Transcriber: Pedro Magosso Reviewer: Thomas Bedin
Hey all. Today, I would like to share my thoughts and ideas about Letter X.
Letter X can mean many different things.
For instance, it can mean X-ray, spaceX.
It can also replace the Christ part in Christmas to make it Xmas.
There are infinite possibilities of what it can mean, even TEDx.
But when I think of letter X, the first thing that hits me is the variable used,
in maths. In many math tests we’re asked to find out the value of X.
We use X because it means “an unknown thing” when translated into Arabic.
There’s a phrase in Arabic called al-jabr and al-jabr roughly translates to:
the system for reconciling disparate parts.
Then al-jabr came to English and became algebra.
One example among many. Math and Arabic both interest me a lot.
Math interests me because it always gives me an extra challenge
to face. Arabic is a new language for me and it interests me in
the same way maths does. It gives me an extra challenge.
Here in the UAE, we learn Arabic in our schools.
When I first came here, I only knew one word in Arabic: “marhaba”.
But after my first few lessons,
I realized that it was a supremely logical language.
To write a word or phrase in Arabic is like copying an equation
because each word or sentence is extremely precise and carries
a lot of information.
The Arabic text containing this mathematical wisdom finally made its way
to Europe. To be more specific, Spain.
In the 11th and 12th centuries, the twelve hundreds and thirteen hundreds,
and when this arrived there,
there was tremendous interest in translating it into Spanish.
But there was a problem. The problem was that there are some sounds in Arabic
that just can’t be said or pronounced correctly without lots of practice for it.
Trust me on that one.
Also, those very sounds tend not to be represented by
the characters that are available in European languages.
Here's one of the main culprits.
This is the letter Sheen. It’s the first letter and sound of the word shayyan,
which translates into the word something.
The problem for the Spanish who were translating this material:
There’s no “sh” sound in Spanish. So, by convention, they created a rule.
In which they borrowed the “CK” sound from the classical Greek in the form of
the letter K.
Then, when this material was translated into Latin,
they simply replaced the greek “kai” with an X to make it.
And then once that happened,
it formed the basis for the mathematical textbooks for almost 600 years.
Imagine that. But now we know why we use the letter X.
Why do we use the letter x?
We use X because Spanish doesn’t have the “sh” sound,
or because Arabic is a way too logical language?
Letter X also comes in other forms in maths,
like it is a multiplication sign.
But let’s start a few centuries ago in 1618.
OK, let's all imagine we're writing this down.
Write: 2+2+2+2+2.
If you wrote it down, it would have been very long.
The multiplication sign was idea of William Oughtred.
If you look at the plus sign and turn it around 45 degrees,
it becomes a multiplication sign.
When I told you the transformation from
the Greek “kai” to Latin X was simply moving her edges,
now all they’re doing is turning the addition sign by forty five degrees to
make it the multiplication sign. I would like to thank you all for being
an X-tremely great audience, and I am X-tremely thankful to have your attention.
And I’m X-tremely thankful for you to taking the time to listen to me.
Thank you.