On September 20, 1982, long before emojis and AOL Instant Messenger, Carnegie Melon professor Scott Fahlman wrote the following on an online message board with fellow computer science geeks:

I propose that the following character sequence for joke markers:


Read it sideways. Actually, it is probably more economical to mark things that are NOT jokes, given current trends. For this, use


And just like that, the course of human communication was altered forever. Here's to you, Scott Fahlman. Smile on.

[via CNET]