1.	A.1.00 Empty demo | Request This is an empty demo to practice the procedure of request.
2.	A.1.10 Coordinate system | Request A model to help to visualize and explain the concept of the three dimensional rectangular coordinate system.
3.	A.1.20 Diagonal of a rectangular block | Request A wireframe to show the Eucledian distance between two opposite corners of a rectangular block.
4.	A.1.30 Handheld vectors | Request Models to help to explain the mathematical concept of vectors, vector addition and vector subtraction.
5.	A.1.40 Right hand rules | Request Three large foam right hands on a wood stick to teach the right hand rules and the vector product.
6.	A.1.50 Radians (ohp) | Request A pie model with plastic wedges to help to explain the geometrical definition of radian.
7.	A.2.00 Another empty demo | Request This is just another empty demo to practice the procedure of request.
8.	A.2.10 Basic metric units | Request Definition of the standard metric units of length, time and mass.
9.	A.2.20 Powers of ten (video) | Request Travels through the length scales from the size of a human to the size of the Universe and back. Then from the size of a human to the size of the atomic nucleus.
10.	B.1.00 Frames of reference (video) | Request The relativity of the reference frames is explained in a very entertaining fashion.
11.	B.1.03 Constant velocity motion on the air track | Request The cart moves with constant velocity between the two ends of the track. At the ends it bounces back.
12.	B.1.05 Uniform acceleration on the air track | Request A cart accelerates downhill on the air track. It passes a marker flag at every metronome click. The distance versus time function is drawn.
13.	B.1.10 Sound of constant acceleration | Request One string has leads at certain distance ratios. When the string is dropped the weights are heard to hit the floor at even time intervals. The other string has leads at even distances. When this string is dropped, the weights hit the floor at an accelerating rate.
14.	B.1.15 Determination of g with electronic timer | Request A metal ball is dropped from a given height. The time of fall is measured by a high resolution electronic timer. The gravitational acceleration is calculated from the height and the time of the fall.
15.	B.1.20 Galileo on the Moon (video) | Request Galileo's feather and heavy weight experiment done on the Moon by an astronaut.
16.	B.1.25 Feather and coin | Request The feather falls much slower than the coin because of the air drag. When the air is removed from the tube, they fall together.
17.	B.1.30 Pop and drop | Request Two balls - one simply dropped the other popped horizontally - hit the floor at the same moment if they are released together.
18.	B.1.35 Ballistic cart | Request A projectile is launched vertically from a cart moving with constant velocity on the horizontal track. The projectile returns to the cart.
19.	B.1.40 Shoot the monkey | Request A hanging monkey is targeted by a spring gun. When the projectile leaves the barrel, the monkey starts to fall freely under gravity. Will the monkey be hit?
20.	B.1.45 Two racing balls | Request Two balls are racing each other on two different tracks. Which one will win?
21.	B.2.00 Newton's first law | Request The cart keeps moving and bouncing between the two ends of the air track when the friction is reduced.
22.	B.2.05 Newton's second law | Request A cart loaded with different masses is accelerated on the dynamics track.
23.	B.2.10 Broken hand | Request A very heavy metal ball is caught in the air by a volunteering student. It is not a problem if yield is allowed. When the student is asked to catch the ball holding the hand on the surface of the table he/she - very wisely - refuses.
24.	B.2.15 Bungee jumpers | Request Bungee jumpers jump using two different cords: an elastic rubber, and a steel cords. The jumper with the rubber cord swings up and down happily, but the jumper with the steel cable breaks his neck.
25.	B.2.17 Catching the egg: wood board versus cloth | Request Two teams of students try to catch an egg dropped from the top of the ladder. One team has a wood board, the other team has a soft cloth. Which team will succeed?
26.	B.2.20 Atwood's machine | Request When the masses on the two sides of the machine are equal they stay at rest, or move at constant velocity. When the masses are not equal, the system accelerates.
27.	B.2.25 String breaker | Request A slow and steady pull on the bottom string breaks the top string. A quick jerk on the bottom string however breaks the bottom string itself.
28.	B.2.30 Inertial mass | Request Masses of different size are accelerated by oscillation on the platform of the balance to measure inertial mass.
29.	B.2.35 Weight in free fall | Request When a mass is accelerating downwards, its apparent weight is reduced. When it falls freely, its apparent weight is zero.
30.	B.2.40 Newton's third law | Request Two force scales are connected to each other and pulled by two volunteering students. The students are instructed to pull different forces. They cannot do that, they always pull each other with the same force.
31.	B.2.50 Sliding block | Request Friction is (approximately) independent of the size of the contact area.
32.	B.2.55 Dragging the box | Request Friction is (approximately) independent of the relative speed of the surfaces in contact.
33.	B.2.60 Angle of repose | Request The slope of the inclined plane is gradually increased until the object starts to slide.
34.	B.2.65 Balancing a meter stick on two fingers | Request A meter stick is held horizontally on our two index fingers. When the two fingers are moved toward each other, they always meet under the center of gravity of the stick.
35.	B.2.70 Kinetic friction and normal force | Request A block is dragged on an iron plate with its nonmagnetic side and the friction force is measured by the force scale. Then the block is turned to the magnetic side. The scale reads larger force this time.
36.	B.3.10 Lifting weight | Request A heavy metal ball is lifted up and carried around by the demonstrator to introduce the concept of mechanical work.
37.	B.3.15 Energy bike: work and power | Request Volunteering students pedal the energy bike. Both the instantaneous power and the total work done is displayed.
38.	B.3.20 Jumping spider | Request A spring driven toy spider is compressed. The work is stored by the spring. When the suction cup releases the toy, it jumps to a height.
39.	B.3.25 Piledriver | Request The piledriver drives a nail into a piece of wood as an example of transforming potential energy into work.
40.	B.3.30 Saving face | Request The bob is pulled back to just touch the demonstrator's nose. The demonstrator releases the pendulum without pushing and stands perfectly still. The pendulum will return to the same position without doing any damage.
41.	B.3.35 Galileo's pendulum | Request As the pendulum swings, the string hits a metal rod forming a shorter pendulum. This short pendulum rises to the same level as the original long one.
42.	B.3.40 One racing ball | Request A metal ball rolls through two different tracks. The tracks start and finish at the same heights, but they differ in the middle. The final velocities of the ball are measured by how far it flies after leaving the tracks.
43.	B.3.45 Uphill cone | Request The uniform rod rolls downhill toward the lower closed end. The double cone rolls uphill toward the higher open end. Which one is right?
44.	B.4.00 Two body system | Request Two spheres with different masses are connected with a thin metal rod. The system pivots freely only around one special point, the center of mass.
45.	B.4.05 Collision at a distance | Request Two carts equipped with magnets are approaching each other. They bounce back before they touch.
