the understanding that he will have regular sessions with a psychiatrist.

A few months later Oppenheimer completely switched to theoretical physics.

Graham Farmelo, "The strangest man"

Scientific glastnost

Interesting Nature Editorial about Russian science:

"A small, but telling example came to light last month when the popular online newspaper gazeta.ru published an interview with Yuri Osipov, president of the Russian Academy of Sciences in Moscow. Pressed by the reporter about the very low citation rate for articles published in Russian-language science journals, Osipov dismissed the relevance of citation indices, questioned the need for Russian scientists to publish in foreign journals and said that any top-level specialist 'will also study Russian and read papers in Russian'."

Well, nothing to discuss here – I second every single word of the Editorial (not Osipov's :-).

Take care,

Misha

27 February, 2010

Not even intelligence

When famous Italian physicist Enrico Fermi was asked what characteristics Nobel prize winning physicists had in common, he said:

"I cannot think of a single one, not even intelligence."

19 February, 2010

Google Buzz

As you probably know, Google launched the Buzz project quite recently. This is something in between blogs and twitter - you post messages that appear in a followers' roll, and those are not restricted to 140 symbols. You can also link Buzz to your blog stream or posts you share in Google Reader - they will appear there immediately.

A few scientists already took advantage of this, for instance here is the Buzz stream of the Field's medalist Terence Tao. For Russian speakers I would recommend the Igor Ivanov one.

If you use Buzz or know anyone from the scientific community who does, drop a comment about it. )

Take care,

Misha

16 February, 2010

Some photos of Albert Einstein

A famous theoretical physicist Michio Kaku posted some historical Einstein photos on his facebook page. These pictures come from Michio's private archive and are mostly not very well known.


13 February, 2010

That's all about the blood, the sweat, the tears

Yesterday Amy Bishop, a Harvard PhD and a faculty member of University of Alabama in Huntsville unfolded a shooting in the biology department over there. Three faculty members were killed and many more were injured as a result of her shooting spree.

The most possible reason is that Dr. Amy Bishop was denied tenure at the University of Alabama at Huntsville last year.

04 February, 2010

Nice post about spam

Tom Martin sent me a link to his post about spam.

I always get lots of spam-like comments with no links to any porn, or warez, or anything else. Just "It was very interesting for me to read this blog post...", and so on. At some point I just gave up on erasing those – who cares about spam with no spam content? But after having a look at Tom's post I understand that I should...

03 February, 2010

History of science: Gulio Racah kicks ass

As many other branches of atomic, molecular, and chemical physics, the field of chemical stereodynamics emerged from nuclear physics. Basically all this business about how molecules rotate after a chemical reaction, or how to boost the reaction efficiency controlling the reagents – it was already there, in nuclear reactions and spectroscopy.

In 30's some people were involved in studying double gamma decays, when a nucleus goes from some excited state A to state B and then to the ground state C, emitting two gamma-quanta. Already in 1940 Dunworth proposed that there might be some correlations between the directions of emission of these two quanta. Here "correlations" mean that, for instance, if we detect the first gamma-ray from the upper side of the nucleus, the second one most likely will be emitted to the left, less likely to the bottom, and never to the right.

Dunworth was not able to check this experimentally, but induced Donald Hamilton to theoretically prove that there should be some correlations. A few years later Edward Brady and Martin Deutsch from MIT found an experimental evidence of gamma-gamma correlations in the decay of Co(60) and Sc(46) nuclei.

In the meantime theorists published lots of papers, step by step trying to improve approximations and thoroughly elaborate the problem. This lasted for more then a decade, from 1940 to 1951, when a brilliant article by Gulio Racah was published.

He starts it literally as: "Hey guys, last ten years I was interested in something else, but I just bumped into you and I see that you are really stuck. Well, the problem becomes very easy if you use the tensor operator algebra that I developed about a decade ago..."

And, of course, the problem turned out to be solvable in a very natural and straightforward manner. Now tensor operators is an important tool, not only in nuclear physics, but anywhere in physics in general. We all use it and like it.

Take care,

Misha


UPD: By the way, I never knew that Gulio Racah was a cousin of Ugo Fano...

02 February, 2010

Learn something every day...

The words "introvert"and "extrovert" appeared in English in 1923 upon translation of the Carl Jung's book "Psychologischen Typen" published in German two years before.

Something you should know about vodka

On the 31-st of January 1865 the author of the periodic table of elements Dmitri Mendeleev defended the doctoral dissertation "On the Combinations of Water with Alcohol":


People often say that in this piece Mendeleev proved that the solubility is the best for 40% of alcohol and 60% of water, and thereby invented vodka as we know it. Unfortunately, that's nothing but an urban legend: Russians were drinking vodka long before Mendeleev was even born.

01 February, 2010

Web of Knowledge - how Google sees it

Everyone knows that ISI Web of Knowledge maintained by Thomson Reuters, is a very raw and unfinished, but still commercial project. Here is what Google thinks about it:


I think that's unlikely to get better unless any substantial alternatives to WoK appear.

