eating cucumbers without permission...

The main lesson I’ve learned from the astronomy-themed lectures so far is, “The universe is very large, and subatomic particles are very small.” Okay, that’s a little unfair. There’s been a lot of discussion of the scientific method and of the history of cosmology, but I’m not going to bother writing up my notes on most of it.

One thing that came up was a strange joke about astronomers and sheep.

It went something like this:

An astronomer, a physicist and a mathematician saw a sheep standing in a field. “All sheep are black!” says the astronomer. “No,” says the physicist, “all we can say is that some sheep are black.” The mathematician shakes his head and says, “No, all you can say is that there exists at least one sheep, at least one side of which is black.”

And then the lecturer asked, “What would a philosopher say?”

I don’t really know. Maybe, “the sheep, like you, are figments of my imagination.” Perhaps “there’s always a chance I’m a brain floating in a vat on Rigel IV; I can’t say for sure”. Or “all sheep are black by definition; a white sheep-like entity is not a sheep”. Best to shut him up if he asks back, “What is ‘black’? What is ’sheep’?”

A reasonable philosopher would probably point out that all three statements might be correct, though the mathematician’s is least likely to be falsified.

The point of the exercise was to illuminate differences in thinking across disciplines, but it seems rather silly. I’d imagine it’s rather hard nowadays to become a physicist without also being a mathematician, and that probably holds true of professional astronomers too. The differences are in scope and methodology. I prefer this analogy:

An astronomer, a physicist and a mathematician are standing in the middle of a field, surrounded by sheep, drinking lukewarm tea from plastic cups and a thermos. The astronomer looks around and exclaims, “All sheep are black!” He continues to watch avidly as they drift around, ever so slowly, doing nothing much at all.

The physicist idly replies that there doesn’t seem to be a theoretical reason for white sheep not to exist in another field, or even just further away in this field. It’s not his fault that the astronomer is myopic.

Turning his attention to things closer, he notices that they’re standing in a strange black substance. He hypothesises that the same material is present on some of the animals, and decides to conduct an experiment. Namely, he throws his cup of tea onto the nearest sheep. The black washes off, leaving a white streak.

While the astronomer and the physicist argue over whether to call the blackness “caliginous energy” or “aphotic phase space”, the mathematician whips out a napkin and deduces from first principles an equation describing the situation, coincidentally proving that the field is, in fact, a beach; the “sheep”, seals, suffering the fallout from an unfortunate collision between two oil tankers.