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Gravimetric analysis describes a set of methods used in analytical chemistry for the quantitative determination of an analyte (the ion being analyzed) based on its mass. The principle of this type of analysis is that once an ion's mass has been determined as a unique compound, that known measurement can then be used to... | {
"page_id": 659899,
"title": "Gravimetric analysis"
} |
Water eliminated in a quantitative manner from many inorganic substances by ignition is an example of a direct determination. It is collected on a solid desiccant and its mass determined by the gain in mass of the desiccant. Another direct volatilization method involves carbonates which generally decompose to release c... | {
"page_id": 659899,
"title": "Gravimetric analysis"
} |
energy is used to precipitate a volatile species. For example, the water content of a compound can be determined by vaporizing the water using thermal energy (heat). Heat can also be used, if oxygen is present, for combustion to isolate the suspect species and obtain the desired results. The two most common gravimetric... | {
"page_id": 659899,
"title": "Gravimetric analysis"
} |
of CO2 and residual water CO2(g) + 2 NaOH(s) → Na2CO3(s) + H2O(l). == Example == A chunk of ore is to be analyzed for sulfur content. It is treated with concentrated nitric acid and potassium chlorate to convert all of the sulfur to sulfate (SO2−4). The nitrate and chlorate are removed by treating the solution with con... | {
"page_id": 659899,
"title": "Gravimetric analysis"
} |
that analysis by these methods is much more efficient. == Solubility in the presence of diverse ions == Diverse ions have a screening effect on dissociated ions which leads to extra dissociation. Solubility will show a clear increase in presence of diverse ions as the solubility product will increase. Look at the follo... | {
"page_id": 659899,
"title": "Gravimetric analysis"
} |
For light and other electromagnetic radiation, the plane of polarization is the plane spanned by the direction of propagation and either the electric vector or the magnetic vector, depending on the convention. It can be defined for polarized light, remains fixed in space for linearly-polarized light, and undergoes axia... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
known as the plane of vibration, is perpendicular to Fresnel's "plane of polarization" but identical with the plane that modern writers tend to call by that name! It has been argued that the term plane of polarization, because of its historical ambiguity, should be avoided in original writing. One can easily specify th... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
direction of the electric (E) vector and leaves the reader to presume that the "plane of polarization" contains that vector — and this interpretation indeed fits the examples he gives. The same vector is used to describe the polarization of radio signals and antennas (Fig. 3). If the medium is magnetically isotropic bu... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
and the ray (i.e., the plane normal to E). In an isotropic medium, E and D have the same direction, so that the ray and wave-normal directions merge, and the planes (2a) and (2b) become one: (2) the plane containing both magnetic vectors and both propagation directions (i.e., the plane normal to the electric vectors). ... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
The term polarization was coined by Étienne-Louis Malus in 1811. In 1808, in the midst of confirming Huygens' geometric description of double refraction (while disputing his physical explanation), Malus had discovered that when a ray of light is reflected off a non-metallic surface at the appropriate angle, it behaves ... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
are exclusively transverse and therefore always polarized in the sense of having a particular transverse orientation, and that what we call unpolarized light is in fact light whose orientation is rapidly and randomly changing. Supposing that light waves were analogous to shear waves in elastic solids, and that a higher... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
changed the "plane of polarization" from (2b) to (2a). Fresnel's definition remains compatible with the Merriam-Webster definition, which fails to specify the propagation direction. And it remains compatible with Stratton's definition, because that is given in the context of an isotropic medium, in which planes (2a) an... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
