Wiggle where you’re at

Even with our eyes closed, we have a sense of body position – where our arms and legs are, for example, and that we are moving them. Muscles, tendons, joints and the inner ear contain proprioceptors, also known as stretch receptors, which relay positional information to our [...]

Who needs expensive optical equipment?

A pinhole in an index card can act like a magnifying glass, helping your eyefocus on a an object that is very close to you. However, by limiting the amount of light that reaches your eye from the object, the pinhole also makes the object appear dimmer.

A 3 x 5 [...]

Objective:
To demonstrate how size affects a star’s apparent brightness.

Standards:
Objects in the Sky (sky object properties, locations, and movements).

Materials:
two flashlights, aluminum foil, pencil, two sheets of blank paper.

Procedure:
Cover the lens end of one of the flashlights with a piece of aluminum foil.
Using the pencil, make a hole in the [...]