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1900 In Science
The year 1900 in science and technology involved some significant events, listed below. Aeronautics * July 2 – The first rigid airship flight is made by the LZ1 designed by Ferdinand von Zeppelin. * c. October 3 – The Wright brothers begin their first manned glider experimental flights at Kitty Hawk, North Carolina; their first few attempts fail. Chemistry * Moses Gomberg identifies the first organic radical (according to the modern definition), triphenylmethyl radical. * Johannes Rydberg refines the expression for observed hydrogen line wavelengths. Earth sciences * January 5 – Physicist Dr Henry A. Rowland of Johns Hopkins University in Baltimore announces his theory that the cause of Earth's magnetic field is its own rotation, based on experiments to produce magnetism by the rotation of a motor. * Richard Dixon Oldham distinguishes between primary, secondary and tertiary waveforms as recorded by seismometers. Exploration * American explorer Robert Peary first s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Rydberg
Johannes (Janne) Robert Rydberg (; 8 November 1854 – 28 December 1919) was a Swedish physicist mainly known for devising the Rydberg formula, in 1888, which is used to describe the wavelengths of photons (of visible light and other electromagnetic radiation) emitted by changes in the energy level of an electron in a hydrogen atom. Biography Rydberg was born 8 November 1854 in Halmstad in southern Sweden, the only child of Sven Rydberg and Maria Anderson Rydberg. When he was 4 years old his father died, and the family was forced to live on a small income. In 1873 he graduated from Halmstads elementärläroverk, where he received high grades in maths and physics. Later that year he enrolled in Lund University, and two years later he was awarded his bachelor's degree. In 1879 he was awarded his Doctor of Philosophy with his dissertation "Konstruktioner af kägelsnitt i 3- och 4-punktskontakt". Rydberg began his career as an amanuensis in the institution. He became a docent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extreme Points Of Earth
This article lists extreme locations on Earth that hold geographical records or are otherwise known for their geophysical or meteorological superlatives. All of these locations are Earth-wide extremes; extremes of individual continents or countries are not listed. Latitude and longitude Northernmost * The northernmost point of land is the northern tip of Kaffeklubben Island, north of Greenland (), which lies slightly north of Cape Morris Jesup, Greenland (). Various shifting gravel bars lie farther north, the most famous being Oodaaq. There have been other islands more northern such as 83-42 and ATOW1996 but they have not been confirmed as permanent. Southernmost * The southernmost continental point of land outside Antarctica is in South America at Cape Froward, Magallanes Region, Chile (). * The southernmost point of (liquid) water is a bay on the Filchner–Ronne Ice Shelf along the coast of Antarctica (), about south of Berkner Island. ** The southernmost point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaffeklubben Island
Kaffeklubben Island or Coffee Club Island (; ) is an uninhabited island lying off the northern shore of Greenland. It contains the undisputed northernmost point of land on Earth. History Kaffeklubben Island does not appear to have ever been inhabited. The northern part of Peary Landknown as ''Johannes J. Jensen Land'' was at least visited by members of the Thule peoples, based on archaeological evidence found in 2023 near Bliss Bay, approximately south. The nearest ruins from the older Independence I culture are located at Cape Bridgman, some to the southeast. The first recorded sighting of Kaffeklubben Island was made by the American explorer Robert Peary in 1900, who believed that Cape Morris Jesup on the mainland was the world's northernmost point of land and who declined to name the island. The island itself was not visited until 1921, when the Danish explorer Lauge Koch set foot on the island and named it after the coffee club in the University of Copenhagen Geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Peary
Robert Edwin Peary Sr. (; May 6, 1856 – February 20, 1920) was an American explorer and officer in the United States Navy who made several expeditions to the Arctic in the late 19th and early 20th centuries. He was long credited as being the discoverer of the geographic North Pole in April 1909, having led the first expedition to have claimed this achievement, although it is now considered unlikely that he actually reached the Pole. Peary was born in Cresson, Pennsylvania, but, following his father's death at a young age, was raised in Cape Elizabeth, Maine. He attended Bowdoin College, then joined the United States Coast and Geodetic Survey as a draftsman. He enlisted in the navy in 1881 as a civil engineer. In 1885, he was made chief of surveying for the Nicaragua Canal, which was never built. He visited the Arctic for the first time in 1886, making an unsuccessful attempt to cross Greenland by dogsled. In the Peary expedition to Greenland of 1891–1892, he was muc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Dictionary Of National Biography
