“A and B” is equivalent to “B and A”, and the order matters

In math, I’m used to making no distinction between saying “A and B” and saying “B and A” — they each assert that both of the component statements are true. In fancy terms, we say that the conjunction “and” is commutative, like addition (a+b=b+a) and multiplication (ab = ba). Many mathematical operations are not commutative in general, … More “A and B” is equivalent to “B and A”, and the order matters

How to hope

Pessimism comes naturally to me. Choosing between optimism and pessimism is like asking whether I would rather be disappointed or pleasantly surprised; it just sounds safer to choose the latter. But over time, pessimism takes its toll on my mood and health, and I’ve been advised many times to be more hopeful. Until recently, I’ve had … More How to hope

Better than binary: four kinds of false dichotomy

I’ve been helping put together some materials for a new class we’re tentatively calling “Math and Public Life”, organized around ten or so concepts from higher mathematics and how they relate to the way we think about life and each other. One of the themes I’m hoping to show is that often as our understanding … More Better than binary: four kinds of false dichotomy

When is a mixture better than a middle?

We often optimize by looking for a nice middle partway along a spectrum: Exercising means challenging your body enough to respond but not so much that you hurt yourself. Astronomers look for potentially habitable planets in the”Goldilocks zones” around other stars, the bands where it’s not too hot and not too cold. It’s appropriate to … More When is a mixture better than a middle?

"I feel stupid."

“I should hang onto this piece of paper, but I don’t want to get out the filing stuff…” “I should get out the packing list and double-check, but I’m pretty sure I’ve got everything…” “If I leave now, I’ll be early, so I’ll get back on the computer and try to just check one thing … More "I feel stupid."