Review: Surely You’re Joking, Mr. Feynman! (Richard Feynmann)

Richard Feynman Surely Youre Joking Mr Feynman v5 ebook download free pdf


this is a fun, easy to read book. i was told to read it by a friend. i read it to avoid doing the linguistics tests im supposed to do. useful procrastination ftw!


As usual, comments and quotes below



Another thing I did in high school was to invent problems and theorems. I mean, if I were doing

any mathematical thing at all, I would find some practical example for which it would be useful. I

invented a set of right-triangle problems. But instead of giving the lengths of two of the sides to

find the third, I gave the difference of the two sides. A typical example was: There’s a flagpole, and

there’s a rope that comes down from the top. When you hold the rope straight down, it’s three feet

longer than the pole, and when you pull the rope out tight, it’s five feet from the base of the pole.

How high is the pole?


tricky, but certainly doable for primary school children. the smart of them. im fairly certain that a lot of high school students wud not be able to solve this.



I tried to explain–it was my own aunt–that there was no reason not to do that, but you can’t say

that to anybody who’s smart, who runs a hotel! I learned there that innovation is a very difficult

thing in the real world.


truth! this is politics in a nutshell, any kind of politics: national, local, office…



The other guy’s afraid, so he says no. So I take the two girls in a taxi to the hotel, and discover

that there’s a dance organized by the deaf and dumb, believe it or not. They all belonged to a club.

It turns out many of them can feel the rhythm enough to dance to the music and applaud the band at

the end of each number.


It was very, very interesting! I felt as if I was in a foreign country and couldn’t speak the

language: I could speak, but nobody could hear me. Everybody was talking with signs to everybody

else, and I couldn’t understand anything! I asked my girl to teach me some signs and I learned a few,

like you learn a foreign language, just for fun.


Everyone was so happy and relaxed with each other, making jokes and smiling all the time; they

didn’t seem to have any real difficulty of any kind communicating with each other. It was the same

as with any other language, except for one thing: as they’re making signs to each other, their heads

were always turning from one side to the other. I realized what that was. When someone wants to

make a side remark or interrupt you, he can’t yell, “Hey, Jack!” He can only make a signal, which

you won’t catch unless you’re in the habit of looking around all the time.


never thought of that, but true!



When it came time for me to give my talk on the subject, I started off by drawing an outline of

the cat and began to name the various muscles.

The other students in the class interrupt me: “We know all that!”

“Oh,” I say, “you do? Then no wonder I can catch up with you so fast after you’ve had four years

of biology.” They had wasted all their time memorizing stuff like that, when it could be looked up

in fifteen minutes.


ive heard this complaint lots of time about biology. i rather like evolutionary biology, which surely cannot be learned in 15 mins, but i dunno abouy plant cell biology or whatever. is biology mostly just remembering stuff? surely things like genetics, pop* genetics, evolutionary theory are hard.



At the Princeton graduate school, the physics department and the math department shared a

common lounge, and every day at four o’clock we would have tea. It was a way of relaxing in the

afternoon, in addition to imitating an English college. People would sit around playing Go, or

discussing theorems. In those days topology was the big thing.

I still remember a guy sitting on the couch, thinking very hard, and another guy standing in front

of him, saying, “And therefore such-and-such is true.”


“Why is that?” the guy on the couch asks.


“It’s trivial! It’s trivial!” the standing guy says, and he rapidly reels off a series of logical steps:

“First you assume thus-and-so, then we have Kerchoff’s this-and-that; then there’s Waffenstoffer’s

Theorem, and we substitute this and construct that. Now you put the vector which goes around here

and then thus-and-so . . .” The guy on the couch is struggling to understand all this stuff, which

goes on at high speed for about fifteen minutes!


Finally the standing guy comes out the other end, and the guy on the couch says, “Yeah, yeah.

It’s trivial.”


We physicists were laughing, trying to figure them out. We decided that “trivial” means

“proved.” So we joked with the mathematicians: “We have a new theorem–that mathematicians can

prove only trivial theorems, because every theorem that’s proved is trivial.”


i thought of that befor. it makes certain theories of tautologies rather implausible. if tautologies, or necessary truths are all trivial, and just restating things – why arent they all obvius? …



One thing I never did learn was contour integration. I had learned to do integrals by various

methods shown in a book that my high school physics teacher Mr. Bader had given me.


