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Edwin Hubble
Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously thought to be clouds of dust and gas and classified as "nebulae" were actually Galaxy, galaxies beyond the Milky Way. He used the strong direct period-luminosity relation, relationship between a classical Cepheid variable's luminosity and periodic function, pulsation period (discovered in 1908 by Henrietta Swan Leavitt) for scaling cosmic distance ladder, galactic and extragalactic distances. Hubble confirmed in 1929 that the recessional velocity of a galaxy increases with its distance from Earth, a behavior that became known as Hubble's law, although it had been proposed two years earlier by Georges Lemaître. The Hubble law implies that the universe is expanding. A decade before, the American astronomer Vesto Slipher had provided the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johan Hagemeyer
Johan Hagemeyer (1 June 1884 21 May 1962) was a Dutch-born horticulturalist and vegetarian who is remembered primarily for being an early 20th century photographer and artistic intellectual. Life and work Hagemeyer was born in Amsterdam, the Netherlands. His family came to California to grow fruit trees, but in 1916 he met photographer Alfred Stieglitz, who convinced him to devote his life to the then emerging world of artistic photography. In 1923 Hagemeyer opened a portrait studio in San Francisco, which he occupied primarily from October thru early April. In 1922 Hagemeyer built a spring-summer studio in Carmel-by-the-Sea, California, at that time the largest art colony on the Pacific coast, and donated his photographs that December to a local fund-raising exhibit. It was here that Hagemeyer met Edward Weston, who encouraged him to further his career in photography. He moved his Carmel address in 1924 to a new "artfully designed studio" at the prominent junction of Mountain Vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard Medal For Meritorious Service To Science
The Barnard Medal for Meritorious Service to Science was established in 1889 by the will of Columbia University president Frederick A. P. Barnard, and has been awarded by Columbia University, based on recommendations by the National Academy of Sciences, every five years since 1895. It is not to be confused with the Barnard Medal of Distinction. Winners * 1895 - John William Strutt, Lord Rayleigh, William Ramsay * 1900 - Wilhelm Röntgen * 1905 - Henri Becquerel * 1910 - Ernest Rutherford * 1915 - William Henry Bragg, William Lawrence Bragg * 1920 - Albert Einstein * 1925 - Niels Bohr * 1930 - Werner Heisenberg * 1935 - Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously ... * 1940 - Frédéric Joliot-Curie, Irène Joliot-Curie * 1945 - No award * 1950 - Enri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a Galaxy#Isophotal diameter, D25 isophotal diameter estimated at , but only about 1,000 light-years thick at the spiral arms (more at the bulge). Recent simulations suggest that a dark matter area, also containing some visible stars, may extend up to a diameter of almost 2 million light-years (613 kpc). The Milky Way has several List of Milky Way's satellite galaxies, satellite galaxies and is part of the Local Group of galaxies, forming part of the Virgo Supercluster which is itself a component of the Laniakea Supercluster. It is estimated to contain 100–400 billion stars and at least that number of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a Physical system, system of stars, stellar remnants, interstellar medium, interstellar gas, cosmic dust, dust, and dark matter bound together by gravity. The word is derived from the Ancient Greek, Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarf galaxy, dwarfs with less than a thousand stars, to the List of largest galaxies, largest galaxies known – Type-cD galaxy, supergiants with one hundred 10^12, trillion stars, each orbiting its galaxy's centre of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few per cent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorised according to their visual morphology (astronomy), morphology as elliptical galaxy, elliptical, Spiral galaxy, spiral, or irregular galaxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebula
A nebula (; or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral, or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the Pillars of Creation in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter and eventually become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects. Most nebulae are of vast size; some are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by. The Orion Nebula, the brightest nebula in the sky and occupying an area twice the angular diameter of the full Moon, can be viewed with the naked eye but was missed by early astronomers. Although denser than the space surrounding them, most nebulae are far less dens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observational Cosmology
Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors. Early observations The science of physical cosmology as it is practiced today had its subject material defined in the years following the Shapley-Curtis debate when it was determined that the universe had a larger scale than the Milky Way galaxy. This was precipitated by observations that established the size and the dynamics of the cosmos that could be explained by Albert Einstein's General Theory of Relativity. In its infancy, cosmology was a speculative science based on a very limited number of observations and characterized by a dispute between steady state theorists and promoters of Big Bang cosmology. It was not until the 1990s and beyond that the astronomical observations would be able to eliminate competing theories and drive the science to the "Golden Age of Cosmology" which was heralde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extragalactic Astronomy
Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy. The closest objects in extragalactic astronomy include the galaxy, galaxies of the Local Group, which are close enough to allow very detailed analyses of their contents (e.g. supernova remnants, Stellar kinematics#Stellar associations, stellar associations). As instrumentation has improved, distant objects can now be examined in more detail and so extragalactic astronomy includes objects at nearly the edge of the observable universe. Research into distant galaxies (outside of our local group) is valuable for studying aspects of the universe such as galaxy evolution and Active galactic nucleus, Active Galactic Nuclei (AGN) which give insight into physical phenomena (e.g. Supermassive black hole, super massive black hole accretion and the presence of dark matter). It is through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
