Presentations

Color Mixing

What it shows:

All colors can be created from a combination of the three primary colors of red, green and blue. The secondary colors of cyan, magenta and yellow are created from a combination of two primaries, and white light is perceived from the combination of all three.

...

Read more about Color Mixing
Bouncing Light Beam

What it shows:

As a simulation of atmospheric refraction, this demonstration shows the gradual and continuous bending of light due to a gradient in the optical density of the medium. In this case the variable refracting medium is a tank of sugar water with a vertical gradient in the concentration of sugar and a HeNe laser provides the light beam. It can be used as a model of mirage formation (except that the direction of increasing refractive index is in the opposite direction) or even as a representation of the refraction of seismic waves through the Earth's...

Read more about Bouncing Light Beam
Brewster's Angle

What it shows:

When unpolarized light is reflected from a non-metallic surface, the reflected ray is plane polarized parallel to the reflecting surface if

θi + θr = 90°

or

tanθi = n

where θi = incident ray (Brewster's angle), θr = refracted ray, n = refractive index

How it works:

We use a black vinyl sheet 1m×4m as the reflecting surface, which has a Brewster angle of 57°. A theatrical spot lamp 1 is used to give a 50cm circle...

Read more about Brewster's Angle
Electron Diffraction

What it shows:

Louis de Broglie predicted that matter under certain circumstances would exhibit wave-like properties. A proof of this is the repeat of X-ray diffraction experiments using electrons, whose de Broglie wavelengths at high accelerating potentials are similar to X-ray wavelengths. Here we accelerate electrons into crystal targets and get diffraction patterns identical to those from X-ray diffraction.

...

Read more about Electron Diffraction
CRT Paddle Wheel

A beam of cathode rays (electrons) impinging on a paddle wheel cause it to spin and travel down the vacuum tube.

crookes tubes

What it Shows

A paddle wheel is suspended by its axle inside a Crookes tube so that when the paddle vanes spin the entire...

Read more about CRT Paddle Wheel
Bouncing Photon

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

Critical Opalescence

What it shows:

The demonstration shows density fluctuations in liquids. These fluctuations are particularly spectacular near critical points. A binary fluid mixture of methanol (29% by weight) and cyclohexane (71%) becomes opalescent when heated up to its critical temperature (about 45˚C) ... the fluids become miscible above this temperature.

How it works:

The two fluids are sealed in a special vial, able to withstand elevated pressure. The fluids are immiscible at room temperature. When brought up to 45˚C, they become miscible...

Read more about Critical Opalescence
Dilatancy of Deformation

What it shows:

When sand in a balloon, just as atoms in a lattice, are close packed, they occupy the least possible volume. Any deformation, even compression, deforms this close-packed arrangement causing an increase in volume.

How it works:

The balloon is filled with sand, and black ink added allowed to percolate down and fill the air gaps. A capillary tube sticking out of the balloon indicates the ink level. When the balloon is squeezed the sand, which had settled down to a closely packed arrangement, is dislocated. Larger gaps...

Read more about Dilatancy of Deformation
Jupiter's Satellites

Static model of satellite orbits.

What it shows:

Static 3-D model showing the orbital paths of Jupiter's satellites.

How it works:

The model marks the orbital paths of the Jovian satellites to a scale of 1.5cm = 106 km. This scale allows the orbit of the outermost satellite Sinope to fit within a 1m × 1m plywood base. The orbits of the outer 8 satellites are marked using loops of 2mm × 1mm spring steel supported to their correct heights by 5mm Plexiglas rods (Pasiphae rising to the greatest height of 42cm). The...

Read more about Jupiter's Satellites

Pages