Things You Can and Cannot Learn from The Feynman Lectures on Physics | Aubrey Henretty

I’m having this problem. It’s kind of embarrassing. Like I’ve been withdrawing from people and doubting my life choices.

I don’t know what you do when you have a problem like this. Some people consult a religious text or a self-help book. Maybe some poetry, if it’s that kind of problem.

But right now, I need something practical — hypothesized, tested, retested. I need something that can accurately predict the future to within three significant digits.

What I need, clearly, is physics.

Specifically, The Feynman Lectures on Physics, which is a boxed set of three giant hardcover books containing lectures on every conceivable physical phenomenon. If you want to know how something works, you can almost always find it in there.

For anyone who doesn’t know, Richard Feynman was a hugely influential physicist in the 20th century. He worked on the Manhattan Project, which was the nuclear bomb thing, and quantum electrodynamics, which deals with the properties of particles and is even weirder and more complicated than it sounds. He also wrote a lot of really beautiful stuff about science and the imagination. You can appreciate a flower, he says, or the taste of wine so much more if you also learn about bees and pollen and the chemical reaction that turns sugar into alcohol.

For all their utility and style, The Feynman Lectures are incomplete. As I pored over them, trying to understand my own problem a little better, I found several important pieces of information missing. So the somewhat ungainly working title of this list is, “Things You Can and Can’t Learn FromThe Feynman Lectures on Physics.

1. Conservation of Energy

Oh, it’s a mouse problem. I mean, the problem is that there are mice in my apartment. I don’t, like, owe money to an organized crime syndicate of mice. They’re in my apartment. There are a lot of them.

Anyway, you guys, remember conservation of energy, right—the First Law of Thermodynamics? Energy is neither created nor destroyed? This is one of the most basic laws of physics, and if you want to learn about it, Feynman is your guy.

The amount of energy in any closed system remains constant no matter how many times it changes form. A mouse—or, more realistically 5,000 mice, where did all these mice come from—skittering around in the dark is a closed system. It can expend only as much energy as it takes in. To keep running, the mice have to eat all the time to replace the energy they’re using up. What are they eating? Feynman doesn’t hazard a guess. Maybe I dropped a couple of Cheerios on the way to the table at breakfast. Maybe the drugstore bags under the sink are made of some kind of corn-derived plastic. The point is I’ve been keeping the kitchen extremely clean and they haven’t run out of energy yet.

I’m not a gross person.

If you studied hard, you might be able to calculate how many Cheerios a mouse has to eat before it can leap out from behind the microwave and into one of the holes around the burners on the stove—gracefully and maniacally, like a ballet dancer on methamphetamines. But the Feynman Lectures are frustratingly silent on how long the mouse had been practicing that move before it felt confident enough to do it right in front of my face.

2. Chemical bonds

Everything is made is of chemicals. Chemicals are everything. Chemical bonds are the reason there are people and tables and french fries and lions. Without them, atoms wouldn’t stick together and the universe would be a very different place. If you have a few minutes, Feynman can show you why the chemical bonds in diamonds are so much harder to break than the ones in table sugar.

Chemical bonds are one way things can stick together. But there is no chapter about adhesives in the Feynman Lectures, which is too bad because I have a lot of questions about the glue in the enormous black glue traps the exterminator has planted all over my apartment. He started with smaller glue traps—the little cardboard ones—but the mice wouldn’t touch them. These new ones are cartoonishly large, like they might hold four or five mice at once.

The mice are very smart. They are the last surviving members of the colony of mice that invaded my building some time before I called the landlord’s office to report that things were getting out of hand. Basically, the nice lady in the office told me they’ve been hunting mice for a while—sealing holes in the walls, inside and outside the building, and the mice are more or less gone from everywhere else.

It’s just my apartment now, and the mice left over are the survivors. These are the mice that evaded the neighbors’ cats, didn’t eat the delicious poison, and stole the cheese off of the snap traps. Now they’re wreaking extremely skillful havoc all over my apartment. They’re chewing holes in boxes and whistling the Mission:Impossible theme song under my stove, watching, waiting for a wedge of mushroom to slip off the cutting board.

There are three giant black sticky traps in my tiny kitchen. If this doesn’t work, I’ll have no choice but to coat the entire floor with rubber cement.

3. Force

If you want to know how much force is exchanged between, say, your kitchen floor and the saucepan you dropped when you caught sight of a mouse darting behind your refrigerator, you will find all the equations you need in The Feynman Lectures. You can learn about gravity and acceleration (which are actually the same thing!). Speed, force, inertia, drag, thrust, torque—it’s all in there.

But there’s at least one kind of force you can’t measure, not with physics, not yet. It’s the force of ten thousand little teeth gnawing at the edges of your brain every hour of every day.

You know that horrible moment when you realize there’s a spider or like one of those giant mutant centipedes INSIDE OF YOUR SHIRT? And you feel like you will die if the shirt touches any part of your skin for another instant? That’s what it’s like to live in a place overrun with brilliant, indestructible vermin. I want to rip my apartment off and fling it across the street and then set it on fire and take a very hot shower forever.

