Light, Sound & Vibrations Explorer

Sound is made by vibrations traveling through air (or water, or solids). When something vibrates fast, it makes a high-pitched sound. When it vibrates slowly, the sound is low-pitched.

• Frequency controls the pitch. Higher frequency = higher pitch, like a whistle.
• Amplitude controls the volume. Bigger amplitude = louder, like turning up a speaker.

On the wave diagram, frequency changes how close the waves are, and amplitude changes how tall they are.

Light travels in straight lines. When an object blocks the light, it creates a shadow on the other side.

• Opaque materials (like wood) block all light and make dark shadows.
• Translucent materials (like frosted glass) let some light through, making lighter shadows.
• Transparent materials (like clear glass) let all light through, so no shadow forms.

Moving the light source closer to the object makes the shadow bigger. Moving it farther away makes the shadow smaller.

When light hits a smooth, shiny surface like a mirror, it bounces off. The Law of Reflection says the angle that light hits the surface equals the angle it bounces away.

• The incoming angle is measured from the "normal" (a line straight out from the mirror).
• The reflected angle is always the same size, on the opposite side of the normal.

This is why you can see yourself in a mirror. The light bounces off you, hits the mirror, and bounces back to your eyes at the same angle.

Mixing colored light is different from mixing paint! With light, adding colors together makes the result brighter. This is called additive color mixing.

• Red + Green light = Yellow
• Red + Blue light = Magenta
• Green + Blue light = Cyan
• Red + Green + Blue light = White!

TV screens and phone displays use tiny red, green, and blue lights to create every color you see.