Expanding Horizons
First Light
Gentleman Astronomers
More Glass
Sky High

Telescope History

Expanding Horizons

A tube and a couple of pieces of glass increase the size of the known universe and set the stage for four centuries of discovery

Hans Lippershey didn’t set out to change the universe. Instead, the Dutch lensmaker saw a business opportunity. But a device that Lippershey began making in 1608 soon expanded humankind’s view of the universe and our knowledge of our place in it.

Lippershey’s device consisted of a tube and a couple of pieces of glass that made objects appear closer. He called it a “looker.” Today, we call it the telescope.

When Galileo Galilei heard about Lippershey’s new device, he built one of his own. And in 1609, he began using it to observe the night sky — from the Moon to the Milky Way.

Galileo’s telescope revealed that the universe is far more extensive than the sprinkling of stars and planets visible to our eyes alone. And it provided solid scientific evidence to confirm that Earth is not the center of the universe.

Since then, the telescope has revealed many other marvels: pillars of star birth, colorful bubbles around dying stars, colliding galaxies, and maelstroms enfolding giant black holes. It has helped to reveal the size and origin of the universe, and provided clues about its fate.

Today’s telescopes — many of which are described and celebrated in these pages — are wonders of technology as well as science. Some have mirrors that cover as much area as an apartment. Others are sensitive to radio waves, heat, or other types of energy. And others have escaped Earth’s obscuring atmosphere.

Yet all are continuing the same basic work as Galileo’s crude telescope four centuries ago: expanding human horizons.