# Physics Experiments

Illustrating the chaotic Bunimovich Stadium.
The logistic map, which demonstrates the bifurcations of the population
levels preceding the transition to chaos.
Looking at the Lorenz Attractor in a chaotic regime, allowing the
attractor to be rotated.
2 fixed suns and 1 planet. Initial conditions are controllable, and up
to 4 different independent planets may be displayed.
A simple animation showing the difference between the
1-dimensional kinematics of a body undergoing constant acceleration.
Includes visually integrating the acceleration and velocity graphs, and
visually differentiating the position and velocity graphs.
A car with a non-zero initial speed has a constant acceleration whose
value can be controlled by the user.
Two balls falling near the Earth's surface under the influence of
gravity. The initial horizontal speed of one of the balls may be varied.
Illustrating Galilean relativity using his example of dropping a ball
from the top of the mast of a sailboat.
Firing a projectile when air resistance is negligible. The initial
height and angle may be adjusted.
A visualization exploration of the kinematics of projectile motion.
An animation of the classic lecture demonstration. The actual
demonstration is preferable if possible; then this animation can be
given to the students for later review.
Two balls roll down two different low-friction tracks near the Earth's
surface. The user is invited to predict which ball will reach the end of
the track first. This problem is difficult for many beginning Physics
students.
The "Racing Balls" animation which is accessed via the above line
sometimes triggers cognitive dissonance and rejection in beginning
students. For some of these, changing the balls to skiers helps to
clarify the situation, and that is what this animation does. The "Racing
Balls" one should be used with students first.
Elastic and inelastic collisions on an air track, with different masses
for the target cart.
A small animation of Newton's Cradle, sometimes known as Newton's Balls.
A simple animation illustrating Hooke's Law.
An unusual coordinate system for describing circular motion.
A mass is in circular motion in the vertical plane. We show the weight
and force exerted by the tension in the string.
The weight, force due to tension, and total force exerted on the bob of
a pendulum are shown.
A simple animation that traces the motion of a point on a rolling disc.
The direction of the angular velocity vector given by a right-hand screw
rule.
A simple animation of the direction of the angular velocity vector.
Curling rocks and tori sliding across surfaces.
The saying is that cats always land on their feet. This animation
explains how they do this.
A simple animation of a spinning top which processes.
Demonstrating that one component of uniform circular motion is simple
harmonic motion.
Illustrating and comparing Simple Harmonic Motion for a spring-mass
system and for a oscillating hollow cylinder.
The damping factor may be controlled with a slider. The maximum
available damping factor of
A harmonic oscillator driven by a harmonic force. The frequency and
damping factor of the oscillator may be varied.
Two simple pendulums connected by a spring. The mass of one of the
pendulums may be varied. Within mathematical rounding errors, the
resolution on the screen of one pixel, and a frame rate of 12 frames per
second the animation is correct, not an approximation.
A simulation of an experiment to determine the dependence of the
electrostatic force on distance.
A simple DC circuit has a DC voltage source lighting a light bulb. Also
shown is a hydraulic system in which water drives a turbine. The two
systems are shown to be similar.
A simple animation of how a common light Switch works.
Illustrating representing an electric field with field lines.
A simple buzzer consisting of a battery, a flexible metal strip, a piece
of iron, and some wire.
An electric charge is executing simple harmonic motion, and the
animation shows the electric field lines around it.
A 3 dimensional animation of the "far" fields of an oscillating charge.
Circular polarization generated from a linearly polarized
electromagnetic wave by a quarter-wave plate.
A spinning charged object passes through an inhomogeneous magnetic
field. This animation is also used in a discussion of the Stern-Gerlach
experiment.
A spinning charged object passes through an array of 3 magnets each
producing an inhomogeneous magnetic field. This animation is also used
in a discussion of the Stern-Gerlach experiment.
A simple animation of using a micrometer to measure the width of a
pencil.
Provides controls to position the micrometer, and when a button is
clicked displays the reading.
A small animation showing a piston compressing a sample of gas. As the
volume of the gas goes down, the density and therefore the pressure goes
up.
An animation illustrating that the derivative of a sine function is a
cosine.
Illustrating that the area of a circle is a limit of the sum of the
areas of interior triangles as the number of triangles goes to infinity.
Illustrating the meaning of the integral sign, including an example.
Simulating nuclear scattering experiments by scattering ball bearings
off targets. This is based on an experiment in the First Year Physics
Laboratory at the University of Toronto.
The decay of 500 atoms of the fictional element Balonium. Uses a
proper Monte Carlo engine to simulate real decays.
