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Henrietta Leavitt
Henrietta Swan Leavitt (; July 4, 1868 – December 12, 1921) was an American astronomer. A graduate of Radcliffe College, she worked at the Harvard College Observatory as a "computer", tasked with examining photographic plates in order to measure and catalog the brightness of stars. This work led her to discover the relation between the luminosity and the period of Cepheid variables. Leavitt's discovery provided astronomers with the first "standard candle" with which to measure the distance to faraway galaxies. Before Leavitt discovered the period-luminosity relationship for Cepheid variables, the only techniques available to astronomers for measuring the distance to a star were based on parallax and triangulation. Such techniques can only be used for measuring distances up to hundreds of light years. Leavitt's work allowed astronomers to measure distances up to about 20 million light years. As a result of this, it is now known that our own galaxy, the Milky Way, has a diamet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lancaster, Massachusetts
Lancaster is a town in Worcester County, Massachusetts, in the United States. Incorporated in 1653, Lancaster is the oldest town in Worcester County. As of the 2020 census, the town population was 8,441. History In 1643 Lancaster was first settled as "Nashaway" (named after the local Nashaway Native American tribe) by a group of colonists known as the Nashaway Company who may have initially been interested in iron deposits in the area. Several of the company were blacksmiths or gunsmiths, including, Herman Garrett, and as early as 1653 a settler, George Adams, was whipped for selling guns and alcohol to the Indians in the area. The town was officially incorporated and renamed "Lancaster on the Nashua" in 1653. Prominent Massachusetts military leader Simon Willard served as an advisor to the company and eventually settled in Lancaster for a period, and provided guns to the local tribe by order of the Massachusetts General Court. Supporters of Lancaster's founder, John Pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation (surveying)
In surveying, triangulation is the process of determining the location of a point by measuring only angles to it from known points at either end of a fixed baseline by using trigonometry, rather than measuring distances to the point directly as in trilateration. The point can then be fixed as the third point of a triangle with one known side and two known angles. Triangulation can also refer to the accurate surveying of systems of very large triangles, called triangulation networks. This followed from the work of Willebrord Snell in 1615–17, who showed how a point could be located from the angles subtended from ''three'' known points, but measured at the new unknown point rather than the previously fixed points, a problem called resectioning. Surveying error is minimized if a mesh of triangles at the largest appropriate scale is established first. Points inside the triangles can all then be accurately located with reference to it. Such triangulation methods were used for accur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Charles Pickering
Edward Charles Pickering (July 19, 1846 – February 3, 1919) was an American astronomer and physicist and the older brother of William Henry Pickering. Along with Carl Vogel, Pickering discovered the first spectroscopic binary stars. He wrote ''Elements of Physical Manipulations'' (2 vol., 1873–76). Personal life Pickering was born at 43 Bowdoin Street in Boston, Massachusetts, on July 19, 1846,Obituary, ''Boston Globe'', February 4, 1919 to a distinguished, cultivated family consisting of his brother, William Henry Pickering, father, Edward Pickering, and his mother, Charlotte Hammond. Edward's brother, William, was a graduate of MIT and professor of physics and astronomy. Edward was interested in the stars as a boy and constructed his own telescope by the age of 12. Pickering enjoyed his work at the observatory, but he was also enjoyed mountain climbing and bicycling in earlier days and later he was an interested spectator of football games. He was co-founder and first presi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard Computers
The Harvard Computers was a team of women working as skilled workers to process astronomical data at the Harvard Observatory in Cambridge, Massachusetts, United States. The team was directed by Edward Charles Pickering (1877 to 1919) and, following his death in 1919, by Annie Jump Cannon. "The women were challenged to make sense of these patterns by devising a scheme for sorting the stars into categories. Annie Jump Cannon's success at this activity made her famous in her own lifetime, and she produced a stellar classification system that is still in use today. Antonia Maury discerned in the spectra a way to assess the relative sizes of stars, and Henrietta Leavitt showed how the cyclic changes of certain variable stars could serve as distance markers in space." Other computers in the team included Williamina Fleming and Florence Cushman. Although these women started primarily as calculators, they made significant contributions to astronomy, much of which they published in resea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massachusetts Bay Colony
The Massachusetts Bay Colony (1630–1691), more formally the Colony of Massachusetts Bay, was an English settlement on the east coast of North America around the Massachusetts Bay, the northernmost of the several colonies later reorganized as the ''Province of Massachusetts Bay''. The lands of the settlement were in southern New England, with initial settlements on two natural harbors and surrounding land about apart—the areas around Salem and Boston, north of the previously established Plymouth Colony. The territory nominally administered by the Massachusetts Bay Colony covered much of central New England, including portions of Massachusetts, Maine, New Hampshire, and Connecticut. The Massachusetts Bay Colony was founded by the owners of the Massachusetts Bay Company, including investors in the failed Dorchester Company, which had established a short-lived settlement on Cape Ann in 1623. The colony began in 1628 and was the company's second attempt at colonization. It was su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puritan