the plane of vibration as "the plane passing through the ray and the direction of vibration" (in agreement with Fig. 1). Now suppose that a fine diffraction grating is illuminated at normal incidence. At large angles of diffraction, the grating will appear somewhat edge-on, so that the directions of vibration will be c... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
field, so that the mechanical vibrations of the shear wave are in the direction of the magnetic vibrations of the EM wave. But Stokes's experiments were bound to detect the electric vibrations, because those have the greater propensity to interact with matter. In short, the MacCullagh-Neumann vibrations were the ones t... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
is one context in which the ambiguity of the term plane of polarization causes no further confusion. There is also a context in which the original definition might still suggest itself. In a non-magnetic non-chiral crystal of the biaxial class (in which there is no ordinary refraction, but both refractions violate Snel... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
translated by T. Young as "Elementary view of the undulatory theory of light", Quarterly Journal of Science, Literature, and Art, vol. 22 (Jan.– Jun. 1827), pp. 127–41, 441–54; vol. 23 (Jul.– Dec. 1827), pp. 113–35, 431–48; vol. 24 (Jan.– Jun. 1828), pp. 198–215; vol. 25 (Jul.– Dec. 1828), pp. 168–91, 389–407; vol. 26 ... | {
"page_id": 55054778,
"title": "Plane of polarization"
} |
The Quake-Catcher Network was an initiative run by the University of Southern California that aimed to use computer-based accelerometers to detect earthquakes. It used the BOINC volunteer computing platform (a form of distributed computing, similar to SETI@home). It supported mobile devices (smartphones and some tablet... | {
"page_id": 18944443,
"title": "Quake-Catcher Network"
} |
The Atwood machine (or Atwood's machine) was invented in 1784 by the English mathematician George Atwood as a laboratory experiment to verify the mechanical laws of motion with constant acceleration. Atwood's machine is a common classroom demonstration used to illustrate principles of classical mechanics. The ideal Atw... | {
"page_id": 725441,
"title": "Atwood machine"
} |
{\displaystyle a=g{\frac {m_{1}-m_{2}}{m_{1}+m_{2}}}} The Atwood machine is sometimes used to illustrate the Lagrangian method of deriving equations of motion. == See also == Frictionless plane – simple kinematic model of an object on a ramp under gravityPages displaying wikidata descriptions as a fallback Kater's pend... | {
"page_id": 725441,
"title": "Atwood machine"
} |
Photosynthetic picoplankton or picophytoplankton is the fraction of the photosynthetic phytoplankton of cell sizes between 0.2 and 2 μm (i.e. picoplankton). It is especially important in the central oligotrophic regions of the world oceans that have very low concentration of nutrients. == History == 1952: Description o... | {
"page_id": 7016898,
"title": "Photosynthetic picoplankton"
} |
methods are needed. Epifluorescence microscopy allows researchers to detect certain groups of cells possessing fluorescent pigments such as Synechococcus which possess phycoerythrin. Flow cytometry measures the size ("forward scatter") and fluorescence of 1,000 in 10,000 cells per second. It allows one to determine ver... | {
"page_id": 7016898,
"title": "Photosynthetic picoplankton"
} |
genus Synechococcus of a size of 1 μm (micrometer) were first discovered in 1979 by J. Waterbury (Woods Hole Oceanographic Institution). They are quite ubiquitous, but most abundant in relatively mesotrophic waters. Cyanobacteria belonging to the genus Prochlorococcus are particularly remarkable. With a typical size of... | {
"page_id": 7016898,
"title": "Photosynthetic picoplankton"
} |
specific ecological niche in the oceanic environment. The Synechococcus cyanobacterium is generally abundant in mesotrophic environments, such as near the equatorial upwelling or in coastal regions. The Prochlorococcus cyanobacterium replaces it when the waters becomes impoverished in nutrients (i.e., oligotrophic). On... | {
"page_id": 7016898,
"title": "Photosynthetic picoplankton"
} |
the DNA content of picoplankton cells over time. This allowed researchers to establish that picoplankton cells are highly synchronous: they replicate their DNA and then divide all at the same time at the end of the day. This synchronization could be due to the presence of an internal biological clock. == Genomics == In... | {
"page_id": 7016898,
"title": "Photosynthetic picoplankton"
} |
Compounds are organized into the following lists: List of inorganic compounds, compounds without a C–H bond List of biomolecules == See also == Chemical substance – Form of matter List of alchemical substances List of chemical elements List of minerals – List of minerals with Wikipedia articles List of named alloys Lis... | {
