Why is “X“ The unknown?

In the first speech, the speaker, Terry Moore proposes one question, he asks why the letter X represent the unknown?. As an analyser this video it also become my question, we usually get the letter X in Mathematics class, the speaker told that, about six years ago he decided to learn Arabic, in his opinion, Arabic is very logical language in writing words,  phrase and sentence and every part of it carries a lot of information.

One of system to compare the different part of Arabic language call Al-Gebra, in the 11th and 12th centuries there was tremendous interest in translating Arabic into European language, but the problem is there are some sounds in Arabic that just don’t make it through a European voice box and the sound not to be represented by characters that are available in European language, the letter is Sheen, the sound is SH, the first letter in the word “ Shaian” which mean “something” if in that word we add “ Al” become Al-Shaian ( the unknown thing) which in English word “ something” it means some undefined or unknown thing.

In this video, the speaker continued that this the problem for the Medieval Spanish scholars who were tasked with translating this material, the letter SHeen(SH) can’t be rendered into Spanish because there is no letter SH in Spanish. So, by one convention they decided to create a rule, which they borrowed the “Ck” sound from classical Greek, they replaced the Greek Kai with the Latin X.

In the last speech, Terry Moore concluded that the reason why the X is unknown because we can’t say “SH” in Spanish, the audience laugh listened to his statement and at the last he said, it was worth sharing. Then all the audiences give applause for him.

I think, this is very short video and very nice to analyze it and the talk is funny, the speaker gave a surprising answer to the question why “X” is the symbol for unknown.