Taken from “Surely You're Joking, Mr.
Feynman!” Adventures of a Curious Character by Richard Phillips Feynman as told to Ralph Leighton edited by
Edward Hutchings
I
learned to pick locks from a guy named Leo Lavatelli. It turns out that picking
ordinary tumbler locks—like Yale locks—is easy. You try to turn the lock by
putting a screwdriver in the hole (you have to push from the side in order to
leave the hole open). It doesn’t turn because there are some pins inside which
have to be lifted to just the right height (by the key). Because it is not made
perfectly, the lock is held more by one pin than the others. Now, if you push a
little wire gadget—maybe a paper clip with a slight bump at the end—and jiggle
it back and forth inside the lock, you’ll eventually push that one pin that’s
doing the most holding, up to the right height. The lock gives, just a little
bit, so the first pin stays up—it’s caught on the edge. Now most of the load is
held by another pin, and you repeat the same random process for a few more
minutes, until all the pins are pushed up.
What
often happens is that the screwdriver will slip and you hear tic-tic-tic, and
it makes you mad. There are little springs that push the pins back down when a
key is removed, and you can hear them click when you let go of the screwdriver.
(Sometimes you intentionally let go of the screwdriver to see if you’re getting
anywhere—you might be pushing the wrong way, for instance.) The process is
something like Sisyphus: you’re always falling back downhill.
It’s
a simple process, but practice helps a lot. You learn how hard to push on
things—hard enough so the pins will stay up, but not so hard that they won’t go
up in the first place. What is not really appreciated by most people is that
they’re perpetually locking themselves in with locks everywhere, and it’s not
very hard to pick them.
When
we started to work on the atomic bomb project at Los Alamos, everything was in
such a hurry that it wasn’t really ready. All the secrets of the
project—everything about the atomic bomb—were kept in filing cabinets which, if
they had locks at all, were locked with padlocks which had maybe only three
pins: they were as easy as pie to open.
To
improve security the shop ouffitted every filing cabinet with a long rod that
went down through the handles of the drawers and that was fastened by a
padlock.
Some
guy said to me, “Look at this new thing the shop put on—can you open the
cabinet now?”
I
looked at the back of the cabinet and saw that the drawers didn’t have a solid
bottom. There was a slot with a wire rod in each one that held a slidable piece
(which holds the papers up inside the drawer). I poked in from the back, slid
the piece back, and began pulling the papers out through the slot. “Look!” I
said. “I don’t even have to pick the lock.”
Los
Alamos was a very cooperative place, and we felt it our responsibility to point
out things that should be improved. I’d keep complaining that the stuff was
unsafe, and although everybody thought
it was safe because there were steel rods and padlocks, it didn’t mean a damn
thing.
To
demonstrate that the locks meant nothing, whenever I wanted somebody’s report
and they weren’t around, I’d just go in their office, open the filing cabinet,
and take it out. When I was finished I would give it back to the guy: “Thanks
for your report.”
“Where’d
you get it?”
“Out
of your filing cabinet.”
“But
I locked it!”
“I know you locked it. The
locks are no good.”
Finally
some filing cabinets came which had combination locks on them made by the
Mosler Safe Company. They had three drawers. Pulling the top drawer out would
release the other drawers by a catch. The top drawer was opened by turning a
combination wheel to the left, right, and left for the combination, and then
right to number ten, which would draw back a bolt inside. The whole filing
cabinet could be locked by closing the bottom drawers first, then the top
drawer, and spinning the combination wheel away from number ten, which pushed
up the bolt.
These
new filing cabinets were an immediate challenge, naturally. I love puzzles. One
guy tries to make something to keep another guy out; there must be a way to
beat it!
I
had first to understand how the lock worked, so I took apart the one in my
office. The way it worked is this: There are three discs on a single shaft, one
behind the other; each has a notch in a different place. The idea is to line up
the notches so that when you turn the wheel to ten, the little friction drive
will draw the bolt down into the slot generated by the notches of the three
discs.
Now,
to turn the discs, there’s a pin sticking out from the back of the combination
wheel, and a pin sticking up from the first disc at the same radius. Within one
turn of the combination wheel, you’ve picked up the first disc.
On
the back of the first disc there’s a pin at the same radius as a pin on the
front of the second disc, so by the time you’ve spun the combination wheel
around twice, you’ve picked up the second disc as well.
Keep
turning the wheel, and a pin on the back of the second disc will catch a pin on
the front of the third disc, which you now set into the proper position with
the first number of the combination.
