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Pocket Universes
A pocket universe or bubble universe, also colloquially called pocket dimension is a concept in inflationary theory, proposed by Alan Guth. Description It defines a realm like the one that contains the observable universe as only one of many inflationary zones. Astrophysicist Jean-Luc Lehners, of the Princeton Center for Theoretical Science, has argued that an inflationary universe does produce pockets. In his 2012 journal, Lehners wrote about how pocket universes can emerge as a result of eternal inflation. The mechanisms of inflation within these pocket universes could function in a variety of manners, such as slow-roll inflation, undergoing cycles of cosmological evolution, or resembling of the Galilean genesis or other 'emergent' universe scenarios. Lehners goes on to discuss which one of these types of universes we live in, and how that is dependent on the measurement of the regulation of infinities inherent in eternal inflation. But, Lehners continues, "the curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflationary Theory
In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from seconds after the conjectured Big Bang singularity to some time between and seconds after the singularity. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago). Inflation theory was developed in the late 1970s and early 80s, with notable contributions by several theoretical physicists, including Alexei Starobinsky at Landau Institute for Theoretical Physics, Alan Guth at Cornell University, and Andrei Linde at Lebedev Physical Institute. Alexei Starobinsky, Alan Guth, and Andrei Linde won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation." It was developed further in the early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Guth
Alan Harvey Guth (; born February 27, 1947) is an American theoretical physicist and cosmologist. Guth has researched elementary particle theory (and how particle theory is applicable to the early universe). He is Victor Weisskopf Professor of Physics at the Massachusetts Institute of Technology. Along with Alexei Starobinsky and Andrei Linde, he won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation." [Baidu] |
Observable Universe
The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. There may be 2 trillion galaxies in the observable universe, although that number was reduced in 2021 to only several hundred billion based on data from '' New Horizons''. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical region centered on the observer and is unique for every unique observational position. The word ''observable'' in this sense does not refer to the capability of modern technology to detect light or other information from an object, or whether there is anything to be detected. It refers to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Luc Lehners
Jean-Luc may refer to: In politics: * Jean-Luc Bennahmias (born 1954), a French politician and Member of the European Parliament * Jean-Luc Dehaene (1940–2014), a Flemish politician * Jean-Luc Laurent (born 1957), a French politician * Jean-Luc Mandaba (1943–2000), a former Prime Minister of the Central African Republic * Jean-Luc Mélenchon (born 1951), a French politician * Jean-Luc Pépin (1924–1995), a Canadian academic, politician, and Cabinet member * Jean-Luc Poudroux (born 1950), a French politician In entertainment: * Jean-Luc De Meyer (born 1957), a Belgian vocalist and lyricist best known as the lead vocalist of Front 242 * Jean-Luc Ponty (born 1942), a French virtuoso violinist and jazz composer * Jean-Luc Picard, a fictional starship captain in the ''Star Trek'' universe * Jean-Luc Bilodeau (born 1990), an actor, played Josh Trager on the television show ''Kyle XY'' and Ben Wheeler on ''Baby Daddy'' * Jean-Luc Pikachu, a fictional animal in the animal capture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. It is one of the highest-ranked universities in the world. The institution moved to Newark, New Jersey, Newark in 1747, and then to the current site nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. It is a member of the Ivy League. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest List of colleges and universities in the United States by endowment, endowment per student in the United States. Princeton provides undergraduate education, undergraduate and graduate education, graduate in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflation (cosmology)
In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from seconds after the conjectured Big Bang singularity to some time between and seconds after the singularity. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago). Inflation theory was developed in the late 1970s and early 80s, with notable contributions by several theoretical physicists, including Alexei Starobinsky at Landau Institute for Theoretical Physics, Alan Guth at Cornell University, and Andrei Linde at Lebedev Physical Institute. Alexei Starobinsky, Alan Guth, and Andrei Linde won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation." It was developed further in the ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eternal Inflation