"page_id": 135619,
"title": "List of compounds"
} |
The Whitley Awards have been awarded annually since 1979 by the Royal Zoological Society of New South Wales (RZSNSW). They commemorate Gilbert Whitley, an eminent Australian ichthyologist, and are presented for outstanding publications, either printed or electronic, that contain new information about the fauna of the A... | {
"page_id": 11407813,
"title": "Whitley Awards (Australia)"
} |
Membrane stabilizing effects involve the inhibition or total abolishing of action potentials from being propagated across the membrane. This phenomenon is common in nerve tissues as they are the carrier of impulses from the periphery to the central nervous system. Membrane stabilization is the method through which loca... | {
"page_id": 15995335,
"title": "Membrane stabilizing effect"
} |
Lemaître coordinates are a particular set of coordinates for the Schwarzschild metric—a spherically symmetric solution to the Einstein field equations in vacuum—introduced by Georges Lemaître in 1932. Changing from Schwarzschild to Lemaître coordinates removes the coordinate singularity at the Schwarzschild radius. == ... | {
"page_id": 13636040,
"title": "Lemaître coordinates"
} |
t + r s r ( 1 − r s r ) − 1 d r d ρ = d t + r r s ( 1 − r s r ) − 1 d r {\displaystyle {\begin{aligned}d\tau =dt+{\sqrt {\frac {r_{s}}{r}}}\,\left(1-{\frac {r_{s}}{r}}\right)^{-1}dr~\\d\rho =dt+{\sqrt {\frac {r}{r_{s}}}}\,\left(1-{\frac {r_{s}}{r}}\right)^{-1}dr~\end{aligned}}} (the numerator and denominator are switch... | {
"page_id": 13636040,
"title": "Lemaître coordinates"
} |
{\displaystyle \tau } used in this article for the time coordinate should not be confused with the proper time. It is true that τ {\displaystyle \tau } gives the proper time for radially infalling observers; it does not give the proper time for observers traveling along other geodesics. == Geodesics == The trajectories... | {
"page_id": 13636040,
"title": "Lemaître coordinates"
} |
be seen by tracing outward-moving radial null geodesics backwards in time. The outward-moving geodesics correspond to the plus sign in the above. Selecting a starting point r > r s {\displaystyle r>r_{s}} at τ = 0 {\displaystyle \tau =0} , the above equation integrates to r → + ∞ {\displaystyle r\to +\infty } as τ → + ... | {
"page_id": 13636040,
"title": "Lemaître coordinates"
} |
Bayesian hierarchical modelling is a statistical model written in multiple levels (hierarchical form) that estimates the parameters of the posterior distribution using the Bayesian method. The sub-models combine to form the hierarchical model, and Bayes' theorem is used to integrate them with the observed data and acco... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
methods and models commonly involve multiple parameters that can be regarded as related or connected in such a way that the problem implies a dependence of the joint probability model for these parameters. Individual degrees of belief, expressed in the form of probabilities, come with uncertainty. Amidst this is the ch... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
{\displaystyle P(y\mid \theta )} respectively: P ( θ , y ) = P ( θ ) P ( y ∣ θ ) {\displaystyle P(\theta ,y)=P(\theta )P(y\mid \theta )} Using the basic property of conditional probability, the posterior distribution will yield: P ( θ ∣ y ) = P ( θ , y ) P ( y ) = P ( y ∣ θ ) P ( θ ) P ( y ) {\displaystyle P(\theta \mi... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
{\displaystyle P(y_{1},y_{2},\ldots ,y_{n})} is invariant under permutations of the indices. That is, for every permutation π {\displaystyle \pi } or ( π 1 , π 2 , … , π n ) {\displaystyle (\pi _{1},\pi _{2},\ldots ,\pi _{n})} of (1, 2, …, n), P ( y 1 , y 2 , … , y n ) = P ( y π 1 , y π 2 , … , y π n ) . {\displaystyle... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
the second draw, which is 1/2: [ P ( y 2 = 1 ∣ y 1 = 1 ) = 0 ≠ P ( y 2 = 1 ) = 1 2 ] {\displaystyle [P(y_{2}=1\mid y_{1}=1)=0\neq P(y_{2}=1)={\frac {1}{2}}]} ). Thus, y 1 {\displaystyle y_{1}} and y 2 {\displaystyle y_{2}} are not independent. If x 1 , … , x n {\displaystyle x_{1},\ldots ,x_{n}} are independent and ide... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
called the hyperparameter, while its distribution given by N ( 0 , 1 ) {\displaystyle {\text{N}}(0,1)} is an example of a hyperprior distribution. The notation of the distribution of Y changes as another parameter is added, i.e. Y ∣ θ , μ ∼ N ( θ , 1 ) {\displaystyle Y\mid \theta ,\mu \sim N(\theta ,1)} . If there is a... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