46.	B.4.10 Inelastic collision of velcro carts | Request A cart collides inelastically with another identical cart which was initially at rest. The velocities are measured with the photogates before and after the collision.
47.	B.4.15 Conservation of momentum in an explosion | Request Two air track carts fly away from each other when the gunpowder cell explodes. After they bounce back from the two ends of the track they meet again and they come to rest they were initially.
48.	B.4.20 Ballistic pendulum | Request A projectile collides with a pendulum inelastically. As a result the pendulum deflects to a certain angle.
49.	B.4.25 Newton's balls (ohp) | Request Steel balls are suspended along a line as bifilar pendula. When a ball or balls are drawn back and released on one end, the same number of balls will swing out on the other end.
50.	B.4.27 Ninja balls | Request Elastic rubber balls are on a rod in the order of decreasing size. When the system is dropped and hits the floor, the smallest ball shoots out at a very high speed.
51.	B.4.30 Elastic collision of unequal (3:1) masses | Request Two suspended metal balls with a mass ratio of 3:1 collide with each other elastically.
52.	B.4.35 Coefficient of restitution | Request Balls made out of different materials are dropped from a given height above a flat steel plate. They rebound to different heights depending on the energy lost in the collision.
53.	B.4.40 Superball and clayball | Request Two identical looking black balls are dropped. One of them bounces back high, the other does not bounce at all.
54.	B.4.45 Time of elastic collision | Request An elastic rubber ball is dropped on an electric sensor pad. The time track of the interaction is displayed on the oscilloscope screen.
55.	B.4.50 Water rocket | Request A rocket driven by pressurized water is launched as an example of the action-reaction principle.
56.	B.5.00 Ball on a string | Request A heavy ball is kept on a circular orbit by a rope.
57.	B.5.03 Whirligig | Request A metal ball is kept on a circular orbit by a rope pulled through a pipe and held by hand or a weight.
58.	B.5.06 Air table centripetal force | Request A puck is kept on a circular orbit on the air table by a rope pulled by a weight.
59.	B.5.09 Leaving circular orbit | Request When the constraining force is gone, the ball leaves the circular orbit along a straight line tangential to the original circle.
60.	B.5.12 Flying poker chips | Request Poker chips are spun on the rotating table. They are kept on orbit by static friction.
61.	B.5.15 Conical pendulum | Request A mathematical pendulum is spun on a cone, the bob orbits on a circle.
62.	B.5.18 Circular motion by normal force | Request Two ball bearings are kept on a circular orbit by normal force on a rotating semicircular constraint.
63.	B.5.21 Flattening of the Earth | Request When a flexible metal circle is rotated around its diameter it deforms.
64.	B.5.24 Loop the loop | Request A small ball rolls down on an incline and then enters a vertical loop.
65.	B.5.27 Meter stick balance | Request Masses of different sizes are balanced on a meter stick at different distances from the point of support.
66.	B.5.30 Where is the doorknob ? | Request Torque is the product of the force and the arm. If the arm is small we need big force to open the door. If the arm is big then a small force is enough.
67.	B.5.33 Short and long wrench | Request When the short wrench is not enough, use the long one.
68.	B.5.36 Pulley races | Request The same weight accelerates the pulley at different rate at different radii.
69.	B.5.39 Rotating weights | Request Two masses at adjustable distance from the axis of rotation are accelerated angularly by several different weights hung on the rope.
70.	B.5.42 Mystery batons | Request Two batons with the same mass but with different mass distribution are spun back and forth by hand.
71.	B.5.45 Off-loaded cylinder | Request A geometrically asymmetric object rotates freely around one of the three mutually orthogonal free axes going through the center of mass when it is thrown in the air.
72.	B.5.48 Descending spool | Request A spool accelerates both linearly and angularly as it descend.
73.	B.5.51 Walking the spool | Request If the rope is at a high enough angle, the spool runs away. If the rope is at a low angle the spool comes back. At a critical angle the spool slides on any surface.
74.	B.5.54 Inclined plane races | Request Solid and hollow cylinders roll down on an incline at different rate.
75.	B.5.57 Falling rods | Request A short and a long rod starts falling at the same time. Which one will land first?
76.	B.5.60 Faster than gravity | Request The free end point of a linear homogeneous straight rod accelerates at three half of the gravitational acceleration when the rod is in a horizontal position.
77.	B.5.63 Bicycle wheel | Request A small and a big bicycle wheel is spun and then held in hand to experience the strange behaviour of spinning objects.
78.	B.5.66 The stranded demonstrator | Request A person tries to spin himself on the rotating chair without any external help.Can he/she succeed?
79.	B.5.69 Rotating chair and throwing weights | Request A person sitting on the rotating chair throws and catches heavy weights in order to spin up him(her)self.
80.	B.5.72 Spinning skater | Request A person is spun sitting on the rotating chair with weights in hands. The weights are then moved in and out to simulate a spinning skater.
81.	B.5.75 Rotating chair and bicycle wheel | Request A person sits on the rotating chair with the rotating bicycle wheel in hands. The wheel is then flipped.
82.	B.5.78 Rotating chair and double bicycle wheel | Request A person sitting on the rotating chair flips the double wheel with the two wheels spun in the same direction, then in the opposite direction.
83.	B.5.81 Hanging bicycle wheel | Request The rotating bicycle wheel is hung on a rope from the ceiling. It behaves very strangely, it does not fall, it precesses under torque.
84.	B.5.84 Suitcase gyroscope | Request A volunteering students walks around with a suitcase. The suitcase behaves very strangely at sharp turns. What is in the suitcase?
85.	B.5.87 Handheld gyroscope | Request A gyroscope is held in hand and moved around to show the conservation of angular momentum.
86.	B.5.90 Wrap around | Request An object orbiting at the end of a rope moves faster and faster as it wraps itself around the constraining cylinder.
87.	B.5.93 Foucault pendulum | Request The plane of a pendulum remains unchanged under a rotation around the vertical axis through the suspension point.
88.	B.5.96 Rotational to translational energy | Request A spool with large radius rolls down an inclined plane, and then touches the table and rolls horizontally. On the incline the spool accelerates slowly, when it touches the table it accelerates swiftly.
89.	B.6.00 Force board | Request Balancing forces with different sizes and directions.
90.	B.6.10 Cable pull | Request You can exert a much bigger force by pulling perpendicularly on a cable than in parallel.
91.	B.6.20 Irregular shape | Request Finding the center of gravity of an irregular object.
92.	B.6.30 Leaning towers | Request Adding the top piece or rotating the top piece on the towers make them unstable. The green block is more stable on one end than on the other.