Eternal inflation is a hypothetical inflationary universe model, which is itself an outgrowth or extension of the Big Bang theory. According to eternal inflation, the inflationary phase of the universe's expansion lasts forever throughout most of the universe. Because the regions expand exponentially rapidly, most of the volume of the universe at any given time is inflating. Eternal inflation, therefore, produces a hypothetically infinite multiverse, in which only an insignificant fractal volume ends inflation. Paul Steinhardt, one of the original researchers of the inflationary model, introduced the first example of eternal inflation in 1983, and Alexander Vilenkin showed that it is generic. Alan Guth's 2007 paper, "Eternal inflation and its implications", states that under reasonable assumptions "Although inflation is generically eternal into the future, it is not eternal into the past." Guth detailed what was known about the subject at the time, and demonstrated that eternal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Cosmology
Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its Cosmogony, origin, structure, Chronology of the universe, evolution, and ultimate fate.For an overview, see Cosmology as a science originated with the Copernican principle, which implies that astronomical object, celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood. Physical cosmology, as it is now understood, began with the development in 1915 of Albert Einstein's general relativity, general theory of relativity, followed by major observational discoveries in the 1920s: first, Edwin Hubble discovered that the universe contains a huge number of external Galaxy, galaxies beyond the Milky Way; then, work by Vesto Sli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galilean Genesis
Generically, a Galilean (; he, גלילי; grc, Γαλιλαίων; la, Galilaeos) is an inhabitant of Galilee, a region of Israel surrounding the Sea of Galilee (Kinneret). The New Testament notes that the Apostle Peter's accent gave him away as a Galilean (Matthew 26:73 and Mark 14:70). The Galilean dialect referred to in the New Testament was a form of Jewish Palestinian Aramaic spoken by people in Galilee from the late Second Temple period through the Apostolic Age . Later the term was used to refer to the early Christians by Roman emperors Julian and Marcus Aurelius, among others. History Biblical narrative According to the Biblical history of the Twelve Tribes, the region of Galilee was allotted to the tribes of Naphtali and Dan, at points overlapping with the domain of the Tribe of Asher and neighboring the region of Issachar. In the First Book of Kings, the Phoenician ruler King Hiram I of Sidon was awarded twenty cities in the region of Galilee, given to him b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Cone
In special and general relativity, a light cone (or "null cone") is the path that a flash of light, emanating from a single event (localized to a single point in space and a single moment in time) and traveling in all directions, would take through spacetime. Details If one imagines the light confined to a two-dimensional plane, the light from the flash spreads out in a circle after the event E occurs, and if we graph the growing circle with the vertical axis of the graph representing time, the result is a cone, known as the future light cone. The past light cone behaves like the future light cone in reverse, a circle which contracts in radius at the speed of light until it converges to a point at the exact position and time of the event E. In reality, there are three space dimensions, so the light would actually form an expanding or contracting sphere in three-dimensional (3D) space rather than a circle in 2D, and the light cone would actually be a four-dimensional version of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measure Problem (cosmology)
The measure problem in cosmology concerns how to compute fractions of universes of different types within a multiverse. It typically arises in the context of eternal inflation. The problem arises because different approaches to calculating these fractions yield different results, and it is not clear which approach (if any) is correct. Measures can be evaluated by whether they predict observed physical constants, as well as whether they avoid counterintuitive implications, such as the ''youngness paradox'' or Boltzmann brains. While dozens of measures have been proposed, few physicists consider the problem to be solved. The problem Infinite multiverse theories are becoming increasingly popular, but because they involve infinitely many instances of different types of universes, it's unclear how to compute the fractions of each type of universe. Alan Guth put it this way: : In a single universe, cows born with two heads are rarer than cows born with one head. ut in an infinitely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble's Law
Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving away from Earth. The velocity of the galaxies has been determined by their redshift, a shift of the light they emit toward the red end of the visible spectrum. Hubble's law is considered the first observational basis for the expansion of the universe, and today it serves as one of the pieces of evidence most often cited in support of the Big Bang model. The motion of astronomical objects due solely to this expansion is known as the Hubble flow. It is described by the equation , with ''H''0 the constant of proportionality—the Hubble constant—between the "proper distance" ''D'' to a galaxy, which can change over time, unlike the comoving distance, and its speed of separation ''v'', i.e. the derivative of proper distance with respect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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