X-ray

Definition

Short wavelength electromagnetic radiation usually produced by bombarding a metal target in a vacuum. Used to create images of the internal structure of objects; this is possible because X-rays pass through most objects and can expose photographic film.

Etymology

From X + ray, a calque of German X-Strahl, coined by Wilhelm Röntgen upon his discovery of the rays in 1895, where X signifies their unknown nature. The chess sense is metaphorical, referring to control passing through a seemingly solid barrier.

Example Sentences

• "X-rays are light with a wavelength between 0.1 and 10 nm."
• "The doctor ordered some X-rays of my injured wrist."
• "And this friendly was not without its injury worries, with defender Gary Cahill substituted early on after a nasty, needless push by Dries Mertens that caused him to collide with goalkeeper Joe Hart, an incident that left the Chelsea defender requiring a precautionary X-ray at Wembley."