This is a funny way to make a big abstract point, but bear with me, because rocket golf.

Rocket Golf, specifically, being Randall Munroe’s latest “What If?” question:

Assuming that you have a spaceship in orbit around the Earth, could you propel your ship to speeds exceeding escape velocity by hitting golf balls in the other direction? If so, how many golf balls would be required to reach the Moon?

Using his trademark mix of being really smart and being really funny, Munroe manages to get the number of golf balls down to a “reasonable” number, but concludes:

my alt text feels inadequate to the task of an xkcd image

There’s the small problem that manufacturing that many golf balls would cost quintillions of dollars.

This is both technically true and, really, totally meaningless; yet really important! Let me explain.

Firstly, I checked his math, and his number is correct. A sphere ~150mi in diameter could contain as many as ~180 quintillion golf balls.

Golf balls: not cheap! Even if you get them recycled:

used to propel amazon drones

Even if you got some crazy economies of scale, you’d end up spending at least $1 quintillion ($1qt?) on golf balls.

To put that in context, the total sum of US GDP since WWII has been around $337 trillion. Based on that estimate, I would probably guess that, if you used the right deflators and made a few assumptions, that gross world product since the beginning of agriculture would probably be less than $1qt.

So what does that mean? Well, it means we can’t make enough golf balls to rocket our ship into orbit. But why? Not because we don’t have enough money – the government could print a $1qt bill and call it a day (obligatory picture to follow):


But that wouldn’t get us enough golf balls. That’s because golf balls are made from rubber and resin; basically, trees, and also probably some petroleum. And there aren’t enough trees on Earth to make over a quintillion golf balls:

you think it's bad now, just wait until generalissimo munroe seizes power

So its not that the “quintillions of dollars” estimate is wrong, per se; it’s that a number that big is telling us to stop thinking about money and just realize that the project is beyond the scope of the economy to accomplish.

Fortunately, rocket fuel is more efficient than golf balls.

Also, hooray for snow days.