Video Transcript
Which of the following is a device
that can be used for observing stars? (A) A magnifying glass, (B) a
microscope, (C) a telescope, (D) a telegraph, (E) a telephone.
To answer this question, we need to
remember that although stars are very large, they are very far away. This makes them appear very small
to us here on Earth. So it’s difficult to observe stars
by just looking at them with our eyes alone. In order to get a better look at a
star, we need to use a certain device. So let’s go through the list of
answer choices and see which one is correct.
Starting with answer option (A),
we’re probably familiar with using a magnifying glass to look at something up
close. We hold the magnifying glass in our
hand and hold it above something small in order to make it appear larger to us. A magnifying glass is designed to
help us look at things that are small and close to us. So it can’t be used to observe
stars. Therefore, we should eliminate
option (A).
Next, option (B) says a
microscope. Microscopes are used to make very
small things, such as plant cells, appear larger. So, like we saw before, this device
is only used to observe things that are small and close to us. So we can’t use it to observe
stars.
Next, option (C) says a
telescope. Now, telescopes also make things
appear larger to us. But we don’t use telescopes to see
things that are nearby. Instead, telescopes are used to see
things that are far away. They’re especially useful for
studying space. Telescopes help us learn about
faraway objects, such as other planets, stars, and even other galaxies. Since telescopes are used to
observe stars, this is the correct answer. Just to be sure, let’s look at the
remaining options.
Option (D) says a telegraph, which
is a device used to communicate over long distances. The telegraph isn’t used to observe
things. So this can’t be the correct
answer.
Finally, we know that the telephone
is also used for communication. Now, many modern telephones, such
as smartphones, do have cameras built into them, which can be used to observe some
things. But they’re not designed to look at
things as far away as stars. The main purpose of the telephone
is communication, so this isn’t the correct answer either.
Thus, we have seen that the only
device listed here that can be used to observe stars is a telescope. So the correct answer is option
(C).
