What the Cuttlefish Sees

Shrimp in Natural and Polarized light

A Shrimp - As We See it vs. How They See It. Courtesy Dr Shelby Temple, University of Bristol

Dr. Shelby Temple  at the University of Bristol and colleagues are doing some fascinating work with the visual systems of cuttlefish, animals that – despite their name – are most closely related to squid and octopi.  The cuttlefish are color-blind, so at first the second, rainbow-colored image might be a bit puzzling.  According to Temple, the cuttlefish are sensitive to differences in angle of polarization as small as a degree.  Explaining polarization is a bit tricky, because quite frankly you are blind to it.    Light can have an orientation (although it doesn’t necessarily need to have one) in addition to the other factors of light that your eyes actually are sensitive to, intensity and color (and if you are blind or color-blind, I apologize for my insensitivity).    In order to demonstrate this, purchase some polarized sun glasses or take some glasses home from your next 3D movie.  Look at a polarized light source (your monitor or TV, if they are LCD, are the closest), slowly cock your head, and note that the light appears to get brighter and darker.  You could measure the angle of polarization by noting at which angle your head is cocked when the light is at its brightest or, conversely, at its darkest.  If you had multiple sources at different orientations (take one of your TVs and rotate it on its side) you wouldn’t be able to turn your head so that everything was bright simultaneously.  And turning your head to take multiple measurements of the same scene is a waste of time and energy.  The cuttlefish doesn’t need to turn its head.  At every point in its visual field, it can measure this angle automatically.  To attempt to represent what it might see using this super-power, we have the rainbow shrimp.  Each color represents a slightly different angle of polarization.  However…

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The Baltic UFOs

A filtered sonar image of the Baltic "UFO." Original courtesy Peter Lindberg www.oceanexplorer.se

Somewhere in the murky waters of the Baltic Sea – only the Ocean X Team knows where – a strange circular object lies 280 feet down on the sea floor.  The story originally broke last August, but some sort of critical mass was reached by a CNN report on January 26 claiming there’s a second such object down there – curiously timed with an announcement on the discoverers’ web page  that begs for investment money for a May 2012 visit to the objects.  Web sites the world over now host the original sonar image with minor variations in orientation, color, contrast enhancement, and sharpening (which unfortunately often highlights stuff that really isn’t there).  Consistent comparisons to the Millenium Falcon are drawn, though it would appear that if Han parked it there, he flew it in backwards.  Poor Chewie will be scraping mud from the sublight engines for days.   Both images are of poor quality – an article in Popular Mechanics suggested the sonar settings were set incorrectly and some have questioned whether this is an image of anything at all.     I believe at least one of the signals is real.  Unfortunately they are disrupted by numerous parallel lines, some sort of periodic, broad-spectrum noise.  Perhaps every time the boat crested a big wave and slapped down into the water behind, the noise from the slap overwhelmed the sound from the sonar ping returning from the deep.  Here I present the same images with a twist – I used a special filter to remove the lines.  You are the first people on the planet to see these enhanced images.
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Visiting Everest in a Broken Time Machine

Everest and Main Rongbuk Glacier

Mallorie's Original 1921 Everest/Rongbuk Photo

I was quite pleased to stumble upon a series of photographs taken in the Himalayas by David Breashears and his GlacierWorks team  in late 20007-8 from the same vantage points as black and white photos from as far back as 1899.  I realized that I could borrow the colors from the new photographs and apply them to the old photographs.  The thought of placing a color camera in the hands of George Mallory (of “Because it’s there” fame) as he faced the Rongbuk Glacier in 1921 was thrilling.  I did not want to do any airbrushing – the color added to the old photo should be as true as possible to the new photo.  I split the colored version into color, hue, and lightness channels, I then combined them back together using the old 1921 photo in place of the lightness.  The result was close to what it must have looked like in 1921, with odd exceptions.  A small purple anti-cloud hangs over Mt. Everest.  A few minor snow fields that existed in 2007 but not 1921 show as bizarrely colored stripes or dots – the algorithm used to extract hue and saturation values has the same problem a human does when pondering what the color of white is.  Continue reading →

The Unicorn’s Heart

 

V838 Monocerotis Composite

A composite image of V838 Mon

In 2002, a previously unknown star in the constellation Monoceros, The Unicorn, briefly became the brightest star in our galaxy.  Although great debate rages about the reasons for V838 Mon’s flareup, there is general consensus that images taken by the Hubble Space Telescope in the months and years afterward are some of the most beautiful and dramatic ever taken.  A common mistake when viewing the series of images is to assume that they portray a single shell of material expanding outward from some vast explosion, but it’s a bit more complicated than that.  The brief flash of light is sweeping outward from the star, lighting up – a few at a time- a series of shells of gas and dust surrounding V838 Mon that it created during previous episodes.  As far as I know, my composite image is the first and only attempt anywhere to portray what these Russian-doll shells might look like together, illuminated by the dim, steady light of the star between it’s infrequent outbursts.  This is not a scientific-quality composition, but I think it captures the essence of the Unicorn’s Heart slowly beating.