Kevin Williamson‘s latest column at National Review Online reminds us that Neil deGrasse Tyson is full of it.
Being an astrophysicist, Neil deGrasse Tyson is familiar with event horizons. He needs a refresher on epistemic horizons.
An event horizon (the term is generally associated with black holes) is a boundary in spacetime surrounding a massive object exerting gravitational force so great that nothing that happens within the borders of the event horizon can ever affect anything outside of it. Which is to say, the escape velocity is equal to the speed of light, meaning that you could spend an eternity staring into it and never see what’s happening inside. If you got close enough to take a peek . . . the result would be what British astrophysicist Martin Rees calls “spaghettification,” and nobody wants to suffer that.
An event horizon is something you cannot see into. An epistemic horizon is something you cannot see out of. …
… Professor Tyson, who may be the dumbest smart person on Twitter, yesterday wrote that what the world really needs is a new kind of virtual state — he wants to call it “Rationalia” — with a one-sentence constitution: “All policy shall be based on the weight of evidence.” This schoolboy nonsense came under withering and much-deserved derision. Conservatives, who always have the French Revolution in their thoughts, reminded him that this already has been tried, and that the results are known in the history books as “the Terror.” Writing with a great deal of reserve in Popular Science, Kelsey D. Atherton notes:
Rationalia puts a burden on science that it cannot bear: to work, it must be immune to the passions of the day, promising an objective world and objective truth that will triumph over obstacles.
That’s true enough, but it shortchanges the scientific objection to Tyson’s Rationalia pipe dream, which is that it implicitly presupposes quantities and types of knowledge that are not, even in principle, available, even if the scientists in question were the dispassionate truth-seekers of Atherton’s ideal.
The epistemic horizon is not very broad. We do not, in fact, know what the results of various kinds of economic policies or social policies will be, and there isn’t any evidence that can tell us with any degree of certainty. The housing projects that mar our cities weren’t supposed to turn out like that; neither was the federal push to encourage home-ownership or to encourage the substitution of carbohydrates for fats and proteins in our diets. A truly rational policy of the sort that Tyson imagines must take into account not only how little we know about the future but how little we can know about the future, even if we consult the smartest, saintliest, and most disinterested experts among us.