Like in arctic, if we know its supposed to be prononced ar [as in arse] tick, not ark tick; why is the extra c there? And why aren't such letters thrown away [where doing so would not make a word with some different meaning]?
The short answer: Unlike every other major European language (except French, which is even worse), English has never had a serious spelling reform.
The language of Modern English didn't really arise until around the 14th century, when the Norman French who ruled England were assimilated into the English population and English replaced French as the language of government and business. Since up until that point English had never been an official language, the few people who both:
- Knew how to read and write, and
- Wanted to bother to write in English,
just tried their best to write words phonetically the way they sounded
in their own regional dialects. This was especially hard because they were stuck with the Roman alphabet, which does not have nearly as many letters as there are sounds in English.
On top of that difficulty, there were three additional problems.
- Because of the Norman occupation, a zillion French words had been adopted into English, and they were written in their original French spelling. This is why "parcel," "queue" and "tableau" are not spelled "parsel," "kew" and "tabloe." It also answers the specific question about "arctic." That C was already silent in French but it just got carried along.
- The second problem is that English phonetics underwent some phenomenal changes since then. Long A, E and I were once "ah," "ey" and "ee" as in most European languages. The E at the end of "wife" and "gone" wasn't always silent, and neither was the GH in "night" or the W in "two." These are just a few of the most prominent phonetic shifts. English words were spelled a lot closer to the way they sounded in those days.
- Finally, as England and later the USA became centers of culture, diplomacy, science and scholarship, our language assimilated thousands of foreign words, usually with their original foreign spellings.
The reason that English spelling was never modernized and normalized as it was in German, Spanish, Italian, Czech, Portuguese, Swedish and many other languages is that there are too many regional accents. If we spelled a word as it's pronounced in London, that won't be the way it's pronounced in either Birmingham, West Midlands, or Birmingham, Alabama. So for most anglophones there would be no advantage, and the results would not be worth the tremendous time, effort and confusion.
Many people today pronounce the C in "arctic" and "antarctic" because they think it's correct and they're trying to pass themselves off as more educated than they are. These are the same people who pronounce the T in "often" (it's been silent for 200 years) and who think that the past tense of "to dive" is "dove" (it's "dived").
I'm waiting for someone to start a fad of pronouncing the S in "island." At least the C in "arctic" and the T in "often" have some vague claim to historical authenticity. But the spelling "island" is a lexicographer's mistake! Somebody in the Dark Ages thought it was related to the word "isle," which is of French origin. It's actually a native Anglo-Saxon compound,
i-land, meaning "water land," i.e., "land surrounded by water."
It's impossible to start correcting ancient spellings. Everybody knows the old way. So do our spell checkers. The countries who did it had either:
- An extremely strong authoritarian government that just mandated the changes, like Germany.
- One region that was dominant culturally so the rest of the people grudgingly accepted its spelling, like Florence in Italy.
The UK and the USA will never accept an "improved" spelling system that represents the other country's pronunciation. Is it "father" or "fathah" -- "just" or "joost" -- "labratory" or "laboratry" -- "skejool" or "shedyool"?