COSMIC CALENDAR

The cosmic calendar was conceived by the famous American astronomer and science communicator Carl Sagan. The calendar is composed of a single Earth year, but within this timeframe, the entire chronology of the universe (about 14 billion years) is compressed.
When we talk about the Universe, we often struggle to grasp the vast scales involved because they are too large compared to our everyday experience. For this reason, when we talk about billions or millions of years, we find it hard to understand their significance and differences. The cosmic calendar is a fascinating tool because it helps you understand universal time scales intuitively, re-scaling them back to one Earth year. This results in a demonstration of how infinitesimal the overall time of human civilization is when compared to the age of the universe: consider that in just the last second of this hypothetical year of the universe (i.e., the last five centuries of our history), humanity developed 99% of the technology we use today. Using this temporal scale, every second of the cosmic calendar corresponds to about 444 Earth years, and 31 of its days correspond to about one billion of our years. Here are just a few examples:

• January 1 - Big Bang
• January 10 - First stars form
• September 9 - The Solar System forms
• October 2 - Life on Earth begins
• December 24 - Dinosaurs appear, dominating for over 160 million Earth years
• December 26 - First mammals
• December 28 - Mass extinction of the Cretaceous, many forms of life, including dinosaurs, die out
• December 31, 10:30 PM - First humans
• December 31, 11:59:50 PM - End of prehistory
• December 31, 11:59:56 PM - Roman Empire
• December 31, 12:00 AM - Beginning of modern culture, French Revolution, World Wars, space exploration.