Philippine Science Centrum Traveling Exhibit

Manual of Exhibits

An Affiliate of PFST

ADDRESS

E-Com Building. Riverbanks Center, A. Bonifacio Ave., , City, Metro

TELEPHONE NUMBERS

(02) 942-5136 (02) 942-5091 (02) 942-4137

E-mail: [email protected] Web site: www.science-centrum.ph This Science Adventures Manual of Exhibits MESSAGE is a publication of the Philippine Science Centrum.

Consultant Elvira R. Galvez It is with pride and joy that we present the Science Researcher-Writer Farah R. Galvez Adventures Traveling Science Centrum Exhibit Manual. This Technical Editor Rolando M. Moya manual encapsulates the various science concepts and their Book Designer and Illustrator Florencio T. Gando, Jr. applications presented through 40 interactive exhibits. Exhibit Fabricator Science Centrum Fabrication, Inc. The Science Adventures is a traveling science exhibition Rejean O. dela Cruz component of the Philippine Science Centrum, the premiere Renato T. Mulat science center-museum in the country. Through hands-on Mario C. Reyes interactive exhibits and challenging activities, the Science Rolly G. Ariola Adventures and the four (4) sets of Traveling Science Centrum have successfully brought a unique medium for science and Traveling Exhibition Staff Nelson H. Natividad, Head technology learning to 174 cities and provinces. It has Jermaine L. Argonza registered more than 3 million visitors. Persistent requests Robin Hermoso from students, teachers and supporters have inspired us to Harold Neil G. Santos produce the Science Adventures Exhibit Manual which will Joselito B. Arellano serve as a handy reference in getting to know and better Executive Director May M. Pagsinohin appreciate science and technology and their relevance in daily life.

It is our ardent hope that this manual will be utilized to maximize science and technology among the general public Copyright 2014 Philippine Science Centrum All Rights Reserved and the Filipino youth in particular who will play an active role in shaping the future of the nation. No part of this manual may be reproduced, stored in a retrieval system or transmitted in any form or by any means - electronic, mechanical, photocopying, recording, or otherwise, without prior permission of the MAY M. PAGSINOHIN Philippine Science Centrum. Executive Director ZOETROPE AMAZING CAKE

Try this!

1. Look through a slit on the disk. Do you see a horse and its rider Try this! on the mirror? 1. Look at the mirrors. How 2. As you look through the slit, many slices of cake do spin the disk slowly then spin it you see? fast. How do the horse and the rider appear? 2. Move the right mirror to 3. Repeat steps 1 and 2 for the left. What happens to cylinders A and B. What images vision causes the brain to retain the number of slices? do you see? images cast upon the retina for a fraction of a second after they have disappeared from the field of sight. The phi phenomenon creates What's going on? apparent movement between images when they succeed one What's going on? Painted on the side of the disk another rapidly. Together, these two With two mirrors that are facing the mirror is a sequence of phenomena permit the succession The number of slices of cake that perpendicular to each other, one pictures of horses and riders. When of still pictures which result in you see depends on the angle image will form from a single you spin the disk slowly, the horse continuous movement, as observed between the mirrors. As you reflection from each mirror (R1 and the rider seem to move in the exhibit. continuously like in a horse race. In decrease the angle, you see and R2). These two reflections cylinders A and B, you see a man The illusion of movement is applied more reflections of the slice of create the third image, R3. hurdling and a man tumbling. in motion pictures and cartoon cake. R1 R3 animation. A motion picture or The illusions of movement are animation is made up of thousands If you have one flat mirror, light mirror based on the optical phenomenon, of still pictures, called frames. In from the object will reflect off the called persistence of vision, and the each frame, the scene or subjects in mirror once. When you have phi phenomenon. Persistence of the scene are slightly different in more than one mirror, you can position from the previous frame. create multiple reflections. R2 For every second, 24 frames of film object flicker onto a screen to produce mirror moving images. We cannot distinguish each still image, but When the angle is decreased, instead see continuous movement. more reflections will occur.

40 Science Adventures Science Adventures 1 WHIRLPOOL ANTI-GRAVITY MIRROR

Try this with a friend!

Try this! 1. Ask your friend to stand on the right side of the mirror and align Press the button. What do you his/her nose to the mirror's see? edge. 2. Position yourself within the 45- degree angle with the mirror. What's going on? Watch as your friend lifts his/her left leg and moves his/her left When you press the button a arm up and down. How does your friend look? propeller in the exhibit rotates. This causes the water to move in 3. Change roles. You will do what a circle around a central area and your friend did and your friend will now observe you. You can form a whirlpool. try other movements. A whirlpool is a large, swirling A whirlpool can form where: body of water. Its formation What's going on? follows the Law of Conservation 1. two currents of water moving in A person standing at the right side of plane, called the sagittal plane, of Angular Momentum, which opposite directions meet, a large mirror such that the left half divides the body into roughly mirror of the body is visible and the right image halves (external appearance states that if an object is rotating half is hidden from view will look only). The two halves can be about a center and is pulled in 2. tides and rock formations in the whole to an observer who is referred to as the right and left closer, it will rotate faster. ocean interfere with the path of positioned within the 45-degree halves. The right half is similar to the an ocean current and the angle with the mirror. The fun left half in size, shape and parts. begins when the person starts to do In a whirlpool, the slowly rotating current is diverted in a circular some movements. When the To an observer the reflection of the water in the outer areas is drawn path, person lifts his/her left leg, the exposed half (left side) on the mirror towards the center. The water observer will see two legs off the appears to be the right half of the 3. wind blows strongly against a ground. When the left arm is moved body, so the person looks whole. begins to rotate faster, exerting a up and down, the person appears to The lifted leg is also reflected by the greater central force and making tidal current, or be flying. Why? mirror. This is why the person appears to be suspended in air and a hole. As a result, you see a 4. flow of water through a The human body exhibits bilateral not pulled down by gravity. vortex. riverbed increases. symmetry. This means that only one

