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Timeline Of Knowledge About The Interstellar And Intergalactic Medium
Timeline of knowledge about the interstellar medium and intergalactic medium * 1848 — Lord Rosse studies M1 and names it the Crab Nebula. The telescope is much larger than the small refactors typical of this period and it also reveals the spiral nature of M51. * 1864 — William Huggins studies the spectrum of the Orion Nebula and shows that it is a cloud of gas * 1904 — Interstellar calcium detected on spectrograph at Potsdam * 1909 — Slipher confirms Kapteyn's theory of interstellar gas * 1912 — Slipher confirms interstellar dust * 1927 — Ira Bowen explains unidentified spectral lines from space as forbidden transition lines * 1930 — Robert Trumpler discovers absorption by interstellar dust by comparing the angular sizes and brightnesses of globular clusters * 1944 — Hendrik van de Hulst predicts the 21 cm hyperfine line of neutral interstellar hydrogen * 1951 — Harold I. Ewen and Edward Purcell observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events. Timelines can use any suitable scale representing time, suiting the subject and data; many use a linear scale, in which a unit of distance is equal to a set amount of time. This timescale is dependent on the events in the timeline. A timeline of evolution can be over millions of years, whereas a timeline for the day of the September 11 attacks can take place over minutes, and that of an explosion over milliseconds. While many timelines use a linear timescale—especially where very large or small timespans are relevant -- logarithmic timelines entail a logarithmic scale of time; some "hurry up and wait" chronologies are depicted with zoom lens metaphors. History Time and space, particularly the line, are intertwined concepts in human thought. The line is ubiquitous in clocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patrick Palmer (astronomer)
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Patrick Palmer may refer to: Sportspeople * Patrick Palmer (rugby union) (born 1988), Welsh rugby union player * Pat Palmer (rugby union) (born 1962), Canadian rugby player * Pat Palmer (boxer) (1914–1988), English boxer Others *Patrick Palmer (British Army officer) (1933–1999), British Army general * Patrick Palmer (politician) (1889–1971), Irish Fine Gael politician from Kerry * Patrick Palmer (astronomer), American astronomer, Helen B. Warner Prize for Astronomy *Pat Palmer, the current owner of Citizendium Citizendium ( ; "the citizens' compendium of everything") is an English-language wiki-based free online encyclopedia launched by Larry Sanger, co-founder of Nupedia and Wikipedia. It was first announced in September 2006 as a fork of the Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin Zuckerman
Benjamin Michael Zuckerman (born August 16, 1943) is an astrophysicist and an emeritus professor in the Department of Physics & Astronomy at UCLA. His recent work focus primarily on formation and evolution of planetary systems around various types of stars. Education Zuckerman completed two degrees in 1963, one in Physics and one in Aeronautic & Astronautics at Massachusetts Institute of Technology. He finished his PhD thesis in Astronomy in 1968 at Harvard University. Scientific publications Since 1965, Zuckerman has published well over 200 refereed papers in journals such as ''Astrophysical Journal'', ''Nature'', ''Astronomy & Astrophysics'' and ''Science'', of which he was first author for close to 100. He also produced a number of review papers in Annual review of astronomy and astrophysics. In 2001, he participated in the Encyclopedia of Astronomy and Astrophysics. Zuckerman was co-author of a 2008 paper reporting first directly-imaged multiplanetary system (arguably, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Buhl
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". was, according to the Hebrew Bible, the third king of the United Kingdom of Israel. In the Books of Samuel, he is described as a young shepherd and harpist who gains fame by slaying Goliath, a champion of the Philistines, in southern Canaan. David becomes a favourite of Saul, the first king of Israel; he also forges a notably close friendship with Jonathan, a son of Saul. However, under the paranoia that David is seeking to usurp the throne, Saul attempts to kill David, forcing the latter to go into hiding and effectively operate as a fugitive for several years. After Saul and Jonathan are both killed in battle against the Philistines, a 30-year-old David is anointed king over all of Israel and Judah. Following his rise to power, David ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Snyder
Lewis may refer to: Names * Lewis (given name), including a list of people with the given name * Lewis (surname), including a list of people with the surname Music * Lewis (musician), Canadian singer * "Lewis (Mistreated)", a song by Radiohead from ''My Iron Lung'' Places * Lewis (crater), a crater on the far side of the Moon * Isle of Lewis, the northern part of Lewis and Harris, Western Isles, Scotland United States * Lewis, Colorado * Lewis, Indiana * Lewis, Iowa * Lewis, Kansas * Lewis Wharf, Boston, Massachusetts * Lewis, Missouri * Lewis, Essex County, New York * Lewis, Lewis County, New York * Lewis, North Carolina * Lewis, Vermont * Lewis, Wisconsin Ships * USS ''Lewis'' (1861), a sailing ship * USS ''Lewis'' (DE-535), a destroyer escort in commission from 1944 to 1946 Science * Lewis structure, a diagram of a molecule that shows the bonding between the atoms * Lewis acids and bases * Lewis antigen system, a human blood group system * Lewis number, a dimension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyman-alpha Line
