Half-Life of Facts

A colleague shared this article, which asks, “Should we really believe scientific facts will last forever when history is full of revolutions in thinking?” I discuss this in a recent post, The Truth about Truth.

The only thing I’ll add is the separate notion of the half-life of knowledge—essentially what we treat as fact will in fact (pun intended) not be true for one or another reason. This article gives the same case I mention, which is the invalid notion of a geocentric world. In some cases, it was true in a particular context, but the context is no longer valid. In other cases, the revision has been one of increased precision or accuracy, perhaps Newtonian versus Einsteinian physics.

Even in the case of tautological facts, things can change and meanings can shift. In the case of the colour spectrum, Newton wanted to mimic the Western musical notion of the octave, so he assigned colour names to the light spectrum when viewed through a prism, but there are two differences between his proclamation and our current understanding.

For one, what he labelled blue, we’d today call cyan. Sure, it’s in the family of blues, but when we think ‘blue’, we aren’t likely imagining cyan.

Moreover, he injected indigo to arrive at the seventh colour note, per the octave. But this was just a shoddy addition made in haste. In fact (there I go again), indigo would likely be named dark blue today.