38 Science Adventures Science Adventures 3 THOMPSON RING BICYCLE WHEEL GYRO Try this with a friend! Try this! 1. Sit on the chair. Stretch your Press the button. What happens arms forward. to the aluminum ring? 2. Ask your friend to spin the bicycle wheel fast and hand it to you as it spins. Make sure What's going on? that the rapidly spinning wheel does NOT touch your When the switch is turned on, the body. (Take note of the ring immediately "jumps" up the direction of the spin.) vertical rod. Why? 3. Tilt the spinning wheel to the The exhibit consists of a left. Does the chair rotate to transformer, an induction coil, and the right or to the left? Tilt the When you tilt the spinning wheel an aluminum ring over the core of wheel to the right. In what you are applying a twisting force the coil. An alternating current direction does the chair or torque on your body. Since you (AC) is used to power the rotate? are seated, the energy transfers to transformer. the chair, and the chair rotates. What's going on? AC is a constantly varying current, The exhibit also demonstrates meaning the electrons change When you tilt the wheel that is Conservation of Angular directions 50 times per second. field (in the coil) has a north pole spinning inward to the right, you Momentum. This is a principle of When the switch is turned on, AC pointing up, then the induced field (on the chair) rotate to the left. motion involved in rotating produces a constantly changing in the ring will have a north pole When you tilt this spinning wheel objects. You, the chair and the magnetic field through the coil. pointing down. As like poles repel, to the left, you rotate to the right. spinning wheel make up a system. This in turn induces a constantly the north poles will repel each Any change in the angular changing current in the ring, other. Thus, the ring jumps up. When you tilt the wheel that is momentum within the system producing a constantly changing spinning outward to the right, you must be accompanied by an equal magnetic field in the ring. This is rotate to the right. When you tilt and opposite change so that the called the Law of Induction. this spinning wheel to the left, you total effect is zero. In order to rotate to the left. Why? counterbalance this torque, the According to the Law of wheel applies an equal and Conservation of Energy, the The exhibit demonstrates opposite twisting force on you. induced fields must be in the Conservation of Energy. Energy Since you are sitting on a low- opposite direction to the original from the spinning wheel transfers friction pivot chair, you (on the fields. For example, if the original to your arms, body and legs. chair) rotate.

36 Science Adventures Science Adventures 5 SYMMETROSCOPE CALYPSO REEF

Try this! Try this! 1. See the drawings of parts of 1. Face the exhibit from a objects on the disk at the distance of two feet. Look at back end. your reflection on the glass. 2. Look through the opening of the three-sided tube. 2. Relax your eyes, free your mind but keep looking at 3. Slowly rotate the disk until a your reflection for at least 30 part of an object fits a corner seconds. Do you see a formed by two sides of the three-dimensional (3D) tube. What happens to this image? What is it? part? Does this part become whole? You may also try these:

What's going on? • As you look at the 3D image, move closer, then farther. The drawings on the disk are Does the image also move? parts of circular objects. As a The slight differences in vertical part fits a corner formed by two • Close one eye. What repetitions of figures or random sides of the tube, that part is happens to the image? dots create this illusion of depth. reflected by the three mirrors. The reflections bounce back and Once you perceive the hidden forth. This is why you see many image and depth, you can look at reflections of whole circular What's going on? the whole 3D image. When you objects–a slice of pizza move closer, the image becomes a whole pizza! Each As you focus on your reflection becomes clearer. When you whole pizza consists of six sides of the rectangular mirrors on the glass, a 3D image of move farther, you see more identical parts. are joined to form a 60-degree dolphin and fish appear. depth. triangle. The sum of the three The arrangement of the three angles total 180 degrees. Each Depth perception enables you to A person with impaired depth m i r r o r s i n s i d e t h e a n g l e p r o d u c e s s i x - f o l d see a 3D image that is hidden perception or a person with only symmetroscope produces the patterns, resulting in a design of within a two-dimensional one eye will have difficulty reflections you see. The longer continuous triangles. pattern, called a stereogram. seeing the 3D image.

34 Science Adventures Science Adventures 7 SHOOT THE BALL COLOR OR WORDS

Try this! Try this! 1. With one hand, hold the goggles close to your eyes. 1. See the printed words on the With the other hand, shoot poster. They are names of the ball into the ring. Did the colors. ball go into the ring? Keep trying. 2. Say aloud the name of the color used in printing each 2. Shoot the ball without word. (Do not read the looking through the goggles. word.) Do this as fast as you Did the ball go into the ring can. Is this an easy task? this time?

What's going on? What's going on? passes from air to the goggles' lenses. This results in the In doing the task, most likely you Young children who cannot read When you shoot the ball while shifting of your visual field. The experienced either one of these: yet but can recognize colors looking through the goggles, you ring appears to be slightly to one would be able to do the task cannot make the ball go into the side when you look through the • Instead of naming the color, easily. Older children or adults ring. Your shot is always way off goggles, but actually the ring is you read the printed word. who can read fast would not be even after several tries. Then, just in front of you. So when you • It took you some time before able to do the task as fast. when you shoot without the aim the ball to that direction the you could name the color. goggles, you still cannot make ball misses the ring. When you Why? There are two theories that may the shot in the first few tries. decide to change the direction of explain the Stroop effect: Why? your shot, you may succeed. What you experienced is the Stroop Effect, named after J. 1. Speed of Processing Theory - Normally, your sense of touch Similarly, when you remove the Ridley Stroop, a psychologist. It Words are read faster than and sense of sight work together goggles and repeat the task, at demonstrates that the words colors are named. (synchronize). You depend on first you have difficulty making themselves have a strong your eyes to tell you where the the shot. After trying several influence over your ability to 2. Selective Attention Theory - ring is, so that you can shoot the times, your eyes adjust back to name the color. The two kinds of Naming colors requires more ball in that direction. However, normal view–you see the ring in information (what the word says attention than reading words. the goggles produce a slight its actual position and you shoot and the color of the printed word) visual distortion–light bends as it the ball in that direction. cause confusion in the brain.

32 Science Adventures Science Adventures 9 ROPE PUZZLE 1 CYCLONE ?? Try this! Try this!

1. See the way the black rope and Press the red button until you the red rope are arranged: see a lot of mist rising. Then, The black rope has its ends looped around the posts. The press the yellow button. spheres prevent the rope from What happens to the mist? being pulled out of the posts.

The red rope forms a loop around What's going on? the black rope. This loop is large enough to pass through a The exhibit simulates the formation sphere. of a cyclone. The mist represents 2. Solve this puzzle: Free the red warm air. The air being blown from rope from its loop around the black holes in the pipes causes the mist to rope, the post and the sphere. rotate.

