Bad Science is very worth reading at the moment: Wi-Fi Wants To Kill Your Children reveals the background to a recent Panorama programme that purported to show reason for concern about electromagnetic radiation risks from the use of Wi-Fi networks in schools.
The school staff involved deserve a great deal of credit for showing the Panorama team the door as soon as they realised they were being set up to provide a scare story. There were problems in methodology that even the students spotted, as well as serious potential conflict of interest (the engineer brought along to make the measurements was Powerwatch's Alasdair Philips, a notable campaigner against Wi-Fi).
Other complaints include Panorama's citation of an expert voted by the Swedish Sceptics Misleader of the Year 2004 on the topic of health effects of electromagnetic fields; and its reference to 'electrosensitivity' based on anecdotal reportage of a single person, rather than than the many studies showing that sufferers from this syndrome can't actually tell whether they're being exposed to a field or not.
May 26, 2007
May 25, 2007
Colmore Fatagravures
Via the Brazilian sceptical website Ceticismoaberto, an interesting Flickr photoset of blurry sepia pictures of fairies and similar, said to date from the 1890s, Parting The Veil of Faery, The Colmore Fatagravures (more information at Crowolf Can Type!).
There's a dog-ate-my-homework flavour to the credits: uncovered lost works, thought destroyed by fire ... by a photographer named Neville Colmore whose work was sidelined because the Cottingley story had more media-friendly aspects ... donor has to remain anonymous ... etc. This lack of verification isn't surprising when you read down and find Colmore described as a friend of "the famed American explorer and author, Walter Traprock ... best known for the popular accounts of his scientific expeditions published in the 1920s, Cruise of the Kawa, Sarah of the Sahara and My Northern Exposure".
Ah, that Walter Traprock, whose Cruise of the Kawa (also on Gutenberg) revealed such wonders as the quaintly-marked eggs of the Fatu-Liva. More about him at Time magazine for Feb 18th 1924: Did Horace Turn? Nice one, Crowolf.
There's a dog-ate-my-homework flavour to the credits: uncovered lost works, thought destroyed by fire ... by a photographer named Neville Colmore whose work was sidelined because the Cottingley story had more media-friendly aspects ... donor has to remain anonymous ... etc. This lack of verification isn't surprising when you read down and find Colmore described as a friend of "the famed American explorer and author, Walter Traprock ... best known for the popular accounts of his scientific expeditions published in the 1920s, Cruise of the Kawa, Sarah of the Sahara and My Northern Exposure".
Ah, that Walter Traprock, whose Cruise of the Kawa (also on Gutenberg) revealed such wonders as the quaintly-marked eggs of the Fatu-Liva. More about him at Time magazine for Feb 18th 1924: Did Horace Turn? Nice one, Crowolf.
Labels:
art,
hoaxes,
photography
May 18, 2007
Best illusions
Returning to a previous topic via a reminder at Bad Science, the winners of Best visual illusion of the year competition. They may appear a trivial amusement, but such illusions reveal significant information about how our visual processing system works. Michael Bach's 71 Optical Illusions & Visual Phenomena provides many illusions, along with references to associated research. I rather like his view that "optical illusion" is rather pejorative, as if it's exposing a malfunction of the visual system. Instead, he argues that they reveal the workings of hard-wired visual processing that is extremely effective under normal situations).
A case in point is the McCollough Effect: looking at some coloured grids induces the appearance of coloured fringes on otherwise similar monochrome grids. The remarkable feature is that unlike ordinary after-images, it lasts for up to a day. As described here - Chromatic chutes and ladders - one theory is that it's something to do with our visual mechanisms for handling edge detection and chromatic aberration, and that neuroransmitters are involved. The paper's author, Bryan Keenedy, writes: "It is unlikely that our visual systems, having evolved over millions of years, would engage in such petty games for the delight of misleading us. Instead, these 'mistaken' perceptions are likely the result of systems that, at other times, are employed to good effect". You can try it out at The McCollough Effect - An On-line Science Exhibit.
Yet another interesting effect is change blindness: you can see demos at the pages for J. Kevin O'Regan and the University of Illinois Visual Cognition Lab. Under various circumstances - for instance, very slow changes, temporary blanking or a distracting overlay - large changes in a scene can go unnoticed. The latter case has nasty implications for the safety of, say, head-up windscreen overlays.
A case in point is the McCollough Effect: looking at some coloured grids induces the appearance of coloured fringes on otherwise similar monochrome grids. The remarkable feature is that unlike ordinary after-images, it lasts for up to a day. As described here - Chromatic chutes and ladders - one theory is that it's something to do with our visual mechanisms for handling edge detection and chromatic aberration, and that neuroransmitters are involved. The paper's author, Bryan Keenedy, writes: "It is unlikely that our visual systems, having evolved over millions of years, would engage in such petty games for the delight of misleading us. Instead, these 'mistaken' perceptions are likely the result of systems that, at other times, are employed to good effect". You can try it out at The McCollough Effect - An On-line Science Exhibit.
Yet another interesting effect is change blindness: you can see demos at the pages for J. Kevin O'Regan and the University of Illinois Visual Cognition Lab. Under various circumstances - for instance, very slow changes, temporary blanking or a distracting overlay - large changes in a scene can go unnoticed. The latter case has nasty implications for the safety of, say, head-up windscreen overlays.
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