[@Yuuta] I'd like to know how advanced science and mathematics are exactly in the world everyone came from.  I gave Zeke lenses and knowledge in optics, which is more of a 1600s concept.  His profession would also require the awareness of heliocentrism, as he's an astronomer.  At this time period would be calculus, gravity, cell theory, all-important oscillatory motion, and of course we can't forget Newton's Laws.  Are these too far ahead of your world?  How much is allowed?