Primordial Black Holes
In cosmology, primordial black holes (PBHs) are hypothetical black holes that formed soon after the Big Bang. In the inflationary era and early radiation-dominated universe, extremely dense pockets of subatomic matter may have been tightly packed to the point of gravitational collapse, creating primordial black holes without the supernova compression typically needed to make black holes today. Because the creation of primordial black holes would pre-date the first stars, they are not limited to the narrow mass range of stellar black holes. In 1966, Yakov Zeldovich and Igor Novikov first proposed the existence of such black holes, while the first in-depth study was conducted by Stephen Hawking in 1971. However, their existence remains hypothetical. In September 2022, primordial black holes were proposed by some researchers to explain the unexpected very large early galaxies discovered by the James Webb Space Telescope (JWST). PBHs have long been considered possibly important i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Gravitational Wave
Gravitational waves are oscillations of the gravitational field that Wave propagation, travel through space at the speed of light; they are generated by the relative motion of gravity, gravitating masses. They were proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as the gravitational equivalent of Electromagnetic radiation, electromagnetic waves. In 1916, Albert Einstein demonstrated that gravitational waves result from his general theory of relativity as ripples in spacetime. Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation. Newton's law of universal gravitation, part of classical mechanics, does not provide for their existence, instead asserting that gravity has instantaneous effect everywhere. Gravitational waves therefore stand as an important relativistic phenomenon that is absent from Newtonian physics. Gravitational-wave astronomy has the advantage that, unlike elec ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics. Over a quarter of Physics Nobel Prize-winning papers between 1995 and 2017 were published in it. ''PRL'' is published both online and as a print journal. Its focus is on short articles ("letters") intended for quick publication. The Lead Editor is Hugues Chaté. The Managing Editor is Robert Garisto. History The journal was created in 1958. Samuel Goudsmit, who was then the editor of '' Physical Review'', the American Physical Society's flagship journal, organized and published ''Letters to the Editor of Physical Review'' into a new standalone journal'','' which became ''Physical Review Letters''. It was the first journal intended for the rapid publication of short articles, a format that eventually became popular in many other fiel ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
BBH Gravitational Lensing Of Gw150914
BBH may refer to: Businesses * Baltic Beverages Holding, now owned by the Carlsberg Group * Bartle Bogle Hegarty, a British advertising agency * Brown Brothers Harriman & Co., an American private investment bank * Bellevue Healthcare Trust, listed on the London Stock Exchange as BBH People * Bruce Barrymore Halpenny, English military historian * Byun Baek-hyun, South Korean singer and actor * BadBoyHalo, a member of the now defunct Dream SMP server * The Darkstalkers character Bbhood#Baby Bonnie Hood, Baby Bonnie Hood Sport * Baseball Heaven, New York, US * Brest Bretagne Handball, a French handball club * Burgos BH, a Spanish cycling team Transport * Brighton Beach railway station, Melbourne * Stralsund–Barth Airport, Germany * Buckeye Bahamas Hub, fuel terminal in The Bahamas See also * BBHS (other) {{disambig ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Massive Compact Halo Object
A MAssive Compact Halo Object (MACHO) is a kind of astronomy, astronomical body that might explain the apparent presence of dark matter in galactic halos. A MACHO is a body that emits little or no radiation and drifts through interstellar space unassociated with any planetary system (and may or may not be composed of normal baryonic matter). Since MACHOs are not luminous, they are hard to detect. MACHO candidates include black holes or neutron stars as well as brown dwarfs and Rogue planet, unassociated planets. White dwarfs and very faint red dwarfs have also been proposed as candidate MACHOs. The term was coined by astrophysicist Kim Griest. Detection A MACHO may be detected when it passes in front of or nearly in front of a star and the MACHO's gravity bends the light, causing the star to appear brighter in an example of gravitational lensing known as gravitational microlensing. Several groups have searched for MACHOs by searching for the microlensing amplification of light. Th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Physical Review D
Physical may refer to: *Physical examination In a physical examination, medical examination, clinical examination, or medical checkup, a medical practitioner examines a patient for any possible medical signs or symptoms of a Disease, medical condition. It generally consists of a series of ..., a regular overall check-up with a doctor * ''Physical'' (Olivia Newton-John album), 1981 ** "Physical" (Olivia Newton-John song) * ''Physical'' (Gabe Gurnsey album) * "Physical" (Alcazar song) (2004) * "Physical" (Enrique Iglesias song) (2014) * "Physical" (Dua Lipa song) (2020) *"Physical (You're So)", a 1980 song by Adam & the Ants, the B side to " Dog Eat Dog" * ''Physical'' (TV series), an American television series *'' Physical: 100'', a Korean reality show on Netflix See also {{disambiguation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Intermediate-mass Black Hole
