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

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.