In the first novel ever written about Sherlock Homes, we learn something peculiar about the London detective. Holmes, supposedly a modern man and a keen expert in the workings of the world, does not know how the solar system works. Specifically he is unfamiliar with the heliocentric Copernican model, which, upon its slow acceptance in the 17th century, revolutionized Western thought about the place of our species in the universe.

“What the deuce is it to me?” Holmes asks his sputtering soon-to-be sidekick, Dr. Watson. “You say that we go ’round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.”

Brains are a kind of “little empty attic,” says the detective, and they should be filled only with furniture that’s useful to one’s line of work. Holmes doesn’t doubt the Copernican model; he simply has no use for it in solving murder cases. “Now that I do know it,” he adds, “I shall do my best to forget it.”

Thursday night, as record lows gripped most of the country’s northern half, President Trump clarified that he does not understand another revolution in our knowledge of the natural order of things: the theory of human-driven climate change.

In the East, it could be the COLDEST New Year’s Eve on record. Perhaps we could use a little bit of that good old Global Warming that our Country, but not other countries, was going to pay TRILLIONS OF DOLLARS to protect against. Bundle up! — Donald J. Trump (@realDonaldTrump) December 29, 2017

Trump is wrong about the science—I’ll get to that in a moment—but, first, let’s not mince words: The president is trolling here. Pointing to cold weather and asking Whither climate change? is, by this point, almost a Republican tradition. In February 2015, Senator James Inhofe of Oklahoma brought a snowball inside the Senate chambers to demonstrate that global warming was not real. “It’s very, very cold out. Very unseasonable,” said Inhofe, then the chairman of the Environment and Public Works Committee. “In case we have forgotten because we keep hearing that 2014 has been the warmest year on record.”