Archive for 'Boys Will Be Boys'

The Physics of Water-skipping Stones

Tuesday, April 28th, 2015

In stone skipping, one tosses a stone with a flattened surface across water (or other fluid) to try to get it to bounce as many times as possible. (There are also military applications, but let’s stick to the fun stuff.)

A few months ago, mechanical engineer Tadd Truscott and collagues wrote a quick study on the physics of water-skipping stones (and spheres) in Physics Today. Among other things, they examined possible angles of attack and how they affect the subsequent skipping. The series of images below comes from this article.

Illustration of water-skipping spheres.


Bonus: This is far from Truscott’s first improbable study of splashing. For example, he has also studied splash damage in urination.

Earthy, tasty probiotic recipes

Sunday, April 19th, 2015

Probiotic starter cultures come in many different flavors. Here are two that qualify as Not-off-the-shelf.

1. “Characterization of Lactic Acid Bacteria Isolated from Infant Faeces as Potential Probiotic Starter Cultures for Fermented Sausages.” This study was honored with the 2014 Ig Nobel Prize for nutrition.

2. Vaginal bacteria as probiotic starter culture for yogurt. Janet Jay, writing in Motherboard, tells the story of how this recipe came into existence, under the headline “How to Make Breakfast With Your Vagina“. Rosanne Hertzberger ponders the result. (Thanks to Charles Oppenheim for bringing this to our attention.)

Critical Studies in Men’s Underwear

Wednesday, April 15th, 2015

2050070XIssue number 2, volume 1, of the journal Critical Studies in Men’s Fashion, might be loosely described as “The Underpants Issue”. See for example the paper ‘What lies beneath? Thoughts on men’s underpants’ by Dr Prudence Black, BA SACAE Hons Macquarie MA UTS PhD Sydney, ARC DECRA Fellow, and colleagues.

“This article consists of a number of thoughts about and meditations on men’s underpants. Beginning with a ‘day in the life’ of a standard pair of underpants, it moves on to explore some of the specific characteristics that accompany the wearing of this particular garment. There follows a consideration of the role played by underpants in the creation of male characters for screen and television. A brief look at Homer Simpson’s Y-fronts is followed by the examination of a crucial moment in the history of Australian undergarments, […]”

Or perhaps, instead, (or as well as) :’Revealing myself: A phenomenological approach to my underwear choices through the years‘ by Professor Jose Blanco F.

“In this article I apply a phenomenological approach to discuss my personal lived experience and creative authorship in selecting my underwear, thus, explaining the meanings created by my interaction with my underwear and how this clothing object has been shaped by my cultural context, socio-economic factors and my relation to my own body and sexuality. Underwear can be directly linked to questions of identity and a person’s location within a social context. Since identity can be read as imbedded in social relations and situations, it can be assumed that underwear is a dynamic tool in the construction of multiple identities. […]”

To peruse the journal’s entire table of contents go here.

How to write an “editor’s note” (about nudie musicals in 1970s New York City)

Monday, April 13th, 2015

A good editor’s note clarifies something vital that some readers might (without guidance from the editor) overlook or under-appreciate, or that some lawyer insists on having stated explicitly. New editors can learn the art of writing editor’s notes by studying classic examples. Here is one such example:

[Editor’s note: This post contains numerous hyperlinks to video and sound files that enrich the text with excerpts from the films and productions that the author discusses. We suggest that you read through the post once without clicking the hyperlinks to get a sense of their context in the discussion, and then go back through to reap the benefits of these additional illustrations.]

That note appears at the very beginning of an essay called “Nudie Musicals in 1970s New York City“, by Elizabeth L. Wollman [pictured here], associate professor of music at Baruch College, City University of New York. The essay was published on June 16, 2014, in the “Sound Matters” blog, produced by the Society for Ethnomusicology.ElizabethWollman

(Thanks to investigator Jim Cowdery for bringing this to our attention.)

BONUS: Baruch College is home to many great essayists. Perhaps the greatest is Professor John Trinkaus, who has written nearly 100 studies about things that annoy him.

New study: “The Tongue as an Excitable Medium”

Saturday, April 4th, 2015

A new article (published in New Journal of Physics), called “The Tongue as an Excitable Medium”, posits an explanation for a condition known as “geographic tongue” by treating the tongue as an excitable medium and conducting a mathematical analysis of pattern formation on it.

Here is the abstract:

Geographic tongue (GT) is a medical condition affecting approximately 2% of the population, whereby the papillae covering the upper part of the tongue are lost due to a slowly expanding inflammation. The resultant dynamical appearance of the tongue has striking similarities with well known out-of-equilibrium phenomena observed in excitable media, such as forest fires, cardiac dynamics, chemically driven reaction-diffusion systems and morphogenesis in multicellular organisms. Here we identify GT as a novel example of excitable media dynamics and explore the evolution of the condition from a dynamical systems perspective. We focus on two characteristic aspects of GT in particular: anisotropic expansion of lesions and re-entry of the inflammation into recovering regions. Our investigation sheds light on the evolution of the inflammation and suggests a practical way to classify the severity of the condition, based on the characteristic patterns observed in GT patients.

I have to compliment the authors on their choice of title, because I bet that pattern formation and the theory of dynamical systems are not what you were thinking when you saw the title of this entry. One of the authors, Gabriel Seiden of the Weizmann Institute of Science, has written about his paper in IFLS. (The picture I have used, which was also used in the IFLS, includes a pattern that is rather canonical of excitable media, though not all geographic tongues have a pattern that is this clearly reminiscent of such systems.)