Now
you have to turn the combination wheel the other way one full turn to catch the
second disc from the other side, and then continue to the second number of the
combination to set the second disc.
Again
you reverse direction and set the first disc to its proper place. Now the
notches are lined up, and by turning the wheel to ten, you open the cabinet.
Well,
I struggled, and I couldn’t get anywhere. I bought a couple of safecracker
books, but they were all the same. In the beginning of the book there are some
stories of the fantastic achievements of the safecracker, such as the woman
caught in a meat refrigerator who is freezing to death, but the safecracker,
hanging upside down, opens it in two minutes. Or there are some precious furs
or gold bullion under water, down in the sea, and the safecracker dives down
and opens the chest.
In
the second part of the book, they tell you how to crack a safe. There are all
kinds of ninny-pinny, dopey things, like “It might be a good idea to try a date
for the combination, because lots of people like to use dates.” Or “Think of
the psychology of the owner of the safe, and what he might use for the
combination.” And “The secretary is often worried that she might forget the
combination of the safe, so she might write it down in one of the following
places—along the edge of her desk drawer, on a list of names and addresses …
and so on.
They
did tell me
something sensible about how to open ordinary safes, and it’s easy to
understand. Ordinary safes have an extra handle, so if you push down on the
handle while you’re turning the combination wheel, things being unequal (as
with locks), the force of the handle trying to push the bolt down into the
notches (which are not lined up) is held up more by one disc than another. When
the notch on that disc comes under the bolt, there’s a tiny click that you can
hear with a stethoscope, or a slight decrease in friction that you can feel
(you don’t have to sandpaper your fingertips), and you know, “There’s a
number!”
You
don’t know whether it’s the first, second, or third number, but you can get a
pretty good idea of that by finding out how many times you have to turn the
wheel the other way to hear the same click again. If it’s a little less than
once, it’s the first disc; if it’s a little less than twice, it’s the second
disc (you have to make a correction for the thickness of the pins).
This
useful trick only works on ordinary safes, which have the extra handle, so I
was stymied.
I
tried all kinds of subsidiary tricks with the cabinets, such as finding out how
to release the latches on the lower drawers, without opening the top drawer, by
taking off a screw in front and poking around with a piece of hanger wire.
I
tried spinning the combination wheel very rapidly and then going to ten, thus
putting a little friction on, which I hoped would stop a disc at the right
point in some manner. I tried all kinds
of things. I was desperate.
I
also did a certain amount of systematic study. For instance, a typical
combination was 69-32-21. How far off could a number be when you’re opening the
safe? If the number was 69, would 68 work? Would 67 work? On the particular
locks we had, the answer was yes for both, but 66 wouldn’t work. You could he
off by two in either direction. That meant you only had to try one out of five
numbers, so you could try zero, five, ten, fifteen, and so on. With twenty such
numbers on a wheel of 100, that was 8000 possibilities instead of the 1,000,000
you would get if you had to try every single number.
Now
the question was, how long would it take me to try the 8000 combinations?
Suppose I’ve got the first two numbers right of a combination I’m trying to
get. Say the numbers are 69-32, but I don’t know it—I’ve got them as 70-30. Now
I can try the twenty possible third numbers without having to set up the first
two numbers each time. Now let’s suppose I have only the first number of the
combination right. After trying the twenty numbers on the third disc, I move
the second wheel only a little bit, and then do another twenty numbers on the
third wheel.
I
practiced all the time on my own safe so I could do this process as fast as I
could and not get lost in my mind as to which number I was pushing and mess up
the first number. Like a guy who practices sleight of hand, I got it down to an
absolute rhythm so I could try the 400 possible back numbers in less than half
an hour. That meant I could open a safe in a maximum of eight hours—with an
average time of four hours.
There
was another guy there at Los Alamos named Staley who was also interested in
locks. We talked about it from time to time, but we weren’t getting anywhere
much. After I got this idea how to open a safe in an average time of four
hours, I wanted to show Staley how to do it, so I went into a guy’s office over
in the computing department and asked, “Do you mind if I use your safe? I’d
like to show Staley something.”
Meanwhile
some guys in the computing department came around and one of them said, “Hey,
everybody; Feynman’s gonna show Staley how to open a safe, ha, ha, ha!” I
wasn’t going to actually open the safe; I was just going to show Staley this
way of quickly trying the back two numbers without losing your place and having
to set up the first number again.
