Mysteries of vernacular: X-ray - Jessica Oreck and Rachael Teel

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The story of the word X-Ray is one of great thinkers. French philosopher Rene Descartes isolated the letters X, Y and Z to stand for unknowns, and centuries later, Wilhelm Röntgen discovered the X-ray, using the X for the unknown nature of the radiation. Jessica Oreck and Rachael Teel shed some light on the etymology of this modern marvel.

Lesson by Jessica Oreck and Rachael Teel, animation by Jessica Oreck.

Mysteries of vernacular:

X-ray,

a form of electromagnetic radiation

capable of penetrating solids.

The word X-ray harkens back

to the work of Rene Descartes,

a French philosopher,

mathematician,

and writer in the 17th century.

One of Descartes innumerable contributions

to the world of numbers

was the invention of a simple yet brilliant convention

most people take for granted today:

the representation of unknowns

within an equation as X, Y, and Z.

When the German scientist Wilhelm Rontgen

discovered what we now call X-rays

in the late 19th century,

he gave them the name X-strahlen.

Strahlen is German for shine,

and X, of course, represented the unknown nature

of the radiation Rontgen had discovered,

the X-factor, so to speak.

The English translation maintained the X

but replaced the German shine with ray,

meaning a beam of light.

Coincidentally, in mathematics,

the word ray refers to a line

with a point of origin that has no end

and extends to infinity,

bringing us neatly back to the unknown.

Today we understand what X-radiation is,

and in spite of the humble objections

of its discoverer,

it is also commonly called Rontgen Radiation,

eliminating with the X

the fundamental mystery of its nature.