Search results
Results from the WOW.Com Content Network
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.. Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, with an uncertainty of around 21 million years at the 68% confidence level.
Earth is the only place in the universe known to harbor life, where it exists in multiple environments. [8] [9] The origin of life on Earth was at least 3.5 billion years ago, possibly as early as 3.8-4.1 billion years ago. [2] [3] [4] Since its emergence, life has persisted in
Diagram of Evolution of the universe from the Big Bang (left) to the present. The timeline of the universe begins with the Big Bang, 13.799 ± 0.021 billion years ago, [1] and follows the formation and subsequent evolution of the Universe up to the present day. Each era or age of the universe begins with an "epoch", a time of significant change ...
The first observation that one can make from this formula is that it is the Hubble parameter that controls that age of the universe, with a correction arising from the matter and energy content. So a rough estimate of the age of the universe comes from the Hubble time, the inverse of the Hubble parameter.
Although the LUCA lived over 4 billion years ago (4 Gya), researchers believe it was far from the first form of life. Earlier cells might have had a leaky membrane and been powered by a naturally occurring proton gradient near a deep-sea white smoker hydrothermal vent. Earth remains the only place in the universe known to harbor life.
Basilosaurus, one of the first of the giant whales, appeared in the fossil record. 38 Ma Earliest bears. 37 Ma First nimravid ("false saber-toothed cats") carnivores — these species are unrelated to modern-type felines. First alligators and ruminants. 35 Ma Grasses diversify from among the monocot angiosperms; grasslands begin to expand.
This runs counter to the knowledge that the universe is filled with a very large number of planets, some of which likely hold the conditions hospitable for life. Life typically expands until it fills all available niches. [5] These contradictory facts form the basis for the Fermi paradox, of which the firstborn hypothesis is one proposed solution.
Within the first fraction of a second of the universe's existence, the four fundamental forces had separated. As the universe continued to cool from its inconceivably hot state, various types of subatomic particles were able to form in short periods of time known as the quark epoch, the hadron epoch, and the lepton epoch. Together, these epochs ...