Recently, our family took a trip to the Griffith Observatory, the historic public astronomy destination with its beautiful views of the Hollywood sign, the Pacific Ocean, and the downtown skyline of Los Angeles.
Being a resident of Southern California, I feel really blessed to have such a wonderful science attraction in my own backyard. And with the special significance of this year and our trip to Griffith, I am even now more appreciative.
This year, the Observatory is celebrating the International Year of Astronomy, marking the 400th anniversary of Galileo Galilei’s pioneering observations of the heavens with his telescope.
In 1609, Galileo created one of the most powerful telescopes of the day, and upon completing his device, he turned it to the skies, observing celestial features such as the Moon and the planet Jupiter. Within the first few days of the following year, he observed, for the first time, four of the moons circling Jupiter – Io, Europa, Ganymede, and Callisto.
Prior to that time, outside of our own Moon, no person had ever seen celestial bodies orbiting planets, so viewing these satellites with such clarity was quite an achievement in and of itself.
Yet, the most powerful impact of Galileo’s observations would be what he chose to present about the moons’ movements.
Galileo, in publishing his observations, “concluded, and decided unhesitatingly, that there are three stars in the heavens moving about Jupiter, as Venus and Mercury around the Sun” and “that there are not only three, but four, erratic sidereal bodies performing their revolutions around Jupiter.”
By concluding that Jupiter’s moon orbited around the planet and further that they were similar to how Venus and Mercury orbited around the Sun, Galileo was siding with the theories of Nicolaus Copernicus. And in Galileo’s times, this was a direct challenge to the conventional wisdom.
In 1543, Copernicus published work describing his heliocentric model, where planets revolved around the Sun, opposing the current thinking of the time that all celestial bodies, including the Sun, revolved around the Earth.
Of course, we know today that the Earth revolves around the Sun, so this certainly doesn’t come as a shocking statement to us. But in the 17th century, this was heresy. This challenged the view that most philosophers and astronomers held – that the Earth was the center of the universe.
Even with over sixty years having passed since Copernicus presented his theories, Galileo was met with bitter opposition. In fact, some of his fellow scientists eventually reported him to the Roman Inquisition in 1615.
While cleared by the Roman Catholic Church at the time, the Church denounced the heliocentric model as “false and contrary to Scripture”. However, this was not the end of the public attack upon Galileo and his scientific work.
When Galileo later defended his views in his work, Dialogue Concerning the Two Chief World Views, in 1632, he was tried for heresy by the Inquisition, forced to recant his public writings, and placed under house arrest by the Pope.
While many people, including other scientists and the leaders of the Catholic Church, didn’t want Galileo’s views to be believed, Galileo was right in the end. His observations provided evidence for a model that better explains what is true about our universe.
He had the courage to present his views publicly, and he pushed human society forward. He chose to challenge the views of the dominant political force of the day, the Catholic Church – not for the sake of challenging it, but for the purpose of presenting the truth.
We can progress as a people when individuals stand up and choose to force us all to recognize the truth. Galileo, with his simple observations of the satellites of Jupiter, profoundly forced that recognition.
If everyone blindly agreed with everyone else, we wouldn’t change or move forward. We wouldn’t progress or become better or improve our understanding.
It takes individuals to present certain countering views, making us think about what is right and what is the truth. These individuals are the ones that ultimately make the positive difference in our human history.
Four hundred years later, we now celebrate Galileo and his creation of the device that changed our understanding of the universe.
But in addition, we should also celebrate Galileo’s willingness to challenge the conventional wisdom and change the world.