3. Return the red rope to its original A cyclone is formed when a large position, that is, the red rope is mass of warm air rises, causing a Tropical cyclone is one of the six looped around the black rope. drop in air pressure in the place main types of cyclones. It usually where it occurs. The cool air from occurs over warm oceans that the surroundings moves toward this supply water vapor to the warm 2. Insert it through the loop of the black low-pressure area. This makes the rising air. The water vapor What's going on? rope. cyclone take a spiral upward condenses and forms clouds and 3. Hold it up and pass it through the motion. The cyclone's center, which rain. The energy given off during the Did you do the following to solve the sphere down to the post. is the area of lowest atmospheric process of condensation causes air puzzle? pressure, is called the eye. to rise faster. A continuous supply of The rope puzzle is an example of energy carried by water vapor A. To take the red rope out of the black topology, a branch of mathematics. rope, the post and the sphere: Topology is sometimes called "rubber- increases wind speed. Based on 1. Hold up the red rope. Pass it through sheet" geometry, because it studies wind speed, there are three types of the sphere down to the post. those properties of figures (like the tropical cyclones: depression 2. Pass it through the loop of the black circular rope) which remain unchanged (60km/h), storm (60-118 km/h), and rope. if the figures are stretched, twisted, typhoon (119 km/h or faster). 3. Pull it up the post and out of the bent or otherwise "elastically" As air pressure below the rising air sphere. deformed. Such elastic deformations decreases further, it causes more Tropical cyclones are also called are continuous functions since points, cool humid air in the surroundings to hurricane, typhoon, tropical storm, B. To return the red rope to its original which start out close together end up move into the eye faster. Air around cyclonic storm or tropical position: c l o s e t o g e t h e r a f t e r t h e a cyclone moves counterclockwise depression depending on their 1. Pass the loosened (freed) red rope deformation–the rope remains circular in the Northern Hemisphere and location and strength. In the through the sphere, then down to after freeing it from its loop around the the post. black rope, the post and the sphere. clockwise in the Southern , tropical cyclones occur Hemisphere of the Earth. most frequently in August.

30 Science Adventures Science Adventures 11 RAINBOW CURTAIN FINGER TINGLER

Try this! Try this! 1. Rotate the crank several times. Slowly pull the cord to raise the Look at the voltmeter. Does the bar until you form a soap film. needle move?

Do you see colors of the 2. Place a finger on a brass plate rainbow on the soap film? and slowly rotate the crank. Does your finger feel anything?

3. Place another finger (from the What's going on? same hand) on the other brass plate You see a beautiful display of all and slowly rotate the colors of the rainbow on the the crank. What soap film. The colors change as do you feel? the film moves, changes shape, nothing in your finger. When you or thins out–a thin part reflects What's going on? place two fingers from the same blue light strongly, a thick part hand on the two brass plates and reflects red light strongly. rotate the crank, you experience a Varying thickness of other parts Generally, we have no way of tingling feeling or mild electric shock reflect other colors. knowing the presence of electricity in your fingers. This indicates that Like water waves, light waves except when it makes appliances electricity flows through your fingers work or when an instrument, like the The soap film consists of two affect each other when they as in a closed circuit. voltmeter, is used. surfaces of soap molecules meet. This can result in the The degree of electric shock that is separated by a layer of water. energy of two waves adding and When you rotate the crank, felt depends on the following: 1) When light strikes the front forming a big wave with more electricity is produced as indicated speed of rotation, 2) presence of surface, some of it is reflected energy. The waves can also by the movement of the voltmeter moisture, and 3) surface area. More and some of it is transmitted to cancel each other out. This wave needle. (Voltage can be present current can pass through when you the back surface. From the back interaction is called interference. without current by cranking the rotate the crank faster, when your surface, some light is also It is what produces the bands of generator and not touching the fingers are moist since moist skin reflected. Light waves reflected beautiful colors, like what you brass plates.) has a lower resistance than dry from the two surfaces meet. see in a rainbow. skin, and when a bigger part of your When you place a finger on a brass fingers is in contact with the brass plate then rotate the crank, you feel plates.

28 Science Adventures Science Adventures 13 PUPIL OF THE EYE GRAVITY WELL

Try this! Try this!

CAUTION: Turn the knob 1. Insert a coin into the groove. SLOWLY to prevent the sudden flash of light from damaging your 2. Observe the coin’s movement. eye. Does the coin go straight down to the hole? 1. Position your eye on the circular shield. What's going on?

2. Look at the reflection of your When the coin lands on the well, the pupil on the mirror. force of gravity should make it go straight down to the hole. Instead, the 3. Turn the knob SLOWLY coin moves round and round the cone • Second Law: A line joining a planet clockwise to brighten the light. gradually moving towards and into the and the sun sweeps out equal What happens to your pupil? hole. areas during equal intervals of time as the planet travels along its orbit. The coin moves in a spiral because This means that the planet travels What's going on? the force toward the center of the well faster while close to the sun and is the only horizontal force. (The gives the eye its color–black, slows down when it is farther from The pupil becomes narrower in vertical component of the force is the sun. bright light. (It becomes wider in dim brown, blue, or green. opposed and canceled by gravity.) light.) This horizontal force is called the • Third Law: The squares of the The iris has two muscles–the dilator central force, which is created by the orbital periods of planets are The pupil is the opening in front of and constrictor muscles. The dilator slope of the gravity well. The slope is directly proportional to the cubes of the eye. Its diameter is controlled muscle makes the iris smaller and steeper towards the hole, hence the the semi-major axes (the "half- automatically by the surrounding therefore the pupil wider, allowing force is greater. This causes the coin length" of the ellipse) of their orbits. iris. The iris is the part of the eye that more light into the eye. The to accelerate towards the hole. This means not only that larger constrictor muscle makes the iris orbits have longer periods, but also larger and the pupil narrower, The gravity well demonstrates that the speed of a planet in a Sclera allowing less light into the eye. Kepler's laws of planetary motion. larger orbit is slower than in a It simulates the effects that the smaller orbit. Pupil size can change from 2 gravitational pull of the Sun has on objects in our Solar System. In space which is essentially a Cornea millimeters to 8 millimeters. Vitreous However, in very bright light we vacuum offering no resistance, Pupil humor have to close our eyes because the • First Law: The orbit of every planet planets and other objects would Optic Iris is an ellipse with the sun at one of iris cannot completely close the continue in their elliptical orbits almost Nerve the foci. An ellipse is characterized pupil. indefinitely. But in the gravity well, the Retina by its two focal points. gravitational pull causes the coin to spiral down to the hole.

