Archive for 'Improbable investigators'

The Acoustics of Breaking Chopsticks

Sunday, January 24th, 2016

What are the acoustics of breaking a bamboo chopstick?

According to a new paper by physicist Tzay-Ming Hong and his colleagues at National Tsing Hua University in Taiwan, it’s kind of like the acoustics of breaking a bundle spaghetti: they both apparently resemble the Gutenberg–Richter scaling law, which relates earthquake magnitude to the frequency of earthquakes with at least that magnitude. Similar relations hold for crackling noise in acoustic emissions from a variety of sources (e.g., fracturing rock, paper, and charcoal). So it’s not exactly the sound of the atom splitting (as far as we know), but it’s still rather impressive.

Here is an excerpt from the authors’ abstract:

By the use of a force-sensing detector, we establish a positive correlation between the statistics of sound intensity and the magnitude of a tremor. We also manage to derive these laws analytically without invoking the concept of a phase transition, self-organized criticality, or fractal. Our model is deterministic and relies on the existence of a structured cross section, either fibrous or layered. This success at explaining the power-law behavior supports the proposal that geometry is sometimes more important than mechanics.

Personally, I’m very pleased that the authors derived their results without having to invoke self-organized criticality. Here is the first figure from the authors’ paper.



New Mathematical Model Helps Explain the Strength of Interleaved Phonebooks

Saturday, January 9th, 2016

Phonebooks made of paper have been going out of style, but they are still of interest to physicists. A few years ago, an episode of Mythbusters explored the strength of interleaved phone books. (Also see the sequel in Mythbusters, or maybe even try it yourself.)

First, some context, in case you are a child of the 21st century, and so perhaps have no personal experience with paper telephone books, which could be hefty. Here’s an old TV advertisement for “the yellow pages”, a telephone directory listing businesses and their telephone numbers:

Now experiments and an accompanying mathematical model have been published in Physical Review Letters by a team of physicists. Frédéric Restagno of the University of Paris-Sud and CNRS in Orsay and his colleagues measured the force needed to separate interleaved pairs of books with between 12 and 100 pages, and they developed a mathematical model based on simple geometric and mechanical ideas to explain the impressive strength of interleaved books.



Figure 1 from the article “Self-Amplification of Solid Friction in Interleaved Assemblies” by Héctor Alarcón, Thomas Salez, Christophe Poulard, Jean-Francis Bloch, Élie Raphaël, Kari Dalnoki-Veress, and Frédéric Restagno


The strength of the interleaved books arises because the book-separating force on each page is applied at a slight angle, and this increases the perpendicular force and hence the friction of each page. Restagno and colleagues also fit the data to a curve of force versus a dimensionless amplification parameter –– following the continuum-mechanics tradition of using cute names for dimensionless parameters, let’s call it the “Hercules number” –– that depends on the number of pages, the page thickness, and the size of the overlap region between the books.

Not very closely related: Another fascinating dimensionless parameter is the “Repunzel number” from research on ponytail physics, which earned the 2012 Ig Nobel Prize in Physics.

A look back at the 20th Dead Duck Day

Friday, January 1st, 2016

DDD20 logo DEF DIt took some time to write-up the things that happened at the 20th edition of Dead Duck Day — commemorating the first scientifically documented case of homosexual necrophilia in the mallard duckHere it is, laced with photographs:

On June 5th, 2015, the 20th Dead Duck Day attracted a crowd of about 50 people. They gathered at the spot where it all began, right below the all glass facade of the Natural History Museum Rotterdam. At exactly 17:55h Kees Moeliker, in company of the stuffed duck (NMR 9989-00232), welcomed everybody … [Read the entire write-up here]

The 21st Dead Duck Day will be on Sunday, June 5th 2016, and – as usual – will include a meal.


Sad News: Harry Lipkin is gone

Monday, December 28th, 2015

I’m very sorry to report that Harry Lipkin has died. Harry was a founding editorial board member of the Annals of Improbable Research, and long before that — in 1955, he and Alex Kohn co-founded the Journal of Irreproducible Results, the forerunner of the Annals. Harry was also, by the way, one of the world’s great physicists. For most of his life he was a professor at the Weizmann Institute.


