The Scientific American book of projects for the amateur scientist

CONTENTS
INTRODUCTION BY VANNEVAR BUSH XVII
". . . the motivation of the scientist, professional or amateur, is the sheer joy of knowing."
PREFACE BY C. L. STONG XXI
". . . the fact that an experiment delivers an
unexpected answer means simply that you
have not asked the question you assume you
have asked"
I. ASTRONOMY
1. ASTRONOMICAL DIVERSIONS 3
A note about the delights of stargazing and
some fascinating instruments devised to overcome the limitations of the human eye.
2 . A SIMPLE TELESCOPE FOR BEGINNERS 5
For about $25 the amateur can construct a
telescope more powerful than Galileo's.
3 . A TRANSISTORIZED DRIVE FOR TELESCOPES 18
Telescopes must be turned slowly to follow
the stars across the sky. Here is a way of
turning one automatically by means of a motor deriving its power from transistors.
A. AN ELECTRONIC STAR-TWINKLE SUPPRESSOR 2 6
How to build an apparatus for making exceptionally clear photographs of the planets.
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5. AN ASTROPHYSICAL LABORATORY IN YOUR 38
BACK YARD
With the addition of a spectrograph the telescope becomes a tool of immense power for
probing, the mysteries of the universe.
6. USING SHADOWED STARLIGHT AS A YARDSTICK 5 3
How to use -fleeting star shadows cast by the
moon for locating with great precision geographical points on earth,
7 A UNIVERSAL SUNDIAL 62
By mounting a globe of the earth this way
you can convert it into a universal sundial
that yields a wealth of information about the
earth's relative motion in the solar system. It
gives you the hour of the day in distant lands,
8. A SUNDIAL THAT KEEPS CLOCK TIME 7 3
Some attractions of the sundial frequently
overlooked by laymen. Instructions for constructing a sundial which can be adjusted
to keep clock time (including daylight saving) anywhere in the Northern Hemisphere.
9. THE MOON IN "3-D" 8 0
With the aid of a mirror, and your own nose
as a measuring rod, the photographs in this
chapter will give you a "3-D" view of the
moon. Notes on how the pictures were taken.
II. ARCHAEOLOGY
1. SHOULD THE AMATEUR DIG? 85
The amateur's role in archaeology. How the
hobby of surveying ancient ruins and arti-
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facts can give pleasure to the amateur and
help his professional colleagues.
2. THE EXCAVATION OF WAPANUCKET NO. 6 9 0
How a group of amateurs with professional
guidance unearthed an ancient Indian village and thereby upset some well-established
conclusions about Indian culture. Important
do's and donts for the beginner.
III. BIOLOGY
1. HOW TO CULTIVATE HARMLESS BACTERIA 105
Adventures in gardening at the microscopic
level. How to experiment with weed-killers
popularly known as wonder drugs.
2. GROWING ALGAE ON A WINDOW SHELF 117
Even if you live in the city you can grow a
pioneer crop of the minute plants which may
some day become an important source of
mans food.
3. HOW TO TRANQUILIZE A RAT 123
An experiment designed by a Michigan highschool girl.
4. HOW TO MEASURE THE METABOLISM 135
OF ANIMALS
An Ohio high-school girl devised this apparatus. She describes its assembly and operation and gives details of a typical experiment
utilizing mice as subjects.
5. CHROMATOGRAPHY 142
An analytic technique, one of the most
powerful known to biochemists, is used to
separate chlorophyll from spinach leaves.
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6. ZONE ELECTROPHORESIS 152
When a solution of chemical compounds is
applied to an electrified sheet of porous paper an extraordinary phenomenon occurs
which the amateur can use for analyzing
subtle chemical mixtures.
IV. TH E NATURAL SCIENCES
1. "NATURES UNIMPORTANT PUZZLES" 167
A note about a great amateur naturalist, the
late Walker Van Riper.
2. THE DELIGHTS OF HUMMINGBIRD STUDY 168
Walker Van Riper devised brilliant techniques for attracting and studying hummingbirds. Here are some of his methods described
in his own words.
3. RAISING MOTHS AND BUTTERFLIES AS 184
EXPERIMENTAL ANIMALS
An amateur lepidopterist explains how he
raises unusual species and prepares them for
scientific study.
4. BIRD-BANDING FOR THE AMATEUR 194
How the amateur who becomes a licensed
bird-bander can make valuable contributions
to science in his own back yard.
5. HOW TO LIVE WITH REPTILES AND 20 2
AMPHIBIANS
Follow these simple direction for raising reptiles at home and you can see a snake shed its
skin, or witness the courting rites (at once
comical and enthralling) of small desert lizards, or watch a dime-store turtle grow to
a length of eight or ten inches.
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CONTENTS
V. TH E EARTH SCIENCES
1. HO W TO KNO W THE ROCKS 217
To the amateur who learns to "read" in
rocks the history of the earth's ever-changing surface, mineral collecting becomes a
doubly rewarding avocation. How to begin.
2. THE ATTRACTIONS OF AMATEUR SEISMOLOGY 22 8
How to locate distant earthquakes by the
vibrations that shake your own back yard.
Typical seismographs. An eminent seismologist shows how amateurs can help the professionals.
3. AN ELECTRONIC SEISMOGRAPH 23 6
From a war-surplus magnet, some scrap
metal, and a few electronic parts, you can
build a sensitive instrument for detecting
earthquakes and the approach of violent
storms.
4. AN AMATEURS SEISMOLOGICAL 24 5
OBSERVATORY
The design and construction of the instruments. How a well was turned into an earthquake detector.
5. HO W TO TRACK EARTH SATELLITES 263
Basic equipment for Method 1: a piano and
a radio set capable of picking up signals
from an artificial satellite. Method 2 employs
a set of sticks and a stop watch.