26 Science Adventures Science Adventures 15 PEDAL GENERATOR LASER DISPLAY

Try this! Try this!

1. Pedal the bike slowly. How Look at the laser display. many bulbs light up? What do you see on the white panel? 2. Pedal faster. Does the top bulb light up? Do you also hear a musical sound? What's going on?

The various designs you see on the What's going on? white panel are actually the path taken by the moving laser spot, When you pedal slowly, the lower called patterns. A laser consists of a gain medium bulbs light up. When you pedal inside an optical cavity with a faster, all the bulbs light up and you LASER is an acronym, which means to supply energy to the gain also hear a musical sound. Energy stands for Light Amplification by medium. The gain medium is a transformation makes these things Stimulated Emission of Radiation. It material (gas, liquid, solid or free happen. magnets inside the generator. The is a device that emits light in a electrons) with appropriate optical resulting current is channeled to narrow, low-divergence beam and properties. The optical cavity Energy exists in one form or the attached power strip to which with a well-defined wavelength consists of two mirrors arranged in another–it cannot be created and it several bulbs and a sound device (corresponding to a particular color such a way that light bounces back cannot be destroyed. In the exhibit, are connected. if the laser is operating in the visible and forth, each time passing energy is transformed this way: spectrum). This is in contrast to a through the gain medium. The • The bulbs use the electrical l i g h t s o u r c e s u c h a s t h e mirror at one end of the laser is • Food is stored chemical energy. energy, which is transformed into incandescent bulb, which emits “half-silvered”, meaning it reflects light energy. light in a large solid angle and over a some light and also allows some • When you pedal the bike, you wide spectrum of wavelength. light to pass through. The light that transform the energy in the food • The sound device also uses the passes through is the laser light.

you eat into the mechanical electrical energy, which is Principal components of a laser: energy that moves the muscles. transformed into sound energy. The most widespread use of lasers is in compact disc and DVD players, • The bike in motion also has The diagram below shows the in which the laser scans the surface mechanical energy. energy transformation in the exhibit: of the disc to play. As bar code readers the laser decodes the price of a product. In industry, lasers are • The electric generator transforms Light Energy 1. Gain medium the mechanical energy of the bike used for cutting metals and for 2. Laser pumping energy inscribing patterns. In medicine, into electrical energy. The rotation Chemical Mechanical Mechanical Electrical 3. Mirror energy energy energy energy lasers are used in some surgical of the front wheel turns the coil of (muscles) (bike) 4. Half-silvered mirror procedures. wire between the poles of the Sound Energy 5. Laser light

24 Science Adventures Science Adventures 17 MUSICAL PIPES MAGNETIC FIELD Try this!

Try this! 1. Hold the magnet against the backside of the casing. Slowly move the magnet in any direction. Hit each pipe with the rubber What happens to the iron filings? pad. From which pipe do you hear a low pitch? From which 2. Hold the magnet in place where the pipe do you hear a high pitch? iron filings are thinly spread. Do the iron filings align in a certain way? Hit the pipes to produce a What's going on? rhythm. A magnet has a magnetic field. The Wand magnet - Field is shape of the magnetic field is strongest standing up determined by the shape of the magnet on long side, and weakest standing up on What's going on? and the location of its poles. tip.

Diagram of sound waves Iron filings are magnetic materials, When you hit the pipes with the meaning they are attracted to magnets. rubber pad, you hear “boink” When you move the magnet, the iron The closer the magnetic field lines are to sounds. The sound from each filings align in the direction of the each other, the stronger is the magnetic field. pipe has a different pitch. magnetic field lines of the magnet, making the field visible. The cow magnet, like the one in the Pitch is a term used to describe exhibit, has an important use in the the frequency of sound waves or Magnetic field lines cattle industry in preventing Hardware of a cow or bar magnet Disease. While grazing, cow may ingest how fast or slow sound waves Low Frequency (Low Pitch) iron objects (nails, staple wires and travel. When the air inside the pieces of bailing wire). These objects pipe vibrates at a fast rate, we There are different shapes of magnets. tend to remain in the stomach walls, say the sound has a high threatening the surrounding organs, frequency. A high frequency Horseshoe magnet - causing irritation and inflammation Field is strongest at the known as Hardware Disease. The cow means a high pitch. south pole standing up, loses appetite, produces less milk, and and weakest at the arched end. loses weight. To Sound waves travel faster p r e v e n t t h i s , through a shorter distance. In High Frequency (High Pitch) ranchers feed cow the shortest pipe, sound waves magnets to their Round magnet - Field is travel the fastest. The sound has cows. The magnet sound waves travel the slowest. strongest standing on settles in the cow's the highest frequency and the The sound has the lowest edge, and weakest lying on flat side. first stomach and highest pitch. In the longest pipe, frequency and the lowest pitch. attracts the iron objects.

22 Science Adventures Science Adventures 19 MOMENTUM MACHINE MONEY DETECTOR

Try this! Try this!

1. Stand on the platform and 1. Place any bill (P20, P50…) lean your body on the handle. under the lamp of the device. Hold the handles tightly. Do you see any glowing marks on the bill? 2. Push on the floor with your left foot. Once you are rotating, 2. Take the bill out of the device raise your left leg backward. and look at it. Do you still see Do you slow down or speed up? the glowing marks?

3. Put your left leg swiftly back on the platform. What happens to your speed? What's going on? The money detector device has a special bulb called the UV When a bill is slid under the What's going on? lamp or black light. This emits lamp, the device will let you ultraviolet light which causes the When you extend your left leg acceleration. This makes the know if it is genuine or fake. fluorescent dye on the bill to light backward, your rotation becomes rotation faster. Some parts of the bill glow and up. Fluorescent marks usually slower. When you put your left leg reveal interesting marks. The portray the denomination of the swiftly back on the platform, your If you are getting dizzy and want to marks are called fluorescent bill. The dye is also incorporated rotation becomes faster. stop, what should you do–will you prints and they fluoresce or glow in the serial numbers and pull in your leg before stepping when exposed to the lamp. security fibers. This causes Your body has a center of gravity down from the platform? them to glow as well. and so does your leg. It is as if Remember, pulling in your leg t h e r e a r e t w o b o d i e s drastically increases your speed! Money detectors can also a c c e l e r a t i n g – y o u r b o d y The proper way is to extend your determine the authenticity of accelerates differently from your leg backward as much as you can. credit cards, traveler's checks, e x t e n d e d l e g . T h e l e g ’ s As the rotation slows down, bring and other special documents. acceleration affects (decreases) your leg slowly back to the Fluorescent dyes on these the body’s acceleration, and so platform then put it down on the documents produce the same rotation of the system slows down. floor to stop while still holding on to effect as bills under the UV lamp. When your legs are close together the handles. on the platform, the system has

20 Science Adventures Science Adventures 21 LOOK INTO INFINITY OPTIC LAND

Try this! Try this! 1. Push the button to switch on the 1. Look through a pair of holes light source. on the panel. What do you see? 2. Rotate the bolt head on a lens holder and observe the light. 2. Push the panel gently. Do 3. Rotate the bolt head on the other you still see the same thing? lens holders. What happens to the light that hits the different What's going on? lenses?