I
began. “Let’s suppose that the first number is forty, and we’re trying fifteen
for the second number. We go back and forth, ten; back five more and forth,
ten; and so on. Now we’ve tried all the possible third numbers. Now we try
twenty for the second number: we go back and forth, ten; back five more and
forth, ten; back five more and forth, CLICK!” My jaw dropped: the first and
second numbers happened to be right!
Nobody
saw my expression because my back was towards them. Staley looked very
surprised, but both of us caught on Very quickly as to what happened, so I
pulled the top drawer out with a flourish and said, “And there you are!”
Staley
said, “I see what you mean; it’s a very good scheme”—and we walked out.
Everybody was amazed. It was complete luck. Now I really had a reputation for opening safes.
It
took me about a year and a half to get that far (of course, I was working on
the bomb, too!) but I figured that I had the safes beaten, in the sense that if
there was a real difficulty—if somebody was lost, or dead, and nobody else knew
the combination but the stuff in the filing cabinet was needed—I could open it.
After reading what preposterous things the safecrackers claimed, I thought that
was a rather respectable accomplishment.
We
had no entertainment there at Los Alamos, and we had to amuse ourselves
somehow, so fiddling with the Mosler lock on my filing cabinet was one of my
entertainments. One day I made an interesting observation: When the lock is
opened and the drawer has been pulled out and the wheel is left on ten (which
is what people do when they’ve opened their filing cabinet and are taking
papers out of it), the bolt is still down. Now what does that mean, the bolt is
still down? It means the bolt is in the slot made by the three discs, which are
still properly lined up. Ahhhh!
Now,
if I turn the wheel away from ten a little bit, the bolt comes up; if I
immediately go back to ten, the bolt goes back down again, because I haven’t
yet disturbed the slot. If I keep going away from ten in steps of five, at some
point the bolt won’t go back down when I go back to ten: the slot has just been
disturbed. The number just before, which still let the bolt go down, is the
last number of the combination!
I
realized that I could do the same thing to find the second number: As soon as I
know the last number, I can turn the wheel around the other way and again, in
lumps of five, push the second disc bit by bit until the bolt doesn’t go down.
The number just before would be the second number.
If
I were very patient I would be able to pick up all three numbers that way, but
the amount of work involved in picking up the first number of the combination
by this elaborate scheme would be much more than just trying the twenty
possible first numbers with the other two numbers that you already know, when
the filing cabinet is closed.
I
practiced and I practiced until I could get the last two numbers off an open
filing cabinet, hardly looking at the dial. Then, when I’d be in some guy’s
office discussing some physics problem, I’d lean against his opened filing
cabinet, and just like a guy who’s jiggling keys absent-mindedly while he’s
talking, I’d just wobble the dial back and forth, back and forth. Sometimes I’d
put my finger on the bolt so I wouldn’t have to look to see if it’s coming up.
In this way I picked off the last two numbers of various filing cabinets. When
I got back to my office I would write the two numbers down on a piece of paper
that I kept inside the lock of my filing cabinet. I took the lock apart each
time to get the paper—I thought that was a very safe place for them.
After
a while my reputation began to sail, because things like this would happen:
Somebody would say, “Hey, Feynman! Christy’s out of town and we need a document
from his safe—can you open it?”
If
it was a safe I knew I didn’t have the last two numbers of, I would simply say,
“I’m sorry, but I can’t do it now; I’ve got this work that I have to do.”
Otherwise, I would say, “Yeah, but I gotta get my tools.” I didn’t need any
tools, but I’d go back to my office, open my filing cabinet, and look at my
little piece of paper: “Christy—35, 60.” Then I’d get a screwdriver and go over
to Christy’s office and close the door behind me. Obviously not everybody is
supposed to be allowed to know how to do this!
I’d
be in there alone and I’d open the safe in a few minutes. All I had to do was
try the first number at most twenty times, then sit around, reading a magazine
or something, for fifteen or twenty minutes. There was no use trying to make it
look too easy; somebody would figure out there was a trick to it! After a while
I’d open the door and say, “It’s open.”
People
thought I was opening the safes from scratch. Now I could maintain the idea,
which began with that accident with Staley, that I could open safes cold.
Nobody figured out that I was picking the last two numbers off their safes,
even though—perhaps because—I was doing it all
the time, like a card sharp walking around all the time with a deck of cards,
I
often went to Oak Ridge to check up on the safety of the uranium plant.
