The purpose of the cosmic calendar is to put into perspective the relative time frame in which everything has happened in the universe. The 13.7 billion years of the universe’s life is condensed down into one Earth calendar year, with the big bang happening on the midnight of January 1st.
Even though the big bang happened in January, our Milky Way did not form until some time in May. In real time, that’s about 5 billion years after the creation of the universe. Even after the Milky Way formed in May, our solar system did not come to be as we know it until around September–more than 9 billion years after the big bang. Later in September we also had single-cell life, and come October we started seeing photosynthesis in some of these cells. By November there was multi-cellular life and gender distinction; however, things start to get even more interesting in December–nearly 13 billion years after the big bang.
Around the 14th of December there was simple life such as arthropods and sea sponges, and by the 17th there were more complex fish. It wasn’t until the 20th to the 21st that we started to see plants and insects living on land, and reptiles didn’t come about until the 23rd. A few days later, some of those reptiles evolved into the first of the Dinosaurs–and around the same time that mammals became more common. The super-continent Pangaea began to split on the 27th, and birds and flowers evolved a day later. The dinosaurs ruled the Earth as a whole for two more days, until suddenly dying off on the 30th. The last day of the year, the 31st, is when mammals finally begin to rise in the food chain.
Mammals spend most of the day of the 31st evolving, and it isn’t until around 8pm on the 31st that humans become distinct from chimpanzees. By 11:54pm humans had evolved up to Homo sapiens, and four minutes later they began to migrate out of Africa and into other parts of the world. At one minute to midnight the neanderthals finally died out, and with 47 seconds left to midnight the first groups migrating to the Americas begin to arrive. Agriculture and the idea of permanent settlement was not formed until about 23 seconds to midnight, and the big Mesopotamian cities weren’t around until 16 seconds to the new year. With six seconds left the Romans reached their peak, and with five Christ was born. With one second until midnight Columbus discovered the New World and we are here today at the metaphoric midnight, one second later.
It really puts into perspective the time scale at which everything thus far has happened. Dinosaurs roamed the world for five to six days while humans haven’t even existed for more than about four hours, much less been at the top. Humans have only topped the food chain for about six minutes. With those timings in mind, it took our galaxy about five months to form, and another four on top of that for our solar system. It’s all really mind blowing when you take the time to think about it.
