Did I post this already? I don’t think I did. Hopefully not.
Why are Twitter messages 140 characters?
Because they were designed to fit into the 160 characters of a text message, with some characters filled up with header information and so on.
So why are text messages 160 characters?
Because they fit into 140 bytes, or 160 7-bit characters.
That, in turn, was so the messages could fit into unused space within the signalling formats used by phone networks.
- How Twitter was born
- The Wikipedia entry on SMS for lots of geeky stuff about its origins.
- Telstra brochure from 1997 explains new-fangled “text messages”