Harry died in September, just a few days before the 25th First Annual Ig Nobel Prize ceremony. Harry and Alex had devised the basic idea of the Ig Nobel Prize many years earlier, and both of them helped me, from afar, found the ceremony back in 1991. Harry was almost-eternally going to come be part of the show — sadly he never quite made it. (Alex died in 1994.)

In 1994, when the then-publisher of the old magazine was going to consign it to oblivion (and it became clear that nothing any of us could do would stop them), I resigned as editor, and with help from Harry and Alex and the rest of the gang, started a brand new magazine — thus was born the Annals of Improbable Research.

Over a long span of years, Harry influenced (and was good friends with) a substantial part of the world’s top layer of physicists, and many, many other people. Here’s part of the appreciation that was published in both the CERN Courier and Physics Today:

Lipkin was born in New York City in 1921 and grew up in Rochester, New York. His life was very rich: he graduated in engineering; contributed to the crucial WWII anti U-boat microwave radar project at MIT; undertook an experimental-physics PhD thesis at Princeton; immigrated to Israel with his wife Malka to start a pioneering life in an agricultural kibbutz on the Lebanese border; was sent to France to study nuclear reactors; joined an early R&D unit of the Israeli army; co-founded and moved into the newly created Department of Nuclear Physics at the Weizmann Institute; became a theoretical nuclear physicist… and we have only reached 1955 in his history. For the remaining 60 years of his life, he also contributed to theoretical condensed-matter physics, particularly the Mössbauer effect; basic problems in quantum mechanics; and, especially, particle physics, with an emphasis on symmetries, quark-model analysis, applications of group theory and a wide variety of other topics. His book Lie Groups for Pedestrians introduced many generations of physicists to the subject. He received several major prizes, including the Wigner Medal, the Emet Prize and the Rothschild Prize. He spent long periods of research in the US, especially at Argonne National Lab and, for decades, was a frequently invited speaker at just about every major physics department and conference.

But his original contributions to physics research were only one aspect of his incredible career. He always felt that one should never take oneself too seriously, even as a scientist. Together with virologist Alexander Kohn, he founded the Journal of Irreproducible Results…

Harry was a thoughtful, funny, prolific writer. For a taste of his thoughts and his personality, read his essay “Why talking to physicists tells you what you can’t hear elsewhere“, which was published in the APS [American Physical Society] News, in 2009.

If you’re a bit more adventurous, take a read through his paper “Quantum Theory of Neutrino Oscillations for Pedestrians – Simple Answers to Confusing Questions“.

Dr. NakaMats, continued!

Sunday, December 27th, 2015

Gamely defying the predictions of his doctors, Dr. NakaMats is (1) still alive, and (2) still holding press conferences. On December 25, 2015 he sent us this note, from his home in Tokyo:

Yesterday I had the press conference at the Foreign Correspondents’ Club for the following important notice:

Nakamats-Dec2015Today is 7 days before estimated death day of Sir Dr. NakaMats of which famous Medical Doctor has predicted.

Today Sir Dr. NakaMats announced that planned 10 inventions of ten therapies to beat cancer has all completed just before 7 day of his death day!

Sir Dr. NakaMats says “I didn’t know the effectiveness of these 10 invented therapies, though I believe my theory of these invented therapy are right. The effectiveness of these inventions will be proven by the fact that Sir Dr. NakaMats will die at Dec. 31, ’15 or survive.”

Sir Dr. NakaMats announced the next press conference will be held on Jan 30, ’16.

At that time, the reporter of press conference will see either the coffin or live Sir Dr. NakaMats.

Best wishes and Merry Christmas

Sir Dr. NakaMats   

BACKGROUND: The final birthday party of Dr. Nakamats

BACKGROUND: The 2005 Ig Nobel Prize for nutrition was awarded to Dr. NakaMats for photographing and retrospectively analyzing every meal he has consumed during a period of 34 years (and counting). The streak has now, in 2015, reached 44 years. Dr. NakaMats is (as most of the world well knows) famed also for his more than 3500 patented inventions, one of which is the self-defense wig. He is still, he informs us, working on new inventions.

BONUS: Improbable Research podcast #17 included an audio recording of part of Dr. NakaMats’s now-legendary train ride from Copenhagen to Stockholm.