What is the Universal Language?

I was reading a great journal entry the other day by a French woman who writes science fiction in English. She was discussing the different aspects of writing in her second language English that are most challenging. Along with grammar she describes usage as a difficult point. I can relate to this because I live in a country in which Spanish is spoken and is my second language and English my first. It is important to understand how certain phrases are used and in what context. I have even purchased some science fiction that has been translated from English to Spanish, and if the translation was done in Spain, the phrases can be very different from those in Mexico. I can tell right away when a book was written or translated in Spain vs. Mexico. Seeing that in one language there can be differences in usage, translating from one language into another can be difficult and inevitably, a little(only a little if it is a good translation) is lost in the translation because sometimes what is said has a cultural and historical root meaning.
When I watch science fiction shows where everyone is speaking in English it makes me laugh. If we have trouble here on good ol' Earth, how could we suddenly understand people from other worlds? The question of culture, language, and history would all be a factor in understanding each other. Or better yet, I really laugh when worlds are presented to us that have one single language, way of life etc. The better written science fiction novels present us with complicated worlds that have diverse languages and cultures.
Star Trek has the universal translator that seems to be ever present but I imagine it is better to have a human translator ( or alien as the case may be) and everyone should become as advanced in foreign language as they appear to be in science and technology. I understand that we are watching a show or movie in English and it would be very tedious to create new languages, but I like pondering the idea of alien vocabularies and for that matter I wish I could speak more Earth languages than I do!
Anyway, I like the journal entry and you can read it here.