IPC Notes

The Behavior of Light

Light & Matter

Opaque material – either absorbs or reflects all light; you can’t see through it

ex) a brick wall

Light & Matter

Transparent material – allows all light to pass through it; you can see through it

ex) clear glass

Light & Matter

Translucent material – allows only some light to pass through it; you can see through it, but not clearly

ex) wax paper

Reflection & Refraction

Reflection– occurs when a light wave strikes an object and bounces off

The law of reflection states that a wave bounces off a surface at the same angle it strikes.

Reflection & Refraction

Refraction– the bending of a wave due to a change in medium

ex) a prism refracts white light into the colors of the visible spectrum

Producing Light

Incandescent Light– produces light by heating a filament until it glows; very inefficient (about 80% of the energy is given off as heat)

ex) typical light bulb

Producing Light

Fluorescent Light– electricity is sent through a gas filled tube; more efficient

ex) classroom light bulbs

Producing Light

Neon Light– electricity is sent through a gas filled tube; different elements produce different colors

Producing Light

Lasers– very narrow and focused light produced when identical atoms send off identical light waves

ex) used in surgical tools,leveling, barcodes