Infrared

Move aside Harry Potter, science has invisibility cloaks too. The non-magical version was inspired by polar bear fur and works by having, excellent thermal insulating properties. Polar bear hair has a hollow core which effectively prevents the infrared…

In a rainbow, the shortest visible wavelength of light is approximately 400nm (blue) and the longest 700nm (red), where all others colors outside this range are invisible to humans. Except not quite. Artal et. al. demonstrate that the eye’s visual acuity…