One day he told me to stay after class. “Feynman,” he said, “you talk too much and you make

too much noise. I know why. You’re bored. So I’m going to give you a book. You go up there in the

back, in the corner, and study this book, and when you know everything that’s in this book, you can

talk again.”


i wish my teachers wud hav don that to me! or that i had grown up with Khan academy!



In another experiment, I laid out a lot of glass microscope slides, and got the ants to walk on

them, back and forth, to some sugar I put on the windowsill. Then, by replacing an old slide with a

new one, or by rearranging the slides, I could demonstrate that the ants had no sense of geometry:

they couldn’t figure out where something was. If they went to the sugar one way and there was a

shorter way back, they would never figure out the short way.

It was also pretty clear from rearranging the glass slides that the ants left some sort of trail. So

then came a lot of easy experiments to find out how long it takes a trail to dry up, whether it can be

easily wiped off, and so on. I also found out the trail wasn’t directional. If I’d pick up an ant on a

piece of paper, turn him around and around, and then put him back onto the trail, he wouldn’t know

that he was going the wrong way until he met another ant. (Later, in Brazil, I noticed some leaf-

cutting ants and tried the same experiment on them. They could tell, within a few steps, whether

they were going toward the food or away from it–presumably from the trail, which might be a

series of smells in a pattern: A, B, space, A, B, space, and so on.)

I tried at one point to make the ants go around in a circle, but I didn’t have enough patience to set

it up. I could see no reason, other than lack of patience, why it couldn’t be done.


yes, that DOES happen by accident in nature.



So Frankel figured out a nice program. If we got enough of these machines in a room, we could

take the cards and put them through a cycle. Everybody who does numerical calculations now

knows exactly what I’m talking about, but this was kind of a new thing then–mass production with

machines. We had done things like this on adding machines. Usually you go one step across, doing

everything yourself. But this was different–where you go first to the adder, then to the multiplier,

then to the adder, and so on. So Frankel designed this system and ordered the machines from the

IBM company because we realized it was a good way of solving our problems.


We needed a man to repair the machines, to keep them going and everything. And the army was

always going to send this fellow they had, but he was always delayed. Now, we always were in a

hurry. Everything we did, we tried to do as quickly as possible. In this particular case, we worked

out all the numerical steps that the machines were supposed to do–multiply this, and then do this,

and subtract that. Then we worked out the program, but we didn’t have any machine to test it on. So

we set up this room with girls in it. Each one had a Marchant: one was the multiplier, another was

the adder. This one cubed–all she did was cube a number on an index card and send it to the next



We went through our cycle this way until we got all the bugs out. It turned out that the speed at

which we were able to do it was a hell of a lot faster than the other way where every single person

did all the steps. We got speed with this system that was the predicted speed for the IBM machine.

The only difference is that the IBM machines didn’t get tired and could work three shifts. But the

girls got tired after a while.





Well, Mr. Frankel, who started this program, began to suffer from the computer disease that

anybody who works with computers now knows about. It’s a very serious disease and it interferes

completely with the work. The trouble with computers is you play with them. They are so

wonderful. You have these switches–if it’s an even number you do this, if it’s an odd number you

do that–and pretty soon you can do more and more elaborate things if you are clever enough, on

one machine.





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!


O_o, very dangerus experiment indeed!



That evening I went for a walk in town, and came upon a small crowd of people standing around

a great big rectangular hole in the road–it had been dug for sewer pipes, or something–and there,

sitting exactly in the hole, was a car. It was marvelous: it fitted absolutely perfectly, with its roof

level with the road. The workmen hadn’t bothered to put up any signs at the end of the day, and the

guy had simply driven into it. I noticed a difference: When we’d dig a hole, there’d be all kinds of

detour signs and flashing lights to protect us. There, they dig the hole, and when they’re finished for

the day, they just leave.





The meeting in Japan was in two parts: one was in Tokyo, and the other was in Kyoto. In the bus

on the way to Kyoto I told my friend Abraham Pais about the Japanese-style hotel, and he wanted

to try it. We stayed at the Hotel Miyako, which had both American-style and Japanese-style rooms,

and Pais shared a Japanese-style room with me.


