10 - 20 min

Chladni Plates - Violin Bow

Recreate E.F.F. Chladni's classic demo of sprinkling sand on a plate and playing it with a violin bow to create and visualize various vibrational patterns. This versatile demo can be adapted to talk about sound wave acoustics, vibrational normal modes, and energy transport to a wide range of audiences. 

Chladni Plates - Speaker

Build a simple Chladni plate using a 6" x 6" metal sheet, a 2 watt speaker, powered with a 20 gain amplifier and phone. Sprinkle sand on the sheet, and play various sound frequencies to reveal the sheet's assortment of resonant vibrational modes. 

Along with the plate demo itself, an amplifier can be made fairly easily with an LM386 op amp. Download instructions for making the amplifier under associated files or can be found here. 

Liquid Nitrogen Ice Cream

Explore the properties of liquid nitrogen while making a tasty treat. This demo is great for chapter socials and smaller outreach events.

Off-Grid Phone Charger

Constructing this simple and inexpensive portable cellphone charger provides an introduction to soldering and electronics.

Practically, these units can be used for charging in regions of the world where grid electricity is not readily available.

Variable Index of Refraction

A sugar-water solution is used to create a liquid with a variable index of refraction. Participants learn about solutions, gradients, and refraction.

Ferrofluids

This demonstration provides a three-dimensional visualization of magnetic field lines using ferrofluid.

Eclipses: Earth-Moon-Sun Model

This demonstration uses a model of the earth-moon-sun system to explain why eclipses occur. This demo is useful for illustrating why total solar eclipses are rare. 

Composition of the Universe

This demonstration briefly explains the history of the universe using jars and colored beads. The jars represent matter/objects and the beads represent the composition of those objects.

Pinhole Projector

Construct a pinhole projector to introduce participants to the basic properties of light. This tool can then be used to view eclipses or other bright sources.

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