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Vannevar Bush

 Luglio 1945









































































































































"As We May Think" 




















"Come potremmo pensare"







































Testo originale inglese, strutturato, provvisto di titoli e sottotitoli in Italiano ed

evidenziazioni in rosso dei concetti chiave per facilitarne la lettura anche veloce e la







































































































































[La fine della guerra]




















[Il futuro della scienza o, meglio, degli scienziati]





















































































































This has not been a scientist's war;

it has been a war in which all have had

a part.



The scientists, burying their old

professional competition in the

demand of a common cause, have

shared greatly and learned much.


It has been exhilarating to work in

effective partnership.


Now, for many, this appears to be

approaching an end.


What are the scientists to do next?



For the biologists, and particularly for

the medical scientists, there can be

little indecision, for their war has

hardly required them to leave the old



Many indeed have been able to carry

on their war research in their familiar

peacetime laboratories.


Their objectives remain much the




It is the physicists who have been

thrown most violently off stride, who

have left academic pursuits for the

making of strange destructive gadgets,

who have had to devise new methods

for their unanticipated assignments.


They have done their part on the

devices that made it possible to turn

back the enemy, have worked in

combined effort with the physicists of

our allies.


They have felt within themselves the

stir of achievement.


They have been part of a great team.


Now, as peace approaches, one asks

where they will find objectives worthy

of their best.  


















































































































































































































[Il progresso dell'umanitā]




















[La limitata fruibilitā della conoscenza collettiva]





















































































































Of what lasting benefit has been man's

use of science and of the new

instruments which his research

brought into existence?


First, they have increased his control

of his material environment.


They have improved his food, his

clothing, his shelter;

they have increased his security and

released him partly from the bondage

of bare existence.


They have given him increased

knowledge of his own biological

processes so that he has had a

progressive freedom from disease and

an increased span of life.


They are illuminating the interactions

of his physiological and psychological

functions, giving the promise of an

improved mental health.



Science has provided the swiftest

communication between individuals;

it has provided a record of ideas and

has enabled man to manipulate and to

make extracts from that record so that

knowledge evolves and endures

throughout the life of a race rather than

that of an individual.



There is a growing mountain of



But there is increased evidence that we

are being bogged down today as

specialization extends.


The investigator is staggered by the

findings and conclusions of thousands

of other workers - conclusions which

he cannot find time to grasp, much less

to remember, as they appear.


Yet specialization becomes

increasingly necessary for progress,

and the effort to bridge between

disciplines is correspondingly



















































































































































































































[La gestione della conoscenza]




















[Metodi e strumenti ormai obsoleti]





















































































































Professionally our methods of

transmitting and reviewing the results

of research are generations old and by

now are totally inadequate for their



If the aggregate time spent in writing

scholarly works and in reading them

could be evaluated, the ratio between

these amounts of time might well be



Those who conscientiously attempt to

keep abreast of current thought, even

in restricted fields, by close and

continuous reading might well shy

away from an examination calculated

to show how much of the previous

month's efforts could be produced on



Mendel's concept of the laws of

genetics was lost to the world for a

generation because his publication did

not reach the few who were capable of

grasping and extending it;

and this sort of catastrophe is

undoubtedly being repeated all about

us, as truly significant attainments

become lost in the mass of the




The difficulty seems to be, not so much

that we publish unduly in view of the

extent and variety of present day

interests, but rather that publication

has been extended far beyond our

present ability to make real use of the



The summation of human experience is

being expanded at a prodigious rate,

and the means we use for threading

through the consequent maze to the

momentarily important item is the same

as was used in the days of square-

rigged ships.



But there are signs of a change as new

and powerful instrumentalities come

into use.


Photocells capable of seeing things in

a physical sense, advanced

photography which can record what is

seen or even what is not, thermionic

tubes capable of controlling potent

forces under the guidance of less

power than a mosquito uses to vibrate

his wings, cathode ray tubes rendering

visible an occurrence so brief that by

comparison a microsecond is a long

time, relay combinations which will

carry out involved sequences of

movements more reliably than any

human operator and thousands of

times as fast - there are plenty of

mechanical aids with which to effect

a transformation in scientific records.


















































































































































































































[I calcolatori]




















[Due secoli persi ma la loro ora č arrivata]





















































































































Two centuries ago Leibnitz invented a

calculating machine which embodied

most of the essential features of recent

keyboard devices, but it could not then

come into use.


The economics of the situation were

against it:

the labor involved in constructing it,

before the days of mass production,

exceeded the labor to be saved by its

use, since all it could accomplish could

be duplicated by sufficient use of

pencil and paper.


Moreover, it would have been subject

to frequent breakdown, so that it could

not have been depended upon;

for at that time and long after,

complexity and unreliability were




Babbage, even with remarkably

generous support for his time, could

not produce his great arithmetical



His idea was sound enough, but

construction and maintenance costs

were then too heavy.