Everything was always in a hurry because it was wartime, and one time I had to
go there on a weekend. It was Sunday, and we were in this fella’s office—a
general, a head or a vice president of some company, a couple of other big
muck-a-mucks, and me. We were gathered together to discuss a report that was in
the fella’s safe—a secret safe—when suddenly he realized that he didn’t know
the combination. His secretary was the only one who knew it, so he called her
home and it turned out she had gone on a picnic up in the hills.
While
all this was going on, I asked, “Do you mind if I fiddle with the safe?”
“Ha,
ha, ha—not at all!” So I went over to the safe and started to fool around.
They
began to discuss how they could get a car to try to find the secretary, and the
guy was getting more and more embarrassed because he had all these people
waiting and he was such a jackass he didn’t know how to open his own safe.
Everybody was all tense and getting mad at him, when CLICK!—the safe opened.
In
10 minutes I had opened the safe that contained all the secret documents about
the plant. They were astonished. The safes were apparently not very safe. It
was a terrible shock: All this “eyes only” stuff, top secret, locked in this
wonderful secret safe, and this guy opens it in ten minutes!
Of
course I was able to open the safe because of my perpetual habit of taking the
last two numbers off. While in Oak Ridge the month before, I was in the same
office when the safe was open and I took the numbers off in an absentminded
way—I was always practicing my obsession. Although I hadn’t written them down,
I was able to vaguely remember what they were. First I tried 40-15, then 15-40,
but neither of those worked. Then I tried 10-45 with all the first numbers, and
it opened.
A
similar thing happened on another weekend when I was visiting Oak Ridge. I had
written a report that had to be OKed by a colonel, and it was in his safe. Everybody
else keeps documents in filing cabinets like the ones at Los Alamos, but he was
a colonel, so he had a much fancier, two-door safe with big handles that pull
four 3/4 -inch-thick steel bolts from the frame. The great brass doors swung
open and he took out my report to read.
Not
having had an opportunity to see any really good
safes, I said to him, “Would you mind, while you’re reading my report, if I
looked at your safe?”
“Go
right ahead,” he said, convinced that there was nothing I could do. I looked at
the back of one of the solid brass doors, and I discovered that the combination
wheel was connected to a little lock that looked exactly the same as the little
unit that was on my filing cabinet at Los Alamos. Same company, same little
bolt, except that when the bolt came down, the big handles on the safe could
then move some rods sideways, and with a hunch of levers you could pull back
all those 3/4 -inch steel rods. The whole lever system, it appeared, depends on
the same little bolt that locks filing cabinets.
Just
for the sake of professional perfection, to make sure it was the same, I took the two numbers
off the same way I did with the filing cabinet safes.
Meanwhile,
he was reading the report. When he’d finished he said, “All right, it’s fine.”
He put the report in the safe, grabbed the big handles, and swung the great
brass doors together. It sounds so good when they close, but I know it’s all
psychological, because it’s nothing but the same damn lock.
I
couldn’t help but needle him a little bit (I always had a thing about military
guys, in such wonderful uniforms) so I said, “The way you close that safe, I
get the idea that you think things are safe in there.”
“Of
course.”
“The
only reason you think they’re safe in there is because civilians call it a
‘safe.’” (I put the word “civilians” in there to make it sound as if he’d been
had by civilians.)
He
got very angry. “What do you mean—it’s not safe?”
“A
good safecracker could open it in thirty minutes.”
“Can
you open it in
thirty minutes?”
“I
said a good
safecracker. It would take me about forty-five.”
“Well!”
he said. “My wife is waiting at home for me with supper, but I’m gonna stay
here and watch you, and you’re gonna sit down there and work on that damn thing
for forty-five minutes and not
open it!” He sat down in his big leather chair, put his feet up on his desk,
and read.
With
complete confidence I picked up a chair, carried it over to the safe and sat
down in front of it. I began to turn the wheel at random, just to make some
action.
After
about five minutes, which is quite a long time when you’re just sitting and
waiting, he lost some patience: “Well, are you making any progress?”
“With
a thing like this, you either open it or you don’t.”
I
figured one or two more minutes would be about time, so I began to work in
earnest and two minutes later, CLINK—it opened.
The
colonel’s jaw dropped and his eyes bugged out.
“Colonel,”
I said, in a serious tone, “let me tell you something about these locks: When
the door to the safe or the top drawer of the filing cabinet is left open, it’s
very easy for someone to get the combination. That’s what I did while you were
reading my report, just to demonstrate the danger. You should insist that
everybody keep their filing cabinet drawers locked while they’re working,
because when they’re open, they’re very, very vulnerable.”
