The Science Discovery Center of Oneonta
EXHIBITS
Teacher, commenting on class during a visit: "The best part is they
think they're playing."
The exhibits are designed to involve some significant aspect of science,
to be easy to use, and to involve an element of surprise or humor so there
is some fun generated through the activity.
We have concentrated on creating as many novel, original exhibits as possible,
although some "classics" commonly also found elsewhere are irresistable
and we have a few. Mostly, our eighty or so exhibits were designed locally
to be unique among science centers.
We also concentrate on using simple and commonly available materials. We
find that this is useful in emphasizing that science can be an every-day
activity, and often does not require exotic materials and equipment. When
teachers, parents, and children look at what we have done in some of our
exhibits with peanut butter jars, soft drink bottles, inexpensive magnets,
and plastic mirrors, they are inspired to become creative in making useful
science activities for their own classrooms or home projects.
One of Oneonta's eighty (or so) exhibits
The "Fish-tickler" (plastic fish model is the target)
A water tank about a foot deep has a plastic fish mounted near the bottom
at one end. An arrow mounted on a swivel can be aimed directly at where
the fish is seen, but when the arrow is slid into the water it appears to
bend at the water's surface and misses the fish by several inches. The effect
is due to the way light rays change direction at the water's surface. (refraction)
Brief descriptions of our exhibits (as of February 1996)
Descriptive List of Exhibits
arranged by topic areas
Properties of Matter
- Lift-a-Brick
- a styrofoam brick, a conventional building brick, and a lead brick,
all practically the same size, can be lifted by the user. Very few people
can lift the lead brick with just one hand, and the notion of "density"
is made vivid
- Water-and-oil bottles
- colored water and mineral oil or vegetable oil are put into the same
plastic bottle, and can be tilted, shaken, or sloshed. When shaken vigorously
and mixed well they separate rather quickly.
- Volume in a tube
- A short wide tube filled with colored water is joined end-to-end with
a tube half as wide but four times longer. When inverted, the water can
flow from one tube into the other, and a volume comparison can be made.
- Orbit Well
- a large plastic funnel with curved sides, into which the user can start
a ball rolling around the upper edge and watch as it rolls around and around,
getting lower gradually. An assortment of materials and sizes of balls gives
variety to the experience.
- Come-back Roller
- a cylindrical plastic jar has a rubber band along its axis, with a rather
heavy weight hung from the center of the rubber band. When the jar is put
on its side and rolled across the table, the hanging weight winds up the
rubber band and gradually stops the rolling cylinder, then makes it roll
back to where it started from as the rubber band unwinds.
- Double-cone Roller
- a roller made of two funnels joined together at their large ends can
roll on a gently sloping track made of two rods close together at their
lower ends and further apart at their upper ends. With the upper ends far
enough apart the double-cone roller apparently rolls uphill, towards the
top of the track, but if the upper ends of the rods moved closer together
the double-cone roller rolls downhill. A cardboard cylinder also provided
always rolls downhill, regardless of the separation of the rods.
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Two-Marble Puzzle
- a shallow, narrow U-shaped covered trough has a cup at each upper end,
and contains two marbles. The goal is to get one marble into each cup at
the same time.
- Lifting Lever
- a metal tube about one meter long is pivoted at one end, and a sandbag,hung
from it by a loose loop of rope, can be slid along the tube to any location.
The user lifts with one finger under any place on the tube, and can observe
how easy or difficult it is depending on the place chosen. If the sandbag
is much farther from the pivot than the finger is, only a very strong person
can lift it.
- Arm Lever
- a device for measuring the upward pull exerted either by hand or by
forearm with elbow resting on padded platform; the user finds that the same
muscular effort produces greater force when lifting with forearm due to
the different leverage.
- Block and Tackle
- a setup for lifting a rather heavy weight with a rope which can be arranged
in any pattern around three movable and four fixed pulleys. The user finds
that with the best possible arrangement the 30 lb weight can be lifted with
a little finger without straining the finger. (Adapted from exhibit at Ann
Arbor's Hands-on Museum)
- Various pulley systems, one of which is a joke
- a set of four different pulley systems lift equal sandbags, two involving
multiple ropes in the
same setup, and one which looks good but doesn't
lift the weight
- Number Balance
- Plastic numbers, 1 through 9, are made so their weight is directly proportional
to the number. An equal arm balance from which the numbers can be hung is
also provided. If the numbers hung from one end of the balance add up to
a sum equal to that of the numbers hung from the other end, it balances.
