100 Physics Ideas in 100 Words

g CONTENTS

Astronomy

In past millennia people had a better view of the stars and planets and built them into their myth-making and into their calendar of the annual cycle of the seasons. Now, more than half of the world’s population lives in cities, where light pollution makes the night skies difficult to observe.

The last four centuries have seen great developments in telescopes. This has allowed us to see far greater distances into space and to see in much greater detail the objects that exist in space. While the images we see are fascinating in themselves, physicists have had to work hard to explain their observations. The ideas used to explain what’s going on “out there” must be compatible with the ideas we use to explain what we observe ...