Friction: Getting Started
In introductory physics classes, many of my favorite problems were about friction. They would go something like this: you lean a ladder against a wall. How close does the ladder’s bottom have to be to the wall for it to hold your weight?
My favorite teachers — like my high school physics teacher, Dr. Roland — would give elaborate stories to go with the problem. Sir Lancelot must reach the treasure in the tower, but it’s across a moat filled with piranhas. If he stretches the ladder across the moat to the far wall, will it hold him up? Or will it slide out from under him and drop him to the piranhas?
These calculations all rely on friction. The standard equation for a force from friction is:¹
F = μ*m*g
where F is the force of friction,
μ is what’s called the coefficient, which depends on the material (that’s the Greek letter “mu”),
m is the object’s mass,
and g is the planet’s gravity.
All these factors make sense. Of course μ would be different for each material, since sandpaper and ice cubes handle friction very differently. It also makes sense that friction would depend on mass, because it’s harder to push heavy things. And it would be easier to push things on the moon, where there’s less gravity. Those are all expected.
But what’s most interesting to me about this equation is that it changes, depending on whether the thing you’re pushing is already in motion. If you’re pushing a wooden bookshelf across a wooden floor, μ is .5 before you get it moving. But after you get started, the number drops to .2. This is also pretty intuitive, but I like how science confirms it. Anyone who has moved furniture before knows that it’s best to slide a heavy thing in one smooth push instead of several smaller bursts.
What I also like about this is that it applies in life too. Starting something is the hardest part. You could be trying a new exercise routine, getting up early, or starting a spiritual practice like reading scripture daily. Whatever you’re trying, it will take the most effort at the beginning.
People disagree over exactly how long it takes until a new habit becomes automatic in your life. Maybe you can make real progress in a week, but it will likely take longer for it to truly take hold. However, everyone agrees that the hardest part is at the beginning.
Writing is a good metaphor for this. As Stephen King says in his great memoir On Writing, “the scariest moment is always just before you start. After that, things can only get better.”² If you persist and chip away, you allow yourself to get into a rhythm. Once you’re in motion, your momentum helps carry you forward. Your coefficient of friction drops down, and it’s easier to keep going.
But you can only reach that place once you’ve cleared the hurdle of beginning. In both physics and life, you just have to get started first.
 It’s technically a little different if you’re on a hill, but that doesn’t matter much here.
 On Writing, Scribner, 2010. Pp269.