Had a Pharaoh been given detailed and

explicit designs of an automobile, and

had he understood them completely, it

would have taxed the resources of his

kingdom to have fashioned the

thousands of parts for a single car, and

that car would have broken down on

the first trip to Giza.



Machines with interchangeable parts

can now be constructed with great

economy of effort.


In spite of much complexity, they

perform reliably.


Witness the humble typewriter, or the

movie camera, or the automobile.


Electrical contacts have ceased to stick

when thoroughly understood.


Note the automatic telephone

exchange, which has hundreds of

thousands of such contacts, and yet is



A spider web of metal, sealed in a thin

glass container, a wire heated to

brilliant glow, in short, the thermionic

tube of radio sets, is made by the

hundred million, tossed about in

packages, plugged into sockets - and it



Its gossamer parts, the precise

location and alignment involved in its

construction, would have occupied a

master craftsman of the guild for


now it is built for thirty cents.


The world has arrived at an age of

cheap complex devices of great


and something is bound to come of it.































































































































































































[La documentazione della ricerca]







































[La tendenza di sviluppo delle








































[Fotografia, minicamera e fotoprocessi a secco]


































































































A record if it is to be useful to science,

must be continuously extended, it must

be stored, and above all it must be



Today we make the record

conventionally by writing and

photography, followed by printing;

but we also record on film, on wax

disks, and on magnetic wires.


Even if utterly new recording

procedures do not appear, these

present ones are certainly in the

process of modification and extension.



Certainly progress in photography is

not going to stop.


Faster material and lenses, more

automatic cameras, finer-grained

sensitive compounds to allow an

extension of the minicamera idea, are

all imminent.


Let us project this trend ahead to a

logical, if not inevitable, outcome.


The camera hound of the future wears

on his forehead a lump a little larger

than a walnut.


It takes pictures 3 millimeters square,

later to be projected or enlarged, which

after all involves only a factor of 10

beyond present practice.


The lens is of universal focus, down to

any distance accommodated by the

unaided eye, simply because it is of

short focal length.


There is a built-in photocell on the

walnut such as we now have on at least

one camera, which automatically

adjusts exposure for a wide range of



There is film in the walnut for a

hundred exposures, and the spring for

operating its shutter and shifting its

film is wound once for all when the film

clip is inserted.


It produces its result in full color.


It may well be stereoscopic, and record

with two spaced glass eyes, for

striking improvements in stereoscopic

technique are just around the corner.



The cord which trips its shutter may

reach down a man's sleeve within easy

reach of his fingers.


A quick squeeze, and the picture is



On a pair of ordinary glasses is a

square of fine lines near the top of one

lens, where it is out of the way of

ordinary vision.


When an object appears in that square,

it is lined up for its picture.


As the scientist of the future moves

about the laboratory or the field, every

time he looks at something worthy of

the record, he trips the shutter and in it

goes, without even an audible click.


Is this all fantastic?


The only fantastic thing about it is the

idea of making as many pictures as

would result from its use.



Will there be dry photography?


It is already here in two forms.


When Brady made his Civil War

pictures, the plate had to be wet at the

time of exposure.


Now it has to be wet during

development instead.


In the future perhaps it need not be

wetted at all.


There have long been films

impregnated with diazo dyes which

form a picture without development, so

that it is already there as soon as the

camera has been operated.


An exposure to ammonia gas destroys

the unexposed dye, and the picture can

then be taken out into the light and



The process is now slow, but someone

may speed it up, and it has no grain

difficulties such as now keep

photographic researchers busy.


Often it would be advantageous to be

able to snap the camera and to look at

the picture immediately.































































































































































































[Termocarta scansione di immagini

televisione e fotografia a distanza]


































































































Another process now in use is also

slow, and more or less clumsy.


For fifty years impregnated papers

have been used which turn dark at

every point where an electrical contact

touches them, by reason of the

chemical change thus produced in an

iodine compound included in the



They have been used to make records,

for a pointer moving across them can

leave a trail behind.



If the electrical potential on

the pointer is varied as it moves, the

line becomes light or dark in

accordance with the potential.



This scheme is now used in facsimile



The pointer draws a set of closely

spaced lines across the paper one after



As it moves, its potential is varied in

accordance with a varying current

received over wires from a distant

station, where these variations are

produced by a photocell which is

similarly scanning a picture.


At every instant the darkness of the

line being drawn is made equal to the

darkness of the point on the picture

being observed by the photocell.


Thus, when the whole picture has been

covered, a replica appears at the

receiving end.



A scene itself can be just as well

looked over line by line by the

photocell in this way as can a

photograph of the scene.


This whole apparatus constitutes a

camera, with the added feature, which

can be dispensed with if desired, of

making its picture at a distance.


It is slow, and the picture is poor in



Still, it does give another process of

dry photography, in which the picture

is finished as soon as it is taken.



It would be a brave man who would

predict that such a process will always

remain clumsy, slow, and faulty in



Television equipment today transmits

sixteen reasonably good pictures a

second, and it involves only two

essential differences from the process

described above.


