A lot of science requires lots of tedious drudgery - be it observation (e.g. ecology / animal behaviour etc.), lab work (e.g. testing novel compounds behaviour against cancer cells) etc.
Theoretical physics is quite different to a lot of science as many theories are hard to test due to us not having the skills / knowledge to build suitable measuring / particle production yet - so you get lots of ideas thrown around that are hard to disprove.
Your everyday journeyman science is not really leap of faith based - yes people have a novel idea, but then its normally quite straightforward (if sometimes slow, expensive, difficult) to conduct experiments to see if the idea has legs
As for leap of faith, Hawking has admitted many of his early theories were wrong - that's science in a nutshell - if your idea is disproved / improved upon (e.g. Newtons laws of motion are great at "normal" conditions but break down in more extreme scenarios which were not really thought about at the time & currently relativity helps to "expand" Newtons ideas by helping explain), then great, it means we now know more than we did.
Plus science is typically collaborative, if you are researching cancer cures you fervently hope (for peoples benefit) your work is improved upon in future (that may be at odds with teh accountants and their ideas of patents etc. !)