Two of my villages have 13 peeps and 5000+ food points. Can I safely leave them all on Research at 2x speed for 12-15 hours or so?

I don't want to go forward with the puzzles (have done about 5-6 of them, just to get to the lagoon or so) until I have the level 3 Medicine and Science. Both of those require huge amount of tech points, so I have almost everyone working on it -- at least, when I am watching them. What they do when I'm not around is their business, but I just know they are all swimming, arguing, and staring at that stupid boulder.