Surely You're Joking, Mr. Feynman!

From Far Rockaway to MIT

—————————-
He Fixes Radios by Thinking!
—————————-

When I was about eleven or twelve I set up a lab in my house. It consisted of an old wooden packing box that I put shelves in. I had a heater, and I’d put in fat and cook french-fried potatoes all the time. I also had a storage battery, and a lamp bank.

To build the lamp bank I went down to the five-and-ten and got some sockets you can screw down to a wooden base, and connected them with pieces of bell wire. By making different combinations of switches–in series or parallel–I knew I could get different voltages. But what I hadn’t realized was that a bulb’s resistance depends on its temperature, so the results of my calculations weren’t the same as the stuff that came out of the circuit. But it was all right, and when the bulbs were in series, all half-lit, they would _gloooooooooow_, very pretty–it was great!

I had a fuse in the system so if I shorted anything, the fuse would blow. Now I had to have a fuse that was weaker than the fuse in the house, so I made my own fuses by taking tin foil and wrapping it around an old burnt-out fuse. Across my fuse I had a five-watt bulb, so when my fuse blew, the load from the trickle charger that was always charging the storage battery would light up the bulb. The bulb was on the switchboard behind a piece of brown candy paper (it looks red when a light’s behind it)–so if something went off, I’d look up to the switchboard and there would be a big red spot where the fuse went. It was _fun_!

I enjoyed radios. I started with a crystal set that I bought at the store, and I used to listen to it at night in bed while I was going to sleep, through a pair of earphones. When my mother and father went out until late at night, they would come into my room and take the earphones off–and worry about what was going into my head while I was asleep.

About that time I invented a burglar alarm, which was a very simple-minded thing: it was just a big battery and a bell connected with some wire. When the door to my room opened, it pushed the wire against the battery and closed the circuit, and the bell would go off.

One night my mother and father came home from a night out and very, very quietly, so as not to disturb the child, opened the door to come into my room to take my earphones off. All of a sudden this tremendous bell went off with a helluva racket–BONG BONG BONG BONG BONG!!! I jumped out of bed yelling, “It worked! It worked!”

I had a Ford coil–a spark coil from an automobile–and I had the spark terminals at the top of my switchboard. I would put a Raytheon RH tube, which had argon gas in it, across the terminals, and the spark would make a purple glow inside the vacuum–it was just great!

One day I was playing with the Ford coil, punching holes in paper with the sparks, and the paper caught on fire. Soon I couldn’t hold it any more because it was burning near my fingers, so I dropped it in a metal wastebasket which had a lot of newspapers in it. Newspapers burn fast, you know, and the flame looked pretty big inside the room. I shut the door so my mother–who was playing bridge with some friends in the living room–wouldn’t find out there was a fire in my room, took a magazine that was lying nearby, and put it over the wastebasket to smother the fire.

After the fire was out I took the magazine off, but now the room began to fill up with smoke. The wastebasket was still too hot to handle, so I got a pair of pliers, carried it across the room, and held it out the window for the smoke to blow out.

But because it was breezy outside, the wind lit the fire again, and now the magazine was out of reach. So I pulled the flaming wastebasket back in through the window to get the magazine, and I noticed there were curtains in the window–it was very dangerous!

Well, I got the magazine, put the fire out again, and this time kept the magazine with me while I shook the glowing coals out of the wastepaper basket onto the street, two or three floors below. Then I went out of my room, closed the door behind me, and said to my mother, “I’m going out to play,” and the smoke went out slowly through the windows.

I also did some things with electric motors and built an amplifier for a photo cell that I bought that could make a bell ring when I put my hand in front of the cell. I didn’t get to do as much as I wanted to, because my mother kept putting me out all the time, to play. But I was often in the house, fiddling with my lab.

I bought radios at rummage sales. I didn’t have any money, but it wasn’t very expensive-they were old, broken radios, and I’d buy them and try to fix them. Usually they were broken in some simple-minded way–some obvious wire was hanging loose, or a coil was broken or partly unwound–so I could get some of them going. On one of these radios one night I got WACO in Waco, Texas–it was tremendously exciting!

On this same tube radio up in my lab I was able to hear a station up in Schenectady called WGN. Now, all of us kids– my two cousins, my sister, and the neighborhood kids–listened on the radio downstairs to a program called the Eno Crime Club–Eno effervescent salts–it was _the_ thing! Well, I discovered that I could hear this program up in my lab on WGN one hour before it was broadcast in New York! So I’d discover what was going to happen, and then, when we were all sitting around the radio downstairs listening to the Eno Crime Club, I’d say, “You know, we haven’t heard from so-and-so in a long time. I betcha he comes and saves the situation.”

