## Archive for June 1st, 2012

### Leaps and Bounds

SMBC: Terminology

(Clear throat, ascend high horse) Quantum does not mean small. Quantum means discrete. The opposite of quantum is continuum, not big.

### Within Epsilon of the Truth

Excellent Approximations and Lying to Children

[I]t’s true that Euclidian geometry is only a special case of the mroe general geometry of spacetime. But it’s an amazingly good approximation to any situation you will ever encounter. Which is why we teach it to children– because it’s vastly simpler, and the cases where it doesn’t work are very far from everyday experience.

The post on which this comment is based seems to propose doing things the hard way — why teach non-Euclidean geometry without having the foundation in Euclidean geometry. Do you really want to teach that kinetic energy is $(\gamma -1)mc^2$   and, perhaps more importantly, do you want to derive how you got that, rather than going with the Newtonian approximation that’s going to hold as long as you are limited to everyday speeds?

Physics curricula aren’t perfect — I think e.g. the Bohr model can do more harm than good — but then again that’s not really an example of a model that’s approximately correct. The suggestion that we abandon teaching classical physics and instead we dive into quantum and relativistic topics (starting with lasers at Eight O’clock on day 1) means explaining the details while simultaneously trying to get across basic ideas like forces and energy. I think that’s a lot to ask a student to digest.