Quote of the day by Carl Sagan: 'We are like butterflies who flutter for a day and think it is forever' - A thought-provoking lesson on human life, mortality and our place in the universe by the American scientist

Human life can feel long when measured in the days of our lives, our personal achievements and our memories. But compared to the age of the universe, we are but a blink of an eye. This is the contrast shown in the quote of the day by American astronomer and science communicator Carl Sagan: "We are like butterflies who flutter for a day and think it is forever.

The quote comes from Sagan’s 1980 book Cosmos, which accompanied his popular television series Cosmos: A Personal Voyage. It gives a viewpoint on how humans comprehend their own existence on a planet that is a piece of a far older and larger universe.

Quote of the day: What does Carl Sagan's butterfly comparison mean?

The comparison between humans and butterflies highlights how limited our understanding of time can be. Just like a butterfly's entire life experience may be its short life span. Similarly, people can be so caught up in their everyday lives that they hardly consider how brief their time is in comparison to the age of the universe.


Sagan’s point is to get us to look beyond our immediate surroundings and consider the larger picture. What is permanent in our lifetime may be a heartbeat in the history of the cosmos.

The quote also touches on a major theme of Cosmos: to understand humanity's place in the cosmos, we need to move beyond an Earth-centered perspective.

Carl Sagan’s Cosmos

Published in 1980, Cosmos examined the history of scientific discovery, the evolution of life on Earth and the vastness of space and time. Sagan took readers on a tour of discoveries in astronomy and described how science-based thinking had changed the human view of the universe.

He also studied the evolution of life on Earth, from simple organisms to more complex forms. Modern humans, in contrast, have been around for a very small fraction of the planet’s history.

Sagan’s work encouraged people to question the notion that Earth or humanity is special in the universe. He also considered the possibility of life beyond our planet and the scientific questions surrounding extraterrestrial intelligence.

Who is Carl Sagan?

Carl Sagan was an American astronomer, astrophysicist and science communicator. He was born on November 9, 1934 in Brooklyn, New York. He spent much of his career at Cornell University, where he worked in planetary science and in the search for life beyond Earth.

Among his popular works are The Dragons of Eden, winner of a Pulitzer Prize, and the science-fiction novel Contact. He also helped bring space science to the public through television and books.

Sagan died on December 20, 1996, but his work remains an entry point for readers to learn about the issues of science, existence and humanity’s place in the cosmos.