That famous symbol (click for source)

## I don’t remember a lot from my high school Physics class, but I do remember liking a lot of it.

I’m one of those people that when it comes to specific recollection can struggle quite a lot, but then has moments of perfect recall for no apparent reason. So despite my enjoyment, much of the field of physics is completely forgotten to me.

For people in my scenario, some of the things you are most likely to remember are useful and simple formulae and constants.

For example (of the top of my head):

• pi = 3.14
• Force exerted by gravity on Earth (g) = 9.8 m/s^2
• Force = Mass X Acceleration
• Kinetic Energy = 0.5(mv^2)
• Potential Energy from gravity = mass X g X height from surface

And that’s about it, right now. Not so great, I’m sure I could come up with more, with time.

Something else though… everything here is wrong.
But at the same time… everything here is right.

How can that be?

##### “Context always matters.”

I think is was Adam T. Glass that specifically said this to me, but it was in a Twitter conversation with him and Frankie Faires, so it was almost a dual statement, really.

One thing about the nature of information is that how useful it is is highly contextual.
Something that may be a critical point at one time is useless noise at another.
“Go for the kidneys!” may be great advice during sparring, but it certainly doesn’t mean I need it being yelled at me 24/7, for instance.

Everyone knows that pi doesn’t really equal 3.14 (I should hope) but that it actually represents a seemingly never-ending number, merely rounded to a convenient 2 decimal places.
As such, that means that the summation is wrong; it isn’t 100% accurate.
That definitely does NOT make it useless, however, it makes it usable.

Think about it. If you wanted to calculate the circumference of a circle, when you only know its radius (a common use for pi), and you wanted a 100% accurate answer,you would likely never complete the task.

How could you? Why should you?

##### Everything’s a guess; some better, some worse.

As human beings, we aren’t really equipped to be accurate. If we were naturally equipped for perfect accuracy, why would we have invented electron microscopes? Or rulers, for that matter?

What we ARE good at is fast approximation to a useful degree.

• I may not know EXACTLY where a ball flying through the air will go, but I can guess well enough to catch it.
• I may not know EXACTLY how much force I need to move an object at a certain speed, but I can guess well enough to get close.
• I may not know the EXACT distance between 2 points, but I am equipped to take a stab at it!

Estimation needs assumptions to work. This is a blessing, as it allows us to operate at greater speed (instead of calculating pi for the rest of eternity), and a curse, as it makes accepting assumptions become very natural behaviour and this can become a Dangerous Thing.

##### What can you use?

There’s a good reason that certain material has stuck in my head better from high school; I would say that it was because these were things I could use.

It is very easy to get caught up fretting over what’s “best” or “right” and lose sight of what is actually usable and what isn’t.
Next time you find yourself caught up in the details of a matter, try taking a moment and asking yourself how much detail you need and how likely it is to change your actions.

Maybe if you’ve already got your 3.14 you should move forward for now?