Much of the science that the public knows about and admires imparts a sense of wonder and fun about the world, or answers big existential questions. It's in the popularization of physics through the television programmes of physicist Brian Cox and in articles about new fossils and quirky animal behaviour on the websites of newspapers. It is sellable and familiar science: rooted in hypothesis testing, experiments and discovery.
Although this science has its place, it leaves the public (not to mention policymakers) with a different, outdated view to that of scientists of what constitutes science. People expect science to offer authoritative conclusions that correspond to the deterministic model. When there's incomplete information, imperfect knowledge or changing advice — all part and parcel of science — its authority seems to be undermined. We see this in the public debate over food and health: first, fat was bad and now it's sugar. A popular conclusion of that shifting scientific ground is that experts don't know what they're talking about.
But the questions that people face in their lives typically rely on incremental science, a kind that accumulates evidence about complex systems with numerous variables and fuzzy social parameters. It feeds into policy and decisions about how to handle environmental pollution, vaccine safety, emerging infections, drug risks, food choices or the impacts of climate change.