Improbable Research

This week’s recommended algebraic geometry paper is:

Quasi-projectivity, Artin-Tits Groups, and Pencil Maps
Authors: Enrique Artal Bartolo, Jose Ignacio Cogolludo-Agustin, Daniel Matei, arXiv:1005.5225v1
(Submitted on 28 May 2010)

Abstract: We consider the problem of deciding if a group is the fundamental group of a smooth connected complex quasi-projective (or projective) variety using Alexander-based invariants. In particular, we solve the problem for large families of Artin-Tits groups. We also study finiteness properties of such groups and exhibit examples of hyperplane complements whose fundamental groups satisfy $\text{F}_{k-1}$ but not $\text{F}_k$ for any $k$.

The July issue of mini-AIR just went out. Topics include: The Thrill of Canadian Cloth Towel Dispensers; Professor Lipscomb Issue Soon; Icky Notes on a Chainsaw Massacre; Mapping Microwaved Chicken Fingers Limerick Competition; Random Balinese-German Poet; Integrated Happiness Accounting; Greek Postmen and Their Cancellation Numbers; etc.

Mel [pictured here] says, “It’s swell.”

(mini-AIR is the simplest way to keep informed about Improbable and Ig Nobel news and events. Just fill in the wee form, and mini-AIR will be emailed to you every month)

Can reading a ‘stupid story’ make you behave less intelligently (more stupidly)?
Assoc. Prof. Dr. Markus Appel (pictured) has examined this question in a recent experimental study at the Johannes Kepler Universität Linz Institut für Pädagogik und Psychologie, Österreich.
81 participants read a story about an extremely unintelligent right-wing soccer hooligan dressed as a skinhead – and were then asked questions such as :
• What is the capital of Libya?
• What kind of speed is expressed by the letter ‘c’ in Physics?
• Who painted La Guernica?
The results were clearcut: “As expected, participants who read a narrative about a stupidly acting soccer hooligan performed worse in the knowledge test than participants who read a narrative about a character with no reference to his intellectual abilities.”
“The present study is, to our knowledge, the first to show media priming effects of story characters on cognitive performance.” say(s) the author(s).
A Story About a Stupid Person Can Make You Act Stupid (or Smart): Behavioral Assimilation (and Contrast) as Narrative Impact is published in Media Psychology, Volume 14, Issue 2, 2011

- and can also be read  in full here.

Resonance is a simple physics concept (which can be expressed in lovely mathematics). Two Korean news reports tell about a recent example:

Aerobic exercise blamed for tremor at Techno-Mart

A form of aerobic exercise performed by dozens of people caused the vertical vibration felt in certain floors at Techno-Mart, a 39-story shopping mall in Gwangjin-gu, Seoul, two weeks ago, an inspection committee tentatively concluded Tuesday. A simulation of the exercise was carried out on the 12th floor of the fitness center of the building Tuesday by inspectors to prove that the group exercise caused the building to vibrate. The same number of people, 23, as was there at the time of the shaking on July 5, participated in the simulation exercise….

—Korea Times

Gym rats shook TechnoMart: Owner

The mystery of what made a Seoul residential-commercial high-rise complex shake for 10 minutes, like in an earthquake, has been solved, according to its owner. The cause, according to TechnoMart owner Prime Group, was 17 middle-aged people in a 12th floor fitness center performing Tae Bo exercises, a mixture of boxing and taekwondo that became popular in the 1990s. And to prove it, Prime Group will stage a demonstration today to show that a bunch of middle-aged people exercising can shake a 39-story skyscraper…

—Korea JoongAng Daily

(HT @TitleOfMagazine)

BONUS: A radio report about the incident.

BONUS: Another example of resonance in a structure: The Tacoma bridge.

Katrin Kania has joined the Luxuriant Flowing Hair Club for Scientists (LFHCfS). H.J. Hopkins, who nominated her, says:

Katrin has recently completed her PhD in the methods of construction of European Medieval garments but I know her as one of the two organiser of textilforum, a European workshop of historic textiles and experimental archaeology. The workshop was set up so that she could stage an experiment investigating the influence of a spindle whorl, in particular its MI (Moment of Inertia), the influence of the fibre and the influence of the spinner in the outcome of spinning. The experiment has now concluded, the data has now been processed and she is in the process of writing up.

Katrin Kania, Ph.D., LFHCfS
Erlangen, Germany