Thanks for down learning the In Our Time podcast. For more details about In Our Time and for our terms of use, please go to BBC.co.uk.

I hope you enjoy the program.

Hello from telescopes to microscopes, from star gazing to the revelation of a magnified flea.

Today we'll be discussing the history of optics.

As Galileo turned his telescope to the heavens in the early 1600s, Kepler began to formulate a theory of optics.

The new and improving instruments went hand in hand with radical new ideas about how we see as well as what we see. Spectacles allowed scholars

to study long into the evening and into old age, while giant telescopes up to 100 feet

long led to the discovery of planets and attempts to map the universe.

The craze for optical trickery swept through Europe with enthusiastic amateurs often providing

valuable discoveries.

But this new view of the world through a lens raised questions too.

How much can you rely on the senses on what you see?

The further into space you can spy, the larger and more unmanageable the universe seems to

become.

At the same time, the microscope was utterly transforming the world close at hand.

So how did these developments inform ideas of knowledge?

If new methods of scientific observations support an empirical approach, what does this mean for divine

inspiration or innate reason?

Joining me to discuss the history of optics, As Simon Schaffer, professor in history and philosophy

of science at Cambridge University.

Jim Bennett, Director of the Museum of the History of Science and Fellow Blinica College at Oxford University,

and Emily Wintavern, Curator of Astron astronomy at the National Maritime Museum.

...