When you look through two What's going on? holes on the panel, you see a tunnel with lights at the sides. The light source projects rays of white When a beam of white light strikes the The tunnel is long and seems to light and colored light on the table. The lenses and prism bend these rays prism, white light separates into have no end. in different ways. rainbow colors. The white light entering the prism is a mixture of What you see is the optical effect The convex lens bends the light and different frequencies, each of which of two mirrors facing each other. b r i n g s t h e b e a m s t o g e t h e r gets bent slightly differently. Blue light The row of lights along the sides (converge). The concave lens makes is slowed down more than red light the beams spread out (diverge). and will therefore be bent more than of a mirror is reflected on the red light. This type of prism is other mirror. This reflection is dispersive. reflected back and forth many Converging Lenses Diverging Lenses times between the two mirrors. Prisms are sometimes used for the Each reflection looks smaller internal reflection at the surfaces than the previous one. These rather than for dispersion. This makes a prism a useful substitute for a mirror r e f l e c t i o n s t h a t b e c o m e curves down and becomes as in binoculars. thicker across the middle thinner across the middle progressively smaller create a shorter. thinner at its edges thicker at its edges sense of apparent depth and serves to converge light serves to diverge light Lenses are used for correcting visual distance. The tunnel effect can be seen in defects such as myopia, hyperopia, light converges light diverges hair salons where there are presbyopia, and astigmatism. They When you push the panel the mirrors on two opposite walls. are also used in imaging systems of mirrors are no longer parallel to binoculars, telescope, spotting scope, microscope, and camera each other and so the tunnel (photographic lens). The magnifying glass uses a single convex lens.

18 Science Adventures Science Adventures 23 JACOB'S LADDER PLASMA SPHERE

Try this! Try this! 1. Push the button. Do you see a spark? Does the spark form an 1. Push the button. What do arc between the two copper you see? rods? What happens to the spark as it reaches the top? 2. Touch the glass sphere. 2. Blow air through the small holes. Move your fingers over the What happens to the arc? surface. What happens to the streaks of light?

What's going on?

A high voltage occurs at the lower end of the pair of electrodes (two What’s going on? copper rods in a V shape). The electric forces due to the high The plasma sphere is made of a voltage difference between the two glass flask that contains a electrodes are strongest at the mixture of inert gases under a bottom where the electrodes are electrodes widens, a path is created reduced pressure. At the center streaks. The gases used in the close together. These forces are for the arc. The arc is much hotter of the flask is an electrode that plasma sphere are argon, neon strong enough to ionize the air a n d l e s s d e n s e t h a n t h e releases electrical energy. and nitrogen, which produce between the electrodes. Atoms that surrounding air. Thus, the arc rises When electrical energy passes blue, red and white colors. make up the ionized air collide with up the electrodes until the available through the gas mixture, atoms each other and release light energy, voltage and current can no longer When you touch the surface of which is the spark you see. maintain the air in an ionized state. that make up the gases become The arc extinguishes, then a new highly ionized. (Ionized atoms the sphere or even just hold your spark forms at the lower end of the are those that have had one of fingers very close to the surface, electrodes and the whole process their electrons knocked off.) You the streaks move towards your begins all over again. see these ionized gases, called fingers. When you move your plasma, streaming from the fingers over the surface, the The arc can be made to stop when central electrode towards the streaks move and follow your air is blown into the tiny holes glass like short lightning bolts. fingers. because the ionized air is blown Spark, which is produced at the away. When this happens, a new Different gases produce lower end of the electrodes, travels spark forms at the lower end. up. As the space between the different colors of the plasma

16 Science Adventures Science Adventures 25 FROZEN SHADOW RADIOMETER Try this! Try this! Press the three buttons and observe 1. Press the button and go near the the rotation of the vanes. wall. Do the vanes in the three radiometers 2. Make a funny pose, wait for the rotate at the same speed? flash, and step away from the wall. Why is your shadow still on What's going on? the wall? The vanes in the three radiometers rotate at different speeds. What's going on? The radiometers are made from glass The wall is painted using glow-in-the- bulbs. There are four vanes in each radiometer. Each vane has a silver has an effect on the amount of light dark pigments and white paint binder. absorbed or reflected, and hence the (This paint is also used in printing t- burst of bright light goes off. No light surface and a black surface. Much of the air inside the bulbs has been removed to speed of the vanes' rotation. When the shirts and signages.) The pigments or hits the part of the wall where you form a partial vacuum. This permits motion light strikes the vanes' surface at a 90- phosphors absorb light and continue stand and so no light is emitted, while of the vanes because there are enough air degree angle, absorption is favored and to glow for 2 to 3 minutes even after the rest of the wall glows in the dark. molecules to cause air molecules to move. reflection less favored. If the light strikes the light switches off. the surface at a low angle, reflection is Additional Information: Phosphors When radiant energy from the spotlight favored over absorption. The pigments have electrons that are have three characteristics: the type of strikes the vanes, the silver surface of one easily excited to higher energy levels In the exhibit, the distance and orientation energy required to energize them, the vane reflects this of the spotlights with respect to the when they absorb light energy. The color of visible light they produce, and energy causing it to radiometers differ. The radiometer on the excited electrons drop to a lower but their persistence–the length of time move. The energy left has its spotlight closest to it and strikes still excited intermediate level. They they glow after being energized. A reflected by the the surfaces of the vanes directly. These stay there for a period of time before glow-in-the-dark product must have a s i l v e r s u r f a c e vanes rotate the fastest. In the middle strikes the black radiometer, the spotlight is farther away returning to their ground state phosphor that is energized by normal surface of the vane (original energy level) and emitting light and has a long persistence. but still strikes the surfaces of the vanes next to it. The black directly. The radiometer on the right has its the excess energy as visible light. surface absorbs the This explains why your shadow spotlight striking the top part of the vanes We usually see phosphors in a energy that strikes rather than its surfaces. These vanes remains on the wall after the short television screen and in fluorescent One-bulb radiometer it–energy reflected rotate the least. light bulbs. In a TV screen, an electron by the silver surface beam strikes the phosphor to and energy from the spotlight. The air Additional information: The amount of Excited State energize it. A color television screen molecules hitting the warm black surface radiant energy absorbed by objects of the vanes pick up some of the heat, actually contains thousands of tiny depends on the color of their surface–dark Intermediate State elements with phosphors that emit bouncing off the vanes with increased colors absorb better than light; flat black + thermal energy three different colors–red, green, and speed. The increased temperature inside absorbs best of all. Light or silver colors the bulb also makes the air molecules blue. In a fluorescent light, ultraviolet reflect better than dark colors. The amount move faster, causing the vanes to rotate of radiant energy reflected by objects also phosphorescence light energizes a mixture of continuously. depends on the smoothness of their phosphors that together create light surface–smooth reflects better than Ground State that appears white to us. The angle at which light strikes the vanes rough.