93.	B.6.40 Hanging hammer | Request Adding a sledgehammer to a hinged bar makes it stable in a horizontal position.
94.	B.6.50 Green wing | Request The center of gravity can exist outside of an object and the object supported at this point will be balanced.
95.	B.7.00 Mass and weight | Request Gravitational mass is measured with a two armed balance. Weight is measured with a spring scale. What would these instruments measure on the Moon for example?
96.	B.7.10 Gravitational equivalence principle | Request In a system accelerated in one direction behavior is the same as in a system at rest, with gravity in the opposite direction.
97.	B.7.20 Cavendish balance | Request The gravitational interaction is detected by the deflection of the Cavendish balance.
98.	B.7.30 Drawing an ellipse | Request Two magnets and a rope help to draw an ellipse with chalk on an iron chalk board.
99.	B.7.40 Solar system model (mechanical) | Request A mechanical model to show the relative positions and phases of the Moon with respect the Earth.
100.	B.7.50 Solar system model (tennis balls on rope) | Request Tennis balls strung on a rope to model the relative positions of the planets.
101.	B.7.60 Celestial sphere | Request A plastic celestial sphere with Earth in the middle.
102.	B.7.70 Black celestial sphere | Request A big black metal sphere to draw with chalk on it.
103.	B.8.10 Hooke's law | Request A spring is stretched by several different weights and the deformation is measured. The force versus deformation function is then drawn.
104.	B.9.00 Manometer | Request A mercury manometer which measures atmospheric air pressure.
105.	B.9.02 Barometer | Request A big barometer which measures air pressure in mercury millimeter.
106.	B.9.05 Hydraulic press | Request A hydraulic press capable to crumple aluminium pipes or other objects.
107.	B.9.10 Magdeburg hemispheres | Request The air is pumped out from inside the two hemispheres. Two volunteering students try to separate them unsuccessfully.
108.	B.9.15 Crush the can | Request When the air is sucked out from inside a metal can the outside air pressure crushes it.
109.	B.9.20 Archimedes' principle: wet | Request When an object is submerged in a liquid, its weight is reduced by the weight of the displaced liquid.
110.	B.9.25 Archimedes' principle: dry | Request In air two objects weigh the same as shown by the balance. When the chamber is evacuated the larger object sinks: there is bouyancy in air.
111.	B.9.30 Archimedes' principle: two fluids | Request When a lighter fluid is carefully poured on top of a heavier one, the floating object rises.
112.	B.9.35 Hydrometer | Request A very simple device which measures the density of a liquid as it floats in it.
113.	B.9.40 Cartesian diver | Request When the pressure of the liquid is increased, the air in the diver compresses resulting larger average density. The diver therefore sinks.
114.	B.9.45 Venturi tube | Request When the speed of the gas flow increases the pressure of the gas decreases.
115.	B.9.50 Bernoulli ball | Request An air balloon or ping-pong ball can be levitated in the air by the blower.
116.	B.9.55 Bernoulli plate | Request A flat metal plate is lifted when air flows above it at high speed.
117.	B.9.60 Bernoulli cart | Request A cart equipped with a vertical rotating cylinder moves perpendicular to the external air-flow.
118.	B.9.65 Rising ball | Request A ping-pong ball is captured in an upside down funnel by the air-flow.
119.	B.9.70 Moving cans | Request When air is blown between two empty cans, they move towards each other.
120.	B.9.75 Spinning cup | Request When the cups are dropped with a spin, they move sideways.
121.	B.9.80 Two coke bottles | Request Two coke bottles are joined together. When simply flipped the water flows turbulently. When spun around, the water forms a vortex.
122.	C.1.00 Ceiling pendulum | Request A long pendulum is hung from a hook on the ceiling and swings back and forth. The periodicity of the motion is demonstrated by measuring the period several times.
123.	C.1.05 Simple harmonic motion on the air track | Request A cart connected to the two ends of the air track with springs oscillates horizontally back and forth. The periodicity of the motion is demonstrated by measuring the period several times.
124.	C.1.10 Mass and spring | Request A mass hangs on a spring and oscillates vertically up and down. The periodicity of the motion is demonstrated by measuring the period several times.
125.	C.1.15 Driven mass on a spring | Request A mass on a spring oscillates very differently as the electromagnetic suspension point is driven by a signal generator at different frequencies.
126.	C.1.20 Circular motion projection (ohp) | Request When an object moves on a circular orbit at constant angular velocity, its projection performs simple harmonic motion.
127.	C.1.25 Lissajous oscilloscope figures (video) | Request Two harmonic voltages are fed into the two perpendicular inputs of the oscilloscope. Lissajous figures are seen on the screen.
128.	C.1.30 Parallel pendula | Request Two pendula with length ratio of 4:1 have period ratio of 2:1.
129.	C.1.40 Period of a physical pendulum | Request A straight wood ruler is suspended at different points between the end and the midpoint. The periods of the oscillations are measured.
130.	C.1.45 Variable g pendulum | Request When the rotational axis of the physical pendulum is tilted around the horizontal axis perpendicular to the rotational axis, the period of the pendulum increases.
131.	C.1.50 Torsional pendulum | Request A torsional pendulum performs angular harmonic motion as an analogous motion to translational harmonic motion.
132.	C.1.55 Wilberforce pendulum | Request A mass hangs at the end of a spiral spring. When set in motion, the system oscillates between the simple translational spring mode and the torsional mode.
133.	C.1.60 Elastic pendulum | Request A mass hangs at the end of a spring. When set in motion, the system oscillates between the simple spring mode and the pendulum mode.
134.	C.1.65 Tonal pendulum | Request A mass hangs from a wire over a resonant box. As it swings, the wire is plucked, and the variation in tension is heard as variation in pitch.
135.	C.1.70 Inverted pendulum | Request Driving the pivot point of a physical pendulum at a high frequency creates an effective gravitational acceleration. The pendulum can be turned sideway or even inverted into upside down position while oscillates.
136.	C.2.10 Rubber hose | Request A long rubber hose hooked to the wall at one end and held by hand at the other to show the propagation and reflection of transverse pulses and waves.
137.	C.2.15 Handheld slinky | Request A long slinky fixed at one end and held in hand at the other end to show the propagation of a longitudinal pulses and waves.
138.	C.2.20 Transverse waves | Request A series of metal bars connected by a metal wire to demonstrate the propagation of transverse pulses and waves.
139.	C.2.25 Longitudinal waves | Request Suspended straight metal rods connected to each other by springs to demonstrate the propagation of longitudinal pulses and waves.
140.	C.2.30 Standing wave machine | Request Transverse standing waves are produced in a rope which is fixed at both ends.
141.	C.2.35 Driven slinky | Request A horizontally suspended slinky is driven at one end. When the condition for the driving frequency is met, longitudinal standing waves are observed.