“Yeah!
I see what you mean! That’s very interesting!” We were on the same side after
that.
The
next time I went to Oak Ridge, all the secretaries and people who knew who I
was were telling me, “Don’t come through here! Don’t come through here!”
The
colonel had sent a note around to everyone in the plant which said, “During his
last visit, was Mr. Feynman at any time in your office, near your office, or
walking through your office?” Some people answered yes; others said no. The
ones who said yes got another note: “Please change the combination of your
safe.”
That
was his solution: I
was the danger. So they all had to change their combinations on account of me.
It’s a pain in the neck to change a combination and remember the new one, so
they were all mad at me and didn’t want me to come near them: they might have
to change their combination once again. Of course, their filing cabinets were
still left open while they were working!
A
library at Los Alamos held all of the documents we had ever worked on: It was a
solid, concrete room with a big, beautiful door which had a metal wheel that
turns—like a safe-deposit vault. During the war I had tried to look at it
closely. I knew the girl who was the librarian, and I begged her to let me play
with it a little bit. I was fascinated by it: it was the biggest lock I ever
saw! I discovered that I could never use my method of picking off the last two
numbers to get in. In fact, while turning the knob while the door was open, I
made the lock close, so it was sticking out, and they couldn’t close the door
again until the girl came and opened the lock again. That was the end of my
fiddling around with that lock. I didn’t have time to figure out how it worked;
it was much beyond my capacity.
During
the summer after the war I had some documents to write and work to finish up,
so I went back to Los Alamos from Cornell, where I had taught during the year.
In the middle of my work I had to refer to a document that I had written before
but couldn’t remember, and it was down in the library.
I
went down to get the document, and there was a soldier walking back and forth,
with a gun. It was a Saturday, and after the war the library was closed on
Saturdays.
Then
I remembered what a good friend of mine, Frederic de Hoffman, had done. He was
in the Declassification Section. After the war the army was thinking of declassifying
some documents, and he had to go back and forth to the library so much—look at
this document, look at that document, check this, check that—that he was going
nuts! So he had a copy of every document—all the secrets to the atomic bomb—in
nine filing cabinets in his office.
I
went down to his office, and the lights were on. It looked as if whoever was
there—perhaps his secretary—had just stepped out for a few minutes, so I
waited. While I was waiting I started to fiddle around with the
combination wheel on one of the filing cabinets. (By the way, I didn’t have the
last two numbers for de Hoffman’s safes; they were put in after the war, after
I had left.)
I
started to play with one of the combination wheels and began to think about the
safecracker books. I thought to myself, “I’ve never been much impressed by the
tricks described in those books, so I’ve never tried them, but let’s see if we
can open de Hoffman’s safe by following the book.”
First
trick, the secretary: she’s afraid she’s going to forget the combination, so
she writes it down somewhere. I started to look in some of the places mentioned
in the book. The desk drawer was locked, but it was an ordinary lock like Leo
Lavatelli taught me how to open—ping!
I look along the edge: nothing.
Then
I looked through the secretary’s papers. I found a sheet of paper that all the
secretaries had, with the Greek letters carefully made—so they could recognize
them in mathematical formulas—and named. And there, carelessly written along
the top of the paper, was pi = 3.14159. Now, that’s six digits, and why does a
secretary have to know the numerical value of pi? It was obvious; there was no
other reason!
I
went over to the filing cabinets and tried the first one: 31-41-59. It didn’t
open. Then I tried 59-41-31. That didn’t work either. Then 95-14-13. Backwards,
forwards, upside down, turn it this way, turn it that—nothing!
I
closed the desk drawer and started to walk out the door, when I thought of the
safecracker books again: Next, try the psychology method. I said to myself,
“Freddy de Hoffman is just
the kind of guy to use a mathematical constant for a safe combination.”
I
went back to the first filing cabinet and tried 27-18-28—CLICK! It opened! (The
mathematical constant second in importance to pi is the base of natural
logarithms, e: 2.71828 …) There were nine filing cabinets, and I had opened the
first one, but the document I wanted was in another one—they were in
alphabetical order by author. I tried the second filing cabinet:
27-18-28–CLICK! It opened with the same combination. I thought, “This is wonderful! I’ve opened
the secrets to the atomic bomb, but if I’m ever going to tell this story, I’ve
got to make sure that all the combinations are really the same!” Some of the
filing cabinets were in the next room, so I tried 27-18-28 on one of them, and
it opened. Now I’d opened three safes—all the same.