14 Science Adventures Science Adventures 27 ELECTRIC FLEAS RING BUBBLES

Try this! Try this! 1. Dip the ring in the soap 1. Rub the plastic surface solution. vigorously with the styro block. What happens to the 2. Wave the ring through the air styropore bits? to make a bubble. Observe the bubble as it floats in the 2. Continue rubbing the surface air. What is the shape of the and observe what happens. bubble?

What's going on? What's going on? The styropore bits represent fleas. At the start, the fleas are A single soap bubble in the air is them. Due to surface tension, electrically neutral. When you a nearly perfect sphere. This the films contract. As the bubble rub the plastic surface, negative shape of the bubble results from contracts, it compresses the air the force acting on it. The force is inside. This increases the charges transfer from the styro upper part of the flea and the called surface tension. internal pressure to a point that block to the plastic. Since the plastic is strong enough to lift this prevents further contraction. plastic is a poor electrical particular flea to the plastic. conductor, these charges do not A soap bubble consists of two Eventually, the pressure on the spherical surface films of soap soap film exerted by the air flow all over the surface but only When the flea touches the with a layer of water between inside and outside the bubble on the part where it is rubbed. plastic, negative charges flow becomes equal. The negative charge on the from the plastic to the flea, plastic attracts the fleas’ positive neutralizing the top of the flea soap film The spherical shape provides charges and concentrate them and so the flea falls. However, water layer the minimal surface area on the upper part of the flea since the flea is electrically air needed to enclose a given while repelling the fleas’ neutral at the start, it now has an volume of air, making it the most n e g a t i v e c h a r g e s a n d excess of negative charge. efficient shape for a bubble. If a concentrating them on the When the flea touches the wood surface bubble were any other shape (it bottom part. Thus, the fleas it loses its charge slowly, and the tension is often oval while being blown), become polarized–positive on process can begin again. force it will keep moving until it takes the upper part and negative on Eventually, the plastic is on a spherical shape. Once it the bottom part. The attraction discharged completely and the has become spherical, the between the charges on the process stops. bubble stops adjusting its shape.

12 Science Adventures Science Adventures 29 COLORED SHADOWS ROPE PUZZLE 2 ?? Try this! Try this! 1. Stand in front of the white wall. What colors are your Get the rope out of the pipes. shadows?

2. Move closer to the wall. Do you see more colors? What's going on?

3. Go to the right side, then to Did you do the following to solve the left side of the wall. What the puzzle? is the color of your shadow at each side? 1. Loop the rope around the blue pipe, then transfer it to the red pipe. What's going on? example, red and green lights 2. Move the rope to the yellow form a yellow shadow in the path pipe. When you stand in front of the of the blue light. 3. Get the rope out of the blue wall, you produce three colored pipe. shadows: cyan, magenta, and When you move closer to the wall, yellow. The color of each shadow parts of your colored shadows is the complement of the color of overlap. These overlapping areas The rope puzzle is an example of the light source–red, green, and are primary colors. The part blue. These three primary colors where all the primary and t o p o l o g y, a b r a n c h o f make up white. complementary colors overlap is mathematics. Topology is black. The complement refers to the sometimes called "rubber- Such elastic deformations are color needed to produce white by When you block The color of your sheet" geometry, because it continuous functions since addition. So, when a shadow shadow is Red Cyan studies those properties of points which start out close removes one color from white, it (mixture of green and blue) must leave the complementary Green Magenta figures (like the circular rope) together end up close together (mixture of red and blue) color. The area of one shadow is Blue Yellow which remain unchanged if the after the deformation–the rope lighted by the two remaining (mixture of red and green) figures are stretched, twisted, primary colored lights. Hence, it Red and Green Blue remains circular after getting it Red and Blue Green can be seen that the two primary Green and Blue Red bent or otherwise "elastically" out of the three pipes. colors add to produce the deformed. complement of the third. For

10 Science Adventures Science Adventures 31 CHANGING COLORS SUBJECTIVE SHAPES

Try this!

Try this! Look at the diagrams. Do you see familiar shapes? 1. Place a colored object in the right compartment. What is the object's color? What's going on?