j , ϕ ) {\displaystyle P(\theta _{j},\phi )} as its prior distribution. Note that the likelihood depends on ϕ {\displaystyle \phi } only through θ j {\displaystyle \theta _{j}} . The prior distribution from stage I can be broken down into: P ( θ j , ϕ ) = P ( θ j ∣ ϕ ) P ( ϕ ) {\displaystyle P(\theta _{j},\phi )=P(\the... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
school grade of the student (freshman, sophomore, junior or senior). That is, θ ∣ ϕ ∼ P ( θ ∣ ϕ ) {\displaystyle \theta \mid \phi \sim P(\theta \mid \phi )} . Moreover, the hyperparameter ϕ {\displaystyle \phi } follows its own distribution given by P ( ϕ ) {\displaystyle P(\phi )} , a hyperprior. These relationships c... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
\theta )P(\theta \mid \phi )P(\phi )} === 3-stage hierarchical model === For 3-stage hierarchical models, the posterior distribution is given by: P ( θ , ϕ , X ∣ Y ) = P ( Y ∣ θ ) P ( θ ∣ ϕ ) P ( ϕ ∣ X ) P ( X ) P ( Y ) {\displaystyle P(\theta ,\phi ,X\mid Y)={P(Y\mid \theta )P(\theta \mid \phi )P(\phi \mid X)P(X) \ove... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
= 1 , … , K . {\displaystyle \theta _{li}=\alpha _{l}+\sum _{b=1}^{P}\beta _{lb}x_{ib}+\eta _{li},\quad \eta _{li}\sim N(0,\omega _{l}^{2}),\quad i=1,\ldots ,N,\,l=1,\ldots ,K.} Stage 3: Prior σ 2 ∼ π ( σ 2 ) , α l ∼ π ( α l ) , ( β l 1 , … , β l b , … , β l P ) ∼ π ( β l 1 , … , β l b , … , β l P ) , ω l 2 ∼ π ( ω l 2... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
posterior density: π ( { θ l i } i = 1 , l = 1 N , K , σ 2 , { α l } l = 1 K , { β l b } l = 1 , b = 1 K , P , { ω l } l = 1 K | { y i j } i = 1 , j = 1 N , M i ) {\displaystyle \pi (\{\theta _{li}\}_{i=1,l=1}^{N,K},\sigma ^{2},\{\alpha _{l}\}_{l=1}^{K},\{\beta _{lb}\}_{l=1,b=1}^{K,P},\{\omega _{l}\}_{l=1}^{K}|\{y_{ij}... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
i o n M o d e l × p ( σ 2 , { α l } l = 1 K , { β l b } l = 1 , b = 1 K , P , { ω l } l = 1 K ) ⏟ S t a g e 3 : P r i o r {\displaystyle =\underbrace {\pi (\{y_{ij}\}_{i=1,j=1}^{N,M_{i}}|\{\theta _{li}\}_{i=1,l=1}^{N,K},\sigma ^{2})} _{Stage1:Individual-LevelModel}\times \underbrace {\pi (\{\theta _{li}\}_{i=1,l=1}^{N,... | {
"page_id": 42734031,
"title": "Bayesian hierarchical modeling"
} |
The placenta of humans, and certain other mammals contains structures known as cotyledons, which transmit fetal blood and allow exchange of oxygen and nutrients with the maternal blood. == Ruminants == The Artiodactyla have a cotyledonary placenta. In this form of placenta, the chorionic villi form a number of separate... | {
"page_id": 8196559,
"title": "Placental cotyledon"
} |
In machine learning, the hinge loss is a loss function used for training classifiers. The hinge loss is used for "maximum-margin" classification, most notably for support vector machines (SVMs). For an intended output t = ±1 and a classifier score y, the hinge loss of the prediction y is defined as ℓ ( y ) = max ( 0 , ... | {
"page_id": 33100241,
"title": "Hinge loss"
} |
{w} _{t}\mathbf {x} )} , where t {\displaystyle t} is the target label, w t {\displaystyle \mathbf {w} _{t}} and w y {\displaystyle \mathbf {w} _{y}} are the model parameters. Weston and Watkins provided a similar definition, but with a sum rather than a max: ℓ ( y ) = ∑ y ≠ t max ( 0 , 1 + w y x − w t x ) {\displaysty... | {
"page_id": 33100241,
"title": "Hinge loss"
} |
SVM with score function y = w ⋅ x {\displaystyle y=\mathbf {w} \cdot \mathbf {x} } that is given by ∂ ℓ ∂ w i = { − t ⋅ x i if t ⋅ y < 1 , 0 otherwise . {\displaystyle {\frac {\partial \ell }{\partial w_{i}}}={\begin{cases}-t\cdot x_{i}&{\text{if }}t\cdot y<1,\\0&{\text{otherwise}}.\end{cases}}} However, since the deri... | {
"page_id": 33100241,
"title": "Hinge loss"
} |
The molecular formula C24H26N2O2 (molar mass: 374.47 g/mol, exact mass: 374.1994 u) may refer to: Carmoxirole Evocalcet Furanylfentanyl | {
"page_id": 58069459,
"title": "C24H26N2O2"
} |
Growing Up in the Universe was a series of televised public lectures given by British evolutionary biologist Richard Dawkins as part of the Royal Institution Christmas Lectures, in which he discussed the evolution of life in the universe. The lectures were first broadcast on the BBC in 1991, in the form of five one-hou... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
of him, Dawkins illustrates the darkness of the distant past and of the unknown future. After expounding on how lucky we are to be alive, and urging us not to waste the precious time that we have, Dawkins brings up the usefulness of science in aiding our understanding of the universe. He mentions the reply that Michael... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
