"The Harmony of the Worlds: When Astronomy Broke Free from Astrology"

"Science allows us to approach, with humility and awe, the great harmony of the universe."

Music always fascinated me, even before I understood it. I remember, as a child, becoming completely absorbed while listening over and over to The Songs of Distant Earth by Mike Oldfield, in my father's Seat 131. I played it so many times that the cassette tape eventually wore off the printed lyrics. Something similar happened to me with science: from an early age, the stars, the planets, and the mysteries of the universe awakened in me a blend of curiosity and wonder.

And I think I never imagined that both passions—music and science—could come together with such elegance… until I watched that episode of Cosmos. It was like discovering that two different languages could express the same thing in complementary ways: that the universe has rhythm, harmony, even beauty.

In The Harmony of the Worlds, Carl Sagan tells us the story of Johannes Kepler, a man who wanted to understand the motion of the planets… and found beauty in their precision. I was moved to discover that Kepler was not only a great scientist, but a dreamer—someone who believed the universe had a melody of its own. His faith was not in dogma, but in the idea that nature made sense, that chaos could be revealed as hidden order if one knew how to listen carefully.

This episode helped me understand that science is not cold or distant: it is profoundly human, made of passion, errors, obsessions, and poetry. It showed us that behind every formula, there can be a love story for knowledge.

As Carl Sagan says in Cosmos:

“When [Kepler] found that his long-cherished beliefs did not agree with the most precise observations, he accepted the uncomfortable facts.”

He chose hard reality over his dearest illusions. To me, that is the heart of science.

I’d say this episode has a theatrical quality to it, with dramatizations of Kepler’s life that reveal not only his genius, but also his humanity. It is not the classic portrait of a cold, methodical scientist, but of a passionate man, deeply emotional, who strove to understand the universe with both his mind and his heart.

We see a man confronted with his time, caught between superstition and scientific method, yet determined to find order in the chaos. Kepler lived in a Europe marked by religious wars, prejudice, and a worldview still dominated by astrology and dogmatic beliefs. And yet, he did not resign himself. He wanted to see beyond.

I was deeply struck by his inner conflict: how he tried to reconcile astrology with science, how he struggled to explain the inexplicable without giving up on wonder. It was as if he refused to choose between reason and beauty—and decided to seek a synthesis. He was a man who endured painful losses—the death of loved ones, poverty, religious persecution—and still he persevered. Not out of ambition, but from a quiet conviction: the planets moved with a logic, and he had to find it.

And he did. His laws of planetary motion not only transformed astronomy, but paved the way for Newton, Einstein, and for all of us who look to the sky with questions. But the most inspiring thing is that he did it not from arrogance, but from doubt, from human fragility. His story made me realize that science moves forward not just with equations, but also with hope.

Some interesting facts:

• Kepler wrote Harmonices Mundi ("The Harmony of the World"), where he attempted to describe planetary motion as a kind of celestial music, assigning notes to planets according to their orbits.

• The episode reflects how Sagan valued both emotion and logic: to him, science was a form of art, a way to connect the rational with the spiritual.

• In a time of religious darkness, Kepler was one of the first to apply mathematics to understand the sky, leaving behind dogma and opening the path toward a cosmology based on natural laws.

• Despite his religious background, Kepler was accused of heresy more than once, and had to defend not only his scientific ideas but also his mother, who was accused of witchcraft.

This episode reminds me that science is also an act of faith—not in gods or doctrines, but in the idea that the universe can be understood. That not everything is random or divine punishment, but that there is an order, a music waiting to be heard, if we know how to listen.

Kepler heard it, and I’d say Sagan did too. Thanks to them, many of us have learned to tune our ears to hear the harmony of the worlds. I came to understand that the pursuit of knowledge is not just about collecting data, but about learning to see the beauty and harmony of the world around us.

I’m left with the feeling that science, when practiced with sensitivity and depth, is not far from art or spirituality. On the contrary, it becomes a form of communion with the universe. And that, to me, is what makes this episode so unforgettable.

Key themes from the episode:

• The life and work of Johannes Kepler

• The shift from astrology to astronomy as a science

• The conflict between mystical beliefs and rational thinking

• The search for patterns in the cosmos

• The relationship between science, art, and spirituality

And so ends The Harmony of the Worlds, an episode that invites us to hear the music of the universe with fresh ears. Kepler's story reminds us that science is born from passion, wonder, and the will to understand beyond the limits imposed by tradition. But the journey is just beginning. In the next episode of Cosmos, Sagan will take us even further—into the heart of the stars—to explore how the universe forged the very elements we are made of. If Kepler taught us to find order in the sky, episode 4 will reveal what that sky is made of. See you next week as we explore Heaven and Hell.