Why is 'x' the unknown? | Terry Moore

Translator: Timothy Covell Reviewer: Jenny Zurawell

Translator: Raquel Uzal Reviewer: Eulalia Baroja

I have the answer to a question that we've all asked.

Teño a resposta a unha pregunta que todos nos fixemos.

The question is,

A pregunta é:

Why is it that the letter X

por que a letra X

represents the unknown?

representa o descoñecido?

Now I know we learned that in math class,

Xa sei que iso é o que nos ensinaron na clase de matemáticas,

but now it's everywhere in the culture --

pero agora está en todas partes na cultura:

The X prize, the X-Files,

O premio X Prize, Expediente X,

Project X, TEDx.

Proxecto X, TEDx.

Where'd that come from?

De onde vén iso?

About six years ago

Fará cousa de seis anos

I decided that I would learn Arabic,

decidín aprender árabe,

which turns out to be a supremely logical language.

que é unha lingua sumamente lóxica.

To write a word or a phrase

Escribir unha palabra ou unha frase

or a sentence in Arabic

ou unha oración en árabe

is like crafting an equation,

é como escribir una ecuación,

because every part is extremely precise

porque cada parte é tremendamente precisa

and carries a lot of information.

e leva consigo unha morea de información.

That's one of the reasons

Ese é un dos motivos

so much of what we've come to think of

polo que gran parte do que agora consideramos

as Western science and mathematics and engineering

a ciencia, as matemáticas e a enxeñería occidentais

was really worked out in the first few centuries of the Common Era

en realidade foi concibido nos primeiros séculos da Era Común

by the Persians and the Arabs and the Turks.

polos persas, os árabes e os turcos.

This includes the little system in Arabic

Isto inclúe un sistema en árabe

called al-jebra.

chamado al-jebra.

And al-jebr roughly translates to

E al-jebr traducido quere dicir

"the system for reconciling disparate parts."

"o sistema para reconciliar partes dispares".

Al-jebr finally came into English as algebra.

Al-jebr introduciuse na nosa lingua como álxebra.

One example among many.

Un exemplo entre moitos.

The Arabic texts containing this mathematical wisdom

Os textos árabes que contiñan esta sabiduría matemática

finally made their way to Europe --

por fin entraron en Europa,

which is to say Spain --

ou mellor dito, España,

in the 11th and 12th centuries.

nos séculos XI e XII.

And when they arrived

E cando chegaron

there was tremendous interest

houbo un interés enorme

in translating this wisdom

en traducir esa sabiduría

into a European language.

a unha lingua Europea.

But there were problems.

Pero había certos problemas.

One problem

Un problema

is there are some sounds in Arabic

é que hai certos sons en árabe

that just don't make it through a European voice box

que son imposibles para as cordas vocais europeas

without lots of practice.

a non ser que se practiquen moito.

Trust me on that one.

Fiádevos do que vos digo.

Also, those very sounds

Ademais, eses sons

tend not to be represented

tenden a non ser representados

by the characters that are available in European languages.

polos caracteres que están dispoñibles nas linguas europeas.

Here's one of the culprits.

Esta é unha das culpables.

This is the letter sheen,

A letra SHeen,

and it makes the sound we think of as SH -- "sh."

que soa como a nosa "xe" en "peixe"

It's also the very first letter

Tamén é a primeira letra

of the word shayun,

da palabra shalan,

which means "something"

que significa "algo"

just like the the English word "something" --

como na palabra inglesa "something",

some undefined, unknown thing.

unha cousa indefinida e descoñecida.

Now in Arabic,

En árabe

we can make this definite

podemos convertir isto en algo definido

by adding the definite article "al."

engadindo o artigo definido "al".

So this is al-shayun --

Así que isto é al-shalan,

the unknown thing.

a cousa descoñecida.

And this is a word that appears throughout early mathematics,

E esta é unha palabra que aparece nas matemáticas antigas,

such as this 10th-century derivation of roots.

coma nesta derivación de probas do século X.

The problem for the Medieval Spanish scholars

O problema para os académicos medievais españois

who were tasked with translating this material

que tiñan que traducir este material

is that the letter sheen and the word shayun

é que a letra SHeen e a palabra shalan

can't be rendered into Spanish

non se poden reproducir en español

because Spanish doesn't have that SH,

porque o español non ten ese SH,

that "sh" sound.

ese son do "xe".

So by convention,

Así que acordaron crear

they created a rule in which

unha regra pola cal

they borrowed the CK sound, "ck" sound,

tomaban prestado o son K, o da letra "q",

from the classical Greek

do grego clásico

in the form of the letter Kai.

na forma da letra khi.

Later when this material was translated

Máis tarde cando este material foi traducido

into a common European language,

a unha lingua europea común,

which is to say Latin,

é dicir, o latín,

they simply replaced the Greek Kai

simplemente substituiron o Khi grego

with the Latin X.

co X latino.

And once that happened,

E unha vez que aconteceu iso,

once this material was in Latin,

en canto ese material estivo en latín

it formed the basis for mathematics textbooks

pasou a ser a base dos libros de texto matemáticos

for almost 600 years.

durante case 600 anos.

But now we have the answer to our question.

E agora temos a resposta á nosa pregunta.

Why is it that X is the unknown?

Por que o X representa o descoñecido?

X is the unknown

X é o descoñecido

because you can't say "sh" in Spanish.

porque non se pode dicir "xe" en español.

(Laughter)

(Risas)

And I thought that was worth sharing.

E pensei que merecía a pena compartilo.

(Applause)

(Aplausos)