142.	C.2.40 Flame wave | Request A long metal pipe with a series of small holes is filled with gas. The gas is ignited and a standing sound wave is set up by a speaker and a signal generator. The heights of the small flames show the nodes and antinodes of the standing longitudinal wave.
143.	C.2.45 Wave open at one end | Request Transverse standing waves are generated in a spring with one end fixed and the other free.
144.	C.2.50 Wave open at both ends | Request Transverse standing waves are generated in a spring with both ends free.
145.	C.2.55 Bead board model of superposition | Request A mechanical model to demonstrate the constructive and destructive superposition of harmonic transverse waves.
146.	C.2.60 Sine wave through a slot | Request A sine wave is painted on a black board. As the board is slid behind a vertical slot we see a dot oscillating up and down.
147.	C.2.65 Squirrel cage projection (ohp) | Request The projection of a spiral on a cylindrical wire cage is a sine wave. When the cage is rotated, the projection becomes a traveling transverse wave.
148.	C.2.70 Standing and traveling wave projection (ohp) | Request A small box containing one planar sine wave and one cylindrical spiral shaped wire. When the wires are rotated, their projections show a standing and a traveling wave respectively.
149.	C.2.75 Ripple tank (ohp) | Request A ripple tank for the overhead projector to show different waves and wave phenomena.
150.	C.2.80 Tacoma Narrows bridge (video) | Request A video showing the catastrophic resonance and collapse of the Tacoma Narrows bridge on November 7th, 1940 caused by strong winds.
151.	C.2.85 Circular loop slinky | Request A closed loop slinky suspended in a horizontal plane to show the different modes of oscillations in a circular system.
152.	C.3.10 Bell in vacuum | Request An electric bell is placed inside a vacuum jar. When there is air in the jar, we can hear the bell. As the air is removed by the vacuum pump the sound becomes fainter and fainter.
153.	C.3.15 Frequency and the limits of audibility | Request A speaker is driven by a signal generator. As the frequency is increased less and less people can hear the sound.
154.	C.3.20 Human ear model | Request A large plastic model of the human ear to show the anatomy of it and explain the function of the parts.
155.	C.3.25 Doppler effect | Request An electronic screamer on a rope is spun around or a metal whistle is rotated quickly as it is blown. The periodic up and down shifts in the frequency of the sound is heard.
156.	C.3.30 Inverse square model (sound) | Request A wire pyramid to help to explain the dependence of sound intensity on the distance from the source.
157.	C.3.35 Decibels (camera) | Request A digital sound level meter is used to measure the noise level in the classroom.
158.	C.3.40 Beat box (camera) | Request Sound is produced by a xylophone with six bars tuned at frequencies from 435 Hz to 440 Hz. The beats can be heard by ear or the waves can be visualized on the oscilloscope screen using a microphone.
159.	C.3.45 Speaker interference | Request Four speakers are mounted along a horizontal line on a rod. As the rod is turned around the vertical axis, the audience can hear constructive and destructive interference of the sound waves.
160.	C.3.50 Resonance of a pipe open at both ends | Request When sound is fed through an open pipe, resonance is heard at certain frequencies.
161.	C.3.55 Speed of sound | Request A tuning fork is struck above a tube of water. The height of the water column is adjusted until the fork and tube resonates. From the height of the column and the frequency of the tuning fork the speed of the sound can be calculated.
162.	C.3.60 Organ pipes | Request Several lead organ pipes and tunable wood pipes are used to create sound and demonstrate resonance in a tube.
163.	C.3.65 Breathing helium and heavy gas | Request When you inhale helium, the frequency of your voice increases. If you inhale heavy gas, the frequency decreases.
164.	C.3.70 Monocord | Request Sound is created by the simplest musical instrument, the monocord. As the length of the cord is increased, the frequency decreases. The cord can also be excited in higher oscillation modes.
165.	C.3.75 Stroke rod | Request An aluminium rod is hit with a small hammer at the end. It gives sound only if it is held by two fingers at the nodal points. Otherwise the sound dies off very quickly.
166.	C.3.80 Sympathetic tuning forks | Request Two tuning forks are placed next to each other. When the first fork is struck, the second one starts to oscillate, if it is tuned to the correct frequency. Otherwise remains silent.
167.	C.3.85 Mechanical resonance strips | Request Metal strips of different lengths are driven at varying frequencies to show the relationship between length and fundamental frequency.
168.	C.3.90 Chladni figures | Request Sand is sprinkled on metal plates of various shapes. The plates are set into oscillation by an electromagnet fed by a signal generator. Standing wave patterns are observed as the sand settles at the nodal lines.
169.	C.3.95 Laser modulation for audio transmission (sound) | Request Laser beam is acoustically modulated and then transmitted. When the laser light is received, the audio signal is recovered and amplified to a speaker.
170.	D.1.10 Types of thermometers | Request Several different types of termometers are displayed and their working is explained.
171.	D.1.15 Linear thermal expansion and contraction | Request A straight aluminium pipe is heated by a torch. As it expands, it turn a pointer. If the pipe is cooled by liquid nitrogen, it contracts. The pointer turns in the opposite way.
172.	D.1.20 Bimetallic strip | Request When the bimetallic strip is heated, it bends in one direction. When it is cooled, it bend the other way.
173.	D.1.25 Ball and ring | Request A metal ball fits through a hole in a ring. If the ball is heated or the ring is cooled, it does not fit anymore.
174.	D.1.30 Ice bomb | Request As water freezes to ice and the ice cools down, it expands. The force exerted by the ice is so large, it can break a metal container with thick wall.
175.	D.1.35 Lead bell | Request Lead is not very hard at room temperature. A bell made out of lead does not ring very well. However when it is cooled down by liquid nitrogen, the bell hardens and rings very well.
176.	D.1.40 Specific heat | Request A lead ball is heated to 100 Celsius by placing it in boiling water. It is then placed into room temperature water of equal mass. The temperature of the water rises only very little, about two Celsius degrees.
177.	D.1.45 Melting ice (heat of fusion) | Request Crushed ice floats in water. The temperature of the water ice mixture does not increase until the ice melts completely.
178.	D.1.50 Dropping nails | Request Rods of different metals radiate outward. Nails are attached to the rods with candle wax. As the apparatus is heated at the center, the nails drop. The time it takes for the nails to fall off depends on the heat conductivity of the rods.
179.	D.1.55 Thermal convection in air | Request A box has two vertical glass chimneys. A lit candle is placed under one of the chimneys. When smoke is produced at the top of the other chimney, the convection currents pull the smoke through the box.
180.	D.1.60 Thermal convection in liquids | Request A glass container with glycerol and small particles in it is heated by the projector light and is projected at the same time. The thermal convection of the liquid is observed.
