The blackest material ever made

The blackest material ever made is a carpet of vertically oriented carbon nanotubes. The darkness or lightness of any object depends on the amount of light that gets reflected from it; as the object’s index of refraction n approaches unity, less light gets reflected. An ideal black object, having n = 1, absorbs all colors of light and reflects none of them. Developed by physicists at Rensselaer Polytechnic Institute (RPI) in Troy, New York, the vertically aligned carbon nanotube array has n less than 1.02 and a reflectivity of only 0.045%. As seen in the flash photograph, the VA-CNT’s reflectivity is 1/30 of the 1.4% NIST reflectance standard, three orders of magnitude lower than glassy carbon (a conventional black standard), and 1/3 of the previously darkest object (not shown). Shawn Lin and his colleagues grow the nanotubes on a prepared silicon wafer. The resulting mat, 10–800 microns thick, is light...