(Commercial item: Playskool "Counting Scale" slightly modified)
- Balancing Unequal Weights
- the user has three different weights available, made from 1 or 2 or
3 half-ounce fishing sinkers, and can hang them from hooks on a balanced
lever at distances of 0, 1, 2, 3, 4, or 5 units from the pivot. By analysis
(using weight times distance from pivot), or by trial-and-error, it is possible
to balance the lever with unequal weights hung at unequal distances from
the pivot.
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- Center of Gravity, Balancing
- A flat plastic triangle has its center of gravity marked on it using
a red dot. There is a small, flat-topped peg projecting upward from the
table, and the triangle can be balanced on it only if the center of gravity
is directly above the peg. The marked location of the triangle's center
of gravity can be verified by hanging it from a post provided and noting
that the center of gravity is always directly beneath any point the triangle
is hung from. A rectangle and a T-shape, similarly marked, are also provided.
- Center of Gravity, Tipping
- One end of a trough is pivoted, and the other end can be raised through
any angle from horizontal to vertical. A vertical reference line goes straight
up from the center of the pivot. Any of several objects (rectangle, triangle,
or T-shape), each of which has its center of gravity marked with a red dot,
can be put in the trough (with one bottom corner against the pivot) and
tilted. It will fall over when the center of gravity passes the vertical
line from the pivot.
- Corbelled Stack
- a set of identical rectangular blocks can be stacked, starting from
the edge of a platform and projecting progressively further and further
out. As a challenge, it is possible using only four blocks to get the top
one completely out beyond the edge of the platform.
- Sand Pendulum
- a funnel-like container of sand is suspended just above a tabletop by
a Y-shaped string suspension, so it swings in a looping pattern. The sand
leaves a multi-looped pattern on the table because the container swings
with a shorter period in the plane of the Y than across it (due to the different
effective lengths of the pendulum). Changing the location of the string
junction (part-way up the Y) changes the loop pattern by changing the effective
length for the shorter period. (commercial item: Sargent-Welch #0833)
- Stroboscope and Whirling Disk
- A disk containing parts of faces drawn in various places on it is mounted
on an electric motor and whirled at constant speed while viewing it with
a rapidly flashing light ("stroboscope"). By controlling the rate
of flashing the disk can be made to seem stationary, or slowly moving forward
or backward, or by flashing several times during one revolution various
face parts can be assembled into either a sad face or a happy face, depending
on the flash rate chosen.
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Weight-Changer
- A board about 3 ft. long is pivoted at one end and has a bathroom scale
under its center. A person standing at various places on the board causes
the scales to register a force considerably less or considerably greater
than the person's weight, depending on where the person stands.
- One-way Spinner
- A plastic rod 100 mm long and 18 mm wide, flat on top and rounded assymetrically
on the bottom, will spin smoothly in one direction. If started spinning
in the opposite direction, it will rattle, slow down, stop, and spontaneously
start turning in its preferred direction. (commerical item: Edmund Scientific
38,912)
- Penny-Bumper
- Pennies lying flat can be slid along a straight groove in a plastic
plate. The user can put one or more pennies in the groove and slide one
or more pennies along the groove so they collide head-on. The number of
pennies slid in can be compared to the number of pennies sliding out of
the collision.
- Bubble Chase
- different size air bubbles can be injected at the bottom of a tall tube
containing a viscous liquid; as they rise at different speeds (depending
on their size) the faster, larger ones catch up with smaller, slower ones
and "swallow" them.
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Tornado-in-a-Bottle
- A pair of two-liter soft drink bottles, one partly filled with water,
are joined at their necks by a coupling with a restricted opening. Putting
the water-filled bottle on top and swirling it produces a vortex (like a
tornado) which persists as long as there is water left in the upper bottle.
(commercial item, Edmund Scientific 37,592))
- Air Torus Shooter
- a small box has a fairly large hole in one face and a flexible membrane
over the opposite face. Tapping the membrane will result in a torus of air
(like a smoke ring without the smoke) coming out the hole with considerable
forward velocity, striking some hanging thin plastic strips half a meter
or so away and making them jump.