For one, the record is made by a

moving beam of electrons rather than a

moving pointer, for the reason that an

electron beam can sweep across the

picture very rapidly indeed.


The other difference involves merely

the use of a screen which glows

momentarily when the electrons hit,

rather than a chemically treated paper

or film which is permanently altered.


This speed is necessary in television,

for motion pictures rather than stills

are the object.



Use chemically treated film in place of

the glowing screen, allow the

apparatus to transmit one picture only

rather than a succession, and a rapid

camera for dry photography results.


The treated film needs to be far faster

in action than present examples, but it

probably could be.


More serious is the objection that this

scheme would involve putting the film

inside a vacuum chamber, for electron

beams behave normally only in such a

rarefied environment.


This difficulty could be avoided by

allowing the electron beam to play on

one side of a partition, and by pressing

the film against the other side, if this

partition were such as to allow the

electrons to go through perpendicular

to its surface, and to prevent them from

spreading out sideways.


Such partitions, in crude form, could

certainly be constructed, and they will

hardly hold up the general
































































































































































































[Microfilm, riproduzione e massdistribuzione

miniaturizzata di documentazione cartacea]


































































































Like dry photography, micro-

photography still has a long way to go.


The basic scheme of reducing the size

of the record, and examining it by

projection rather than directly, has

possibilities too great to be ignored.


The combination of optical projection

and photographic reduction is already

producing some results in microfilm

for scholarly purposes, and the

potentialities are highly suggestive.


Today, with microfilm, reductions by a

linear factor of 20 can be employed and

still produce full clarity when the

material is re-enlarged for examination.


The limits are set by the graininess of

the film, the excellence of the optical

system, and the efficiency of the light

sources employed.


All of these are rapidly improving.



Assume a linear ratio of 100 for future



Consider film of the same thickness as

paper, although thinner film will

certainly be usable.


Even under these conditions there

would be a total factor of 10,000

between the bulk of the ordinary record

on books, and its microfilm replica.


The Encyclopoedia Britannicacould be

reduced to the volume of a matchbox.


A library of a million volumes could be

compressed into one end of a desk.



If the human race has produced since

the invention of movable type a total

record, in the form of magazines,

newspapers, books, tracts, advertising

blurbs, correspondence, having a

volume corresponding to a billion

books, the whole affair, assembled and

compressed, could be lugged off in a

moving van.


Mere compression, of course, is not


one needs not only to make and store a

record but also be able to consult it,

and this aspect of the matter comes



Even the modern great library is not

generally consulted;

it is nibbled at by a few.



Compression is important, however,

when it comes to costs.


The material for the microfilm

Britannica would cost a nickel, and it

could be mailed anywhere for a cent.


What would it cost to print a million



To print a sheet of newspaper, in a

large edition, costs a small fraction of a



The entire material of the Britannica in

reduced microfilm form would go on a

sheet eight and one-half by eleven



Once it is available, with the

photographic reproduction methods of

the future, duplicates in large

quantities could probably be turned out

for a cent apiece beyond the cost of



The preparation of the original copy?


That introduces the next aspect of the
































































































































































































[Comandi vocali, riproduzione - codificazione

/decodificazione digitale - di linguaggi naturali]


































































































To make the record, we now push a

pencil or tap a typewriter.


Then comes the process of digestion

and correction, followed by an intricate

process of typesetting, printing, and



To consider the first stage of the

procedure, will the author of the future

cease writing by hand or typewriter and

talk directly to the record?


He does so indirectly, by talking to a

stenographer or a wax cylinder;

but the elements are all present if he

wishes to have his talk directly

produce a typed record.


All he needs to do is to take advantage

of existing mechanisms and to alter his




At a recent World Fair a machine called

a Voder was shown.


A girl stroked its keys and it emitted

recognizable speech.


No human vocal chords entered into

the procedure at any point;

the keys simply combined some

electrically produced vibrations and

passed these on to a loud-speaker.


In the Bell Laboratories there is the

converse of this machine, called a



The loudspeaker is replaced by a

microphone, which picks up sound.


Speak to it, and the corresponding

keys move.


This may be one element of the

postulated system.



The other element is found in the

stenotype, that somewhat

disconcerting device encountered

usually at public meetings.


A girl strokes its keys languidly and

looks about the room and sometimes

at the speaker with a disquieting gaze.


From it emerges a typed strip which

records in a phonetically simplified

language a record of what the speaker

is supposed to have said.


Later this strip is retyped into ordinary

language, for in its nascent form it is

intelligible only to the initiated.


Combine these two elements, let the

Vocoder run the stenotype, and the

result is a machine which types when

talked to.



Our present languages are not

specially adapted to this sort of

mechanization, it is true.


It is strange that the inventors of

universal languages have not seized

upon the idea of producing one which

better fitted the technique for

transmitting and recording speech.


Mechanization may yet force the issue,

especially in the scientific field;

whereupon scientific jargon would

become still less intelligible to the