The Physics of Water-skipping Stones

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.

The Fuzzification of Candlesticks

April 27th, 2015

Having difficulty predicting the ups and downs of the stock market? Have you considered the fuzzification of candlesticks? Authors Partha Roy, Sanjay Sharma and M.K. Kowar (at the Bhilai Institute of Technology, Durg, India) have – and present their approach in the International Journal of Hybrid Information Technology, Vol. 5, No. 3, July, 2012.

candlesticks

The team’s fuzzification technique, which looks at the bullish and bearish aspects of both black and white fuzzified candlesticks is described on page 4 [of the pdf] of their paper ‘Fuzzy Candlestick Approach to Trade S&P CNX NIFTY 50 Index using Engulfing Patterns’

“Human brain creates rules through experience and uses it at appropriate instances, similarly for our system, at every phase we develop Fuzzy-Rules. The accumulated Fuzzy-Rules from every phase would become the Fuzzy Rule-base. This Fuzzy-Rule-base guides the system and helps to decide the course of action whether to buy or sell.”

The team go on to explain that there is room for further work, possibly including, but not limited to, defuzzification of trend values towards crispness.

Trojan Butterflies

April 26th, 2015

The name is alcon. Maculinea alcon.

Like a suave British superspy, or maybe even a trojan horse or the proverbial cute abandoned baby left on a doorstep, some butterfly larvae mimic the chemicals of ants to get worker ants to bring them home to the nest.

But that’s not all: as Francesca Barbero and Luca Pietro Casacci discuss in their recent quick study in Physics Today, the adoptees also trick their foster parents with sound. After arriving in their adopted home, the trojan butterflies start mimicking the sounds of ants too. One type (M. alcon) mimics the queen in order to get the royal treatment (e.g., they are fed in preference to the ant larvae). Another (M. teleius) lays low until it becomes a beautiful butterfly, and it then starts eating the ant brood.

Bonus (not terribly related): In the song Puss ‘n Boots by Adam Ant, the main character goes to London and becomes the queen.

“Can’t get enough of the poo”

April 25th, 2015

The University of the Watwatersrand writes, on its web site:

Can’t get enough of the poo
BY ERNA VAN WYK
24 April 2015

“Tonight you will hear about small animals that play around in poo.”

With this, Professor Marcus Byrne started off his inaugural lecture delivered in the Senate Room at Wits University on Tuesday, 14 April 2015, following his promotion last year to Personal Professor in Zoology in the School of Animal, Plant and Environmental Sciences.

Thirty years ago he encountered this enigmatic insect that would “entertain” him, and in turn let him to entertain many others, in the name of science: the dung beetle.

It’s all about the poo

Since he joined Wits in 1987 Byrne had used dung beetles effectively as a vehicle to show evolution at its best. “It is a particularly good vehicle because of its relationship with poo,” Byrne chuckled. “It simply loves its poo and cannot get enough of it.”

“There are over 800 species in South Africa, 2 000 in Africa and 6 000 in the world. And only about 10% roll dung!” Byrne said….

Science makes up for our flaws

As a child growing up in the UK with its “limited fauna”, Byrne’s love for science was sparked by watching the great science communicator, David Attenborough, on television. In his own right, Byrne is an exceptional science communicator. His TEDx talk has attracted over 900 000 hits and with his team was awarded the 2013 Ig Nobel Prize for Astronomy and Biology….

WE WANT YOUR TECH ADVICE about the future of our magazine!

April 24th, 2015

We beg your knowledgeable advice:
What is a good, reliable system to sell PDFs?
If you know, please tell us!

OUR MAGAZINE’S IMPROBABLE FUTURE: PDFs will replace paper.

Teeth-Issue-v21i1-250wWe are going to gradually (no rush!) phase out the paper version of the magazine — the Annals of Improbable Research — and phase in PDFs.

Our technical requirements are listed below.

We have so far identified only one promising system: Gumroad.

If you have experienced advice about Gumroad — or if you know of something else that’s good — please tell us. Please e-mail Marc Abrahams <MARC aaattt IMPROBABLE dddooottt COM>.

WHY WE ARE DOING THIS.

PDF-symbolWe are good at producing a magazine full of research that makes people LAUGH then THINK. But we are tiny, and we are not very good at handling the maddening mechanics of paper subscriptions — dealing with the ever-increasing vaguaries, complexities and breakdowns of the world’s postal systems, subscription agencies, etc. — those things have been driving us (and some of you, our ever-patient, beloved subscribers) nuts.

WHAT THIS MEANS FOR EVERYONE.

The price of buying a year’s subscription will go way down. And(!) you will be able to easily, cheaply obtain any or all of the back issues. There are more than 120 back issues —six timelessly improbable issues from every year since 1995! See all of them, at <http://www.improbable.com/magazine/>

WHAT THIS MEANS FOR CURRENT SUBSCRIBERS.

We intend to keep producing the paper version for a while (maybe a year, maybe longer), while we find and test a truly good way to sell the PDF version. After we have a good PDF-sales system in place, and have seen that it really does work well, we will present some nice options to everyone who is subscribing to the paper version.

OUR TECHNICAL REQUIREMENTS.

Here’s what we want the PDF sales system to do.

1A. It should be EASY and QUICK for a customer to buy and download any ONE magazine issue.
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BACKGROUND: Things we have tried, that failed.

1. Amazon and iTunes.
Ideally, we would sell the PDFs through the two biggest, easy-to-use online stores: Amazon.com and iTunes.
But Amazon and iTunes refuse to sell PDFs.
Damn, damn, damn.

2. Ebooks (EPUB files).
We have tried selling EPUB versions of the magazine, on Amazon, iTunes, and elsewhere. But EPUBs and nicely formatted magazines, as a combination, are a complicated can-of-worms. Buy us a beer and we’ll tell you all about that. We might some day make additional EPUBs, but not in the very near future.

3. E-junkie.
We do now sell some back issues as PDFs, via E-junkie. E-junkie has its virtues, BUT… E-junkie does not have any good way to handle subscriptions.