31 January, 2010

Two quotes from Paul Dirac's letters

I certainly loose it if I don't write it up somewhere. These two quotes picked from letters to Manci Balázs, entirely describe Dirac's childhood:

i) 'I did not know of anyone who liked someone else – I thought it did not happen outside novels', 7 March 1936

ii) 'I found it to be the best policy as a child [...] to make my happiness depend only on myself and not on other people', 9 April 1935


Take care,

Misha

30 January, 2010

The Gunning-Fog index

Nature publishing group has a science blogroll with a bit of statistics for each blog, here is how it looks like for mine:
  • Ranked 18 in science (377 overall)
  • 2 post(s) per week (on average)
  • 65 post(s) collected so far
  • 7,032 words per post (on average)
  • 14% complex words (on average)
  • Readability by Flesch-Kincaid : best understood by university graduates
  • Readability by Gunning-Fog : 146.0
  • On 0 blogroll(s)
  • 2 links to other science blogs
  • 0 links from other science blogs
The first thing that crossed my mind was "what the hell this Gunning-Fog index is?". If you follow the link you get that "The Gunning-Fog index [...] is a rough estimate of the number of years of formal education that a person requires in order to understand the text on a first reading."

So, basically an average person needs to study for 146 years to get a rough idea what I'm writing about, while a well understandable text should have the index below 12. First I thought that this is due to appalling English I'm used to, but if you read further you'll see that there is nothing to do with that. The Gunning-Fox index comes from analysis of the average sentence length and the average number of syllables in words.

I never thought those indexes even exist. I promise, I promise to keep sentences shorter... )

Take care,

Misha

In fifty words or less

In his book “Indiscrete thoughts” famous Italian-born American mathematician Gian-Carlo Rota mentions that Stan Ulam was used to say “Whatever is worth saying can be stated in fifty words or less”.

Well, these days he would probably adjust it a bit:

“Whatever is worth saying can be stated in 140 symbols or less”

)

29 January, 2010

True random numbers: linguistics may be of help

I'm completely ignorant in computer science, but even I know that it's tough to get true random numbers. The problem is that any software-based algorithm generates "pseudo-random" numbers, that is there is still some regularity in a row of those, and the sequence will repeat itself after a while.

People are used to get the real randomness from the outside, like picking up the thermal noise of the sound card, the displacements of mouse (that are supposed to be random), or even monitoring the atmosphere. But, there is at least one challenging method to get true random numbers out of the software part.

Let's take a block of English text (say, a .pdf of a paper), written by a native Russian speaker. What is to do, is to analyze the articles "a" and "the" over there. If the correct article is used, we have "1", if not – "0". In such a way, we get a truly random sequence of 1's and 0's, and we can generate true random base-10 numbers out of it.

Is there anyone who wants to give it a try? )

Take care,

Misha

A bug in Mathematica: Clebsch-Gordan coefficients

A technical issue for those of you using Wolfram Mathematica. Apparently there is a bug in the function furnishing Clebsch-Gordan coefficients, check it out:


These two inputs are equivalent, but the outputs are different somehow. Actually, this Clebsch-Gordan coefficient is zero, because the angular momentum j=9/2 cannot give a projection of m=0. In general, for a coefficient to be nonzero all the (j+m)'s should be nonnegative integer numbers.

The ClebschGordan[] function in Mathematica is used to test all the conditions of existence, such as the triangle rule, but as we see it fails when it comes to substitutions of parameters.

I dropped a message to the Wolfram support team, and they promised to do their best to figure out where the problem comes from. I hope to hear from them soon and I'll keep you posted about it.

Take care,

Misha

22 January, 2010

arxiv.org seeks donations

Keeping it short, the arxiv.org preprints server faced serious problems after significant budget cuts for Cornell university library. The annual budget is as large as $400,000 and the library will provide only 15% of it. The rest is expected to be donated by top 200 heavy user institutions, allowing to keep both submission and downloading of preprints free of charge. Here is the arXiv support FAQ.

21 January, 2010

Fake structures published in Acta Crystallographica

Stop press from the wonderful world of scientific misconduct:


"Regrettably, this editorial is to alert readers and authors of Acta Crystallographica Section E and the wider scientific community to the fact that we have recently uncovered evidence for an extensive series of scientific frauds involving papers published in the journal, principally during 2007. Although several thousands of structures published in Acta Crystallographica Section E every year will continue to reflect results of serious scientific work, the extent of these problems is significant with at least 70 structures demonstrated to be falsified and meanwhile acknowledged by the authors as such...

...The falsified structures have many features in common: in each case, a bona fide set of intensity data, usually on a compound whose structure had been correctly determined and reported in the literature, was used to produce a number of papers, with the authors changing one or more atoms in the structure to produce what appeared to be a genuine structure determination of a new compound. The worst example generated no fewer than 18 supposedly original structures from a single common set of data. There is nothing to suggest that the authors of the original papers describing the real structures are in any way aware of, or complicit in, this fraud...

...The initial set of falsified structures arises from two groups. The correspondence authors are Dr H. Zhong and Professor T. Liu, both from Jinggangshan University, Jian, China. The co-authors on these papers included other workers from Jinggangshan University together with authors from different institutions in China. Both these correspondence authors and all co-authors have signed forms agreeing to the retraction of 41 papers published by Dr Zhong and 29 by Professor Liu. Details of these retractions appear elsewhere in this issue of the journal. Having found these problems with articles from Jinggangshan University, all submissions from this University to Acta Crystallographica Sections E or C have now been identified and are being checked for authenticity. Preliminary results indicate that further retractions will result from this exercise."


Huh, this way they will end up with checking every single submitted structure by hands soon...