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[★★★★]

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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Rotating Saddle

Mechanical analog of a Paul Trap particle confinement—a ball is trapped in a time-varying quadrupole gravitational potential.

How it works:

A large saddle shape (attached to a plywood disk) is mounted on a multi-purpose...

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Stonehenge

Static model of site; can be used with light source to simulate a mid-summer's morning.

What it shows:

1:50 scale model of the Stonehenge site with the positions of Sun and Moon on important dates marked. It can be used with a light show to reproduce Sunrise on Midsummer's morning, June 21.

How it works:

The Stonehenge site consists of the sarsen circle of 30 megaliths capped with 30 lintels. Within this circle is a horseshoe pattern of five trilithons. 80m north-east of the circle's center is the Heel Stone; it is the...

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Brownian Motion of Latex Spheres

“Under the microscope one, to some extent, immediately sees a part of thermal energy in the form of mechanical energy of the moving particles.” —A. Einstein 1915

What it Shows

Tiny latex spheres in water, viewed under a microscope, undergo a kind of random jiggling motion called Brownian motion—named after the botanist Robert Brown, who observed this kind of motion in 1827 when looking at tiny pollen grains. The spheres are all 1.054 micron in diameter. Each particle can be seen...

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Shive Wave Machine

Rods attached to metal spine; transverse wave generator shows the reflection of waves free, fixed, terminated and transition boundaries.

What it shows

Mechanical demonstration of transverse standing or traveling waves using the Shive wave machine.

How it works

The Shive wave machine consists of a series of horizontal metal rods 1.25 cm apart coupled by a torsion wire. A pulse can be sent down the machine by displacing the end rods (when doing this by hand, pull down on more than one rod as the connections are delicate and do break). The far...

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Samples of Elements

First day of Gen Chem: Metals and non-metals; solids, liquid and gas elements; compound of elements.

Copper, sulfur, lead, iron, antimony, iodine, carbon as powder and graphite sample, mercury, copper iodate, oxygen balloon.

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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