181.	D.1.65 Absorption of radiation | Request A black and a white plate is exposed to the same heat radiation. The temperature of the black plate increases faster than the temperature of the white one.
182.	D.1.70 Transmission of infrared radiation | Request Two concave mirrors face each other. One of the mirrors have an electric heater, the other one has a match at the focal point. After the heater is turned on, the match ignites.
183.	D.2.10 Cold cannon | Request Liquid nitrogen or dry ice is put in a pipe cannon. As the pressure of the gas builds up, the cannon shoots the cork across the lecture hall.
184.	D.2.20 Pressure as a function of temperature | Request A metal sphere containing gas at constant volume is placed in different temperature baths and the resultant pressure is measured. The graph is extrapolated to absolute zero temperature.
185.	D.2.30 Pressure as a function of volume (ohp) | Request A syringe is connected to a pressure gauge. As the syringe is compressed, the pressure of the gas increases. If the pressure is not too far from atmospheric, the pressure volume product is a constant.
186.	D.2.40 Fire syringe | Request Air is compressed very quickly in a piston. The generated heat ignites a small piece of paper.
187.	D.2.50 Energy bike: heat equivalent of work | Request Elecricity is generated by the energy bike, and it is used to heat up water. The electric energy produced is read from the display, and the change in temperature is measured by a thermometer.
188.	D.2.60 Stirling engine | Request A Stirling engine driven by an alcohol burner turning a small propeller.
189.	D.2.70 Low delta T Stirling engine | Request A high precision Stirling engine, which is able to spin from the heat of your hand.
190.	D.2.80 Flame eating engine | Request A small working model of an external combustion engine.
191.	D.3.10 Liquid nitrogen and air balloon | Request An air balloon is placed in a glass beaker and liquid nitrogen is poured on it. The balloon shrinks and becomes deflated. When it warms up to room temperature, it grows back to its original size.
192.	D.3.20 Small and large molecules (video) | Request A short movie about pucks colliding on an air table. Smaller pucks move faster than the larger ones. The motion of the pucks is monitored and the histogram of the velocity distribution is drawn.
193.	D.3.30 Brownian motion (video) | Request A very short movie about the phenomena of Brownian motion.
194.	D.3.40 Crookes radiometer (camera) | Request Four vanes are suspended inside a glass bulb containing vacuum. Each vane has a black and a shiny side. When the radiometer is lit or heated the vanes rotate with the black side away from the source. When the radiometer is cooled it reverses the direction of its rotation.
195.	D.3.50 Maxwell's demon | Request A sealed glass bottle contains black and white balls. When the bottle is spun around the black balls almost always end up at the bottom.
196.	E.1.00 Two types of electric charge (camera) | Request Electric charge is produced by rubbing a glass rod with silk, or an ebonite rod with cat or rabbit fur. The charges are detected with an electroscope or an electrometer.
197.	E.1.04 Van de Graaff generator and wig | Request A wig is placed on the top of the generator. When the generator is turned on, the hair raises.
198.	E.1.08 Wimshurst machine | Request Electric charge is produced by rubbing the rotating plexiglass disks with metal brushes. The charge then can be stored in two Leyden jars for more energetic sparks.
199.	E.1.12 Electric field lines (ohp) | Request Electric field lines for different geometries of charged conductors are displayed with a device containing a thick yellow liquid with tiny particles in it.
200.	E.1.16 Pith balls inside a conducting cylinder (camera) | Request Only the outside pith ball reacts to the charged rod. The pair of pith balls inside the metal cylinder are shielded, they do not feel anything.
201.	E.1.20 Faraday's ice pail (ohp) | Request When charge is placed on a hollow conductor, the charge cannot be found in the inside, but only on the outside.
202.	E.1.24 Faraday cage | Request The wire cage is connected to the Van de Graaff generator. Large sparks are drawn from the cage. However the person sitting inside the cage is protected against electric fields and sparks.
203.	E.1.28 Styrofoam shower | Request Styrofoam chips are placed on the top of the Van de Graaff generator first in a metal then in a plastic container. The chips stay inside the metal container when the generator is turned on, but they fly away from the plastic one.
204.	E.1.32 Electrostatic induction: two charges from one | Request Electric charge is induced on an initially neutral and grounded conductor by approaching it with a charged ebonite or glass rod.
205.	E.1.36 Polarizing water (camera) | Request A narrow stream of water is deflected by a charged ebonite or glass rod placed close to the stream.
206.	E.1.40 Obedient ruler | Request A wood ruler starts spining when it is approached by a charged ebonite or glass rod. This behavior does not change when the wood is covered with aluminium foil.
207.	E.1.44 Dipole models | Request Two models with balls at the end of a straight rod serve as dipole models. One of them has larger charge, the other one has larger distance between the charges.
208.	E.1.48 Electrostatic ping-pong | Request A conducting ping-pong ball bounces back and forth between the plates of a charged capacitor.
209.	E.1.52 Sharp conductor | Request The sharp end of an asymmetric conductor draws sparks more frequently from the Van de Graaff generator than the rounded end.
210.	E.1.56 Electrostatic whirl (camera) | Request A small three armed or a larger two armed metal wheel spins when it is placed on the top of the Van de Graaff generator. The wheels are driven by the intense discharging effect on the top of the sharp peaks.
211.	E.1.60 Cylindrical Gaussian surface model | Request A large cylindrical metal can and a straight rod through it serves as a model of the Gaussian surface in cylindrical problems.
212.	E.1.64 Rubber sheet potential model (camera) | Request Electric potential surface is modeled with an elastic rubber sheet held inside a frame and stretched around a complex geometry.
213.	E.1.68 Parallel plate capacitor | Request The voltage on a parallel plate capacitor is measured as a function of the distance between the plates.
214.	E.1.72 Dielectrics (ohp) | Request Several different kind of dielectric materials are placed between the plates of a charged capacitor. The decrease in voltage is observed.
215.	E.1.76 Dissectable Leyden jar | Request A Leyden jar - as the oldest device to store electric charge - is disassembled and the function of the parts is explained.
216.	E.1.80 Types of capacitors | Request Several different kind of capacitors are displayed and explained.
217.	E.1.84 Big spark | Request A large capacitor is charged up from a battery. When it is discharged with a metal screw driver, it gives a big and loud spark.
218.	E.1.88 Jacob's ladder | Request High voltage in two metal wires generates sparks in the air. As the air heats up within the spark it rises.
219.	E.2.00 Potentiometers | Request Different types of voltmeters are displayed and their function and operation is explained and demonstrated.
220.	E.2.05 Potential along a long wire | Request Constant current is driven through a long straight metal wire. The potential drop at different lengths is measured with a voltmeter.
