The Physicist’s Rabbit Hole

A physicist, a mathematician, and an engineer are all attempting to measure the volume of a plastic ball.  The mathematician derives a theorem that allows her to prove to herself she can find the volume of any such ball.  The physicist explains that the ball’s volume is infinite because the outer electrons of its atoms are only probably in the vicinity of the ball but could be anywhere in the universe.  The engineer pulls out a table of plastic ball volumes and decides to assume the ball in question is like entry #4.

Jokes like that one – yes, that was supposed to be a joke – proliferate in the engineering circles in which I run, poking fun at the way engineers do their jobs by way of making a lot of assumptions.  This one shows up often in basic orbital mechanics: assume the Earth is a uniform point mass.  This “uniform” assumption is particularly common: uniform planets, uniform distributions, uniform beams, uniform heating…engineers couldn’t do their/our jobs without making assumptions, and a lot of real engineering is about knowing which assumptions are appropriate to make in a given circumstance.  As a species, we just don’t know enough, nor have the technology to implement the knowledge if we had it, to engineer things without making assumptions.

As much as I advocate the importance of questioning everything, remind myself of Socrates’ line about the beginning of wisdom (“the beginning of wisdom is in knowing you know nothing”), and encourage the salience of why beyond relegation to an unfortunate and oft-maligned childhood phase, I am as guilty as the next engineer of making assumptions.  Making explicit assumptions is a necessary evil; the assumptions we don’t realize we’re making are far more pernicious.  They limit our worldview, whether they are the assumptions I sometimes refer to when we talk about storytelling, or more fundamental assumptions about the way the world works.  These can be the most difficult to question, because you have to change your very thinking even to realize they’re assumptions.

Reading Charge: Why Does Gravity Rule prompted me to think about assumptions afresh, and specifically the assumptions we make about how the world works at fundamental levels which we must learn to question in order to advance our understanding of the universe.  The book was a reminder that there is always another layer to peel back, and to not be satisfied with the current less wrong answers we might have to questions we might ask.  The seemingly familiar phenomenon of electricity, which we have harnessed in so many intricate ways to achieve such amazing feats, and which I once heard brilliantly described as a magic system that does one thing with which we have contrived to run the entire world, is not so well understood when you start attempting to look deeper into it, when you ask more of those why questions.

What is electricity?  The flow of electrons…but if it were just the flow of inert particles, it would not behave the way it does.  These particles have charge, but what is charge?  Ultimately, we don’t know, even now, other than describing it as a property of certain particles.  Why do some particles have charge and some particles do not have charge?  Why does charge come in the intervals it does?  These are the sorts of rabbit holes down which physicists peer in an attempt to answer these questions, and to find the next question to ask.  The truly brilliant part, beyond realizing that these are questions we should be asking, is the clever mechanisms which they devise to probe them and seek answers.

How far should you go?  Asking these questions, digging deeper into the mysteries of the universe, expands the mind and helps us think in new ways, but our time is limited, and you can dedicate an entire career (indeed, people do) to plumbing a single line of questioning.  I tend to say you should go as far as your curiosity will take you, and then ask one more question.  That’s how I try to keep expanding my mind.  After all, a good storyteller, like a good engineer, needs to know what assumptions to make, and be aware of the assumptions which could undermine a project.