- Cartesian Diver
- a medicine dropper with transparent bulb is partly filled with water
so that it just floats in water, and then it is put into a plastic beverage
bottle full of water and the cap is screwed on tightly. Squeezing the bottle
makes the dropper sink; releasing the bottle permits the dropper to float,
because of the effect of pressure on the size of the air bubble in the dropper
(and therefore changing the buoyant force on the dropper)
- Submarine
- an adaptation of the Cartesian Diver, in which the dropper partly filled
with air is adjusted so that it just barely sinks in a sealed vertical plastic
tube filled with water. It is made to float by pulling on the piston of
a syringe attached to the tube, thus reducing the pressure, causing the
air bubble in the dropper to expand and to increase the buoyant force.
- Ball on an Air Stream
- A ball can be placed in a swift stream of air blown upward out of a
tube by a variable-speed blower, and the ball will hover in mid-air, even
if the stream is slowly tilted over so it blows diagonally upward at nearly
a 45° angle. The Bernoulli Effect is responsible (as a fluid moves
faster, it exerts less pressure sidewards than if it were at rest.)
- Air Stream between two disks
- While air comes through a hole in the center of one disk a second disk
held parallel and coaxial to the first one, is brought closer and closer
against the air stream. At a certain close distance the second disk suddenly
begins to adhere to the first one, and considerable force is required to
pull them apart. The rapidly-moving sheet of air between them produces a
strong Bernoulli effect.
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Air stream between two golf balls
- Two golf balls are suspended from strings so they hang side by side
but an inch or so apart. A puff of air blown directly through the space
between them will cause them to move towards each other, due to the Bernoulli
effect.
- Automatic Siphon
- Water can be pumped from a small reservoir into a small upper tank having
a tube bent into in inverted U leading back to the reservoir. When the water
level in the tank reaches the bend in the U a siphon starts, draining the
tank.
- Two-Way Fountain
- Two 2-liter plastic bottles, one partly full of water, are joined by
a coupling having two long tubes, one projecting nearly to the bottom of
each bottle. The tubes are perforated just before they enter the coupling.
Inverting produces a fountain. (commercial item: Edmund Scientific 39,997)
- Bottle Swinger
- An empty 2-liter beverage bottle is pivoted loosely on a horizontal
rod through its neck. Blowing air past one side of the bottle causes the
bottle to swing towards the moving air.
- Air Tube Cork Submerger
- A tube, open at both ends, can be plunged endwise into a tank of water
in which is floating a cork small enough to fit into the tube. The cork
has a hook attached underneath. The tank also has a hook coming up out of
its bottom. By using a finger to trap air in the tube, the cork can be floated
down below the surface and hooked to the bottom of the tank.
- "Suction" Cup
- A small knee-high platform with a smooth plastic top is mounted at the
center of a board large enough to stand on, straddling the platform. A suction
cup about 3 inches in diameter has two sturdy finger-hold rings molded into
it. When the cup is pressed firmly onto the plastic it required about a
force greater than 40 or 50 lbs to overcome the atmospheric pressure pressing
the cup to the table.
Sound and Vibration, Waves
- Musical Tubes
- a stream of air blown successively across the tops or bottoms of a sequence
of precisely-sized tubes plays Yankee Doodle in F-major
- Sonic Length Sorter
- a stream of air blown across each of three tubes of slightly different
length enables the listener to select the longest tube and the shortest
tube
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Music Box Soundboard
- A small music-box mechanism, hand-cranked, can either be held in mid-air
and heard only by getting ear close to it, or can be rested on any of a
number of available surfaces and become loud enough to be heard by anyone
nearby.
- Wave Machine
- mechanical waves (transverse) can be set up in a set of vibrating cross
rods joined to a steel "spine" wire by wiggling the end of one
rod up and down (commerical item: Pasco SE-9600)
- Electromagnetic Sound (Also described under the "Electricity and
Magnetism" heading.)
- A variable electric oscillator is connected to a coil of wire fastened
to a sheet of plastic; holding a magnet near the coil causes the sheet to
vibrate audibly, and the frequency and amplitude of the vibration can be
varied through the entire audible range and beyond. This is an open, flat
loudspeaker.
- Sound Delay Tube
- speak into one end of a 250 foot coil of tube while listening to your
own voice delayed noticably as it comes out the other end
- Water Slosh Resonance
- a shallow basin partly filled with water can be sloshed from side to
side with a leaky paddle; the amplitude of the slosh can be dramatic if
the slosher is reversed in time with the water's natural frequency of vibration.
- Resonating rods
- a set of rods of various length can be vibrated at various frequencies
by a small motor; the rod whose natural frequency is the same as the motor's
will vibrate with much greater amplitude than its neighbors.
