Light, Insignificant, and Tyndall effect

When you look up at the sky at night, you see this thing:

Photo by Ganapathy Kumar on Unsplash

What is this?

You might answer: this is the moon.

When you look at your desk, you see this thing:

What is this?

You might answer: this is a cup.

But when you see these pictures, then ask what you saw:

This time, you may answer: I see the light.

We can see the moon because the moon reflects the sun’s light, and what we see is, in essence, light.

We can see the cup because the cup reflects the light, and what we see is, in essence, light.