[XL]

Will take up most of the hall.
Telescope Resolution

What it shows

A telescope (with video output) at the front of the lecture hall is focused on two point light sources at the rear of the hall. Although the light sources are only 1/2 mm apart, they are readily resolved. The Rayleigh limit of resolution can be clearly shown by reducing the telescope aperture to the point where the two light sources can barely be resolved, similar to the following images (from: Cagnet/Francon/Thrierr, Atlas of Optical Phenomena). At the Rayleigh limit the centers of both point sources coincide with the the first minimum of the other source....

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Air Table Center-of-Mass Motion Monday, May 2, 2016

What it shows:  Two bodies, rotating about each other, rotate about their common center-of-mass (COM). The COM exhibits uniform motion (or none at all) regardless of what the two bodies are doing.

How it works:  The "bodies" are 4-1/2" diameter acrylic disks that float on a cushion of air on a large air table.1 Presently we have three versions ready to go. (1) The first version has two disks connected by means of a 12"- long plastic ruler. A large "dot" at the center of the ruler marks the COM. The disks can be made to simply...

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Inverse Square Law

[XL | t++ | ***]  inverse square law, luminosity

What it shows:  The intensity of light from a point source decreases as 1/r2, where r is the distance from the source.

How it works:  For the point light source, we use a 1500 watt clear light bulb. The detector is a small solar panel.1 The output current is directly proportional to the intensity of the light falling on the panel and the current is displayed on an analog milliameter. (The current can also be measured by a digital meter or computer.) Measured...

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Coriolis Effect

As demonstrated by two people throwing a volleyball to each other while sitting on rotating platform.

What it shows: 

The Coriolis force is a pseudo force existing in a frame that rotates with constant angular velocity to a reference frame. It acts on a body moving in the rotating frame to deflect its motion sideways. Here the audience sits in the reference frame, while two volunteers on a rotating platform experience the coriolis force by trying to basket a volleyball.

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Bouncing Photon

A photon (modeled by a bouncing ping-pong ball) is observed from two reference frames and provides the motivation for time dilation.

Relativity Train

What it shows:

The Relativity Train is a realization of the famous Einstein gedanken experiments involving traveling trains carrying clocks and meter sticks. The demonstration is used to show how the preservation of the postulated constancy of physical laws and the speed of light in all inertial frames requires length contraction and time dilation in the train frame relative to the lab frame of reference. The demonstration is, of course, not a real experiment but rather a visual means of showing (without using any equations) how length contraction and time dilation are...

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Wooden Dowel Wave Machine

Large (20 feet long) Shive wave machine that can clearly show the reflection and transmission of a pulse at the boundary of fast and slow media.

What it shows:

Being so large (20 feet long), transverse traveling waves on this apparatus are easily seen by a large audience. The propagation speed of the waves is much slower than on the Shive Wave Machine, giving the audience time to process what's going on. The apparatus can be used to show three properties of waves: (1) wave speed is inversely proportional to the square root of the medium's inertia, (2) waves traveling from a...

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Coriolis Force

What it shows:

The Coriolis force is a pseudo force existing in a frame that rotates with constant angular velocity to a reference frame. It acts on a body moving in the rotating frame to deflect its motion sideways. Here the audience sits in the reference frame, while two volunteers on a rotating platform experience the coriolis force by trying to basket a volleyball.

...
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