Why be Streetwise?

So if most things don't give out light, how can we see them? Well if you think about it, when you switch off your bedroom light at night, you can't see much in your room.

This is because we need light from light sources to bounce off things and then into our eyes so we can see them.

If there is no light source, we can't see. When light bounces off something, it is said to be reflected.

Our eyes need to pick up the reflected light to see the thing it bounced off.