The Lyman-alpha line, typically denoted by Ly-α, is a spectral line of hydrogen (or, more generally, of any one-electron atom) in the Lyman series. It is emitted when the atomic electron transitions from an ''n'' = 2 orbital to the ground state (''n'' = 1), where ''n'' is the principal quantum number. In hydrogen, its wavelength of 1215.67 angstroms ( or ), corresponding to a frequency of about , places Lyman-alpha in the ultraviolet (UV) part of the electromagnetic spectrum. More specifically, Ly-α lies in vacuum UV (VUV), characterized by a strong absorption in the air. Fine structure The Lyman-alpha doublet. Because of the spin–orbit interaction, the Lyman-alpha line splits into a fine-structure doublet with the wavelengths of 1215.668 and 1215.674 angstroms. These components are called Ly-α3/2 and Ly-α1/2, respectively. The eigenstates of the perturbed Hamiltonian are labeled by the ''total'' angular momentum ''j'' of the electron, not just the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruce Peterson
Bruce A. Peterson (May 23, 1933 – May 1, 2006) was an American aeronautical engineer, and test pilot for NASA. Biography Early life and education Peterson was born on May 23, 1933. A native of Washburn, North Dakota, he attended the University of California at Los Angeles from 1950 to 1953, and California Polytechnic State University from 1958 to 1960. While at UCLA he held a job as an aircraft assembler for Douglas Aircraft Company. Peterson graduated with a Bachelor of Science degree in Aeronautical Engineering from Cal Poly in 1960. Flight experience and NASA career Following attending UCLA, Peterson enlisted as a naval aviation cadet and was commissioned a second lieutenant in the U.S. Marine Corps in 1954. He was released from active duty three years later. Upon receiving his bachelor's degree from Cal Poly, Peterson joined NASA in August 1960 as an engineer at the Dryden Flight Research Center. After graduating from the U.S. Air Force Test Pilot School (Class 62C) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Gunn (astronomer)
James Edward Gunn (born October 21, 1938) is the Eugene Higgins Professor of Astronomy at Princeton University. Gunn's early theoretical work in astronomy has helped establish the current understanding of how galaxies form, and the properties of the space between galaxies. He also suggested important observational tests to confirm the presence of dark matter in galaxies, and predicted the existence of a Gunn–Peterson trough in the spectra of distant quasars. Much of Gunn's later work has involved leadership in major observational projects. He developed plans for one of the first uses of digital camera technology for space observation, a project that led to the Sloan Digital Sky Survey, the most extensive three-dimensional mapping of the universe ever undertaken. He also played a major role with the Wide Field and Planetary Camera on the Hubble Space Telescope. Gunn graduated from A.C. Jones High School in Beeville, Texas in 1957. He earned his bachelor's degree at Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Cloud
A prominence, sometimes referred to as a filament, is a large plasma and magnetic field structure extending outward from the Sun's surface, often in a loop shape. Prominences are anchored to the Sun's surface in the photosphere, and extend outwards into the solar corona. While the corona consists of extremely hot plasma, prominences contain much cooler plasma, similar in composition to that of the chromosphere. Prominences form over timescales of about a day and may persist in the corona for several weeks or months, looping hundreds of thousands of kilometers into space. Some prominences may give rise to coronal mass ejections. Scientists are currently researching how and why prominences are formed. A typical prominence extends over many thousands of kilometers; the largest on record was estimated at over long, roughly a solar radius. History The first detailed description of a solar prominence was in 14th-century Laurentian Codex, describing the Solar eclipse of 1 May ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyman Spitzer
Lyman Spitzer Jr. (June 26, 1914 – March 31, 1997) was an American theoretical physicist, astronomer and mountaineer. As a scientist, he carried out research into star formation, plasma physics, and in 1946, conceived the idea of telescopes operating in outer space. Spitzer invented the stellarator plasma device and is the namesake of NASA's Spitzer Space Telescope. As a mountaineer, he made the first ascent of Mount Thor, with Donald C. Morton. Early life and education Spitzer was born to a Presbyterian family in Toledo, Ohio, the son of Lyman Spitzer Sr. and Blanche Carey (née Brumback). Through his paternal grandmother, he was related to inventor Eli Whitney. Spitzer graduated from Scott High School. He then attended Phillips Academy in 1929 and went on to Yale College, where he graduated Phi Beta Kappa in 1935 and was a member of Skull and Bones. During a year of study at Cambridge University, he was influenced by Arthur Eddington and the young Subrahmanyan Cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