221.	E.2.10 Ohm's law | Request Ohm's law is demonstrated by applying different voltages on a given resistor and then measuring the current through the resistor.
222.	E.2.15 Series and parallel light bulbs | Request The brightness of the bulbs is observed when the same kind of lightbulbs are connected in series and in parallel.
223.	E.2.20 Power dissipation | Request Current is driven through resistors of different power ratings. The resistor with low power rating overheats and burns out.
224.	E.2.25 Wheatstone bridge | Request Measuring an unknown resistance with the Wheatstone bridge is demonstrated and explained.
225.	E.2.30 Time constant in an RC circuit | Request A large capacitor is charged and then discharged through a light bulb. The change in the brightness of the bulb shows the change of electric current as a function of time.
226.	E.2.35 Marbles and nails model of resistance | Request Marbles roll down on a nail board as a model of electron-flow through a metal crystal.
227.	E.2.40 Resistance versus temperature | Request When a metal wire is heated, its resistance increases. When it is cooled the resistance decreases. The change in resistance is observed when the brightness of the light bulb in series with the wire changes.
228.	E.2.43 Jacob's ladder | Request High voltage between two metal wires generates sparks in the air. Electric current flows through the ionized air and heats it up. The heated spark rises.
229.	E.2.45 Current in molten glass | Request At room temperature glass is a very good insulator. When it is melted, it becomes a conductor lighting up a lightbulb in series with it.
230.	E.2.50 Lemon juice battery | Request Voltage difference is measured, when two different kind of metals are submerged in lemon juice, or sticked in a lemon or other fruits or vegetables.
231.	E.3.00 Compass needle, lodestone, magnets | Request The behavior of a compass needle in Earth's magnetic field is demonstrated. The compass needle is deflected by a loadstone or a magnet.
232.	E.3.04 Earth's magnetic field (model) | Request Iron filings around a small magnetic sphere help to visualize the Earth's magnetic field.
233.	E.3.08 Overhead projector magnetic field lines | Request The magnetic fields of several different magnet arrangements are visualized using iron filings.
234.	E.3.12 Overhead projector compass needles | Request Tiny compass needles in an array line up along the field lines of an external magnetic field. This instrument can also be used to model the behavior of magnetic domains inside a ferromagnet.
235.	E.3.16 Walking the paper clip | Request A paper clip on a thread probes the magnetic field of a big, strong horseshoe magnet.
236.	E.3.20 Oersted's experiment | Request A magnetic needle is deflected when current flows through a straight conductor close to the needle.
237.	E.3.24 Magnetic field from a current | Request The magnetic field of a current flowing though a wire is visualized using iron filings.
238.	E.3.28 Magnetic field of a solenoid | Request The magnetic field of a solenoid is visualized using iron filings.
239.	E.3.32 Picking up nails with a solenoid | Request Nails are picked up by a solenoid with a soft iron core when the current is turned on. The nails are released when the current is turned off.
240.	E.3.36 Jumping wire | Request The force on a current carrying wire in a magnetic field is demonstrated.
241.	E.3.40 Linear engine | Request A straight conductor rod is driven through a magnetic field when current flows through it.
242.	E.3.44 Parallel wires | Request Two currents attract each other if they flow in the same direction, they repel when they flow in the opposite direction.
243.	E.3.48 Current balance | Request Two currents attract each other if they flow in the same direction, they repel when they flow in the opposite direction.
244.	E.3.52 Bending the beam | Request A straight electron beam inside an oscilloscope tube is deflected by an external magnetic field.
245.	E.3.54 Circular beam | Request Electrons from a beam in a vaccum tube are kept on a circular orbit by an external magnetic field. The kinetic energy of the electrons and the magnetic field is varied.
246.	E.3.60 Magnetic accelerator | Request An air track cart with a bar magnet on it is accelerated linearly by three large solenoid around the track. The currents are switched by teams of volunteering students.
247.	E.3.64 Hanging coil in a magnetic field | Request A solenoid hangs inside a Helmholtz coil. When the currents are turned on the torque turns the hanging coil so that it is lined up with the Helmholtz coil.
248.	E.3.68 Floating magnets | Request Ring shaped magnets held on a straight vertical rod floats on top of each other by their repulsion.
249.	E.3.72 Levitron | Request A quickly spinning magnetic top levitates in an external magnetic field.
250.	E.3.76 Newton's folly | Request A tiny ball bearing floats in the magnetic field of an electromagnet controlled by electronics which detects the position of the ball.
251.	E.3.80 Spatula in magnet | Request An iron spatula is held inside the same magnetic field with a much stronger force, if the blade of the spatula is parallel to the field than when it is perpendicular.
252.	E.3.84 Reversing the poles | Request A bar magnet is demagnetized and then magnetized in the opposite direction to show the nonmechanical nature of magnetism.
253.	E.3.88 Barkhausen effect | Request The motion of ferromagnetic domain walls in a slowly changing external magnetic field is detected and amplified to be heard through a speaker.
254.	E.3.92 Curie point | Request A small piece of soft iron is heated to a temperature where it loses its matnetism induced by a nearby permanent magnet. When it cools down, it regains its magnetism.
255.	E.4.00 Coil, magnet and galvanometer | Request When a bar magnet is moved in and out of a solenoid or rotated close to the solenoid the induced current is detected by the galvanometer.
256.	E.4.05 Wire cutting a magnetic field | Request The galvanometer connected to a wire is deflected when the wire moves through a magnetic field of a horseshoe magnet.
257.	E.4.10 Inductive seesaw | Request Bar magnets suspended on springs hang inside two connected solenoids. When one of the magnets is set oscillating, the induced current starts the other magnet oscillating.
258.	E.4.15 Energy bike: generating electricity | Request Electricity is produced by a volunteering student on the energy bike. Both the instantaneous power and the total electric work produced is displayed.
259.	E.4.20 Genecons | Request A handheld generator produces electricity to lit a small light bulb. When connected to another generator the second generator works as an electric motor.
260.	E.4.25 Eddy current braking | Request A solid copper plate quickly stops swinging between the poles of a strong permanent magnet or electromagnet when the power is turned on. The hollow plate with long slits however keeps swinging.
261.	E.4.30 Lenz's law pipes | Request A small but strong magnet falls through one aluminium and two copper pipes of different wall thickness. The copper pipes can be cooled with liquid nitrogen to further enhance the effect.
262.	E.4.35 Eddy current pennies | Request Pennies and aluminium coins slide down on a plexiglass incline. They slow down significantly when they are passing a strong magnet.
263.	E.4.40 Jumping ring | Request Metal rings made out of copper and aluminium are placed on the top of a large electromagnet. When the current is turned on, the rings jump into the air. The rings can be cooled with liquid nitrogen to enhance the effect.
264.	E.4.45 Faraday repulsion ring | Request An aluminium ring suspended on two threads tries to avoid the insertion or the removal of a strong bar magnet. The aluminium ring can be cooled with liquid nitrogen to further enhance the effect.
265.	E.4.50 Magnetic levitation | Request A small ring magnet on a thread levitates above a quickly spinning copper plate.
266.	E.4.55 Induced light | Request When a coil is brought near a large electromagnet driven with alternating voltage, the light bulb connected to the coil glows.
267.	E.4.60 Inductive spark | Request When a circuit with large inductance is opened, there is a large discharge of energy in the form of an electric spark.
268.	E.5.00 Diode board | Request Rectification is demonstrated on a Graetz bridge by observing the brightness of the light bulbs in each branch and on the output of the bridge.
269.	E.5.10 Switching paradox | Request Two bulbs and two switches are in series. The switches control the bulbs in a logical OR fashion instead of AND as it should be. What is the secret?
270.	E.5.20 RLC resonance | Request Voltage on the elements of an RLC-ciruit is measured and displayed on an oscilloscope screen as the circuit is tuned toward and away from resonance.
271.	E.5.30 Visual RLC resonance | Request The inductive reactance is varied in an RLC-circuit by raising and lowering the core of the coil. The bulb is brightest at resonance.
272.	E.6.00 Radio in a Faraday cage | Request A pocket radio is tuned to an AM station. When the radio is placed inside a Faraday cage of fine wire mesh it is silenced.
273.	E.6.10 Spark radio | Request An electric spark - either from the Van de Graaff generator or from the Wimshurst machine - generates electromagnetic waves over a broad range of frequencies. These waves are detected by an electronic spark radio.
274.	F.1.10 Inverse square model (optics) | Request A wire pyramid to help to understand the inverse square dependence of a light intensity on the distance from the point source.
275.	F.1.14 Refraction tank | Request A water tank to show the refraction of a light beam going from air to water or in the opposite way from water to air.
276.	F.1.18 Broken finger (camera) | Request When your finger is viewed through a very thick layer of plexiglass which is at an angle, the finger seems to be broken.
277.	F.1.22 Total internal reflection rod | Request Once light enters at one end of a spiral shaped lucite rod, it stays inside until it reaches the end where it exits.
278.	F.1.26 Fire water | Request Water flows out of a glass bottle forming a narrow stream. Light from a laser beam pointing at the hole stays inside the water stream coloring the water red.
279.	F.1.30 Bending a laser beam | Request Sugar solution with concentration gradient is prepared in a water tank. As laser light travels through the tank it bends downward.
280.	F.1.34 Dispersion: prism and slide projector | Request White light from a slide projector is separated into its component colors.
281.	F.1.38 Achromatic prism pair | Request One prism separates white light into its colored components. The second prism - in the opposite orientation - recombines those back to white light.
282.	F.1.42 Continuous and discrete spectra (optics) | Request The light from several different light sources is viewed through a diffraction grating. The difference between continuous and discrete spectra is observed.
283.	F.1.46 Additive color mixing | Request Red, green and blue lights are mixed together at different intensities to form other colors or white light.
284.	F.1.48 Polarization at Brewster's angle | Request
285.	F.1.50 Color disks | Request Disks with different patterns and colors are rotated. The human eye detect colors and patterns not seen on the standing disks.
286.	F.1.54 Color fan | Request A fan with four blades painted red, green, blue, and yellow is viewed with a strobe light. Depending on the relative frequency of the strobe light to the fan speed different colors are seen.
287.	F.1.58 Polarization at Brewster's angle | Request Light is observed through a big polaroid plate both directly from a lamp and reflected from a planar glass. As the polaroid is rotated the reflected light changes in intensity. The direct light is unchanged.
288.	F.1.62 Calcite on overhead projector (ohp) | Request Unpolarized light is doubly refracted in some crystals. The two refracted beams are polarized differently.
289.	F.1.66 Polaroid sun glasses (ohp) | Request A pair of polaroid sun glasses are placed between the polarizer and the analyzer on the overhead projector. As the analyzer is rotated, change in the light intensity is observed.
290.	F.1.70 Karo syrup polarization (ohp) | Request Karo syrup is poured into a beaker between the polarizer and analizer plates. As the height of the syrup increases, its color changes.
291.	F.1.74 Optical activity box | Request Polarized light passes through a box containing glass objects and Karo syrup. As the analyzer rotates a changing pattern of colors is produced.
292.	F.1.78 Scotch tape polarization (ohp) | Request Cellophane tape pictures on glass plates are placed between the polarizer and the analyzer. As the analyzer is rotated, the colors in the pictures change.
293.	F.1.82 Polarmotion (ohp) | Request Special polaroid pictures are placed on the overhead projector. When they are viewed through a quickly spinning analyzer, the pictures seem to move.
294.	F.1.86 Stress analysis by polarization (ohp) | Request A U-shaped plastic is stressed in a metal frame between the polarizer and the analyzer. As the stress is varied with the screws, the pattern of colors changes.
295.	F.1.90 Scattering: artificial sun set | Request White light shines through the water tank with some milk or creamer added to the water. When viewed from the side, the light appears blueish, while the direct light from the lamp appears reddish.
296.	F.1.94 Laser modulation for audio transmission (optics) | Request Laser beam is acoustically modulated and then transmitted. When the laser light is received, the audio signal is recovered and amplified to a speaker.
297.	F.2.10 Arrows of reflection (model) | Request Large colored arrows to show the law of the light reflection from a plane mirror.
298.	F.2.15 How tall a mirror ? | Request How tall mirror do we need in order to see ourselves from the top of our head to the tip of our toes?
299.	F.2.20 Angle mirrors (camera) | Request It looks like there are three numbered metal balls resting on a plate. When ball number one is taken away, the other two balls also disappear.
300.	F.2.25 Concave and convex mirrors | Request A large mirror - one side concave, other side convex - is displayed, and the difference in the images is shown.
301.	F.2.30 Images in spherical mirrors (camera) | Request A concave and a convex mirror is moved on the optical bench until a sharp image is seen in the camera. The sizes and the orientations of the images are observed and compared.
302.	F.2.35 Magnifying and reducing glasses (camera) | Request A magnifying glass is used for the simplest job: to see an object better. When a reducing glass is used, the image is smaller than the object.
303.	F.2.40 Large lens | Request A large thick planar convex lens is displayed. When the demonstrator looks into it, the students see a very large, but distorted face.
304.	F.2.45 Image from a single lens (camera) | Request A converging lens is moved on the optical bench until a sharp image is formed on the screen. When a diverging lens is used there is no image.