A simple illustration of electron-positron production and annihilation.
Illustrating the 3 principle modes by which X-rays interact with matter.
Illustrating that when a mirror is rotated by an angle, the reflected
ray is rotated by twice that angle.
Illustrating reflection and refraction, including total internal
reflection.
Ray tracing for a thin lens showing the formation of a real image of an
object.
A simulation of an optical bench with a light source, object, thin lens
and an image. The screen that displays the image is moved.
Shows the effect of changing the time base control on the display of an
oscilloscope. There is no input voltage.
Shows the effect of changing the time base control on the display when
there is an input voltage varying in time.
Shows the effect of changing the time base control on the display when
there is an input voltage varying in time when the frequency of the
voltage is high.
Shows the effect of changing the voltage control on the display.
Shows the effect of changing the trigger level on the display.
The photon excitation and photon emission of the electron in a Hydrogen
atom as described by the Bohr model.
Here we visualize a hydrogen atom, which consists of an electron in
orbit around a proton. In one view the electron is a
The famous "Feynman Double Slit Experiment" for electrons. Here we fire
one electron at a time from the electron gun, and observe the build-up
of electron positions on the screen.
Here we illustrate
Up to three Stern-Gerlach filters with user-controlled orientations are
placed in an electron beam.
Based on an analysis by Mermin, this animation explores correlation
measurements of entangled pairs.
A simple analogy involving two swimmers that sets up the
Michelson-Morley Experiment.
A demonstration that the phenomenon of time dilation from the special
theory of relativity necessarily follows from the idea that the speed of
light is the same value for all observers.
A tutorial that shows how relativistic length contraction must follow
from the existence of time dilation.
This series of animations demonstrates that the relativistic length
contraction is invisible.
A tutorial that shows how the relative nature of the simultaneity of two
events must follow from the existence of length contraction.
There are many ways of approaching this classic "paradox". Here we
discuss it as an example of the relativistic Doppler effect.
This began as an animation of the Foucault Pendulum, but then I
generalized it to illustrate Mach's Principle.
A simple animation showing Newton's and Einstein's predictions for the
orbit of Mercury.
Illustrating beats between 2 oscillators of nearly identical
frequencies.
Illustrating the wave fronts of a wave for a moving source. There are a
few similar animations on the web: this is my re-invention of that
wheel.
Illustrating the classical Doppler Effect for sound waves.
A small animation of a vibrating tuning fork producing a sound wave.
This animation shows air molecules vibrating, with each molecule
"driving" its neighbor to the right. It is used to illustrate that when
the displacement wave is at a maximum then the density of the molecules,
and thus the pressure wave, is at a minimum and vice versa.
A very brief introduction to the physics and psychophysics of music,
with an emphasis on temperament, the relationship between notes.
A simple demonstration of adding 2 vectors graphically. Also
demonstrates that vector addition is commutative.
A simple demonstration of adding 3 vectors graphically. Also
demonstrates that vector addition is associative.
A simple demonstration that subtracting 2 vectors graphically is the
same as adding the first one to the negative of the second one.
A simple demonstration that to add 2 vectors numerically, just add the
cartesian components.
A simple animation of unit vectors and vector addition.
A simple demonstration of the relation between the dot product of 2
vectors and the angle between them.
The direction of the angular velocity vector given by a right-hand screw
rule. Requires Flash 6; file size is 196k. Also linked to from the
The direction of the cross product of 2 vectors is demonstrated. The
magnitude shown is correct but not discussed.
Illustrating the sign of the time term for traveling waves moving from
left to right or right to left.
A wave is reflected from a barrier with a phase reversal. This is the
behavior for transverse waves and the
A wave is reflected back and forth between two barriers, setting up a
standing wave.
The first three standing waves for nodes at both ends. The frequencies
of the waves are proportional to one over the wavelength.
The first three standing waves for a node at one end and an antinode at
the other. The frequencies are proportional to one over the wavelength.

Chaos
Classical Mechanics
*distance* and
the* displacement*.
*100* corresponds
to critical damping.
Electricity and Magnetism
Micrometer Caliper
Miscellaneous
Nuclear
Optics
Oscilloscope
Quantum Mechanics
*particle* and
in the other view it is a *probability
distribution*. The reality is neither view by itself, but a
composite of the two.
*Complementarity* using
the double slit experiment. We view the path of the electron from the
gun to the observing screen as a particle and as a wave.
Relativity
Sound Waves
Vectors
*Classical
Mechanics* section.
Waves
*displacement* aspect
of a longitudinal wave.