I
thought to myself, “Now I
could write a safecracker book that would beat every one, because at the
beginning I would tell how I opened safes whose contents were bigger and more
valuable than what any safecracker anywhere had opened—except for a life, of
course—but compared to the furs or the gold bullion, I have them all beat: I
opened the safes which contained all the secrets to the atomic bomb: the schedules
for the production of the plutonium, the purification procedures, how much
material is needed, how the bomb works, how the neutrons are generated, what
the design is, the dimensions—the entire information that was known at Los
Alamos: the whole shmeer!
”
I
went back to the second filing cabinet and took out the document I wanted. Then
I took a red grease pencil and a piece of yellow paper that was lying around in
the office and wrote, “I borrowed document no. LA4312—Feynman the safecracker.”
I put the note on top of the papers in the filing cabinet and closed it.
Then
I went to the first one I had opened and wrote another note: “This one was no
harder to open than the other one—Wise Guy” and shut the cabinet.
Then
in the other cabinet, in the other room, I wrote, “When the combinations are
all the same, one is no harder to open than another—Same Guy” and I shut that
one. I went back to my office and wrote my report.
That
evening I went to the cafeteria and ate supper. There was Freddy de Hoffman. He
said he was going over to his office to work, so just for fun I went with him.
He
started to work, and soon he went into the other room to open one of the filing
cabinets in there—something I hadn’t counted on—and he happened to open the
filing cabinet I had put the third note in, first. He opened the drawer, and he
saw this foreign object in there—this bright yellow paper with something
scrawled on it in bright red crayon.
I
had read in books that when somebody is afraid, his face gets sallow, but I had
never seen it before. Well, it’s absolutely true. His face turned a gray,
yellow green—it was really frightening to see. He picked up the paper, and his
hand was shaking. “L-l-look at this!” he said, trembling.
The
note said, “When the combinations are all the same, one is no harder to open
than another—Same Guy.”
“What
does it mean?” I said.
“All
the c-c-combinations of my safes are the s-s-same!” he stammered.
“That
ain’t such a good idea.”
“I-I
know that n-now!” he said, completely shaken.
Another
effect of the blood draining from the face must be that the brain doesn’t work
right. “He signed who it was! He signed who it was!” he said.
“What?” (I hadn’t put my
name on that one.)
“Yes,”
he said, “it’s the same guy
who’s been trying to get into Building Omega!”
All
during the war, and even after, there were these perpetual rumors: “Somebody’s
been trying to get into Building Omega!” You see, during the war they were
doing experiments for the bomb in which they wanted to get enough material
together for the chain reaction to just get started. They would drop one piece
of material through
another, and when it went through, the reaction would start and they’d measure
how many neutrons they got. The piece would fall through so fast that nothing
should build up and explode. Enough of a reaction would begin, however, so they
could tell that things were really starting correctly, that the rates were
right, and everything was going according to prediction—a very dangerous
experiment!
Naturally,
they were not doing this experiment in the middle of Los Alamos, but off
several miles, in a canyon several mesas over, all isolated. This Building
Omega had its own fence around it with guard towers. In the middle of the night
when everything’s quiet, some rabbit comes out of the brush and smashes against
the fence and makes a noise. The guard shoots. The lieutenant in charge comes
around. What’s the guard going to say—that it was only a rabbit? No.
“Somebody’s been trying to get into Building Omega and I scared him off!”
So
de Hoffman was pale and shaking, and he didn’t realize there was a flaw in his
logic: it was not clear that the same guy who’d been trying to get into
Building Omega was the same guy who was standing next to him.
He
asked me what to do.
“Well,
see if any documents are missing.”
“It
looks all right,” he said. “I don’t see any missing.”
I
tried to steer him to the filing cabinet I took my document out of. “Well, uh,
if all the combinations are the same, perhaps he’s taken something from another
drawer.”
“Right!”
he said, and he went back into his office and opened the first filing cabinet
and found the second note I wrote: “This one was no harder than the other
one—Wise Guy.”
By
that time it didn’t make any difference whether it was “Same Guy” or “Wise
Guy”: It was completely clear to him that it was the guy who was trying to get
into Building Omega. So to convince him to open the filing cabinet with my
first note in it was particularly difficult, and I don’t remember how I talked
him into it.
He
started to open it, so I began to walk down the hall, because I was a little
bit afraid that when he found out who did it to him, I was going to get my
throat cut!