Two seconds later, _bup-bup_, he comes! So they all got excited about this, and I predicted a couple of other things. Then they realized that there must be some trick to it–that I must know, somehow. So I owned up to what it was, that I could hear it upstairs the hour before.

You know what the result was, naturally. Now they couldn’t wait for the regular hour, They all had to sit upstairs in my lab with this little creaky radio for half an hour, listening to the Eno Crime Club from Schenectady.

We lived at that time in a big house; it was left by my grandfather to his children, and they didn’t have much money aside from the house. It was a very large, wooden house, and I would run wires all around the outside, and had plugs in all the rooms, so I could always listen to my radios, which were upstairs in my lab. I also had a loudspeaker–not the whole speaker, but the part without the big horn on it.

One day, when I had my earphones on, I connected them to the loudspeaker, and I discovered something: I put my finger in the speaker and I could hear it in the earphones; I scratched the speaker and I’d hear it in the earphones. So I discovered that the speaker could act like a microphone, and you didn’t even need any batteries. At school we were talking about Alexander Graham Bell, so I gave a demonstration of the speaker and the earphones. I didn’t know it at the time, but I think it was the type of telephone he originally used.

So now I had a microphone, and I could broadcast from upstairs to downstairs, and from downstairs to upstairs, using the amplifiers of my rummage-sale radios. At that time my sister Joan, who was nine years younger than I was, must have been about two or three, and there was a guy on the radio called Uncle Don that she liked to listen to. He’d sing little songs about “good children,” and so on, and he’d read cards sent in by parents telling that “Mary So-and-so is having a birthday this Saturday at 25 Flatbush Avenue.”

One day my cousin Francis and I sat Joan down and said that there was a special program she should listen to. Then we ran upstairs and we started to broadcast: “This is Uncle Don. We know a very nice little girl named Joan who lives on New Broadway; she’s got a birthday coming–not today, but such-and-such. She’s a cute girl.” We sang a little song, and then we made music: “_Deedle leet deet, doodle doodle loot doot; deedle deedle leet, doodle loot doot doo_ We went through the whole deal, and then we came downstairs: “How was it? Did you like the program?”

“It was good,” she said, “but why did you make the music with your mouth?”

One day I got a telephone call: “Mister, are you Richard Feynman ?”

“Yes.”

“This is a hotel. We have a radio that doesn’t work, and would like it repaired. We understand you might be able to do something about it.”

“But I’m only a little boy,” I said. “I don’t know how–“

“Yes, we know that, but we’d like you to come over anyway.”

It was a hotel that my aunt was running, but I didn’t know that. I went over there with–they still tell the story–a big screwdriver in my back pocket. Well, I was small, so _any_ screwdriver looked big in my back pocket.

I went up to the radio and tried to fix it. I didn’t know anything about it, but there was also a handyman at the hotel, and either he noticed, or I noticed, a loose knob on the rheostat–to turn up the volume–so that it wasn’t turning the shaft. He went off and filed something, and fixed it up so it worked.

The next radio I tried to fix didn’t work at all. That was easy: it wasn’t plugged in right. As the repair jobs got more and more complicated, I got better and better, and more elaborate. I bought myself a milliammeter in New York and converted it into a voltmeter that had different scales on it by using the right lengths (which I calculated) of very fine copper wire. It wasn’t very accurate, hut it was good enough to tell whether things were in the right ballpark at different connections in those radio sets.

The main reason people hired me was the Depression. They didn’t have any money to fix their radios, and they’d hear about this kid who would do it for less. So I’d climb on roofs to fix antennas, and all kinds of stuff. I got a series of lessons of ever-increasing difficulty. Ultimately I got some job like converting a DC set into an AC set, and it was very hard to keep the hum from going through the system, and I didn’t build it quite right. I shouldn’t have bitten that one off, but I didn’t know.

One job was really sensational. I was working at the time for a printer, and a man who knew that printer knew I was trying to get jobs fixing radios, so he sent a fellow around to the print shop to pick me up. The guy is obviously poor–his car is a complete wreck–and we go to his house which is in a cheap part of town. On the way, I say, “What’s the trouble with the radio?”