“It is the mark of an instructed mind to rest satisfied with the degree of precision which the nature of the subject permits and not to seek exactness where only an approximation of the truth is possible” Aristotle.

Once there was a farmer who was not happy with his milk farm and wanted to increase the milk production. He invited 3 people to check out what was going on!

The first one was a Psychologist – who observed the farm and told the farmer to paint the walls green, so that the cows will be happy and produce more milk.

The farmer thought: Huh, if life were that easy!

So he invited another person – the Engineer – who observed the farm and said, “The milking machine is not very effective. So I will design a new one for you.”

The farmer thought: Can I get a better perspective?

Well, now he invited a Physicist – who looked around the place and drew a spherical cow on the board saying, “Let me consider a spherical cow in a vacuum, emanating milk uniformly in all directions!”

The farmer now was totally confused!

This is a joke used to explain the fact that it is impossible for scientists to model a phenomenon by getting an explanation for all factors involved in the process. It is always important to understand which factors to include in your study and which should or could be ignored. How successful you are as a scientist depends on how well you have mastered the art of making meaningful approximations.

What is the Spherical Cow all about?

Imagine that you dropped a twig into a river, and now would like to know its velocity.

There are many things you might want to consider to solve this:

♦ How rigid is the twig?
♦ Did it rotate? Or did it oscillate?
♦ How is the atmosphere?
♦ What is the velocity of the moving water?

Huh, it looks like a complicated problem, doesn’t it?

But you might be happy to simply come up with a rough number to start off with!

You would eventually ignore all of these factors and deduce a value based on the distance the twig traveled in a given amount of time. Though you might note be absolutely correct, you have simplified the problem and made it doable.

In science, we don’t need perfect models – rather we look for models that work.

The real world has infinite details that could decide the outcome, but starting with a basic model is what’s most needed to understand the velocity of the stick. Even if it means removing details, we should be okay with the unavoidable imperfection of making the most legitimate approximation. Not all factors contribute appreciably to the problem, after all!

“Having a good question, a fundamental question, and having some tools of inquiry that allow you to take the first step towards an answer – those are the conditions that make for exciting science” Herbert A. Simon