Mneptok let me know that comments on my blog were broken (I had forgotten to reinstall Image Magick when I upgraded the operating system). That should be fixed now. Let the comments commence!
Xerox printers use a watermarking technique to insert codes onto all printed documents from their Docucolor color laser printers. These identify date, time and printer serial number with a grid of yellow dots which appear in the printout. Presumably these codes are inserted to make the job of the Secret Service simpler in tracking their use in creating counterfeit money. What’s kind of cool though is that the EFF has figured out how to decode them. Interesting bit: the dots are simple to see when viewed under an intense blue light, like one of those blue Photon LEDs.
Wow: another terrific article from The Panda’s Thumb, which is quickly becoming one of my favorite destinations on the web. This article is discussing some of the interesting research surrounding prions, self-propagating variants of certain proteins that are the infectious agents behind diseases like scrapie, bovine spongiform encephalopathy, and variant Cruetzfeld-Jakob disease. What’s really interesting is that they may enable a form of Lamarckian evolution where traits which are not encoded genetically but are rather acquired through infection can be passed to offspring, subject to normal natural selection.
In certain conditions, for instance when an organisms recurrently but unpredictably encounters a specific, strong selective condition, prion systems may result in the environmental induction of adaptive, acquired heritable phenotypes.
At this point, we don’t have any bona fide examples of this actually happening, but in principle it’s possible. Moreover, this model provides a real, testable mechanism to explain such a phenomenon, should it occur (scientists don’t mind testable mechanisms and hypotheses, even when they are “heretical”).
Nothing stimulates science better than a good heresy, I always say.
Courtesy of the Bad Astronomy Blog, some very nice images of our closest galactic neighbor M31, the Andromeda Galaxy taken with the Spitzer telescope in infrared. It shows a great deal of detail which is missing from visible light photographs. Very nice.
(Okay, okay, there are the Magellenic clouds, and other dwarf galaxies that are closer, but you get the idea.)