If Feynman ever calculated the force it would require to do all those things, he didn’t bother to mention it in any of his lectures.

4. Sound

Somewhere toward the end of Volume One of The Feynman Lectures, we come to the chapter on sound. It’s complicated. SOUND is complicated. Have you ever taken a good long look at the wave equation? There’s a lot going on in there.

Feynman explains that sound is basically a disturbance in pressure that moves through the air (and through solid objects like my kitchen walls). When the disturbance reaches your eardrums, your brain interprets it as a nearby piano or a screaming mouse.

The equations in this chapter will, if you have the patience to learn them, help you calculate all the most important properties of sound. But nowhere in The Feynman Lectures will you find a description of what it sounds like when there are two screaming mice caught in a giant glue trap in my kitchen. Here, you will have to use your imagination.

Imagine that the eagle from the opening credits of the Colbert Report (which isn’t really an eagle, it turns out), but that sound, the animal that makes that squawky sound, imagine it’s being tortured by government military contractors in a secret prison located inside of my kitchen.

This is a real noise mice can make.

Another thing you won’t find in The Feynman Lectures is a chapter on the most humane ways to kill screaming trapped mice, rather than letting them chew their own legs off in a desperate attempt to escape or starve to death in the dumpster. Believe me, I checked all three indices.

So I put down The Feynman Lectures and do the two things any one of you would do in this situation:

1. I Google “humane ways to kill mice.”

2. I send frantic texts to all my friends and loved ones. THE MICE ARE

The Internet is uncharacteristically worthless. There are a bunch of search results, but they all lead to these comment threads where the person at the top tells a version of my story: “There were just so many mice and now they’re stuck in a glue trap oh god the noise it’s so horrible I just want to put them out of their misery”—et cetera—but then everybody who commented after them would say things like “Oh, you never use glue traps. They’re so cruel. Mice are living creatures, you know. Maybe you should just kill yourself instead.” And then they didn’t give the person any advice! How did those people even FIND this thread? Were they just bored at work one day, like, “Hmmm, I think I’ll find some vulnerable people who know they’ve made a mistake and instead of offering any practical advice that might help mitigate the damage and make them feel less alone, I’ll just shame them as hard as I can! I wonder if anyone has caught a mouse in a glue trap recently.”

My friends have some advice, but I don’t want to take any of it.

One said drown them in the sink.


Another said stick them in the freezer—apparently the cold causes them to lose consciousness quickly before they die. In the freezer. Next to my ice cream. Nope.

Here is what you do, said a friend who had a mouse problem last year. You put the whole screaming, shuddering trap inside two garbage bags, tie it up tight, and then you stomp on it as hard as you can.

Really?? What if I don’t stomp hard enough? What if I get just one of the mice and the other one has to watch his mouse friend die horribly? Even my gigantic Chicago-winter boots didn’t seem big or heavy enough for the job. If I’m going to crush the mice (which does seem like the best option), I’m going to need something really heavy with a wide flat surface area. Something like a large hardcover textbook.

Or a set of three large hardcover textbooks.

Feynman said it himself: Equations, laws, data, and diagrams won’t get you all the way there. You have to use your imagination.

Back in the kitchen, I put on my headphones and crank up the noisiest song on my iPod to drown out the screaming (I bet there’s an equation somewhere about noises that cancel out other noises—maybe I’ll have time to read up on it later). And I put on a big pair of rubber gloves–

Look, I’m gonna be civilized about this. I don’t want to mess up the nice box the lectures came in. I throw a plastic bag over the glue trap, which should keep glue and mouse guts off of the case.

I lift all three volumes of The Feynman Lectures high above my head and drop them. They land squarely on top of the trap.

5. Time

The Feynman Lectures have plenty to say about time: How we measure time. Short times, long times, REALLY long times, time as distance and vice versa.

For time to pass, something has to change. A radioactive particle has to decay somewhere or a mouse has to have its spine broken in a glue trap.

It’s a lot easier to measure the passage of time than it is to define it. If enough time passes, all kinds of things can happen. You can invite people into your apartment again without fear that a fleet of rodents will burst through the living room wall and tell them you’re a gross person who is always dropping Cheerios all over the place, for example. Your startle reflex can slowly return to normal.

I mean, none of those things have happened to me. I still have mice in my apartment. The days all blend together. It’s impossible to say how much time has passed.

But if you want to know what time is, even the most important physicist of his generation will advise you not to hurt yourself trying to figure it out.

“Maybe,” says Feynman, “it is just as well if we face the fact that time is one of those things we probably cannot define (in the dictionary sense), and just say that it is what we already know it to be: it is how long we wait!”

Aubrey Henretty was last seen giving a fake book talk at a real conference. Her stories about cheerful stalkers and mysterious night rashes have been featured at Story Club, and her science writing has appeared on theOddments podcast. She writes about language and critical thinking at
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