I thought this would take longer....It's been 18 hours. A day and a half.... and I have the beginnings of sour dough. It's bubbling away already. Can you tell from the pictures?
Here is what John Ross says:
Within 3 or 4 days (it can take longer, a week or more, and it can happen more quickly) you should start getting lots of bubbles throughout, and a pleasant sour or beery smell.
Okay, it has begun to have bubbles throughout, but it doesn't smell sour or beery yet.
I will give it another day.