305.	F.2.50 Light paths through lenses (camera) | Request Laser beams pass through various lenses in the smoke box.
306.	F.2.55 Air lens | Request When a double concave hollow lens is placed in water, it acts as a converging lens.
307.	F.2.60 Pinhole camera | Request An inverted real image is formed with a camera which does not have any lens just a small hole. A picture is taken on polaroid film.
308.	F.2.65 Light bulb illusion | Request The image of a light bulb formed by a convex mirror appears to be in a socket which is actually empty.
309.	F.2.70 Edmund mirage (camera) | Request A green "START" button seems to float in the air. When you try to press it, you realize it is just an image.
310.	F.2.75 Anamorphic art | Request A cone shaped mirror forms an image which is very different from the original picture.
311.	F.2.80 Human eye model | Request A large plastic model to show the anatomy of the human eye and to help to explain the functions of its parts.
312.	F.3.10 Interference patterns on overhead (ohp) | Request Concentric circles are printed on two transparencies. When they are placed on the overhead projector the pattern of constructive and destructive interferences is seen.
313.	F.3.15 Meter stick model of interference | Request Two long meter sticks are hooked onto a wood bar on the side of the black board. The pattern of maximas and minimas is drawn on the board as the meter sticks are swept along.
314.	F.3.20 Soap film interference | Request When white light is reflected from a soap film, colorful interference pattern is seen. As the fluid in the film moves downwards, the pattern changes.
315.	F.3.25 Newton's rings (ohp, camera) | Request A planar convex lens with a large radius of curvature is lying on a planar glass. Circular interference rings are seen when it is lit.
316.	F.3.30 Testing optical surfaces by interference (camera) | Request Interference patterns are used to test the flatness of optical surfaces.
317.	F.3.35 Single and multiple slit diffractions | Request Laser beam is diffracted from single and multiple slits of different widths and slit separations. The diffraction pattern is projected to a screen.
318.	F.3.40 Hinged arrows and rubber tube models of diffraction | Request Hinged wood arrows or a rubber tube is used to explain the diffraction pattern from a single slit.
319.	F.3.45 Single variable slit diffraction | Request As the width of a slit is decreased, the spacing between the peaks in the diffraction pattern increases.
320.	F.3.50 Shrinking mirror | Request As the two razor blades approach each other on the surface of the mirror, the reflected laser light spreads and shows diffraction patterns.
321.	F.3.55 Diffraction grating | Request Laser light is passed through a high line density diffraction grating. The resulting diffraction pattern is projected to a screen.
322.	F.3.60 Red and green diffraction | Request Red and green laser light is passed through the same diffraction grating. In the resulting diffraction pattern the red spots are farther apart from each other than the green spots.
323.	F.3.65 Two dimensional gratings | Request Laser light is passed through two perpendicular diffraction gratings and several two dimensional gratings. The resulting patterns are projected to a screen.
324.	F.3.70 Diffraction from a CD and a DVD | Request Laser light is reflected from a CD and a DVD. The differences between the two diffraction patterns are observed.
325.	F.3.75 Babinet's hair | Request Laser light is diffracted from a single piece of hair. The diffraction pattern is the same as from a single slit. The width of the hair can be determined from the diffraction pattern.
326.	F.3.80 Circular aperture | Request Diffraction pattern from a circular aperture is produced and observed on the screen. It is a circular central maximum and several concentric alternating rings of minima and maxima.
327.	F.3.85 Diffraction by a circular object (video) | Request A video about the diffraction pattern and the Poisson Fresnel bright spot behind circular objects.
328.	F.4.10 Holograms | Request Several different holograms are displayed and the students can take a closer look.
329.	G.1.10 Twin paradox (video) | Request The twin paradox is explained in an entertaining short film.
330.	G.1.20 Lorentz transformation (video) | Request Lorentz transformation is explained in an entertaining film.
331.	G.2.10 Photoelectric effect (ohp) | Request When a negatively charged zinc plate is lit with ultraviolet light, the plate loses its charge. If visible light is used - no matter how intense - the plate retains its charge.
332.	G.2.20 Maltese cross | Request Electrons produced by a heated cathode propagate along a straight line like light. A metal cross inside the tube blocks both the photons and the electrons. A cross shaped shadow is seen on the screen of the tube.
333.	G.2.30 Diffraction of electrons | Request When monoenergetic electrons hit powdered crystal, concentric rings are seen on the screen of the tube. Changing the accelerator voltage causes the rings to shrink or grow.
334.	G.2.40 Compton effect | Request X-rays from a radioactive source are detected first directly, then after being scattered from an aluminum block. The Compton-peak appears on the screen shifted with respect to the original X-ray peak.
335.	G.3.10 Fluorescent light tube | Request Half of a light tube is coated inside with flurescent material as usual. The other half is left uncoated. The difference in light output is clearly visible by eye.
336.	G.3.20 Fluorescent rocks (camera) | Request A collection of rocks is exposed to ultraviolet light. They fluoresce in many different colors.
337.	G.3.30 Fluorescent tonic water (camera) | Request Tonic water fluoresce in bright blue color when exposed to ultraviolet light due to its quinine content.
338.	G.4.10 Cold LED | Request As a light emitting diode (LED) is cooled down by liquid nitrogen the light changes from green to yellow.
339.	G.4.20 Meissner effect (camera) | Request A tiny magnet floats above a high temperature superconductor.
340.	G.5.10 Becquerel's photo plate | Request A radioactive source emitting X-rays is placed on top of a polaroid film in its original packaging for about half an hour. When the film is developed, an overexposed spot appears on black background.
341.	G.5.20 Geiger counter | Request The activity of various radioactive sources are measured with a Geiger counter.
342.	G.5.30 Half-life of Barium | Request Gamma emission from Barium-137 is counted for several minutes, and the half-life is calculated. Alternatively, a multichannel analyzer automatically graphs the decay curve for Barium-137.
343.	G.5.40 Shielding | Request Plates made out of different materials and thickness are inserted between the Geiger counter and different kind of sources.
344.	G.5.50 Mouse trap chain reaction | Request Wound-up mouse traps are inside a wire cage. When an extra cork is dropped in, the whole array of traps explode.
345.	G.5.60 Nuclear fusion model | Request The "electron" sides of two tricky magnets always repel. The "proton" sides repel only if the temperature is not very high. As the temperature rises (the shaking intensifies), they click together, they fuse.
346.	G.6.10 Wilson expansion cloud chamber | Request A small cylindrical chamber containing an alpha source and saturated ethanol water vapor is connected to a rubber ball. After squeezing and quickly releasing the ball tracks of alpha particles can be seen.
347.	G.6.20 Diffusion cloud chamber | Request Alpha particles from Thorium and Radium sources and other particles from the background radiation are seen in a layer of oversaturated ethanol vapor when they pass through the chamber and leave contrails.