btw these large scary math symbols are just for-loopspic.twitter.com/Kq6dcihPp4
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
I think that falls into the same camp as using a fancy-sounding Latin phrase instead of the mundane-sounding [whatever your native language happens to be] equivalent. QED ;)
Sigma is very basic notation and is taught in any decent first-semester calculus class. Analysis of algorithms requires understanding summations. Algorithms are a foundation of computer science (with or without quotes).
That has nothing to do with it. I know sigma notation, but it is much slower to read than a for loop if you work with computers. People who program regularly read for loops faster than sigmas, if they are of any appreciable complexity.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.