|
Pocket Universe
A pocket universe or bubble universe, also 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 current leading m ... [...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 very early universe. Following the inflationary period, the universe continued to expand, but at a slower rate. The re-acceleration of this slowing 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 1980s, 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. Starobinsky, Guth, and Linde won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation". It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Guth
Alan Harvey Guth (; born February 27, 1947) is an American theoretical physicist and cosmologist who is the 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." Guth's research focuses on elementary particle theory and how particle theory is applicable to the early universe. [Baidu] |
Observable Universe
The observable universe is a Ball (mathematics), spherical region of the universe consisting of all matter that can be observation, observed from Earth; the electromagnetic radiation from these astronomical object, objects has had time to reach the Solar System and Earth since the beginning of the metric expansion of space, cosmological expansion. Assuming the universe is isotropy, isotropic, the distance to the edge of the observable universe is equidistant, the same in every direction. That is, the observable universe is a sphere, spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth. 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 physical limit created by the speed of light itself. No signal can travel faster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Luc Lehners
Jean-Luc may refer to: Politics * Jean-Luc Bennahmias (born 1954), a French politician and Member of the European Parliament * Jean-Luc Bourgeaux (born 1963), a French politician * Jean-Luc Dehaene (1940–2014), a Flemish politician * Jean-Luc Fichet (born 1953), French 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 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'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. 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. The institution moved to Newark, New Jersey, Newark in 1747 and then to its Mercer County, New Jersey, Mercer County campus in Princeton nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. 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 instruction in the hu ... [...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 very early universe. Following the inflationary period, the universe continued to expand, but at a slower rate. The re-acceleration of this slowing 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 1980s, 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. Starobinsky, Guth, and Linde won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation". It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified t ... [...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 etern ... [...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 in 1915 with the development 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 Sliph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galilean Genesis
Generically, a Galilean (; ; ; ) is a term that was used in classical sources to describe the inhabitants of Galilee, an area of northern Israel and southern Lebanon that extends from the northern coastal plain in the west to the Sea of Galilee and the Jordan Rift Valley to the east. Later the term was used to refer to the early Christians by Roman emperors Julian and Marcus Aurelius, among others. Markus Cromhout describes 1st century Galileans as descendants of Hasmonean-era Judean immigrants. However, they identified as numerous identities, including Galilean, Sepphorean and more broadly, Judean or Israelite. Whilst they all adhered to a 'common Judaism', Galileans 'had a different social, economic and political matrix than Jews living in Judea or the Diaspora'. Other scholars disagree and attribute the conflation between Galileans and Judeans to Hellenistic-Roman culture, which grouped all 1st century Palestinian Jewish groups, and their related diasporas, as "Judean". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergent Universe
An emergent Universe scenario is a cosmological model that features the Universe being in a low-entropy "dormant" state before the Big Bang or the beginning of the cosmic inflation. Several such scenarios have been proposed in the literature. "Cosmic egg" scenarios A popular version proposed by George Ellis and others involves the Universe shaped like a 3-dimensional sphere (or another compact manifold) until a rolling scalar field begins inflating it. These models are notable as potentially avoiding both a Big Bang singularity and a quantum gravity Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics. It deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the v ... era. Criticism This proposal has been criticised by Vilenkin and Mithani and on different grounds by Aguirre and Kehayias as inconsistent if quantum-mechanical effects are taken i ... [...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 (relativity), 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 (geometry), 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 Dimension (vector 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measure Problem (cosmology)
The measure problem in cosmology concerns how to compute the ratios 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 ratios 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 is 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 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
