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## Beyond spherical cows

So I’m attending a workshop at the Clay Institute right now. After having to wake up yesterday at 3 am to catch a flight and the usual “I’m too tired to be able to get anything done”, I thought I would post something light. If I’m in a really good mood I might even consider blogging about the workshop, but don’t count on it.

I thought it would be nice to tell you that in physics we don’t just make oversimplified models of cows, like a spherical cow. We also sometimes do more complicated models as well, and hope to say something useful with them. It’s just that it doesn’t always work the way one wants to and one has to learn that models are only good insofar as they actually help you in solving a problem.

A spherical cow eating square grass.

Here to my left is a cow eating grass. Notice that this is a more sophisticated cow than “just a spherical cow” because this one is doing something more than just rolling in the ground.

A spherical rat: a bad model of physics.

Sometimes our models are not really robust like cows, but they have the personality of a rat: if you look at them too much they run and disappear. But before that, they might bite you. They can also eat your good ideas and leave a lot of holes in them. When one invents a model, one has to look at it carefully to see if it is a rat or not. If one finds oneself trapped with one of these, there is only one thing one can do.

A spherical cat: eats spherical rats for breakfast

One has to call for a spherical cat. These are the models that eat other bad models for breakfast. They are spherical because of their over-indulgence in eating other models. These are the guys that show that spherical rats are what they are, and after playing with the rat for a while, they kill it without mercy.

Spherical cats also show up in quantum mechanics. They were a favorite pet of Schrodinger

And if your pet cat looks like this, put it on a diet. The vet can help you with that.

## Scientific notation for money.

Where I was born, a billion was $10^{12}$, this is, a million millions. However, when I moved to the USA, I learned that a billion should be $10^9$, while a trillion should be $10^{12}$. But in the long notation a trillion is $10^{18}$: a million billions. You can imagine that this is very confusing, especially when talking about money. If you want to get confused, read the wikipedia. This is why I propose that we do away with all those phony numbers when we talk about money and use scientific notation instead.

## Should you trust statistics?

OK, so I admit I occasionally wander around and fill random tests on the web as well. It seems a lot of people do, so what is the harm in admitting it?

This is not a rhetorical question. One might do a bit of social calculus: does filling this test say something about me? What will my colleagues think of me for admitting it? Will I go up or down on their esteem? By how many points? Will they forget quickly or will they remember this and tease me forever?

## Hook’s law: Peter Pan must walk the plank.

Yarr, ye scurvy dogs. Me here talkin’ pirate, seeing as it’s talk like a Pirate day (Thanks Todd) and me thinkin what would Pirate’s physics must look like. Being prone to long explanations and other yarring expletives, methinks we shall talk about proper designs of planks fer walking the plank.

Seeing as planks are ye olde version of good ole trampolines, we should be talking about trampolines and other springy designs to entertain the pirate, modern and old, yarr. And we be seein’ you turned into chum, yarr. So stay hooked fer we wil talk endlessly about our honorary Pirate, ye olde Robert Hooke, friend and chum of ye olde Captain Hook.

## My sword is longer than yours.

Well, that is what I imagine a friendly bet over beer in the middle ages would look like. Let us say two vikings taking a break after some invading of Europe. Not that things have changed that much. We still have silly bar bets over the sizes of *ahem*…

Graff and Olaff are in desperate need of a meter stick.

So after some potato bliss, I had to think at great length about how to introduce some other elementary (in the sense of being fundamental, not easy) physics concepts. You see, it is hard to talk about physics without the three basic elementary irreducible concepts: mass, length, time.