Donald Trump says that “no one knows what magnets are” during a strange Oval Office press conference. During the swearing in of a new ambassador to India on Monday (10 November), the President launched into a rant about China, whilst discussing their recent agreement to start easing rare earth export rules. “China was going to hit us with rare-earth. Now, everybody says, ‘Oh, what does that mean?’ Magnets. If China refused to give magnets, because they have a monopoly on magnets… there wouldn’t be a car made in the entire world.” He then claimed that “nobody knows what magnets are”, before going on to praise the “great deal” the two nations made in October. Whilst the talks did not end in a formal agreement, Mr Trump agreed to reduce tariffs on some Chinese goods entering the US, whilst Beijing agreed to suspend export control measures it had placed on rare earths.
Having worked in my checkered past in aerospace for a decade or so, there’s a very small grain of truth in that. While there is a lot of enginneering that goes back to first principles (physics and math), there are also what are euphemistically called “empirically determined constants.” That’s because, even when the equations are known, they can sometimes be a pig to actually compute (“ill-conditioned”), requiring absurd amounts of computer power.
So if I were on the plane next to that couple, I’d have said “Yep, we’re flyin’ on a wing and a prayer and there’s a non-zero chance we could auger into the ground at any time. But don’t fret, it doesn’t happen all that often.”