The next morning the young woman taking care of our room fixes the bath, which was right in

our room. Sometime later she returns with a tray to deliver breakfast. I’m partly dressed. She turns

to me and says, politely, “Ohayo, gozai masu,” which means, “Good morning.”

Pais is just coming out of the bath, sopping wet and completely nude. She turns to him and with

equal composure says, “Ohayo, gozai masu,” and puts the tray down for us.

Pais looks at me and says, “God, are we uncivilized!”


We realized that in America if the maid was delivering breakfast and the guy’s standing there,

stark naked, there would be little screams and a big fuss. But in Japan they were completely used to

it, and we felt that they were much more advanced and civilized about those things than we were.


stupid puritanism and fear of nakedness.



There was a sociologist who had written a paper for us all to read–something he had written

ahead of time. I started to read the damn thing, and my eyes were coming out: I couldn’t make head

nor tail of it! I figured it was because I hadn’t read any of the books on that list. I had this uneasy

feeling of “I’m not adequate,” until finally I said to myself, “I’m gonna stop, and read one sentence

slowly, so I can figure out what the hell it means.”

So I stopped–at random–and read the next sentence very carefully. I can’t remember it precisely,

but it was very close to this: “The individual member of the social community often receives his

information via visual, symbolic channels.” I went back and forth over it, and translated. You know

what it means? “People read.”


Then I went over the next sentence, and I realized that I could translate that one also. Then it

became a kind of empty business: “Sometimes people read; sometimes people listen to the radio,”

and so on, but written in such a fancy way that I couldn’t understand it at first, and when I finally

deciphered it, there was nothing to it.


There was only one thing that happened at that meeting that was pleasant or amusing. At this

conference, every word that every guy said at the plenary session was so important that they had a

stenotypist there, typing every goddamn thing. Somewhere on the second day the stenotypist came

up to me and said, “What profession are you? Surely not a professor.”

“I am a professor,” I said.

“Of what?”

“Of physics–science.”

“Oh! That must be the reason,” he said.

“Reason for what?” He said, “You see, I’m a stenotypist, and I type everything that is said here. Now, when the other

fellas talk, I type what they say, but I don’t understand what they’re saying. But every time you get

up to ask a question or to say something, I understand exactly what you mean–what the question is,

and what you’re saying–so I thought you can’t be a professor!”


yes, it is mor difficult to say somthing clearly than to obscure it.



There was a special dinner at some point, and the head of the theology place, a very nice, very

Jewish man, gave a speech. It was a good speech, and he was a very good speaker, so while it

sounds crazy now, when I’m telling about it, at that time his main idea sounded completely obvious

and true. He talked about the big differences in the welfare of various countries, which cause

jealousy, which leads to conflict, and now that we have atomic weapons, any war and we’re

doomed, so therefore the right way out is to strive for peace by making sure there are no great

differences from place to place, and since we have so much in the United States, we should give up

nearly everything to the other countries until we’re all even. Everybody was listening to this, and

we were all full of sacrificial feeling, and all thinking we ought to do this. But I came back to my

senses on the way home.


The next day one of the guys in our group said, “I think that speech last night was so good that

we should all endorse it, and it should be the summary of our conference.”

I started to say that the idea of distributing everything evenly is based on a theory that there’s

only X amount of stuff in the world, that somehow we took it away from the poorer countries in the

first place, and therefore we should give it back to them. But this theory doesn’t take into account

the real reason for the differences between countries–that is, the development of new techniques

for growing food, the development of machinery to grow food and to do other things, and the fact

that all this machinery requires the concentration of capital. It isn’t the stuff, but the power to make

the stuff, that is important. But I realize now that these people were not in science; they didn’t

understand it. They didn’t understand technology; they didn’t understand their time.


sounds like sorryaboutcolonialism (see


these inequalities ar ther becus of ppl ar unequal to begin with. even if we redistributed wealth, it wudnt take long b4 whites and asians were superior again.



Once I was asked to serve on a committee which was to evaluate various weapons for the army,

and I wrote a letter back which explained that I was only a theoretical physicist, and I didn’t know

anything about weapons for the army.


The army responded that they had found in their experience that theoretical physicists were very

useful to them in making decisions, so would I please reconsider?