Sure
enough, he came running down the hall after me, but instead of being angry, he
practically put his arms around me because he was so completely relieved that
this terrible burden of the atomic secrets being stolen was only me doing
mischief.
A
few days later de Hoffman told me that he needed something from Kerst’s safe.
Donald Kerst had gone back to Illinois and was hard to reach. “If you can open
all my safes
using the psychological method,” de Hoffman said (I had told him how I did it),
“maybe you could open Kerst’s safe that way.”
By
now the story had gotten around, so several people came to watch this fantastic
process where I was going to open Kerst’s safe—cold. There was no need for me
to be alone. I didn’t have the last two numbers to Kerst’s safe, and to use the
psychology method I needed people around who knew Kerst.
We
all went over to Kerst’s office and I checked the drawers for clues; there was
nothing. Then I asked them, “What kind of a combination would Kerst use—a
mathematical constant?”
“Oh,
no!” de Hoffman said. “Kerst would do something very simple.”
I
tried 10-20-30, 20-40-60, 60-40-20, 30-20-10. Nothing.
Then
I said, “Do you think he would use a date?”
“Yeah!”
they said. “He’s just the kind of guy to use a date.”
We
tried various dates: 8-6-45, when the bomb went off; 86-19-45; this date; that
date; when the project started. Nothing worked.
By
this time most of the people had drifted off. They didn’t have the patience to
watch me do this, but the only way to solve such a thing is patience!
Then
I decided to try everything from around 1900 until now. That sounds like a lot,
but it’s not: the first number is a month, one through twelve, and I can try
that using only three numbers: ten, five, and zero. The second number is a day,
from one to thirty-one, which I can try with six numbers. The third number is
the year, which was only forty-seven numbers at that time, which I could try
with nine numbers. So the 8000 combinations had been reduced to 162, something
I could try in fifteen or twenty minutes.
Unfortunately
I started with the high end of the numbers for the months, because when I
finally opened it, the combination was 0-5-35.
I
turned to de Hoffman. “What happened to Kerst around January 5, 1935?”
“His
daughter was born in 1936,” de Hoffman said. “It must be her birthday.”
Now
I had opened two safes cold. I was getting good. Now I was professional.
That
same summer after the war, the guy from the property section was trying to take
back some of the things the government had bought, to sell again as surplus.
One of the things was a Captain’s safe. We all knew about this safe. The
Captain, when he arrived during the war, decided that the filing cabinets
weren’t safe enough for the secrets he was going to get, so he had to have a
special safe.
The
Captain’s office was on the second floor of one of the flimsy wooden buildings
that we all had our offices in, and the safe he ordered was a heavy steel safe.
The workmen had to put down platforms of wood and use special jacks to get it
up the steps. Since there wasn’t much amusement, we all watched this big safe
being moved up to his office with great effort, and we all made jokes about
what kind of secrets he was going to keep in there. Some fella said we oughta
put our stuff in his safe, and let him put his stuff in ours. So everyone knew
about this safe.
The
property section man wanted it for surplus, but first it had to be emptied, and
the only people who knew the combination were the Captain, who was in Bikini,
and Alvarez, who’d forgotten it. The man asked me to open it.
I
went up to his old office and said to the secretary, “Why don’t you phone the
Captain and ask him the combination?”
“I
don’t want to bother him,” she said.
“Well,
you’re gonna bother me
for maybe eight hours. I won’t do it unless you make an attempt to call him.”
“OK,
OK!” she said. She picked up the telephone and I went into the other room to
look at the safe. There it was, that huge, steel safe, and its doors were wide
open.
I
went back to the secretary. “It’s open.”
“Marvelous!”
she said, as she put down the phone.
“No,”
I said, “it was already
open.”
“Oh!
I guess the property section was able to open it after all.”
I
went down to the man in the property section. “I went up to the safe and it was
already open.”
“Oh,
yeah,” he said; “I’m sorry I didn’t tell you. I sent our regular locksmith up
there to drill it, but before he drilled it he tried to open it, and he opened
it.”
So!
First information: Los Alamos now has a regular locksmith. Second information:
This man knows how to drill safes, something I know nothing about. Third
information: He can open a safe cold—in a few minutes. This is a real professional, a real source of
information. This guy I have to meet.
I
found out he was a locksmith they had hired after the war (when they weren’t as
concerned about security) to take care of such things. It turned out that he
didn’t have enough work to do opening safes, so he also repaired the Marchant
calculators we had used. During the war I repaired those things all the time—so
I had a way to meet him.
