They don't.
The scientific method requires independently verifiable evidence.
It's also very results based. We don't need to be theoretical physicists to realize that relativity and atomic theory are quite accurate, because GPS works and nukes explode.
You have to have faith in the people that did the experiments and the research and dug up the artifacts.
No.
You require such "faith" when a religious person says they witnessed a miracle. Because you have nothing else but their word for it and it isn't independently verifiable, so there is no evidence. Only anecdote.
You don't require such "faith" when it comes to the conclusions of a scientific experiment detailed in a published paper, because by its very nature it will have a form factor that
requires evidence and independent verifiability. It will also have been peer reviewed (which is to say, peers will evaluate the methods used of the experiment, see if the conclusions are sound based on the data, review the data itself, etc).
After publication, other scientists will jump on it and review it also, build further upon it, conduct new experiments and / or repeat the experiments, compare the results, etc etc etc etc.
The process by which scientific conclusions are obtained is very very rigorous.
In some cases it took scientists
decades to have their ideas accepted by the community eventhough they were spot on on day 1, for the simple reason that their evidence and methods were lacking in peer review or -for whatever reason- the experiments couldn't be repeated and / or evaluated right away.
Take Big Bang Theoy for example. Did you you know where the name "big bang" came from? When George Lemaitre (a physicist and catholic priest, btw) came out with his theory of an expanding universe in a world where the consensus was a static universe, he was met with laughter. He didn't name it "big bang". Other people did that, in a derogatory way. But then the evidence accumulated and eventually the community accepted the theory as the best explanation.
This just to show you how the scientific process
actually works.
When somebody comes with a new idea / hypothesis, it is
NEVER just accepted on their word. Ever.
Evidence is required.
And sure, it can still turn out wrong in the end. The point is, "faith" is not part of the equation.
The entire scientific method is geared
specifically to the opposite of that.
Whenever as a scientist you invoke "faith" to reach a conclusion, even just a tiny bit, your idea will be rejected at face value. They'll tell you to try again and to use evidence instead of "faith".