by Daniel Ranard
You must have seen the iconic image of the blue-white earth, perfectly round against the black of space. How did NASA produce the famous “Blue Marble” image? Actually, Harrison Schmitt just snapped a photo on his 70mm Hasselblad. Or maybe it was his buddy Eugene Cernan, or Ron Evans – their accounts differ – but the magic behind the shot was only location, location, location: they were aboard the Apollo 17 in 1972.
Since then, NASA has produced images increasingly strange and absorbing. Take a look at the “Pillars of Creation” if you never have. Click it, the inline image won’t do. That’s from the Hubble telescope, not a Hasselblad handheld.
Meanwhile, this week an international collaboration gave us the world’s first photograph of a black hole. The image appears diminutive, nearly abstract. It’s no blue marble; it offers no sense of scale. Though we may obtain better images soon, the first image has its own allure. The photograph is appropriately intangible, desiring of context, not quite structureless.
Maybe “photograph” is a stretch. For one, the choice of orange is purely aesthetic. The actual light captured on earth was at radio wavelengths (radio waves are a type of light), much longer than the eye can see. The orange-yellow variations depicted in the image do not correspond to color at all: scientists simply colored the brighter emissions yellow, the dimmer ones orange. Besides, even if we could see light at radio wavelengths, no one person could see the black hole as pictured. Multiple telescopes collected the light thousands of kilometers apart, and sophisticated algorithms reconstructed the final image by interpolating between sparse data points.
Should we marvel at this image as a photograph? Or is it a more abstract visualization of scientific data? First let’s ask what it means to see a thing, at least usually. Read more »