For X-rays, the phenomenon of diffraction by crystals was a natural consequence of the idea that X-rays are waves analogous to light and differ from it only by having a smaller wavelength.

The electron can no longer be conceived as a single, small granule of electricity; it must be associated with a wave, and this wave is no myth; its wavelength can be measured and its interferences predicted.

When dust is smaller than or comparable to the wavelength of light, the reflected color is dominated by particle size effects rather than the intrinsic color of the material.

A room is not a room without natural light.

This hydrogen gas emits radio waves with a wavelength of 21 centimeters, so they come in at about 1,420 megahertz on the radio dial. We were able to find that there is a magnetic field permeating this gas cloud and that its direction is pointing towards us above the cloud and then flips to pointing away from us on the bottom.

The idea was to bring in natural light where we could. There may be days ... when they won't have lights on in here.