A Lucky Haul, an Evasive Fish, and the Ultra-Black Materials of the Future
A new study shows that some fish can absorb up to 99.5% of all light — on par with Vantablack and the darkest known materials.
Evolution has the extraordinary ability to devise multiple solutions to a single problem. In the dense forests of Papua New Guinea, a male bird of paradise (Lophorina superba) approaches a potential mate, puffs out its chest, and spreads its feathers into an intimidating fan. Its ultra-black feathers are accentuated with a deep shade of green, made to impress the onlooking female. The superba’s plumage is such a deep black that it absorbs up to 99.95% of all light, on par with the darkest materials ever studied.
Now hop a few islands west, to the rainforests of Borneo and Sumatra, where the Rajah Brooke’s Birdwing, a butterfly, touts wings with a similar shade of black. First documented by Alfred Russell Wallace in 1855, it was only recently that scientists analyzed the ultra-black Birdwing, which reflects less than 0.3% of incident light at certain wavelengths.
Though these creatures share “ultra-black” features, that is also where their similarities end. Ultra-black butterflies achieve their coloration via two layers of thin, honeycomb structures on their wings, which effectively trap light. Birds of paradise, conversely, scatter and deflect light via tiny filaments that project from their feathers. According to a 2018 study, this works for the ultra-black birds because “each time light scatters at a surface interface, a proportion of that light is transmitted into the material, where it can be absorbed. By increasing the number of times light scatters, structurally absorbing materials can increase total light absorption to produce a profoundly black appearance.”
For several years, the unique, ultra-black coloration of these creatures appeared to be confined to the land and the skies, mainly in the south Pacific islands. That is, until a 17-day fishing expedition led to the discovery of another ultra-black creature, hiding in the ocean’s depths, that could have the serendipitous benefit of helping scientists find novel ways to…