The Paradoxical Power of Uncertainty

Carl Sagan once said “Science is a way of thinking much more than it is a body of knowledge.” See Figure 1 (left) for an example.

In this insightful comic, the way that the scientist thinks has a defining characteristic: uncertainty.

For the “normal person,” one piece of data is enough to produce a certain conclusion about cause (*pulls lever*) and effect (ZAP). But the scientist will not claim certainty in her theory that pulling the lever causes a “ZAP.” In her mind, this theory must be tested many times by many different people under many different conditions.

Even then, when documenting her findings in a report, she would state all conceivable reasons why this conclusion might be wrong. Then, in future studies, she (or another scientist) will test all of those possible reasons – while also listing the ways that those data too could be wrong.

This bent toward persistent uncertainty is what drives discovery.  That is, if scientists were content with the current state of knowledge, scientific progress would grind to a halt.

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Science is just one way of understanding the world. Other modes take a very different approach: such as prioritizing certainty and demonizing deviations from the canon of dogma.

Paradoxically, science’s special relationship with uncertainty is what makes it so trustworthy. Almost every scientific theory – from physics to paleontology to psychology – is repeatedly bombarded by a barrage of rigorous stress-tests, in which skeptical experts try to find ways in which that theory does not quite fit the evidence. This perpetual assault on the status quo is precisely why we can trust science. Bad ideas are consistently exposed. The reigning best ideas are consistently challenged. Better ideas eventually rise to the top.

We used to think the Earth was flat. Then we thought it was a sphere. Now our best data shows it’s not quite a perfect sphere – it’s slightly wider at the waist. In the future, we’ll probably be proven slightly wrong and have to adjust our opinions accordingly. But being proven wrong is a good thing. Science is process by which opinions become gradually more correct.

And then one of us discovers something that upends the entire paradigm — which opens a whole new box of uncertainties. And we all benefit from it. It’s how we move forward.

I love that.
I love that we aren’t stuck with the imperfect ideas we currently have.
I love that we aren’t forced to defend imperfect ideas.
I love that even when we think ideas are pretty darn good, we keep challenging them anyways.

The persistent uncertainty of science is what makes it so powerful.