Page 180 - Science Coursebook

Reference

Ideas and evidence
During your Cambridge Secondary Science course, you have learnt how to plan
experiments to try to find the answers to questions. You have learnt how to collect
results and use them to make conclusions.

In this section, you can read about some examples of how scientists have
investigated some ‘big’ questions. You will see that not every question can be
answered yet. You will also see that some experiments have not been very well
planned!
Question: Is there intelligent life beyond Earth?
Many people have wondered: Are there people like us walking around on a planet
orbiting a distant star? In other words, is there extra-terrestrial intelligence? (‘Extra-
terrestrial’ means beyond the Earth.)
We can be fairly sure that there are not intelligent creatures living on another
planet or moon in our solar system. However, there are billions of stars in our
galaxy and billions of galaxies in the universe, so many scientists think that there
must be large numbers of planets similar to Earth. Life may have appeared on
them, and intelligent creatures like us may have evolved.
In 1960, a young scientist called Frank Drake decided to find out if he could detect
any radio signals coming from space which might be from a distant civilisation. He
used a radio telescope to collect radio waves from space. Then he analysed them to
see if there were any patterns that looked like messages from intelligent beings.
He had no luck. Since then, scientists have
used bigger and better radio telescopes to
hunt for signals. They set up a project called
the Search for Extra-Terrestrial Intelligence
(SETI).

Today, the SETI project has even bigger and
better telescopes. They collect lots of data
which must be checked to see if it contains
extra-terrestrial signals. Anyone can join the
project and use their computer to help check
the scientists’ data to see if there is any sign
of messages from space.
So far, no signs of alien intelligence
have been detected. However, because
astronomers now have better telescopes,
they have been able to detect planets going
around other stars in our galaxy. They can If someone signs up to help with the SETI project, their
analyse the atmospheres of these planets. home computer can help to analyse the radio signals
This may show if any of them are home from space.
to life.

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