them how far he would have to walk to get back to the time of each one. By imagining what an advanced alien species would think of humans if they were to arrive on Earth, Dawkins suggests that their science would be similar to ours. They would know about pi, the Pythagorean theorem, and the theory of relativity. Howeve... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
ignore his natural instinct to run because he has faith in his scientific prediction of what will happen – the cannonball should stop about an inch short of his forehead. He releases the cannonball, and his prediction is proved correct. === Part 2: Designed and Designoid Objects === Dawkins' second lecture of the serie... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
the marsupial wolf (which looks like a dog but is actually a marsupial). He illustrates the reason why convergent evolution occurs by using two small models of commercial aircraft. The reason they look similar isn't due to industrial espionage, it is due to the fact that they are both built to fly, so they must make us... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
the computer to selectively breed more and more generations. At this point, Dawkins switches from explaining artificial selection to explaining natural selection. To demonstrate natural selection in a computer program, Dawkins uses a program written by Peter Fuchs to simulate the evolution of the spiderweb. The program... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
in the foot." While it is true that designoid objects cannot come about by chance, evolution provides a non-random method of creation – namely, natural selection. After developing the argument against a divine creator, Dawkins examines a number of designoid objects that contain imperfections, which is something you wou... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
which basically looks exactly like a dead leaf. He gives some more examples for this amazing imitation of the surrounding, e.g. a Potoo, which looks like a branch of tree and a thorn bug, which gains protection by looking like a rose thorn. He, once again, makes the point that you can compare these beings with a key, w... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
Similar efficiencies are achieved with random mutation without any change in probability. After addressing the claim by Fred Hoyle that probability alone could not produce the complexity of a typed text by Shakespeare, Dawkins introduces the notion of inherited improvements over a number of generations. Nature proceeds... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
idea that the natural world exists for our benefit. He considers the question of flowers seen through the eyes of bees and other pollinators, and performs a series of demonstrations which use ultraviolet light to excite fluorescence in various substances. === Part 5: The Genesis of Purpose === Dawkins opens by talking ... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
the retina. Dawkins gets someone to wear a virtual reality headset and move around in a 3-D computer generated world and draws an analogy between the model of the universe developed in one's head with the virtual reality universe developed in the computer. He then goes on the show that the brain uses models to describe... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
develop intent and purpose; and over time our collective understanding of the Universe will improve as we continue to study and exchange ideas. == Quotations == Life makes the wonders of technology seem commonplace. So where does life come from? What is it? Why are we here? What are we for? What is the meaning of life?... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
But nevertheless, it is worthwhile also from time to time shaking off the anaesthetic of familiarity and awakening to the wonder that is really all around us all the time. Natural selection – nature – is constantly choosing which individual shall live, [and] which individual shall breed. And the result, after many gene... | {
"page_id": 11080148,
"title": "Growing Up in the Universe"
} |
Decrepitation is the noise produced when certain chemical compounds are heated, or it refers to the cracking, or breaking up of lumps of limestone during heating. Such compounds include lead nitrate and calcine. == Mineralogy == Decrepitation is one of the most accurate ways to calculate a mineral-deposit scale so that... | {
"page_id": 9572821,
"title": "Decrepitation"
} |
starting heat range of about 300-700 °C, the temperature can also increase rapidly for a few hundred degrees, such as in solid inclusions. D3 decrepitation is continuously heated until the rate reaches its maximum out at about 350-450 °C, D3 decrepitation can be observed in carbonates and is defined by the effect of an... | {
