Close-ups
Its huge, glittering eyes stare at you. Its big mouth opens and closes,
opens and closes. But suddenly it swims to the other side of the bowl.
It’s only a small goldfish, after all!
Why did the goldfish look so big when it swam next to the curved glass?
The bowl filled with water acted as a lens. It bent the light that
bounced off the goldfish and came through the bowl. This made the
goldfish look much bigger than it really is.
Most of the lenses we use are made of plastic or glass. But anything can
be a lens if it is curved and if light can pass through it. A curved
shape makes light bend and spread. And spreading the light that bounces
off a thing makes that thing look bigger. A lens with the right curve
will make something look larger or closer than it really is.
A magnifying glass is just a single lens with two curved sides. You can
use it for a close-up look at things like paper or cloth or even your
finger. Move it up and down until
The curved lens in a magnifying glass bends and spreads the light. It
makes things look bigger than they really are.
it is the right distance from what you are looking at. You will get a
sharp, clear view— and what you see may surprise you.
A microscope gives you close-ups of very small things. It lets you see
things that are so tiny you couldn’t see them with your eyes alone. A
microscope has two sets of lenses. These are lined up in a tube that can
be moved up and down. When the lenses are the right distance from the
thing you are looking at, they spread the light just as the magnifying
glass does. But with two sets of lenses, whatever you look at is
magnified twice. It looks much larger than it really is.
A telescope makes faraway things seem close. The simplest kind of
telescope has two lenses in a tube, something like a microscope. Part of
the telescope moves in and out to change the distance between the
lenses. When the distance is right, a clear picture is formed.
In big telescopes, light from the sky shines down a tube onto a large,
curved mirror. The mirror takes the place of the first lens—it gathers
and bends the light. It reflects the picture up to a smaller mirror.
This smaller mirror reflects the picture through a lens to your eye.
With one of these telescopes, you can see faraway planets and stars.
A telescope gives you a close-up view of faraway things, like the moon.