2. Place the same object in the The shapes you see in the diagrams left compartment. Do you see have no real outlines. Yet you see the same color of the object? outlines so distinct that you could draw a line along them. Your brain creates these outlines to fill in missing parts of the diagrams and make sense of what you see. Thus, What's going on? Yellow light consists of red and you see a circle, triangle, square green light. When yellow light and curved line where there are In the right compartment (with white shines on a blue object, the object none. In many situations, the light), you see the actual color of the will absorb yellow light, meaning, it object. In the left compartment (with will absorb both the red and green yellow light), you see the same light. Since no light will be reflected object with a different color. Why? from the object, you see the object as black. The exhibit demonstrates the principle of Color Subtraction. White Yellow - Yellow = (Red + Green) - light consists of the three primary (Red + Green) = No reflected light = colors–red, green and blue. When Black white light shines on an object, red, A B C green and blue light also shine on When yellow light shines on a red that object. If the object absorbs object, the object will absorb cyan person's visual system fills in Diagrams A, B and C are three blue light, then only red and green light (a mixture of blue and green missing gaps in edges and images with subjective contours. In light will be reflected from the object. light). When green is subtracted, b o u n d a r i e s , b u i l d i n g a n d diagram A, a solid triangle in the Red and green light give the red light is reflected which is the completing information that is not center appears to have well defined appearance of yellow, and so the color of the object you see. (What present. The person is drawn to a contour even in completely object will appear yellow. you see is not purely red, but with a reference point within the image. homogeneous areas. In diagram B, tinge of blue.) From that reference point, the a large rectangle is perceived. In White - Blue = (Red + Green + Blue) completion process is constructed. diagram C, a white square seems to - (Blue) = Red + Green = Yellow Yellow - Cyan = (Red + Green) - be partially blocked by a gray circle. (Blue + Green) = Red - Blue

8 Science Adventures Science Adventures 33 BIRD IN THE CAGE TALK AND LISTEN Try this! Try this with a friend! 1. Look at the red bird steadily for at least one minute, then 1. Talk directly into the ring look at the empty cage. Do while your friend listens at you see a bird in the cage? the ring of the other dish. What is this bird's color? 2. Switch roles. Your friend will 2. Repeat step 1 for the green talk while you listen. Can you and blue birds. What is the hear your friend clearly? color of the bird that appears in the cage? What's going on?

Despite the great distance What's going on? between the two dishes, you and each type being sensitive to a your friend hear each other After looking at the birds in the clearly. Why? picture one at a time, you see the particular range of color. following afterimages in the cage: When you stare at the red bird, the As you talk into the ring, the sound talks and you listen. It is the image falls on one region of your waves travel from your mouth to parabolic shape of the dish that retina. The red-sensitive cells in the dish in front of you. From this focuses the sound onto the ring, Color of bird Color of afterimage dish, the sound waves are in picture that region start to get tired, then which is the focal point. reflected toward the opposite dish light bluish-green stop responding strongly to red red where your friend is. Your friend (cyan) light. The white board reflects red, The parabola is used in many hears you clearly because the ways to collect or distribute green light reddish-blue blue and green light to your eyes (magenta) (since light is made up of all these dish focuses the sound of your energy such as sound, light, and blue light reddish-green colors). When you suddenly shift voice onto the ring. The same radio waves. As a sound reflector, (yellow) your gaze to the blank white thing happens when your friend it is used in radio and cassette board, the tired red-sensitive cells s p e a k e r s , s u r v e i l l a n c e The color of an afterimage is the do not respond to the reflected microphones, and other acoustic complement of the bird's color in light, but those sensitive to blue devices. As a light reflector, it is the picture. and green respond strongly to the used in searchlights, spotlights, reflected blue and green light. As a Talk here Listen here car headlights, and solar cookers. The back of the eyes (retina) is result, you see a bluish-green It is also used in communication lined with light-sensitive cells (cyan) afterimage of the bird. satellites as radio wave and called rods and cones. Rods are microwave reflectors. sensitive to colored light, while Sound waves traveling across the room

6 Science Adventures Science Adventures 35 BERNOULLI BLOWER TINY BUBBLES

Try this! Try this! 1. Turn on the switch and place the ball on top of the air 1. Dip the wire frames in the stream. soap solution.

2. Hold the ball with both hands 2. Wave the frames through and pull it partly out of the the air to form bubbles. Do air stream, then release the the bubbles have the shape ball. What happens to the of the wire frames? ball?

What's going on? What's going on? A soap bubble is a sandwich of Notice that when only a part of air on the inside, a layer of soap the ball is out of the air stream molecules, a layer of water and you can feel the ball being finally another layer of soap sucked back. If you release the molecules. The inner and outer ball, it will move back to the upward force on the ball. The layers of soap can stretch a lot center of the air stream and stay maximum capacity of the blower while the water helps hold the afloat. makes the ball stay at a certain bubble together. height. In other words, when a When the ball is pulled partly out stronger source of moving air is Scientists refer to bubbles as of the air stream, the air that is used, the higher the ball will "minimal surface structures”. moving fast along the side of the float. This means that bubbles always ball exerts less sideways hold the air inside of them with pressure on the ball than the still Additional Information: An the least possible surface area. air in the room. The greater airplane wing is designed in The geometric form with the pressure of the surrounding air such a way that the air moves least surface area for any given pushes the ball back to the faster over the top of the wing volume is always a sphere, not a center. than it does below. The higher air pyramid, a cube or any other pressure on the bottom of the shape. This is why soap bubbles The ball stays afloat because the wing pushes the airplane up, formed by frames of different air from the blower exerts an giving it a lift. shapes end up as spheres.

4 Science Adventures Science Adventures 37 ANIMAL SOUNDS YOU AND ME ARE ONE

Try this! Try this with a friend! 1. Choose an animal you like. Cover the eye of this animal. 1. Sit on one side of the exhibit What do you hear? and have your friend sit on the other side. Be sure that 2. Cover the eyes of the other both of you are at the same animals. Do you hear different sounds? distance from the mirror. 2. Slightly turn the knob. Ask What's going on? your friend to do the same. Do you see each other? A sensor has been placed in the eye of each animal. When you cover an 3. Ask your friend to turn animal's eye, it blocks the light reaching the sensor. The sensor the knob on his/her side responds to the blocking of light by halfway. This makes your What's going on? closing the electric circuit and this friend's side brighter. turns on the switch for the sound. The The glass is both a mirror and a sounds you hear are recordings of 4. Align your face with that of window. It reflects some light but sounds that real animals make. your friend. allows an equal amount of light to pass through. By adjusting the Additional Information: Since sensors Other sensors are combined with an are programmed to detect and alarm mechanism. An example is the 5. Ask your friend to dim her amount of light in the two sides of respond, they are used in buildings for photoelectric smoke detector. This side. Then, brighten your the exhibit, an interesting thing safety and security. Sensors using utilizes light as a detection side. happens. When you and your photo cells are used for exterior and m e c h a n i s m b a s e d o n l i g h t friend turn the switch slightly perimeter lighting where they obscuration (blocking). It requires that 6. Ask your friend to align halfway, you see each other maintain lights throughout the night smoke particles obscure or block a his/her face with yours. through the glass. and shut off during the daylight hours. portion of a light beam transmitted to a This can help save energy because sensor. Smoke between the light people often forget to turn off outdoor source and light sensor will reduce 7. Both of you should dim and By alternately brightening the lights during the day. Sensors are also the amount of incident light on the brighten the light alternately. lights, you and your friend will used in hallways and lobbies where sensor. If the light is reduced to a low Do this fast. What do you see a face that has features from nighttime entry and exit is made more level, an alarm is sounded. see? both of you, like you have your secure. Motion detectors turn on friend's hair or your friend's lights automatically when motion is detected in the room. eyeglasses and likewise your friend has your nose and lips.