The Puritans were English Protestants in the 16th and 17th centuries who sought to purify the Church of England of Catholic Church, Roman Catholic practices, maintaining that the Church of England had not been fully reformed and should become more Protestant. Puritanism played a significant role in English history, especially during the Protectorate. Puritans were dissatisfied with the limited extent of the English Reformation and with the Church of England's toleration of certain practices associated with the Roman Catholic Church. They formed and identified with various religious groups advocating greater purity of worship and doctrine, as well as personal and corporate piety. Puritans adopted a Reformed theology, and in that sense they were Calvinists (as were many of their earlier opponents). In church polity, some advocated separation from all other established Christian denominations in favour of autonomous gathered churches. These English Dissenters, Separatist and Indepe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Leavitt
Deacon John Leavitt (1608–1691) was a tailor, public officeholder, and founding deacon of Old Ship Church in Hingham, Plymouth County, Massachusetts, the only remaining 17th-century Puritan meeting house in America and the oldest church in continuous ecclesiastical use in the United States. Hingham's Leavitt Street is named for the early settler, whose descendants have lived in Hingham for centuries. Biography Leavitt was born in 1608 in England, in Beverly, Yorkshire. Leavitt first appears in the annals of the Massachusetts Bay Colony in 1634, when he is shown in records of Dorchester, Massachusetts, as having been granted a house lot. Within two years, the early settler had moved to nearby Hingham, where he was granted land in 1636. In his early history of Hingham, attorney Solomon Lincoln recited the oft-told tale of Leavitt's supposed origins: "The family tradition concerning John Leavitt is that he was an indented apprentice in England," wrote Lincoln in 1827, "and that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congregational Church
Congregational churches (also Congregationalist churches or Congregationalism) are Protestant churches in the Calvinist tradition practising congregationalist church governance, in which each congregation independently and autonomously runs its own affairs. Congregationalism, as defined by the Pew Research Center, is estimated to represent 0.5 percent of the worldwide Protestant population; though their organizational customs and other ideas influenced significant parts of Protestantism, as well as other Christian congregations. The report defines it very narrowly, encompassing mainly denominations in the United States and the United Kingdom, which can trace their history back to nonconforming Protestants, Puritans, Separatists, Independents, English religious groups coming out of the English Civil War, and other English Dissenters not satisfied with the degree to which the Church of England had been reformed. Congregationalist tradition has a presence in the United States ... [...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] |
Lowell Observatory
Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark in 1965. and In 2011, the Observatory was named one of "The World's 100 Most Important Places" by Time Magazine. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh. The observatory was founded by astronomer Percival Lowell of Boston's Lowell family and is overseen by a sole trustee, a position historically handed down through the family. The first trustee was Lowell's third cousin Guy Lowell (1916–1927). Percival's nephew Roger Putnam served from 1927 to 1967, followed by Roger's son Michael (1967–1987), Michael's brother William Lowell Putnam III (1987–2013), and current trustee W. Lowell Putnam. Multiple astronauts attended the Lowell Observatory in 1963 while the moon was being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesto Slipher
Vesto Melvin Slipher (; November 11, 1875 – November 8, 1969) was an American astronomer who performed the first measurements of radial velocities for galaxies. He was the first to discover that distant galaxies are redshifted, thus providing the first empirical basis for the expansion of the universe. He was also the first to relate these redshifts to velocity. Biography Slipher was born in Mulberry, Indiana, and completed his doctorate at Indiana University in 1909. He spent his entire career at Lowell Observatory in Flagstaff, Arizona, where he was promoted to assistant director in 1915, acting director in 1916, and finally director from 1926 until his retirement in 1952. His great grandfather helped established a Lutheran church. His brother Earl C. Slipher was also an astronomer and a director at the Lowell Observatory. Slipher used spectroscopy to investigate the rotation periods of planets and the composition of planetary atmospheres. In 1912, he was the first to obse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in frequency and energy, is known as a negative redshift, or blueshift. The terms derive from the colours red and blue which form the extremes of the visible light spectrum. In astronomy and cosmology, the three main causes of electromagnetic redshift are # The radiation travels between objects which are moving apart (" relativistic" redshift, an example of the relativistic Doppler effect) #The radiation travels towards an object in a weaker gravitational potential, i.e. towards an object in less strongly curved (flatter) spacetime (gravitational redshift) #The radiation travels through expanding space (cosmological redshift). The observation that all sufficiently distant light sources show redshift corresponding to their distance from Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