Now
I have never been surreptitious or tricky about meeting somebody; I just go
right up and introduce myself. But in this case it was so important to meet
this man, and I knew that before he would tell me any of his secrets on how to
open safes, I would have to prove myself.
I
found out where his room was—in the basement of the theoretical physics
section, where I worked—and I knew he worked in the evening, when the machines
weren’t being used. So, at first I would walk past his door on my way to my
office in the evening. That’s all; I’d just walk past.
A
few nights later, just a “Hi.” After a while, when he saw it was the same guy
walking past, he’d say “Hi,” or “Good evening.”
A
few weeks of this slow process and I see he’s working on the Marchant
calculators. I say nothing about them; it isn’t time yet.
We
gradually say a little more: “Hi! I see you’re working pretty hard!”
“Yeah,
pretty hard”—that kind of stuff.
Finally,
a breakthrough: he invites me for soup. It’s going very good now. Every evening
we have soup together. Now I begin to talk a little bit about the adding
machines, and he tells me he has a problem. He’s been trying to put a
succession of spring-loaded wheels back onto a shaft, and he doesn’t have the
right tool, or something; he’s been working on it for a week. I tell him that I
used to work on those machines during the war, and “I’ll tell you what: you
just leave the machine out tonight, and I’ll have a look at it tomorrow.”
“OK,”
he says, because he’s desperate.
The
next day I looked at the damn thing and tried to load it by holding all the
wheels in my hand. It kept snapping back. I thought to myself, “If he’s been
trying the same thing for a week, and I’m trying it and can’t do it, it ain’t
the way to do
it!” I stopped and looked at it very carefully, and I noticed that each wheel
had a little hole—just a little hole. Then it dawned on me: I sprung the first
one; then I put a piece of wire through the little hole. Then I sprung the
second one and put the wire through it. Then the next one, the next one—like
putting beads on a string—and I strung the whole thing the first time I tried
it, got it all in line, pulled the wire out, and everything was OK.
That
night I showed him the little hole and how I did it, and from then on we talked
a lot about machines; we got to be good friends. Now, in his office there were
a lot of little cubbyholes that contained locks half taken apart, and pieces
from safes, too. Oh, they were beautiful! But I still didn’t say a word about
locks and safes.
Finally,
I figured the day was coming, so I decided to put out a little bit of bait
about safes: I’d tell him the only thing worth a damn that I knew about
them—that you can take the last two numbers off while it’s open. “Hey!” I said,
looking over at the cubbyholes. “I see you’re working on Mosler safes.”
“Yeah.”
“You
know, these locks are weak. If they’re open, you can take the last two numbers
off …”
“You
can?” he said, finally showing some interest.
“Yeah.”
“Show
me how,” he said. I showed him how to do it, and he turned to me. “What’s your
name?” All this time we had never exchanged names.
“Dick
Feynman,” I said.
“God!
You’re Feynman!” he said in awe. “The great safecracker! I’ve heard about you;
I’ve wanted to meet you for so long! I want to learn how to crack a safe from
you.”
“What
do you mean? You know how to open safes cold.”
“I
don’t.”
“Listen,
I heard about the Captain’s safe, and I’ve been working pretty hard all this
time because I
wanted to meet you.
And you tell me you don’t know how to open a safe cold.”
“That’s
right.”
“Well
you must know how to drill a safe.”
“I
don’t know how to do that either.”
“WHAT?”
I exclaimed. “The guy in the property section said you picked up your tools and
went up to drill the Captain’s safe.”
“Suppose
you had a job as a locksmith,” he said, “and a guy comes down and asks you to
drill a safe. What would you do?”
“Well,”
I replied, “I’d make a fancy thing of putting my tools together, pick them up
and take them to the safe. Then I’d put my drill up against the safe somewhere
at random and I’d go vvvvvvvvvvv,
so I’d save my job.”
“That’s
exactly what I was going to do.”
“But
you opened it! You must know how to crack safes.”
“Oh,
yeah. I knew that the locks come from the factory set at 25-0-25 or 50-25-50,
so I thought, ‘Who knows; maybe the guy didn’t bother to change the
combination,’ and the second one worked.”
So
I did learn
something from him—that he cracked safes by the same miraculous methods that I
did. But even funnier was that this big shot Captain had to have a super, super
safe, and had people go to all that trouble to hoist the thing up into his office,
and he didn’t even bother to set the combination.
I
went from office to office in my building, trying those two factory
combinations, and I opened about one safe in five.