Introduction

Look at the world and at color pictures through red and green filters, notice the differences in how things look.

Material

Color pictures or a colorful world around you.
Transparent red and green filters

To Do and Notice

Look at the color pictures through the red filter.

Look at the color pictures through the green filter.

Look at the color pictures with no filter and then quickly look through a color filter.

Notice how some things stand out prominently when examined through the color filters, while other things vanish.

Look through a colored filter and then look at a color photo for the first time, guess how you think it might look when you remove the filter.
Then remove the filter.
Surprise?

What's Going On?

Birds and insects have color vision that uses different color receptors than humans.

Birds that pollinate flowers have excellent vision in the red.
Some insects, bees for example, can see ultraviolet, others are more sensitive to blue light than to red light.

By looking through the red filter you can imagine how different the world might look to a bird.

By looking through the green filter you can imagine how different the world looks to an insect.

So What?

Some flowers have ultraviolet markings that can only be seen by insects.

Activity written by Paul Doherty
Inspired by an activity by Karen Kalumuck, color guessing activity by Marie Wallum.

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Scientific Explorations with Paul Doherty

© 1999

22 May 2000