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Seeing Sound Waves
- a small electronic two-note polyphonic 2 1/2 octave keyboard (with 100
different voices, 39 rhythms and accompaniments, and a demo tune) is connected
to an oscilloscope so the various wave forms can be seen and heard at the
same time.
- Lissajous Figures
- two electronic variable-frequency oscillators connected respectively
to the vertical and horizontal inputs of an oscilloscope permit creation
of many patterns depending on the relative frequencies chosen.
- Spoon Sounds
- a metal tablespoon suspended from a pair of strings, the free ends of
which can be pressed to the ear and surrounding bone, can be struck gently
and the resulting very low frequency vibrations can heard by conduction
through the string.
- Singing Corrugated Tube
- An air stream directed through a corrugated tube a few feet long will
induce the air in the tube to oscillate successively at various discrete
frequencies, (whole-number multiples of tube's fundamental frequency) depending
on air's speed.
- Cup-and-string "telephone"
- A 25 meter (80-foot) string is stretched snugly from the bottom of one
paper cup to the bottom of another at the far end of the room. Sounds made
in one cup cause the cup's bottom to vibrate, and the vibration is transmitted
by the string to the other cup's bottom, vibrating it so the sounds can
be heard.
Electricity and Magnetism
- Electrostatic Generator
- a Van de Graaff generator is set up with 15 cm. lengths of yarn attached
to the large knob, which stand up as the knob and yarn become charged and
drop when a spark jumps, discharging the knob. A graphite-coated pingpong
ball suspended from a 30 cm. nylon thread at the end of a 50 cm. long plastic
handle is provided for further explorations of electrostatic repulsion and
attraction.
Magnetic chaotic pendulum
- a small magnet is attached to the end of a long rod, and swings freely
over a shelf on which other magnets may be arranged in various patterns.
The magnetic forces alter the path of the swinging magnet.
Silent Collisions
- a row of suspended magnets, arranged so each repels its neighbors, mimics
the behavior of the familiar set of steel balls suspended in a row, in which
one or more swinging into the row at one end causes the same number to swing
out from the other end of the row-but the magnets collide noiselessly, without
matter-to-matter contact.
Magnetic Stacks
- a set of four washer-shaped magnets can be speared on either of two
non-metallic rods in any combination of repulsion/attraction between adjacent
magnets. Each magnet's N face is painted red and its S face painted white
for ready identification.
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Magnetic Sculpture
- a commercially-available item ("CRDL") in which a large number
of small iron washers are held in a cohesive pile on a base containing a
strong magnet. The washers can be moulded into very intricate shapes held
in place by the magnetic force.
Earth's Magnetic Field
- a transparent globe with the outlines of the continents painted on it
has a strong bar magnet mounted inside it skewed to give the proper locations
of the Earth's magnetic poles, and with its polarity (magnetic S near geographic
N) clearly marked. Exploration of the model's magnetic field can be done
with a conventional magnetic compass .
Electromagnet for Lifting
- a hand-cranked generator is connected by a long flexible wire to a many-turn
coil mounted on a plastic handle. With an iron core put into the coil, and
with the generator being cranked steadily, iron washers can be lifted from
the tabletop to a small shelf; the faster the cranking, the greater the
number of washers lifted.
Magnetic Dancers
- a large number of short lengths (~6 mm) of steel wire cut from sewing
pins, contained in a shallow transparent plastic box with transparent lid,
can be manipulated either from above or beneath the box with a strong bar
magnet.
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Magnets and Iron Filings
- iron filings in a sealed, shallow transparent plastic box can be manipulated
by one or both of a pair of strong bar magnets, and the interactions between
the two magnets themselves can also be explored.
Magnetic Repulsion
- two long iron finishing nails are suspended adjacent to each other by
long strings, and a large coil attached to a hand-cranked generator can
be put around the pair. Cranking the generator makes the nails move away
from each other.
Hand-Powered Generator
- a hand-cranked generator is connected to three bulbs in parallel, with
switches so that each bulb can be turned on or off separately, and a master
switch controlling the entire circuit. The additional force needed to cause
the bulbs to light can be clearly felt.
Generators and Motors
- small finger-powered generator can be connected either to a bulb (which
can be lit by the generator) or to another similar generator (which runs
like a motor when current is fed into it) or to a dry cell (which runs the
finger-powered generator like a motor). The electric current is monitored
with a center-zero meter.