"page_id": 9572821,
"title": "Decrepitation"
} |
Gunpowder is the first explosive to have been developed. Popularly listed as one of the "Four Great Inventions" of China, it was invented during the late Tang dynasty (9th century) while the earliest recorded chemical formula for gunpowder dates to the Song dynasty (11th century). Knowledge of gunpowder spread rapidly ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
of gunpowder technology also spread throughout the Islamic world and to India, Korea, and Japan. The so-called Gunpowder Empires of the early modern period consisted of the Mughal Empire, Safavid Empire, and Ottoman Empire. The use of gunpowder in warfare during the course of the 19th century diminished due to the inve... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
quest for the elixir of life attracted many powerful patrons, one of whom was Emperor Wu of Han. One of the resulting alchemical experiments involved heating 10% sulfur and 75% saltpeter to transform them. The next reference to gunpowder occurred in the year 300 during the Jin dynasty (266–420). A Taoist philosopher by... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
China into the present day, a reminder of its heritage as a side result in the search for longevity increasing drugs. A book published in 1185 called Gui Dong (The Control of Spirits) also contains a story about a Tang dynasty alchemist whose furnace exploded, but it is not known if this was caused by gunpowder. The ea... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
the use of fire arrows was by the Southern Wu in 904 during the siege of Yuzhang. An officer under Yang Xingmi by the name of Zheng Fan (鄭璠) ordered his troops to "shoot off a machine to let fire and burn the Longsha Gate", after which he and his troops dashed over the fire into the city and captured it, and he was pro... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
the latter half of the 13th century. Rockets are recorded to have been used by the Song navy in a military exercise dated to 1245. Internal-combustion rocket propulsion is mentioned in a reference to 1264, recording that the 'ground-rat,' a type of firework, had frightened the Empress-Mother Gongsheng at a feast held i... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
for the military production complex in the capital of Kaifeng. One surviving source circa 1023 lists all the artisans working in Kaifeng while another notes that in 1083 the imperial court sent 100,000 gunpowder arrows to one garrison and 250,000 to another. Evidence of gunpowder in the Liao dynasty and Western Xia is ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
the Song army had performed against Liao forces. Realizing the weakness of Song, the Jin grew tired of waiting and captured all five of the Liao capitals themselves. They proceeded to make war on Song, initiating the Jin-Song Wars. For the first time, two major powers would have access to equally formidable gunpowder w... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
of the use of gunpowder weapons in warfare." Records show that the Jin used gunpowder arrows and trebuchets to hurl gunpowder bombs while the Song responded with gunpowder arrows, fire bombs, thunderclap bombs, and a new addition called the "molten metal bomb" (金汁炮). As the Jin account describes, when they attacked the... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
(火炮藥), rather than simply "fire medicine." This could imply the use of a new more potent formula, or simply an acknowledgement of the specialized military application of gunpowder. Peter Lorge suggests that this "bomb powder" may have been corned, making it distinct from normal gunpowder. Evidence of gunpowder firecrac... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
a thunderclap bomb was let off: It was made with paper (carton) and filled with lime and sulphur. (Launched from trebuchets) these thunderclap bombs came dropping down from the air, and upon meeting the water exploded with a noise like thunder, the sulphur bursting into flames. The carton case rebounded and broke, scat... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
even saddle themselves and trampled over each other trying to get away. Two to three thousand Jin troops were slaughtered along with eight to nine hundred horses. === Hard-shell explosives === Traditionally the inspiration for the development of the iron bomb is ascribed to the tale of a fox hunter named Iron Li. Accor... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
they were unable to match the explosive power of the Jin iron bombs. Yurong describes the uneven exchange thus, "The barbaric enemy attacked the Northwest Tower with an unceasing flow of catapult projectiles from thirteen catapults. Each catapult shot was followed by an iron fire bomb [catapult shot], whose sound was l... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
returning at a later date to search the ruins, he found that the "bones and skeletons were so mixed up that there was no way to tell who was who." === Hand cannon === The early fire lance, considered to be the ancestor of firearms, is not considered a true gun because it did not include projectiles, whereas a gun by de... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
poisonous chemicals into orifices, and the more conventional "phalanx-charging fire gourd" which shot out lead pellets. The earliest artistic depiction of what might be a hand cannon – a rock sculpture found among the Dazu Rock Carvings – is dated to 1128, much earlier than any recorded or precisely dated archaeologica... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
weighing just over six kilograms and thirty-five centimeters in length. Although the Xanadu Gun is the most precisely dated gun from the 13th century, other extant samples with approximate dating likely predate it. The Heilongjiang hand cannon is dated a decade earlier to 1288, but the dating method is based on context... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
be much larger prior to its highly corroded state at the time of discovery. While large in size, the weapon is noticeably more primitive than later Yuan dynasty guns, and is unevenly cast. A similar weapon was discovered not far from the discovery site in 1997, but much smaller in size at only 1.5 kg. Chen Bingying dis... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
not accomplished until 1234. In 1232 the Mongols besieged the Jin capital of Kaifeng and deployed gunpowder weapons along with other more conventional siege techniques such as building stockades, watchtowers, trenches, guardhouses, and forcing Chinese captives to haul supplies and fill moats. Jin scholar Liu Qi (劉祈) re... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
rips open, and the iron pieces fly in all directions. That is how it is able to kill people and horses from far away." Heaven-shaking-thunder bombs, also known as thunder crash bombs, were used prior to the siege in 1231 when a Jin general made use of them in destroying a Mongol warship. The Jin general named Wanyan Ek... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
the tube isn't destroyed." While Mongol soldiers typically held a view of disdain toward most Jin weapons, apparently they greatly feared the flying fire lance and heaven-shaking-thunder bomb. Kaifeng managed to hold out for a year before the Jin emperor fled and the city capitulated. In some cases Jin troops still fou... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
Li Zengbo was dispatched to inspect frontier city arsenals. Li considered an ideal city arsenal to include several hundred thousand iron bombshells, and also its own production facility to produce at least a couple thousand a month. The results of his tour of the border were severely disappointing and in one arsenal he... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
was probably the largest army the Mongols had ever used. Such an army was still unable to successfully storm Song city walls, as seen in the 1274 Siege of Shayang. Thus Bayan waited for the wind to change to a northerly course before ordering his artillerists to begin bombarding the city with molten metal bombs, which ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
retrospect, another development would overshadow them all, the birth of the gun. In 1280, a large store of gunpowder at Weiyang in Yangzhou accidentally caught fire, producing such a massive explosion that a team of inspectors at the site a week later deduced that some 100 guards had been killed instantly, with wooden ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
they contained gunpowder and were also packed with scrap iron. Japanese descriptions of the invasions also talk of iron and bamboo pao causing "light and fire" and emitting 2–3,000 iron bullets. The Nihon Kokujokushi, written around 1300, mentions huo tong (fire tubes) at the Battle of Tsushima in 1274 and the second c... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
guns between Europe and China before 1326, and emphasize the appearance of earlier or superior gunpowder weapons. For example, Stephen Morillo, Jeremy Black, and Paul Lococo's War in World History argues that "the sources are not entirely clear about Chinese use of gunpowder in guns. There are references to bamboo and ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
instantaneous and seamless transition into firearm warfare, as its name suggests. Furthermore, early European gunpowder recipes shared identical defects with Chinese recipes such as the inclusion of the poisons sal ammoniac and arsenic, which provide no benefit to gunpowder. Bert S. Hall explains this phenomenon in his... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
of gunpowder incendiaries. Early Muslim sources suggest that knowledge of gunpowder was acquired from China and may have been introduced by invading Mongols. This is implied by al-Rammah's usage of "terms that suggested he derived his knowledge from Chinese sources." Early Arab texts on gunpowder refer to saltpeter as ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
died in 1350. Dating from around 1320–1350, the illustrations show gunpowder weapons such as gunpowder arrows, bombs, fire tubes, and fire lances or proto-guns. The manuscript describes a type of gunpowder weapon called a midfa which uses gunpowder to shoot projectiles out of a tube at the end of a stock. Some consider... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
at the siege of Algeciras in 1343. A metal cannon firing an iron ball was described by Shihab al-Din Abu al-Abbas al-Qalqashandi between 1365 and 1376. === Europe === A common theory of how gunpowder came to Europe is that it made its way along the Silk Road through the Middle East. Another is that it was brought to Eu... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
brilliant lightning." In the early 20th century, British artillery officer Henry William Lovett Hime proposed that another work tentatively attributed to Bacon, Epistola de Secretis Operibus Artis et Naturae, et de Nullitate Magiae contained an encrypted formula for gunpowder. This claim has been disputed by historians... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
by him, known as De Nobilitatibus, sapientii et prudentiis regum (Concerning the Majesty, Wisdom, and Prudence of Kings), which displays a gun with a large arrow emerging from it and its user lowering a long stick to ignite the gun through the touchole In the same year, another similar illustration showed a darker gun ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
The Battle of Crécy in 1346 was one of the first in Europe where cannons were used. By 1350 Petrarch wrote that the presence of cannons on the battlefield was 'as common and familiar as other kinds of arms'. Around the late 14th century European and Ottoman guns began to deviate in purpose and design from guns in China... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
to local weaponry after the capture of Malacca (1511) resulted in a new type of hybrid tradition matchlock firearm, the istinggar.: 53 Saltpeter harvesting was recorded by Dutch and German travelers as being common in even the smallest villages and was collected from the decomposition process of large dung hills specif... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
by Timurid leader Shah Rukh (1405–1447), 'Abd al-Razzaq mentioned naphtha-throwers mounted on elephants and a variety of pyrotechnics put on display. Roger Pauly has written that "while gunpowder was primarily a Chinese innovation," the saltpeter that led to the invention of gunpowder may have arrived from India, altho... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
rockets. Korea also began producing cannons in 1377. The multiple rocket launcher known as hwacha ("fire cart" 火車) was developed from the juhwa and singijeon in Korea by 1409 during the Joseon Dynasty. Its inventors include Yi To (이도, not to be mistaken for Sejong the Great) and Ch'oe Hae-san, the son of Ch'oe Mu-sŏn. ... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
recorded appearance of the Fire lances in Japan was in 1409. The use of gunpowder bombs in the style of Chinese explosives is known to have occurred in Japan from at least the mid-15th century onward. The first recorded appearance of the cannon in Japan was in 1510 when a Buddhist monk presented Hōjō Ujitsuna with a te... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
the wheel. Each of these ethnic groups was aided in its use of these two pieces of cultural equipment by its link to other members of the wider religious civilization which habitually used them, and were willing to replenish their stock." – Ernest Gellner == Transition to early modern warfare == === Early Ming firearms... | {
"page_id": 12063194,
"title": "History of gunpowder"
} |
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