6. EXPERIMENTING WITH THE EARTHS CHARGE 27 2
Normally the air around your head is some
200 volts positive with respect to the ground
underfoot, but what happens in a thunderXI
storm? Facts about the earth's electric charge
and icays to measure it.
7. AN ELECTRONIC WEATHER FORECASTER 281
How to build a device for making accurate
short-term forecasts.
8. DETECTING THE EARTHS ROTATION 29 0
Leon Foucault's pendulum and directions
for duplicating his results. R. Stuart Mackay
explains his novel method of driving the
Foucault pendulums.
VI. NUCLEAR PHYSICS
1. EXPLORING THE ATOM AT HOME 305
Atoms can he investigated with simple apparatus. A practical cloud chamber may he
made from a whiskey glass. Some old tin
cans, glass jars, discarded inner tubes, etc. —
.and you re on your way.
2. CLOUD CHAMBERS FOR DETECTING 307
NUCLEAR EVENTS
How the circular rainbows made by clouds
in sunlight led C. T. R. Wilson to invent a
powerful instrument for investigating the
structure of the atom. How the amateur can
make and operate a) a simple peanut-butterjar cloud chamber, b) a "rubber plunger'
cloud chamber, c) a dry-ice diffusion cloud
chamber, and others.
3. A SIMPLE MAGNETIC-RESONANCE 335
SPECTROMETER
At the center of every atom there is a minute
top, the nucleus, which spins on its axis
with incredible speed. How to flip it over
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CONTENTS
and make it wobble — and thereby identify
itself.
4. A HOMEMADE ATOM SMASHER 344
For less than the average cost of a set of
golf clubs you can equip yourself for playing
with electrons — and learn much at first hand
about the structure of matter.
5. THE MILLIKAN OIL-DROP EXPERIMENT 36 0
Suspend a drop of oil in mid-air by means
of electrostatic attraction — and you can accurately measure the charge on a single
electron.
VII. MATHEMATICAL MACHINES
1. A PUZZLE-SOLVING MACHINE 37 7
It attacks the classic problem of the farmer,
the fox, the goose and the corn — and signals when it's in trouble.
2. A TICKTACKTOE MACHINE 38 4
The design of this simple machine closely
resembles that of all electric calculating
devices.
3. SOME COMPUTER THEORY 386
Puzzle machines are not merely entertaining
gadgets. They offer insight into mathematical problems — and the working of digital
computers.
4. HOW TO DESIGN A "PIRCUIT" OR 38 8
PUZZLE CIRCUIT
An amateur describes three "pircuits" he
constructed at the age of sixteen.
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5. AN ELECTRONIC MOUSE THAT LEARNS 39 4
FROM EXPERIENCE
With a few hand tools and junk parts, the
amateur can build a robot that exercises
choice and never makes the same mistake
twice.
6. COMPUTERS AND THE TERROR OF 39 8
MATHEMATICS
A short sad note.
7. THE PLEASURES OF MATHEMATICS 399
The amateur scientist is lured into an encounter with integral calculus.
VIII. AERODYNAMICS
1. LOW VS. HIGH 413
The charms of low-speed aerodynamics —
strangely neglected in contrast to rocket
problems.
2. A LOW-SPEED WIND TUNNEL 416
How a group of amateurs constructed the
most accurate apparatus of its kind ever
made.
3. HOW TO MAKE THE FLOW OF AIR VISIBLE 421
A smoke tunnel that can he made for $3.00
if you already have a vacuum cleaner and
a camera.
4. AN AMATEUR-BUILT SMOKE TUNNEL 42 8
Described by a high-school student who built
it at home.
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5. KITCHEN-SIN K AERODYNAMIC S 4 3 2
Equipped with a sheet of glass, some balsa
wood and a source of running water, the
amateur can investigate forces set up by
wind on objects of various shapes.
6. BATHTU B AERODYNAMIC S 43 9
What you can learn by "flying" model airplanes in water.
7 . AMATEU R ROCKETR Y 44 7
Detailed instructions for building and launching two research rockets.
IX. OPTICS, HEAT AND
ELECTRONICS
1. AMATEU R MICROSCOP Y 46 3
How to make a powerful microscope from a
glass stirring rod. Diversions and challenges
that await the amateur. A typical microscope
project. Microphotography.
2 . HOMEMAD E ELECTROSTATI C GENERATOR S 47 7
A little history, some basic principles. Instructions for building a 100,000-volt generator for less than $5.00.
3. A N INEXPENSIV E X-RA Y MACHIN E SOO
From an old radio tube, some copper wire
and other inexpensive materials (total cost:
roughly $20) you can construct a machine
that will make good pictures through an
inch of wood. A review of X-ray theory.
CONTENTS
4. THE "HILSCH" VORTEX TUBE 514
A simple device for attaining moderately
low temperatures. It separates high-energy
molecules from those of low energy.
5. A HOMEMADE INTERFEROMETER 521
An experiment with the optical effect that
imparts color to soap bubbles and blueness
to the bluebird.
6. A PIEZOELECTRIC CLOCK 53 2
The accuracy of electric clocks depends on
the care with which the operator at the
power station maintains constant frequency
on the mains. How to use the piezoelectric
effect to make an electric clock keep accurate time.
7. SOME AFTER-DINNER EXPERIMENTS 54 6
Scientific diversions requiring almost no special equipment or experience: 3-D drawing;
a pseudoscope (it alters the way your eyes
normally present information to the brain);
miniature heat engines.
X. A CLOSING CHALLENGE
The amateur is invited to design experi- 56 1
ments of his own — and to consider, as a
starter, the as yet unsolved riddle of the
skipping stones.
REFERENCES FOR FURTHER READING 56 5
INDEX 571
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