In his writings, American astronomer Carl Sagan introduced the “Cosmic Calendar,” a model that compresses the 13.8-billion-year history of the universe into a single year. According to this scale, the Big Bang takes place at midnight on January 1, and the present moment falls at the final stroke of midnight on December 31. This framework offers a striking perspective on the vast timeline of the cosmos.
Within the Cosmic Calendar, one second represents 475 years on Earth; a single day spans 38 million years, and a month amounts to roughly 1.1 billion years. Earth appears in early September, and modern humans emerge only in the final moments of December 31. All of human civilization fits within less than a minute, and the entire history from the Middle Ages to today barely takes up a single second. Confronted with such an immense scale, even scientists cannot help but be humbled.
You turn people back to dust, saying, “Return to dust, you mortals.” A thousand years in your sight are like a day that has just gone by, or like a watch in the night. Ps 90:3–4
Our familiar concepts of time and space become almost insignificant when viewed through the lens of the universe. And yet, we who live but a fleeting moment have, by the grace of God, received the promise of salvation and eternal life. What greater cause for gratitude could there be? As I dream of the day when we will journey freely through the vast expanse of the cosmos, I will fill each day I am given with meaning and purpose.