This is a male Sapphirina copepod or Sea Sapphire, transparent and only a few millimeters long, but attention-grabbing when they seem to emit an incredible blue flash. What causes luminous color from nothing? The “microscopic layers of crystal plates inside their cells” catch light and reflect back the violet-blue. Rebecca R. Helm writes:
Like their namesake gem, different species of sea sapphire shine in different hues, from bright gold to deep blue. Africa isn’t the only place they can be found. I’ve since seen them off the coasts of Rhode Island and California. When they’re abundant near the water’s surface the sea shimmers like diamonds falling from the sky. Japanese fisherman of old had a name for this kind of water, “tama-mizu”, jeweled water…
In the case of blue sea sapphires, these crystal layers are separated by only about four ten thousandths of a millimeter; about the same distance as a wavelength of blue light. When blue light bounces off these crystal layers, it is perfectly preserved and reflected. But for other colors of light, these small differences in distance interfere, causing the colors to cancel out. So while white light is composed of all colors, only blue light is reflected back.
More iridescence: the Blue Morpho Butterfly, Peacock Spiders, and the Birds of Paradise.
via Deep Sea News.
In 1999, near the Cape Verde Islands, “an unusually large Caulophryne pelagica [anglerfish] was captured in perfect condition, due perhaps to a lethargy induced by a prodigious meal which had expanded the stomach in excess of the standard length.” Not long after, the rare, deep-sea specimen was a part of the Natural History Museum's collection in London.
Only 17 examples of the hairy anglerfish have been discovered thus far, and this was the largest, so scientists were reluctant to cut it open for examination. However, a 3D scan of the fish could easily reveal its huge last meal.
Related watching: The Brilliance of Bioluminescence, skeletons, and more fish.
How can the physics and engineering of wind and water change a country? From the world of European travel guides, here’s a quick primer: The Netherlands: Working Windmills.
300 years ago, half of what we know as The Netherlands was under water. Slowly, the former seabed was reclaimed and the Dutch went to work drying the ground with the country’s leading natural resource - the wind. Over 1000 windmills, some still functioning, survive in the Netherlands today, reminding locals and tourists alike of the clever engine that powered the creation of this land.
Related reading: Archimedes’ screw. Related watching: how wind turbines work, wingtip vortices, Windswept, The Old Mill, and more amazing videos about The Netherlands.