|
Firstborn Hypothesis
The firstborn hypothesis is a proposed solution to the Fermi paradox which states that no extraterrestrial intelligent life has been discovered because humanity is the first form of intelligent life in the universe. Background There is no reliable or reproducible evidence that aliens have visited Earth. No transmissions or evidence of intelligent extraterrestrial life have been observed anywhere other than Earth in the universe. 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. These contradictory facts form the basis for the Fermi paradox, of which the firstborn hypothesis is one proposed solution. Avi Loeb, an astrophysicist and cosmologist, has suggested that Earth may be a very early example of a life-bearing planet and that life-bearing planets may be more likely trillions of years from now. He has put fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermi Paradox
The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. Those affirming the paradox generally conclude that if the conditions required for life to arise from non-living matter are as permissive as the available evidence on Earth indicates, then extraterrestrial life would be sufficiently common such that it would be implausible for it not to have been detected. The quandary takes its name from the Italian-American physicist Enrico Fermi: in the summer of 1950, Fermi was engaged in casual conversation about contemporary UFO reports and the possibility of faster-than-light travel with fellow physicists Edward Teller, Herbert York, and Emil Konopinski while the group was walking to lunch. The conversation moved on to other topics, until Fermi later blurted out during lunch, "But where is everybody?" ( the exact quote is uncertain.) [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraterrestrial Life
Extraterrestrial life, or alien life (colloquially, aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been scientifically conclusively detected. Such life might range from simple forms such as prokaryotes to Extraterrestrial intelligence, intelligent beings, possibly bringing forth civilizations that might be Kardashev scale, far more, or far less, advanced than humans. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology. Speculation about the possibility of inhabited worlds beyond Earth dates back to antiquity. Early Christianity, Christian writers discussed the idea of a "plurality of worlds" as proposed by earlier thinkers such as Democritus; Augustine of Hippo, Augustine references Epicurus's idea of innumerable worlds "throughout the boundless immensity of space" in ''The City of God''. Pre-modern writers typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering Water distribution on Earth, 70.8% of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is at least somewhat humid and covered by vegetation, while large Ice sheet, sheets of ice at Polar regions of Earth, Earth's polar polar desert, deserts retain more water than Earth's groundwater, lakes, rivers, and Water vapor#In Earth's atmosphere, atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's outer core, Earth has a liquid outer core that generates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SETI
Seti or SETI may refer to: Astrobiology * SETI, the search for extraterrestrial intelligence. ** SETI Institute, an astronomical research organization *** SETIcon, a former convention organized by the SETI Institute ** Berkeley SETI Research Center, an astronomical research organization *** SETI@home, a distributed computing project ** Active SETI, the attempt to send messages to intelligent aliens Egyptology * Seti (commander), grandfather of Seti I * Seti (Viceroy of Kush) * Seti I (died 1279 BC), pharaoh * Seti II (died 1197 BC), pharaoh * Seti-Merenptah, a son of Seti II * Seti, son of Amun-her-khepeshef * Sethi, one of List of children of Ramesses II#, the sons of Ramesses II Music * SETI (band), an ambient music band from New York City * SETI (The Kovenant album), ''SETI'' (The Kovenant album), an album by metal band The Kovenant Places * Seti River, a tributary of the Karnali River in Nepal * Seti Gandaki River or Seti River, a tributary of the Trishuli River in Nepal * S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universe
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 matter and energy, and the structures they form, from sub-atomic particles to entire Galaxy filament, galactic filaments. Since the early 20th century, the field of cosmology establishes that space and time emerged together at the Big Bang ago and that the Expansion of the universe, universe has been expanding since then. The observable universe, portion of the universe that can be seen by humans is approximately 93 billion light-years in diameter at present, but the total size of the universe is not known. Some of the earliest Timeline of cosmological theories, cosmological models of the universe were developed by ancient Greek philosophy, ancient Greek and Indian philosophy, Indian philosophers and were geocentric model, geocentric, placing Earth at the center. Over the centuries, more prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avi Loeb
Abraham "Avi" Loeb (; born February 26, 1962) is an Israeli and American theoretical physicist who works on astrophysics and cosmology. Loeb is the Frank B. Baird Jr. Professor of Science at Harvard University, where since 2007 he has been Director of the Institute for Theory and Computation at the Center for Astrophysics. He chaired the Department of Astronomy from 2011 to 2020, and founded the Black Hole Initiative in 2016. Loeb is a fellow of the American Academy of Arts and Sciences, the American Physical Society, and the International Academy of Astronautics. In 2015, he was appointed as the science theory director for the Breakthrough Initiatives of the Breakthrough Prize Foundation. Loeb has published popular science books including '' Extraterrestrial: The First Sign of Intelligent Life Beyond Earth'' (2021) and '' Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars'' (2023). In 2018, he suggested that alien space craft may be in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hart–Tipler Conjecture
The Hart–Tipler conjecture is the idea that an absence of detectable Von Neumann probes is contrapositive evidence that no intelligent life exists outside of the Solar System. This idea was first proposed in opposition to the Drake equation in a 1975 paper by Michael H. Hart titled "Explanation for the Absence of Extraterrestrials on Earth". Assuming that the probes traveled at 1/10 the speed of light and that no time was lost in building new ships upon arriving at the destination, Hart surmised that a wave of Von Neumann probes could cross the galaxy in approximately 650,000 years, a comparatively minimal span of time relative to the estimated age of the universe at 13.7 billion years. Hart’s argument was extended by cosmologist Frank Tipler in his 1981 paper entitled "Extraterrestrial intelligent beings do not exist". The conjecture is the first of many proposed solutions to the Fermi paradox (the conflict between the lack of obvious evidence for alien life and various high p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare Earth Hypothesis
In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity, such as sexually reproducing, multicellular organisms on Earth, and subsequently human intelligence, required an improbable combination of astrophysical and geological events and circumstances. According to the hypothesis, complex extraterrestrial life is an improbable phenomenon and likely to be rare throughout the universe as a whole. The term "Rare Earth" originates from '' Rare Earth: Why Complex Life Is Uncommon in the Universe'' (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist, both faculty members at the University of Washington. In the 1970s and 1980s, Carl Sagan and Frank Drake, among others, argued that Earth is a typical rocky planet in a typical planetary system, located in a non-exceptional region of a common barred spiral galaxy. From the principle of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Search For Extraterrestrial Intelligence
The search for extraterrestrial intelligence (usually shortened as SETI) is an expression that refers to the diverse efforts and scientific projects intended to detect extraterrestrial signals, or any evidence of intelligent life beyond Earth. Researchers use methods such as monitoring electromagnetic radiation, searching for optical signals, and investigating potential extraterrestrial artifacts for any signs of transmission from civilizations present on other planets. Some initiatives have also attempted to send messages to hypothetical alien civilizations, such as NASA's Voyager Golden Record, Golden Record. Modern SETI research began in the early 20th century after the advent of radio, expanding with projects like Project Ozma, the Wow! signal detection, and the Breakthrough Listen initiative; a $100 million, 10-year attempt to detect signals from nearby stars, announced in 2015 by Stephen Hawking and Yuri Milner. Since the 1980s, international efforts have been ongoing, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
