Where did he get the 2050ish number from?

Have you ever chatted with a bot before? They're not so advanced. Even if they could get good enough to trick a human into thinking it's a person, it'd still just be automated responses and wouldn't signify self-awareness.

What is this theory anyway, I don't see how it's "technological singularity" it sounds more like it should be called the "terminator" theory from this youtube video.