You can use a simple cat toy (laser pointer) to demonstrate the Tyndall effect. “The Tyndall effect, also known as Tyndall scattering,” according to Wikipedia, “is light scattering by particles in a colloid or particles in a fine suspension.” You can use the laser to test three different mixtures: colloids, suspensions, and solutions. I’ll demonstrate Tyndall scattering in a colloid (milk), in a suspension (dirt), and a solution (sugar) with a cat toy (Laser pointer).

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Parts needed:

I’ll demonstrate how to build a simple magnetic optical mount for a cat toy (laser pointer). Though it is simple—that is, there aren’t any fine tuning mechanisms one would find on an optical bench—it is, nonetheless, inexpensive and flexible enough to use for simple optical experiments such as demonstrating the Tyndall effect, .

I used a magnetic chip clip to clamp the laser pointer switch (a press switch) in the on position and attach the laser pointer to the Erector set mount.

My wife bought me a “selfie-stick” (sometimes called Wand of Narcissus), which is ironic since I so rarely actually take selfies. But, once I took a look at its simplicity of design, I couldn’t leave well enough alone and decided to create the “Super Selfie-Stick.”

At first I tried attaching a camera mount on the end of a golf ball retriever.

I finally received a Foldscope beta test kit. “Foldscope is an origami-based print-and-fold optical microscope that can be assembled from a flat sheet of paper,” according to the website. The Foldscope “can provide over 2,000X magnification with sub-micron resolution (800nm), weighs less than two nickels (8.8 g), is small enough to fit in a pocket (70 × 20 × 2 mm3), requires no external power, and can survive being dropped from a 3-story building or stepped on by a person.”

The kit came with instructions, perforated cardboard for the microscope assembly parts, lenses, magnetic strips to attach the microscope to a cell phone, and a light module.