Image
© Don Dixon
I became interested in astronomy when I was 11 years old, on my first visit to a planetarium. When they turned out all the lights and flashed the stars onto that domed ceiling, I was hooked for life.

Astronomy is not only beautiful and exciting, it's been crucially important to our existence. It even led to the development of democracy.

Our ancestors were watching the night sky during the ice age. Paleontologists have discovered a fossilized bone some 30,000 years old that has the phases of the moon carved into it.

About 20,000 years later, when they invented agriculture, astronomy became a matter of life and death. Farming societies need to know when to plant their crops. If you plant at the wrong time of year and your crops don't grow, you starve.

In ancient Egypt, the Nile River's annual flood brought fresh, fertile silt to the parched land. It was vital to know when the Nile would rise. Stargazers determined that when the bright star Sirius rose just before dawn, the river's flood was only a few days away.

In cloudy, dank, chilly Britain, Stone Age farmers built gigantic circles of stone or wood, such as the famous Stonehenge, in part to serve as astronomical computers that predict the seasons.

Building Stonehenge must have cost those people as much of their resources, proportionately, as the Apollo lunar missions cost us. That's how important it was to them.

By the way, Stonehenge still accurately shows the beginnings of the seasons - and even predicts eclipses of the moon!

By the time of the Renaissance in Europe, most people believed that the Earth was the center of the universe, and the sun and stars revolved around us. This Earth-centered system was the keystone of Christian cosmology, part of the concept that our Earth was made specifically for humankind by a benevolent God who created the universe and everything in it in six days.

A timid Polish cleric, Nicolaus Copernicus, came up with the idea that the sun is at the center of it all, not the Earth. Knowing that the Roman Catholic Church would not take kindly to the idea, Copernicus proposed his heliocentric theory as merely a thought exercise. Even so, he wouldn't let his work be published until he was on his death bed.

Thanks to the contemporaneous invention of the printing press, Copernicus' idea spread through Europe. A flamboyant Italian monk, Giordano Bruno, proclaimed that the universe was infinite in extent and contained many worlds like our Earth - worlds peopled with intelligent creatures.

The church would not tolerate such ideas. Bruno was burned at the stake in 1600.

But ideas don't burn easily. Another Italian, Galileo Galilei, was the first to use a telescope to investigate the heavens. He found plenty of evidence that Copernicus was right.

For his brilliant work Galileo was arrested, threatened with torture and forced to recant his "heretical" views. He ended his life under house arrest, slowly going blind.

Yet the evidence he had uncovered shook all of Europe. Among other things, Galileo's homemade telescope showed that the planet Jupiter has moons circling around it. Not every object in the heavens rotates around the Earth! To this day, the four Jovian moons that Galileo discovered are called Jupiter's Galilean satellites.

It became obvious to thinking men that the church's official cosmology was wrong. This helped in no small measure to break the political - and even the moral - power of the church.

And if the authority of the church could be challenged, why not the authority of kings? People began to question the divine right of kings. In England, Parliament won ascendancy over the monarch, although it took two civil wars - one of them virtually bloodless - to accomplish that.

In Britain's North American colonies, political leaders opted to rebel against the king and Parliament both. Once the colonies won their freedom from Britain, they invented a system of government that didn't have a king at all.

Astronomy didn't cause these changes all by itself. But that quest for knowledge that makes us study the sky has helped considerably to break the shackles not only of ignorance, but of tyranny as well.