Wow! The Universe is getting bigger every day!
Cosmology is a branch of science which studies the evolution of our
Universe. A scientist who studies cosmology is called a cosmologist.
Cosmologists want to know what the Universe was like billions of years ago.
They want to understand how it is today. They also want to find out what
the Universe will be like billions of years in the future. To understand the Universe, cosmologists first needed to know our place
in it. About 400 years ago, most people believed that Earth was at the
center of the Universe. They thought the Moon, the Sun, and the other
planets all traveled around Earth. Nicholas Copernicus, Galileo Galilei,
and Isaac Newton helped us to learn the truth. We now know that the Moon
travels around Earth. Earth and the other planets in our solar system
travel around the Sun.
About 100 years ago, astronomer Edwin Hubble made observations that
showed the Universe was getting bigger and bigger! This led most
cosmologists to believe in a theory called the Big Bang. The Big Bang
theory says the Universe began with a huge explosion ten to twenty billion
years ago. Cosmologists think the Universe did not exist before the
Big Bang. Some cosmologists think the Universe will keep getting bigger
forever. Other cosmologists think the Universe will someday start
getting smaller. They think it will shrink until it no longer exists. No
one knows yet which opinion is correct. Cosmologists use the data gathered by telescopes and astronomy satellites
to help them understand the Universe. They also use computers to model
their ideas. Each new discovery helps them to understand more about the
past, present, and future of our Universe.
Cosmology
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A Question Use one or more of the underlined words to help you fill in the blank. People used to believe the Sun, the other planets and the Moon traveled around Earth. Today we know that only the __________________ travels around Earth. |
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