Archive for 'Arts and science'

More Bite than an Old Saw? A Saw Made with Shark Teeth

Monday, January 19th, 2015

Francie Diep’s article “Watch a Power Saw Made with Shark Teeth Slice Through Salmon“, in Popular Science magazine, is well headlined, and has a video that shows a power saw, made with shark teeth, slicing through salmon. The research Diep describes was itself described by the researchers at a meeting earlier this month:

Jawzall: Effects of Shark Tooth Morphology and Repeated Use on Cutting,” CORN, K*; BRASH, J; FARINA, S; SUMMERS, A; Society for Integrative and Comparative Biology, 2015 Meeting, P2-196 Monday, Jan. 5 15:30.

The investigators, at Cornell University; Valley Steel and Stone; Cornell University; and the University of Washington, report:

“Shark teeth both pierce and cut their prey, which is viscoelastic and structurally and materially heterogeneous. We propose a device for testing the function of shark teeth in a biologically relevant context with respect to their movement relative to the prey. We used this device to test whether tooth shape has an effect on cutting efficiency on a large actinopterygian prey item (salmon) and how quickly teeth dull. Teeth from four sharks, tiger (Galeocerdo cuvier), sandbar (Carcharhinus plumbeus), silky (C. falciformis), and sixgill (Hexanchus griseus), were attached to 30.5cm straight saw blades with epoxy. Each blade was mounted in a reciprocating saw and applied to a chum salmon with constant force. Published data report that Carcharodon carcharias shakes its head at 0.5Hz (~15cm/s). Our saw moved the teeth 35 cm/s. Our ‘bite force’ was substantially below that reported for sharks, due to of limitations of our system. There was not a significant effect of tooth shape on the area of prey cut per linear distance traveled. The mean area cut per cm traveled across all tooth shapes was 69 cm^2/cm. There was a significant effect of repeated use on cutting speed. After 12 reciprocations, a tooth cut only 7% of the tissue it cut on the first 6 reciprocations (at 5.7cm/reciprocation). This rapid dulling is enhanced by the high speeds at which we are cutting, as the fish tissues appear much stiffer at high strain rates. Sharks have very rapid tooth replacement and we propose this is driven by the speed of dulling from use.”

(Thanks to investigator Paula Gramm for bringing this to our attention.)

Here is a photo of Adam Summers, the final-named author of the study, engaged in a different activity:


Professor Wright meets Professor Wrong (Toronto, c. 1921)

Monday, January 19th, 2015

If you’re looking for a (documented) example of an occasion when Professor Wright encountered Professor Wrong, then your search is over. One such event happened somewhere around March 1921, at the University of Toronto Winter Short Course for farmers. Here’s an account, in Volume XXI of the University of Toronto Monthly, March 1921, No. 6. [Use the slider at the bottom of the screen to visit page 243]


“The special Winter Short Course intended primarily for farmers, was an outstanding success in every phase of its activity. For the two weeks’ course 280 students registered and many visitors including members of the Legislature attended a number of the lectures. East Hall proved too small for the classes and Convocation Hall had to be used. The students expressed their appreciation of the lectures given them by Professors Wrong, Wallace, Wright, Fitzgerald, and Jackman. [our emphasis]

The lectures were delivered in the mornings and the afternoons were devoted to conducted visits to places of interest in the city. Abattoirs were visited, the Massey Harris Works, the Royal Ontario Museum, and a number of the University Buildings. One afternoon was spent in the Biological Building where a series of demonstrations and experiments was arranged for the visitors. Another afternoon was spent in the Antitoxin Laboratories, and the visit which, as one of the women students expressed it, was the climax of all, was the tour of Hart House under the guidance of Warden Bowles. During their fortnight’s stay at the University the class developed considerable esprit de corps. A class yell was chosen and this yell was given at every possible opportunity with remarkable vigour.

Lady Falconer entertained the class on two afternoons during the curse [sic] [continues]

May we also recommend:

“Keep clean inside” (page 239)
“The Goblin” (page 269)
“What are your brains worth?” (page 35)

Here’s the Wright-Wrong passage, reproduced as it appears in the original publication:


Self-made bread (sort of): A delicious video

Sunday, January 18th, 2015

This video illustrates the life cycle of self-made bread:

It shows an analog to what might (metaphorically or poetically, or in some other vague way) be loosely described as the life cycle of Dyctiostelium discoideum, which is better known to most folks who know it as slime mold.

BONUS: Video of Dyctiostelium discoideum itself:

Dramatic improbable readings from bizarre research studies, at Arisia on Saturday

Friday, January 16th, 2015

Arisia Logo

This Saturday, Jan 17th at 12:30pm, Improbable Research will hold a special session at Arisia“New England’s largest science fiction and fantasy convention“.

Brave volunteers will emote brief excerpts from published academic studies and patent documents. (Some of those studies and patents won Ig Nobel Prizes).

The people reading these studies were nominated (and commented on) by attendees of Arisia and readers of this website. They will each, upon arriving at the event, choose an appealing paper (or patent), and dramatically read two minutes’ worth of it. They will then answer questions from the audience, being scrupulously clear about what they do NOT know, as well as what they do.

Excerpted from our Notes for Readers and Audience at Dramatic Improbable Readings:


  • Please arrive a little early
  • There will be a stack of printed, genuine studies. Choose the one that most appeals to you
  • Skim through it, and choose one or more passages that your favorite actor would find delightful to real aloud in some extremely colorful way. Keep it short — enough words to last about two (2) minutes
  • Today, you will be that actor. Treat the words as fantastic theatrical prose — nothing more, nothing less. Perform it in any style you like


  • The person reading this paper to you probably has no familiarity with what they are reading. They saw it for the first time just a few minutes ago
  • After the reading, you may ask questions


  • If you don’t know the answer, say so. If you want to speculate, make that clear
  • Answer any way you like, with just one rule: NO BULLSHITTING

NOTE: If you are a member of the LFHCfS and are planning to attend this event, you are entitled to take a bow, allowing the audience to shower you and your hair with applause. Please let a member of our event staff know that you are a member so we can give you this important moment in the sun (or rough substitute for the sun).

Discarded dog-poop bags – a photo essay

Friday, January 16th, 2015

It was somewhere around 2007, that Dr. John Darwell, who is a senior lecturer in photography at the University of Cumbria, UK, began researching and photographically documenting the phenomenon ofddsbs‘.

DDSBsOver the past two years I have observed with increasing fascination the growing number of discarded dog shit bags (ddsbs) I encounter whilst out walking in both open countryside, urban parklands and even suburban streets. This has led to a great deal of speculative thought on my part as to why this situation has developed. I can fully understand dog owners simply ignoring their dogs output (unpleasant as it is for anyone who encounters it with all its negative health associations) as it will in a relatively short time biodegrade and essentially disappear. I can also appreciate dog owners who scoop and bag dog mess and place it in a bin for disposal. What I fail to understand is the increasing number of dog owners who bag their dog’s mess and then discard in bushes or hang on fences/tree branches or leave in the middle of pathways and playing fields. Is this purely about not wishing to be fined and thereby picking the right moment to surreptitiously dispose of the offending article? Whatever the reasoning the ddsb has very quickly become a feature of our environment. The images presented here become typologies that reflect on the nature of function and style and confront the viewer with the (often unseen) contents of the bags leading to a mixture of amusement, bemusement, curiosity and revulsion.”

The author’s photographic gallery, with 44 examples of ‘ddsbs’ can be found here.

Note: The ddsbs project, which was originally solely UK based, has now gone international, with photos from Western Australia (mainly yellow), Isle of Man, Norway, Belgium, Norway and Germany (mainly red).