An intermediate-mass black hole (IMBH) is a class of black hole with mass in the range of one hundred to one hundred thousand (102–105) solar masses: significantly higher than stellar black holes but lower than the hundred thousand to more than one billion (105–109) solar mass supermassive black holes. Several IMBH candidate objects have been discovered in the Milky Way galaxy and others nearby, based on indirect gas cloud velocity and accretion disk spectra observations of various evidentiary strength. Observational evidence The gravitational wave signal GW190521, which occurred on 21 May 2019 at 03:02:29 UTC, and was published on 2 September 2020, resulted from the merger of two black holes. They had masses of 85 and 65 solar masses and merged to form a black hole of 142 solar masses, with 8 solar masses radiated away as gravitational waves. Before that, the strongest evidence for IMBHs came from a few low-luminosity active galactic nuclei. Due to their activity, these gal ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Supermassive Black Hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical objects that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, including light. Observational evidence indicates that almost every large galaxy has a supermassive black hole at its center. For example, the Milky Way galaxy has a supermassive black hole at its center, corresponding to the radio source Sagittarius A*. Accretion of interstellar gas onto supermassive black holes is the process responsible for powering active galactic nuclei (AGNs) and quasars. Two supermassive black holes have been directly imaged by the Event Horizon Telescope: the black hole in the giant elliptical galaxy Messier 87 and the black hole at the Milky Way's center (Sagittarius A*). Descr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Baryonic Dark Matter
In astronomy and cosmology, baryonic dark matter is hypothetical dark matter composed of baryons. Only a small proportion of the dark matter in the universe is likely to be baryonic. Characteristics As "dark matter", baryonic dark matter is undetectable by its emitted radiation, but its presence can be inferred from gravitational effects on visible matter. This form of dark matter is composed of "baryons", heavy subatomic particles such as protons and neutrons and combinations of these, including non-emitting ordinary atoms. Presence Baryonic dark matter may occur in non-luminous gas or in Massive Astrophysical Compact Halo Objects (MACHOs) – condensed objects such as black holes, neutron stars, white dwarfs, very faint stars, or non-luminous objects like planets and brown dwarfs. Estimates of quantity The total amount of baryonic dark matter can be inferred from models of Big Bang nucleosynthesis, and observations of the cosmic microwave background. Both indicate that the am ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Hawking Radiation
Hawking radiation is black-body radiation released outside a black hole's event horizon due to quantum effects according to a model developed by Stephen Hawking in 1974. The radiation was not predicted by previous models which assumed that once electromagnetic radiation is inside the event horizon, it cannot escape. Hawking radiation is predicted to be extremely faint and is many orders of magnitude below the current best telescopes' detecting ability. Hawking radiation would reduce the mass and rotational energy of black holes and consequently cause black hole evaporation. Because of this, black holes that do not gain mass through other means are expected to shrink and ultimately vanish. For all except the smallest black holes, this happens extremely slowly. The radiation temperature, called Hawking temperature, is inversely proportional to the black hole's mass, so micro black holes are predicted to be larger emitters of radiation than larger black holes and should dissipat ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Live Science
Live Science is a science news website. The publication features stories on a wide range of topics, including space, animals, health, archaeology, human behavior, and planet Earth. It also includes a reference section with links to other websites. Its stated mission is to inform and entertain readers about science and the world around them.{{r, mission History Live Science was originally made in 2004. It was acquired by ediaNetwork, later called Purch, in 2009.{{r, purch Purch consumer brands (including Live Science) were acquired by Future The future is the time after the past and present. Its arrival is considered inevitable due to the existence of time and the laws of physics. Due to the apparent nature of reality and the unavoidability of the future, everything that currently ex ... in 2018. Reception In 2011, the '' Columbia Journalism Review''{{'s "News Startups Guide" called Live Science "a purebred Web animal, primarily featuring one-off stories and photo gall ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound Planetary system, system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a hydrostatic equilibrium, balanced equilibrium by the thermonuclear fusion, fusion of hydrogen into helium at its stellar core, core, releasing this energy from its outer photosphere. As ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |