搜尋結果
Definition Finding the direction of the cross product by the right-hand rule The cross product of two vectors a and b is defined only in three-dimensional space and is denoted by a × b.In physics and applied mathematics, the wedge notation a ∧ b is often used (in conjunction with the name vector product), although in pure mathematics such notation is usually reserved for just the exterior ...
Viète. de Moivre. Euler. Fourier. v. t. e. In trigonometry, trigonometric identities are equalities that involve trigonometric functions and are true for every value of the occurring variables for which both sides of the equality are defined. Geometrically, these are identities involving certain functions of one or more angles.
the free encyclopedia that anyone can edit. After the Deluge is an oil painting by English artist George Frederic Watts. Completed in 1891, it shows a scene from the story of Noah's Flood, in which Noah opens the window of his Ark to see that after 40 days the rain has stopped. The Symbolist painting is a stylised seascape, dominated by a ...
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is. The parameter is the mean or expectation of the distribution (and also its median and mode ), while the parameter is its standard deviation.
- History
- Project Overview
- Research
- Instrumentation and Operation
- Site
- Related Facilities
- Conspiracy Theories
- In Popular Culture
- See Also
- Further Reading
The High-frequency Active Auroral Research Program began in 1990. Ted Stevens, Republican U.S. senator from Alaska, helped win approval for the facility,and construction began in 1993. In early May 2013, HAARP was temporarily shut down, awaiting a change between contractors to operate the facility. In July 2013, HAARP program manager James Keeney s...
The HAARP project directs a 3.6 MW signal, in the 2.8–10 MHz region of the HF band, into the ionosphere. The signal may be pulsed or continuous. Effects of the transmission and any recovery period can be examined using associated instrumentation, including VHF and UHF radars, HF receivers, and optical cameras. According to the HAARP team, this will...
HAARP's main goal is basic science research in the uppermost portion of the atmosphere, termed the ionosphere. Essentially a transition between the atmosphere and the magnetosphere, the ionosphere is where the atmosphere is thin enough that the Sun's X-rays and UV rays can reach it, but thick enough that there are enough molecules present to absorb...
The main instrument at HAARP is the Ionospheric Research Instrument (IRI). This is a high-power, high-frequency phased array radio transmitter with a set of 180 antennas, disposed in an array of 12×15 units that occupy a rectangle of about 30–40 acres (12–16 hectares). The IRI is used to temporarily energize a small portion of the ionosphere. The s...
The project site (WikiMiniAtlas62°23′30″N 145°09′03″W / 62.39167°N 145.15083°W / 62.39167; -145.15083) is north of Gakona, Alaska just west of Wrangell-Saint Elias National Park. An environmental impact statement led to permission for an array of up to 180 antennas to be erected. HAARP was constructed at the previous site of an over-the-horizon ...
In the United States, there have been two related ionospheric heating facilities: the HIPAS, near Fairbanks, Alaska, which was dismantled in 2009, and one at the Arecibo Observatory in Puerto Rico, which collapsed in 2020. The European Incoherent Scatter Scientific Association (EISCAT) operates an ionospheric heating facility capable of transmittin...
HAARP is the subject of numerous conspiracy theories. Various individuals have speculated about hidden motivations and capabilities of the project. For example, Rosalie Bertell warned in 1996 about the deployment of HAARP as a military weapon. Michel Chossudovsky stated in a book published by the Committee on Monetary and Economic Reform that "rece...
HAARP gave rise to a live album by the rock band Muse and became the theme of novels like La Route de Gakona by Jean-Paul Jody[Wikidata]. The HAARP facility appears in the 2004 video game X-Men Legends. In the game, the X-Men track the Brotherhood of Mutants to HAARP. The facility is significantly different from its real life counterpart, with snow...
"Evidence for Precipitation of Energetic Particles by Ionospheric "Heating" Transmissions". National Geophysical Data Center. 7 December 2004. Retrieved 27 September 2009.J. E. Smith (6 May 2006). "HAARPCompleted!". Indybay. Retrieved 27 September 2009.U. S. Inan; T. F. Bell. "Polar Aeronomy and Radio Science (PARS):ULF/ELF/VLF Project". STAR Laboratory, Stanford University. Archived from the original on 27 August 2009. Retrieved 27 September 2009.U. S. Inan; M. Golkowski; D. L. Carpenter; N. Reddell; R. C. Moore; T. F. Bell; E. Paschal; P. Kossey; E. Kennedy; S. Z. Meth (2004). "Multi-hop whistler-mode ELF/VLF signals and triggered emission...The number π (/ p aɪ /; spelled out as "pi") is a mathematical constant that is the ratio of a circle's circumference to its diameter, approximately equal to 3.14159.The number π appears in many formulae across mathematics and physics.It is an irrational number, meaning that it cannot be expressed exactly as a ratio of two integers, although fractions such as are commonly used to ...
Liu Cixin (Chinese: 刘慈欣; pinyin: Liú Cíxīn, pronounced [ljo ʊ tsʰɨ ɕi n]; English: / l j uː (t) s ə ˈ ʃ iː n /; born 23 June 1963) is a Chinese computer engineer and science fiction writer. He is a nine-time winner of China's Galaxy Award and has also received the 2015 Hugo Award for his novel The Three-Body Problem as well as the 2017 Locus Award for Death's End.
