Physics and Folly: The physicist’s world



Physics and Folly applies real world science to familiar and fantastic situations. Discover the answers no one has heard, to the questions no one ever asked.

So there’s this thing us physicists do pretty much any time we have to model something about the real world: we simplify the situation. We have a basketball? Who cares about air resistance or a bit of energy lost on the bounce? Of course the ground is perfectly flat and frictionless, the ball changes direction instantaneously, and you know what, let’s not even worry about that pesky third dimension. Who needs depth anyways?

But what would the world look like if these assumptions weren’t just assumptions, but rather traits of the world we lived in? And so I present to you a new world, one where the physicists get to run the simulation for a change.

Part One: Death and destruction. Probably the most common assumption within any first-year student’s calculations is that all surfaces are smooth and frictionless.

It’s hard to say exactly how many people are driving a car at any given time, but the average American adult spends about 100 minutes a day driving in a country of about 260 million cars.

The rest of the world combined, however, only has about three times as many cars as the U.S., but if they’re all driven roughly as much as an American car is, we can estimate that there’s about 60 million people on the road at any given time, or rather, there were 60 million people on the road until friction was turned off to save on computation time.

Now there are 60 million people in a ditch, or sliding across some hapless farmer’s field, or more likely, hitting a bunch of small objects traffic cones, tumbleweeds, shrapnel from nearby collisions — which sends them scattering across a slip-n’-slide world, while their car slides with nothing but air resistance to… Hmm, that reminds me.

Part Two: More death and destruction. I think we can all agree that air resistance is really pesky. It’s not the easiest factor to model in the first place. Air is a fluid and fluids are notoriously hard to apply physics to. So let’s turn that off, too.

Newton’s first law states that an object in motion will remain in motion. Never has this statement been more true. Physicists everywhere rejoice, slip, and fall over. Meanwhile, about 20,000 pilots and co-pilots are suddenly very surprised when they find themselves falling out of the sky. You see, planes could be said to stay in the air due to air resisting the pull of gravity. It’s not a good description, but it is a description.

Using a gloriously simple kinematics calculation, we’ll find that exactly 24.9 seconds pass before the world’s passenger planes — all flying neatly at 10,000 feet off course — come smashing into the ground. At the moment of impact, the horizontal speed of the plane matches almost exactly the vertical speed, roughly 250 metres per second or 880 kilometres per hour.

The statisticians on board find brief satisfaction in this fact before being crushed under the force of the collision.

Part three: Peace and harmony. I’m just kidding, of course. Emboldened by the sudden ease of physics everywhere (and the necessity-no-longer of wool socks to slide around your living room) the physicists in charge of our simulation decide to flip all the switches at once, turning the world into a homogenous frictionless sphere of uniform density in a vacuum, but without all those crazy and difficult equations of special and general relativity, where everything is nice and no energy is lost during collisions and — oh wait, we need air to breathe, right?

Part four: The universe is now blissfully simple. Across the black void of the universe, all that remains is a single, perfect blue marble.

A man in a creaky office chair glances over at his computer that, after 13.8 billion years, finally stops whirring. “Huh,” he says to no one in particular. Following wisdom older than time, he turns it off and on again.

Image: Simer Haer/The Cascade

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