Board of Many Circuits
- by using selected combinations of seven knife switches, four bulbs can
be connected to each other and to a dry cell in many possible combinations,
such as all in series, all in parallel, any one bulb alone, various seriesp;parallel
connections. An ammeter measures the current provided to the circuit.
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Electromagnetic Sound - (Also described under the "Sound and Vibration,
Waves" heading.)
- A variable electric oscillator is connected to a coil of wire fastened
to a sheet of plastic; holding a magnet near the coil causes the sheet to
vibrate audibly, and the frequency and amplitude of the vibration can be
varied through the entire audible range and beyond. This is an open, flat
loudspeaker.
Magnetic "Follow-the-Leader"
- A vertical rigid plastic sheet has a disk magnet placed on either side
of the sheet, so they cling to each other. If one disc magnet is slid around,
the other follows it.
Magnetic Hanger
- A strong magnet projecting horizontally is mounted several feet above
a base, and two paper clips are tethered to the base by string slightly
shorter than the height of the magnet. The clips can be "hung"
just below the magnet, both being attracted to the magnet p; but they
are observed to repel each other.
Upstairs-Downstairs Switch
- A model stairway has a light over it controlled by a switch at the bottom
of the stairs and also by a switch at the top, such that the light can be
turned on at either switch and turned off at either switch. The model, including
the internal working of the switches, is transparent so the circuit paths
can be traced visually.
Magnetic Marble Challenge
- six magnetic marbles can be placed in six depressions in a triangular
plate only if their magnetic polarities are oriented vertically. The depressions
hold them with about one marble-diameter of empty space between them. A
magnetic compass is also supplied to explore pole locations.
Humpty-Dumpty Magnet
- a disc-shaped ceramic magnet with hole in center had its N pole face
painted red and S painted white. It was broken into two nearly-equal C-shaped
pieces. The challenge is to put it back together as it was originally, but
this is difficult because of the repulsion force between the two parts of
the original N face and also repulsion between the two parts of the original
S face.
- Fish Tickler
- an arrow mounted in an adjustable tilting guide can be aimed at a plastic
minnow near the bottom of a water tank, but when the arrow is slid along
the guide into the water it appears to bend upward at the water's surface
and misses the minnow.
Light Rays
- a light source sends three parallel rays of light out of its front side
across a table top, and also single rays from its left and right sides.
A variety of flat and curved mirrors, concave and convex lens cross-sections,
and prisms are available to permit the user to reflect and refract the light
rays in various directions.
Images with Lenses and Pinholes
- the image of a light bulb's filament can be formed on an adjacent wall
with any of several lenses (or combinations of them), or with any of a variety
of "pinholes" (small circular, large circular, rectangular, V-shaped),
or with an "anti-pinhole", consisting of an opaque dot in a transparent
sheet.
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Mirror Alcove
- a walk-in alcove with walls made of mirrors, with angles of either 120°
or 60° between adjacent mirrors, and with two of the mirrors parallel
to each other. Due to multiple reflections, one can see oneself in many
different places at once, and can observe the parallel-mirror infinity effect
in several different orientations.
Flip-Over Mirror
- a pair of mirrors mounted one above the other at exactly a right angle
to each other, in which one sees oneself upside down.
Mirror Image Locator
- a flat transparent plastic sheet mounted vertically in the center of
a horizontal board with a movable bulb in front of it which can be lighted
and another movable bulb behind it which never lights, but which can be
made to seem to be lit by proper adjustment of the positions of the bulbs,
showing where the lighted bulb's reflection seems to be located.
Large Prism
- a very large water-filled prism is mounted on a turntable so it can
be rotated freely. If one looks through the prism at objects in the room
while rotating it, they appear to be somewhere else, and have colored fringes.
Shadow Storage
- a sheet of phosphorescent material mounted is on a wall with a bright
light which can shine on it when turned on. The material glows where the
light hits it for many seconds after the light is turned off. Objects casting
shadows on the material when the light is on can leave their shadows behind
after the light is turned off.
Adjustable Birthday Cake
- Two large flat mirrors hinged along a vertical edge are mounted on a
table with a fake candle between them. As the angle between the mirrors
is made smaller there are more and more candles seen by multiple reflections.
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Parallel Mirrors
- one flat mirror is attached flat on a table and a second flat mirror
with a hole drilled through its middle is held above it, reflecting surfaces
facing each other. Looking through the hole permits the user to adjust the
alignment of the upper mirror to be exactly parallel to the lower mirror,
and the reflections go on to infinity.