I wrote back again and said I didn’t really know anything, and doubted I could help them.

Finally I got a letter from the Secretary of the Army, which proposed a compromise: I would

come to the first meeting, where I could listen and see whether I could make a contribution or not.

Then I could decide whether I should continue.

I said I would, of course. What else could I do?

I went down to Washington and the first thing that I went to was a cocktail party to meet

everybody. There were generals and other important characters from the army, and everybody

talked. It was pleasant enough.


One guy in a uniform came to me and told me that the army was glad that physicists were

advising the military because it had a lot of problems. One of the problems was that tanks use up

their fuel very quickly and thus can’t go very far. So the question was how to refuel them as they’re

going along. Now this guy had the idea that, since the physicists can get energy out of uranium,

could I work out a way in which we could use silicon dioxide–sand, dirt–as a fuel? If that were

possible, then all this tank would have to do would be to have a little scoop underneath, and as it

goes along, it would pick up the dirt and use it for fuel! He thought that was a great idea, and that

all I had to do was to work out the details. That was the kind of problem I thought we would be

talking about in the meeting the next day.


i wonder… ar they still so depressingly dumb?



This question of trying to figure out whether a book is good or bad by looking at it carefully or

by taking the reports of a lot of people who looked at it carelessly is like this famous old problem:

Nobody was permitted to see the Emperor of China, and the question was, What is the length of the

Emperor of China’s nose? To find out, you go all over the country asking people what they think

the length of the Emperor of China’s nose is, and you average it. And that would be very “accurate”

because you averaged so many people. But it’s no way to find anything out; when you have a very

wide range of people who contribute without looking carefully at it, you don’t improve your

knowledge of the situation by averaging.


F seems to be wrong, but he might hav a point about the conditions under which wisdom of the crowds averaging works.



I thought: “Now where is the ego located? I know everybody thinks the seat of thinking is in the

brain, but how do they know that?” I knew already from reading things that it wasn’t so obvious to

people before a lot of psychological studies were made. The Greeks thought the seat of thinking

was in the liver, for instance. I wondered, “Is it possible that where the ego is located is learned by

children looking at people putting their hand to their head when they say, ‘Let me think’? Therefore

the idea that the ego is located up there, behind the eyes, might be conventional!” I figured that if I

could move my ego an inch to one side, I could move it further. This was the beginning of my


Feynmann didnt do his research properly.

”During the second half of the first millennium BC, the Ancient Greeks developed differing views on the function of the brain. It is said that it was the Pythagorean Alcmaeon of Croton (6th and 5th centuries BC) who first considered the brain to be the place where the mind was located. In the 4th century BC Hippocrates, believed the brain to be the seat of intelligence (based, among others before him, on Alcmaeon’s work). During the 4th century BC Aristotle thought that, while the heart was the seat of intelligence, the brain was a cooling mechanism for the blood. He reasoned that humans are more rational than the beasts because, among other reasons, they have a larger brain to cool their hot-bloodedness.[2]



Other kinds of errors are more characteristic of poor science. When I was at Cornell, I often

talked to the people in the psychology department. One of the students told me she wanted to do an

experiment that went something like this–it had been found by others that under certain

circumstances, X, rats did something, A. She was curious as to whether, if she changed the

circumstances to Y, they would still do A. So her proposal was to do the experiment under

circumstances Y and see if they still did A.


I explained to her that it was necessary first to repeat in her laboratory the experiment of the

other person–to do it under condition X to see if she could also get result A, and then change to Y

and see if A changed. Then she would know that the real difference was the thing she thought she

had under control.


She was very delighted with this new idea, and went to her professor. And his reply was, no, you

cannot do that, because the experiment has already been done and you would be wasting time. This

was in about 1947 or so, and it seems to have been the general policy then to not try to repeat

psychological experiments, but only to change the conditions and see what happens.


sadly, this is STILL the case!



So I have just one wish for you–the good luck to be somewhere where you are free to maintain

the kind of integrity I have described, and where you do not feel heed by a need to maintain your

position In the organization, or financial support, or so on, to lose your integrity. May you have that




Feynmann wud hav been sad to see the state of affairs of the modern publish or perish science, the lack of repetitions in various fields, the publication bias, the near impossibility of politically incorrect science.

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