The biosphere, also known as the ecosphere, is the worldwide sum of all ecosystems. It can also be termed the zone of life on Earth. The biosphere is virtually a closed system with regard to matter, with minimal inputs and outputs. Regarding energy, it is an open system, with photosynthesis capturing solar energy at a rate of around 100 terawatts. By the most general biophysiological definition, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, cryosphere, hydrosphere, and atmosphere. The biosphere is postulated to have evolved, beginning with a process of biopoiesis or biogenesis, at least some 3.5 billion years ago.
In physical cosmology, the Copernican principle states that humans, on the Earth or in the Solar System, are not privileged observers of the universe, that observations from the Earth are representative of observations from the average position in the universe. Named for Copernican heliocentrism, it is a working assumption that arises from a modified cosmological extension of Copernicus' argument of a moving Earth.
The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. Dates in this article are consensus estimates based on scientific evidence, mainly fossils.
The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of energy and matter, and the structures they form, from sub-atomic particles to entire galaxies. Space and time, according to the prevailing cosmological theory of the Big Bang, emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since. Today the universe has expanded into an age and size that is physically only in parts observable as the observable universe, which is approximately 93 billion light-years in diameter at the present day, while the spatial size, if any, of the entire universe is unknown.
The cosmos is an alternative name for the universe or its nature or order. Usage of the word cosmos implies viewing the universe as a complex and orderly system or entity. The cosmos, and understandings of the reasons for its existence and significance, are studied in cosmology – a broad discipline covering scientific, religious or philosophical aspects of the cosmos and its nature. Religious and philosophical approaches may include the cosmos among spiritual entities or other matters deemed to exist outside the physical universe.
The Archean Eon, in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history, preceded by the Hadean Eon and followed by the Proterozoic. The Archean represents the time period from 4,031 to 2,500 Ma. The Late Heavy Bombardment is hypothesized to overlap with the beginning of the Archean. The Huronian glaciation occurred at the end of the eon.
An order of magnitude of time is usually a decimal prefix or decimal order-of-magnitude quantity together with a base unit of time, like a microsecond or a million years. In some cases, the order of magnitude may be implied, like a "second" or "year". In other cases, the quantity name implies the base unit, like "century". In most cases, the base unit is seconds or years.
The Big Crunch is a hypothetical scenario for the ultimate fate of the universe, in which the expansion of the universe eventually reverses and the universe recollapses, ultimately causing the cosmic scale factor to reach zero, an event potentially followed by a reformation of the universe starting with another Big Bang. The vast majority of evidence indicates that this hypothesis is not correct. Instead, astronomical observations show that the expansion of the universe is accelerating rather than being slowed by gravity, suggesting that a Big Freeze is more likely. However, there are new theories that suggest that a "Big Crunch-style" event could happen by the way of a dark energy fluctuation; however, this is still being debated amongst scientists.
The Dragons of Eden: Speculations on the Evolution of Human Intelligence is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on how human intelligence may have evolved.
In physical cosmology, the age of the universe is the time elapsed since the Big Bang. Astronomers have derived two different measurements of the age of the universe: a measurement based on direct observations of an early state of the universe, which indicate an age of 13.787±0.020 billion years as interpreted with the Lambda-CDM concordance model as of 2021; and a measurement based on the observations of the local, modern universe, which suggest a younger age. The uncertainty of the first kind of measurement has been narrowed down to 20 million years, based on a number of studies that all show similar figures for the age. These studies include researches of the microwave background radiation by the Planck spacecraft, the Wilkinson Microwave Anisotropy Probe and other space probes. Measurements of the cosmic background radiation give the cooling time of the universe since the Big Bang, and measurements of the expansion rate of the universe can be used to calculate its approximate age by extrapolating backwards in time. The range of the estimate is also within the range of the estimate for the oldest observed star in the universe.
This more than 20-billion-year timeline of our universe shows the best estimates of major events from the universe's beginning to anticipated future events. Zero on the scale is the present day. A large step on the scale is one billion years; a small step, one hundred million years. The past is denoted by a minus sign: e.g., the oldest rock on Earth was formed about four billion years ago and this is marked at -4e+09 years, where 4e+09 represents 4 times 10 to the power of 9. The "Big Bang" event most likely happened 13.8 billion years ago; see age of the universe.
Cosmology is a branch of physics and metaphysics dealing with the nature of the universe, the cosmos. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis. Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology. In the science of astronomy, cosmology is concerned with the study of the chronology of the universe.