Infinity Kaleidoscope
- a kaleidoscope made of three equal rectangular mirrors joined along
their long edges with reflecting surfaces inside has a fourth mirror placed
across one end. By looking into the open end at various angles, one can
see multiple reflections going on to infinity, with images of one's own
eye infinitely replicated.
Open-ended Kaleidoscope
- a kaleidoscope made of three equal rectangular mirrors joined along
their long edges with reflecting surfaces inside is left open at both ends.
By looking into the open end at various angles, one can see multiple replications
of parts of the room going to infinity in all directions.
Magician's Box
- A small, cubical box has a transparent window front and a coin slot
in the top. A washer tied to a string substitutes for a coin, and is dropped
into the box through the coin slot, but vanishes: it cannot be seen through
the front window. Sliding back the top of the box enables the user to see
how a mirror strategically mounted can produce this illusion.
Perpendicular Mirrors
- two mirrors joined along one edge at exactly a right angle can give
a reflection of a person which is not reversed left/right (if the edge joining
the mirrors is vertical), and printing on an object seen in the mirror can
be read normally. The mirrors are mounted on a horizontal shaft so they
can be rotated, and then the user's reflection turns upside-down.
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Disappearing Hand
- A box has a hole in each end so the user can look into one hole and
see out of the other. The box also has a slot in the top, in line with the
two holes, but putting one's hand in the slot does not interrupt the line
of sight through the holes (due to an arrangement of internal mirrors inside
the box; t.hey can be seen by the user by opening a door in the bottom of
the box)
Concave and Convex Hemispherical Mirrors
- A silvered plastic hemisphere a few inches in diameter is mounted in
a holder so a person can see own reflection upside-down in concave side,
right-side-up in convex side, and can get a finger to meet its reflected
image when poked part-way in to concave side.
- See your own eye's iris change
- Look at a magnified image of your own eye in a concave mirror, and see
the iris change as a small light shines into your eye.
- Microscope
- a 100-power microscope has a set of common things to get uncommon views
of, like a fly's wing, salt crystals, mosquito, milkweed fibers, feather,
light bulb filament, etc.
- Video Microscope
- An assortment of objects, including things provided by the visitor,
can be viewed on a TV monitor at magnifications variable from 30X to 200X.
Full-Length Mirror
- A flat mirror 1 ft. wide and 4 ft. high is fastened to a wall so its
top is 6 ft.above the floor. Short horizontal lines are painted at 4-inch
intervals up one side of the mirror and labelled A, B, C, etc.
- A person looking at reflection of self can measure how much mirror is
actually used, can note that this is equal to just half the person's height,
and can observe while backing farther away that same amount of mirror is
used regardless of distance.
Corner Reflector
- Three flat mirrors are joined together, each at a right angle to the
other two, to form a shape like a corner of a box. You can see your reflected
image from either one, two, or all three mirrors, depending how you hold
the mirror. Your mirror images respectively will be reversed, non-reversed,
or reversed and inverted, and some of them do not move when you rock the
mirror left-right or up-down.
Vanisher
- A plywood box about 0.5 m(20 inches) long, 0.25 m (10 inches) high and
wide, has a transparent front and a slot in the top. Large washers dropped
through the slot vanish. To heighten the illusion, a black strip of tape
is placed on the center of the window so its image appears to be the under-side
of the slot in the box's top when seen through the window. The top lifts
to reveal the unseen compartment behind a mirror.
- Uranium Flipper
- A sealed transparent acrylic plastic tube about 1 inch diameter is half-full
of water. A small sign mounted a short distance below the tube says "choice
uranium oxide" in block capital letters. When the sign is viewed through
the tube, and the tube tipped so that end is filled with water, the word
"uranium" is inverted, whereas if the tube is empty or only half-filled
that word is not inverted.
- ·See Through Hole in Hand -
-
With one eye look through a tube about an inch in diameter and
a foot long. Hold open hand a few inches in front of other eye. Keep both
eyes open. The brain merges the hole seen by one eye with the hand seen
by the other into a surprising composite, your hand with a hole you can
look through. (from Exploratorium Science Snackbook, 17)
Science Discovery Center of Oneonta, Physical Science Bldg, State University
College, Oneonta, NY 13820
phone (607)436-2011; FAX (607)436-2654; e-mail scdisc@oneonta.edu
information entered 2/22/96 by A.J.Read