The ''Dictionary of National Biography'' (''DNB'') is a standard work of reference on notable figures from History of the British Isles, British history, published since 1885. The updated ''Oxford Dictionary of National Biography'' (''ODNB'') was published on 23 September 2004 in 60 volumes and online, with 50,113 biographical articles covering 54,922 lives. First series Hoping to emulate national biography, biographical collections published elsewhere in Europe, such as the (1875), in 1882 the publisher George Murray Smith, George Smith (1824–1901), of Smith, Elder & Co., planned a universal dictionary that would include biographical entries on individuals from world history. He approached Leslie Stephen, then editor of the ''Cornhill Magazine'', owned by Smith, to become the editor. Stephen persuaded Smith that the work should focus only on subjects from the United Kingdom and its present and former colonies. An early working title was the ''Biographia Britannica'', the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismometer
A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The output of such a device—formerly recorded on paper (see picture) or film, now recorded and processed digitally—is a ''seismogram''. Such data is used to locate and characterize earthquakes, and to study the internal structure of Earth. Basic principles A simple seismometer, sensitive to up-down motions of the Earth, is like a weight hanging from a spring, both suspended from a frame that moves along with any motion detected. The relative motion between the weight (called the mass) and the frame provides a measurement of the vertical ground motion. A rotating drum is attached to the frame and a pen is attached to the weight, thus recording any ground motion in a seismogram. Any movement from the ground moves the frame. The mass tends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waveform
In electronics, acoustics, and related fields, the waveform of a signal is the shape of its Graph of a function, graph as a function of time, independent of its time and Magnitude (mathematics), magnitude Scale (ratio), scales and of any displacement in time.David Crecraft, David Gorham, ''Electronics'', 2nd ed., , CRC Press, 2002, p. 62 ''Periodic waveforms'' repeat regularly at a constant wave period, period. The term can also be used for non-periodic or aperiodic signals, like chirps and pulse (signal processing), pulses. In electronics, the term is usually applied to time-varying voltages, electric current, currents, or electromagnetic fields. In acoustics, it is usually applied to steady periodic sounds — variations of air pressure, pressure in air or other media. In these cases, the waveform is an attribute that is independent of the frequency, amplitude, or phase shift of the signal. The waveform of an electrical signal can be visualized with an oscilloscope or an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Dixon Oldham
Richard Dixon Oldham FRS (; 31 July 1858 – 15 July 1936) was a British geologist who made the first clear identification of the separate arrivals of P-waves, S-waves and surface waves on seismograms and the first clear evidence that the Earth has a central core. Life Born on 31 July 1858 to Thomas Oldham, a Fellow of the Royal Society and geologist, Oldham was educated at Rugby School and the Royal School of Mines. In 1879 Oldham became an assistant-superintendent with the Geological Survey of India, working in the Himalayas. He wrote about 40 publications for the Survey on geological subjects including hot springs, the geology of the Son Valley and the structure of the Himalayas and the Ganges plain. His most famous work was in seismology. His report on the 1897 Assam earthquake went far beyond reports of previous earthquakes. It included a description of the Chedrang fault, with uplift up to 35 feet and reported accelerations of the ground that had exceeded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetism
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, magnetism is one of two aspects of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt, nickel, and their alloys. All substances exhibit some type of magnetism. Magnetic materials are classified according to their bulk susceptibility. Ferromagnetism is responsible for most of the effects of magnetism encountered in everyday life, but there are actually several types of magnetism. Paramagnetic substances, such as aluminium and oxygen, are weakly attracted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Magnetic Field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from structure of Earth, Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole (Ellesmere Island, Nunavut, Canada) actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baltimore
Baltimore is the most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 census and estimated at 568,271 in 2024, it is the 30th-most populous U.S. city. The Baltimore metropolitan area is the 20th-largest metropolitan area in the country at 2.84 million residents. The city is also part of the Washington–Baltimore combined statistical area, which had a population of 9.97 million in 2020. Baltimore was designated as an independent city by the Constitution of Maryland in 1851. Though not located under the jurisdiction of any county in the state, it forms part of the central Maryland region together with the surrounding county that shares its name. The land that is present-day Baltimore was used as hunting ground by Paleo-Indians. In the early 1600s, the Susquehannock began to hunt there. People from the Province of Maryland established the Port of Baltimore in 1706 to support the tobacco trade with Europe and established the Town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