2 Science Adventures Science Adventures 39 REFERENCES

CONTENTS Bruman, Raymond. 1987. Exploratorium http://www.bobvila.com Cookbook I: A Construction Manual for http://www.boston.com Name of Exhibit Page Name of Exhibit Page Exploratorium Exhibits. California: The http://www.chaosscience.org.uk Exploratorium http://www.charleskaradimos.com Amazing Cake 1 Money Detector 21 http://www.eia.doe.gov/kids Hipschman, Ron. 1980. Exploratorium http://www.energyquest.ca.gov Animal Sounds 2 Musical Pipes 22 Cookbook II: A Construction Manual for http://www.en.wikipedia.org Exploratorium Exhibits. California: The http://www.exploratorium.edu Anti-Gravity Mirror 3 Optic Land 23 Exploratorium http://www.glenbrook.k12.il.us Pedal Generator 24 http://www.hands-on-optics.org Bernoulli Blower 4 Hipschman, Ron. 1987. Exploratorium http://www.mada.org.il Bicycle Wheel Gyro 5 Plasma Sphere 25 Cookbook III: A Construction Manual for http://www.magiceye.com Exploratorium Exhibits. California: The http://www.magnetsource.com Bird In A Cage 6 Pupil of the Eye 26 Exploratorium http://www.maths.usyd.edu.auhttp http://www.nanosweb.org Calypso Reef 7 Radiometer 27 IBM. 1989. Mathematica. IBM Australia http://www.nei.nih.gov/heaolth Changing Colors 8 Rainbow Curtain 28 Limited. http://www.newton.dep.anl.gov http://www.newtrier.k12.il.us Color or Words 9 Ring Bubbles 29 Science Education Center. 1983. Earth http://www.opticsforkids.org Science: The Philippines in Focus. http://www.pbs.org/wgbh/nova Colored Shadows 10 Rope Puzzle 1 30 : Science Education Center. http://www.physicsclassroom.com Cyclone 11 Rope Puzzle 2 31 http://www.physics.ubc.ca Young, Hugh D. 1992. University http://www.phys.ufl.edu Electric Fleas 12 Shoot The Ball 32 Physics, Eighth Edition. USA: Addison- http://www.pubmedcentral.nih.gov Wesley Publishing Company, Inc. http://www.questacon.edu.au Finger Tingler 13 Subjective Shapes 33 http://www.randommotion.com Frozen Shadows 14 Symmetroscope 34 http://www.repairfaq.org Http://4in1keychain.com http://www.sas.org Gravity Well 15 Talk and Listen 35 http://acept.asu.edu http://www.techniquest.org http://bubbles.org http://www.tedmontgomery.com Jacob's Ladder 16 Thompson Ring 36 Http://education.usace.army.mil http://www.theoldschoolhenstead.co.uk Tiny Bubbles 37 http://faculty.washington.edu http://www.tomnoddy.com Laser Display 17 http://go.hrw.com/resources http://www-toys.science.unitn.it Look Into Infinity 18 Whirlpool 38 http://homeschooling.gomilpitas.com Http://www.waynesthisandthat.com http://library.thinkquest.org Magnetic Field 19 You And Me Are One 39 http://littleshop.physics.colostate.edu http://members.tm.net Momentum Machine 20 Zoetrope 40 http://mombian.com http://philmoney.blogspot.com http://pubs.acs.org http://scampy.ph.unimelb.edu.au http://science.howstuffworks.com http://uk.answers.yahoo.com The Philippine Foundation for Science and Technology

In 1984, the Philippine Foundation for Science and Technology was established by a group of private individuals as a VISION response to the government’s call for private sector support in the task of creating an environment of Science conscious and A nation of science- literate populace, especially among the youth sector. The culture and productive citizenry. Department of Science and Technology has accorded two recognitions to PFST: as an Outstanding S&T Foundation in MISSION 1997 and as the 1st GAWAD LIDER Awardee for Exemplary Leadership- Institution Category in 2007. In 2012, the To promote science Association of Science and Technology Centers based in and technology Washington DC accorded the Roy Shafer Award to the Philippine consciousness and Science Centrum as an Outstanding Science Center outside of literacy among the United States.The Department of Education recognizes the the youth, general effectiveness of PFST’s Philippine Science Centrum by issuing public and various annual National Advisory encouraging all schools to visit the PSC sectors of the society through the for educational field trips. Philippine Science It has been vigorously conducting innovative programs Centrum. aimed at improving public awareness, understanding and OBJECTIVES interest in science and technology.

To promote S&T MAJOR PROGRAMS, ACTIVITIES AND SERVICES appreciation and consciousness; PHILIPPINE SCIENCE CENTRUM (PSC) - established in 1990 as the foundation’s flagship program.It is a combination of a To develop and science center and museum featuring overr 100 interactive fabricate interactive exhibits. To date, over 3 million students, teachers and the public exhibits; in general have already been accommodated.

To implement TRAVELING EXHIBITIONS – since its maiden travel to Lapu- educational and Lapu City in 1995, the PSC’s mobile exhibitions have already outreach accommodated more than 3 million Filipinos from all over the programs/trainings; country. There are now 5 sets of PSC’s mobile exhibitions – To conduct studies in Science Adventures, Sci-Fun Caravan, Science On the Move, the field of S&T Science Works!, and Science Sparks! promotion; TEACHERS TRAINING - recognizing the importance of teacher To address key issues factor in the youth’s education, this module is being offered to in S&T affecting our teachers and school administrators on the interactive country; and approaches in science teaching.

To become a conduit in EXHIBIT DEVELOPMENT AND FABRICATION SERVICES- – the exchange of S&T In 2007, the Science Centrum Fabrication Inc. (SCFI) was information created to solely undertake the exhibit development and fabrication requirements of the PSC and other science centers locally and abroad.