Big History is an academic discipline which examines history from the Big Bang to the present. Big History resists specialization, and searches for universal patterns or trends. It examines long time frames using a multidisciplinary approach based on combining numerous disciplines from science and the humanities, and explores human existence in the context of this bigger picture. It integrates studies of the cosmos, Earth, life, and humanity using empirical evidence to explore cause-and-effect relations, and is taught at universities and primary and secondary schools often using web-based interactive presentations.
The history of the Big Bang theory began with the Big Bang's development from observations and theoretical considerations. Much of the theoretical work in cosmology now involves extensions and refinements to the basic Big Bang model. The theory itself was originally formalised by Father Georges Lemaître in 1927. Hubble's Law of the expansion of the universe provided foundational support for the theory.
Cosmos is a popular science book written by astronomer and Pulitzer Prize-winning author Carl Sagan. It was published in 1980 as a companion piece to the PBS mini-series Cosmos: A Personal Voyage with which it was co-developed and intended to complement. Each of the book's 13 illustrated chapters corresponds to one of the 13 episodes of the television series. Just a few of the ideas explored in Cosmos include the history and mutual development of science and civilization, the nature of the Universe, human and robotic space exploration, the inner workings of the cell and the DNA that controls it, and the dangers and future implications of nuclear war. One of Sagan's main purposes for both the book and the television series was to explain complex scientific ideas in a way that anyone interested in learning can understand. Sagan also believed the television was one of the greatest teaching tools ever invented, so he wished to capitalize on his chance to educate the world. Spurred in part by the popularity of the TV series, Cosmos spent 50 weeks on the Publishers Weekly best-sellers list and 70 weeks on the New York Times Best Seller list to become the best-selling science book ever published at the time. In 1981, it received the Hugo Award for Best Non-Fiction Book. The unprecedented success of Cosmos ushered in a dramatic increase in visibility for science-themed literature. The success of the book also served to jumpstart Sagan's literary career. The sequel to Cosmos is Pale Blue Dot: A Vision of the Human Future in Space (1994).
The Rose Center for Earth and Space is a part of the American Museum of Natural History in New York City. The Center's complete name is The Frederick Phineas and Sandra Priest Rose Center for Earth and Space. The main entrance is located on the northern side of the museum on 81st Street near Central Park West in Manhattan's Upper West Side. Completed in 2000, it includes the new Hayden Planetarium, the original of which was opened in 1935 and closed in 1997. Neil deGrasse Tyson is its first and, to date, only director.
Early Earth is loosely defined as Earth in its first one billion years, or gigayear (Ga, 109y). Early Earth is defined as encompassing approximately the first gigayear in the evolution of the planet from its initial formation in the young Solar System at about 4.55 Ga to sometime in the Archean eon in approximately 3.5 Ga. On the geologic time scale, this comprises all of the Hadean eon, starting with the formation of the Earth about 4.6 billion years ago, and the Eoarchean, starting 4 billion years ago, and part of the Paleoarchean era, starting 3.6 billion years ago, of the Archean eon.
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.
The earliest known life forms on Earth may be as old as 4.1 billion years old according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a stratigraphic unit, not just a single mineral grain, is the 3.7 Ga metasedimentary rocks containing graphite from the Isua Supracrustal Belt in Greenland. The earliest direct known life on land may be stromatolites which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation of the Pilbara Craton of Western Australia. Various microfossils of microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates from Barberton, South Africa. Much later in the geologic record, likely starting in 1.73 Ga, preserved molecular compounds of biologic origin are indicative of aerobic life. Therefore, the earliest time for the origin of life on Earth is at least 3.5 billion years ago, possibly as early as 4.1 billion years ago — not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago.
Timelapse of the Entire Universe is a 2018 short epic animated pseudo-documentary web film created by American astronomy-themed musician and filmmaker John D. Boswell. Inspired by the Cosmic Calendar, the 10-minute film is a hyperlapse of the universe from its start to current humanity, with every second representing 22 million years, with the entire humanity represented in a short time, using current knowledge. The film was originally released on Boswell's YouTube channel Melodysheep on March 7, but it was eventually taken down due to a copyright infringement regarding Morgan Freeman's voice. A revised version was uploaded 3 days later, on March 10, 2018. A year and 10 days later, a follow-up, Timelapse of the Future, was released.
