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Inverse-square law

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1352:(1666) in which he discussed, among other things, the relation between the height of the atmosphere and the barometric pressure at the surface. Since the atmosphere surrounds the Earth, which itself is a sphere, the volume of atmosphere bearing on any unit area of the Earth's surface is a truncated cone (which extends from the Earth's center to the vacuum of space; obviously only the section of the cone from the Earth's surface to space bears on the Earth's surface). Although the volume of a cone is proportional to the cube of its height, Hooke argued that the air's pressure at the Earth's surface is instead proportional to the height of the atmosphere because gravity diminishes with altitude. Although Hooke did not explicitly state so, the relation that he proposed would be true only if gravity decreases as the inverse square of the distance from the Earth's center. 22: 1251: 436:. Otherwise, if we want to calculate the attraction between massive bodies, we need to add all the point-point attraction forces vectorially and the net attraction might not be exact inverse square. However, if the separation between the massive bodies is much larger compared to their sizes, then to a good approximation, it is reasonable to treat the masses as a point mass located at the object's 1443: 674:, the effective origin is located far behind the beam aperture. If you are close to the origin, you don't have to go far to double the radius, so the signal drops quickly. When you are far from the origin and still have a strong signal, like with a laser, you have to travel very far to double the radius and reduce the signal. This means you have a stronger signal or have 693:, the inverse-square law is used to determine the “fall off” or the difference in illumination on a subject as it moves closer to or further from the light source. For quick approximations, it is enough to remember that doubling the distance reduces illumination to one quarter; or similarly, to halve the illumination increase the distance by a factor of 1.4 (the 1212:, in his 2020 paper "Non-Euclidean Newtonian Cosmology," elaborates on the behavior of force (F) and potential (Φ) within hyperbolic 3-space (H3). He illustrates that F and Φ obey the formulas F ∝ 1 / R^2 sinh^2(r/R) and Φ ∝ coth(r/R), where R and r represent the curvature radius and the distance from the focal point, respectively. 697:), and to double illumination, reduce the distance to 0.7 (square root of 1/2). When the illuminant is not a point source, the inverse square rule is often still a useful approximation; when the size of the light source is less than one-fifth of the distance to the subject, the calculation error is less than 1%. 1312:
Virtus autem illa, qua Sol prehendit seu harpagat planetas, corporalis quae ipsi pro manibus est, lineis rectis in omnem mundi amplitudinem emissa quasi species solis cum illius corpore rotatur: cum ergo sit corporalis imminuitur, & extenuatur in maiori spatio & intervallo, ratio autem huius
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The concept of the dimensionality of space, first proposed by Immanuel Kant, is an ongoing topic of debate in relation to the inverse-square law. Dimitria Electra Gatzia and Rex D. Ramsier, in their 2021 paper, argue that the inverse-square law pertains more to the symmetry in force distribution than
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both expounded gravitation in 1666 as an attractive force. Hooke's lecture "On gravity" was at the Royal Society, in London, on 21 March. Borelli's "Theory of the Planets" was published later in 1666. Hooke's 1670 Gresham lecture explained that gravitation applied to "all celestiall bodys" and added
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Hooke's gravitation was also not yet universal, though it approached universality more closely than previous hypotheses: See page 239 in Curtis Wilson (1989), "The Newtonian achievement in astronomy", ch.13 (pages 233–274) in "Planetary astronomy from the Renaissance to the rise of astrophysics: 2A:
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As for the power by which the Sun seizes or holds the planets, and which, being corporeal, functions in the manner of hands, it is emitted in straight lines throughout the whole extent of the world, and like the species of the Sun, it turns with the body of the Sun; now, seeing that it is corporeal,
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Sicut se habent spharicae superificies, quibus origo lucis pro centro est, amplior ad angustiorem: ita se habet fortitudo seu densitas lucis radiorum in angustiori, ad illamin in laxiori sphaerica, hoc est, conversim. Nam per 6. 7. tantundem lucis est in angustiori sphaerica superficie, quantum in
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If the moon and earth were not retained in their orbits by their animate force or some other equivalent, the earth would mount to the moon by a fifty-fourth part of their distance, and the moon fall towards the earth through the other fifty-three parts, and they would there meet, assuming, however,
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Just as spherical surfaces, for which the source of light is the center, from the wider to the narrower, so the density or fortitude of the rays of light in the narrower , towards the more spacious spherical surfaces, that is, inversely. For according to 6 & 7, there is as much light in the
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gets farther from the source, it is spread out over an area that is increasing in proportion to the square of the distance from the source. Hence, the intensity of radiation passing through any unit area (directly facing the point source) is inversely proportional to the square of the distance from
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depends on the strength of the light source and is constant with increasing distance, where a greater density of flux lines (lines per unit area) means a stronger energy field. The density of flux lines is inversely proportional to the square of the distance from the source because the surface area
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In a letter to Edmund Halley dated 20 June 1686, Newton wrote: "Bullialdus wrote that all force respecting ye Sun as its center & depending on matter must be reciprocally in a duplicate ratio of ye distance from ye center." See: I. Bernard Cohen and George E. Smith, ed.s,
248: 334: 704:(Φ) for indirectly ionizing radiation with increasing distance from a point source can be calculated using the inverse-square law. Since emissions from a point source have radial directions, they intercept at a perpendicular incidence. The area of such a shell is 4π 838:
would decrease by 6.02 dB per doubling of distance. When referring to measurements of power quantities, a ratio can be expressed as a level in decibels by evaluating ten times the base-10 logarithm of the ratio of the measured quantity to the reference value.
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Within the realm of non-Euclidean geometries and general relativity, deviations from the inverse-square law might not stem from the law itself but rather from the assumption that the force between bodies depends instantaneously on distance, contradicting
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The force of attraction or repulsion between two electrically charged particles, in addition to being directly proportional to the product of the electric charges, is inversely proportional to the square of the distance between them; this is known as
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The gravitational attraction force between two point masses is directly proportional to the product of their masses and inversely proportional to the square of their separation distance. The force is always attractive and acts along the line joining
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the principles that the gravitating power decreases with distance and that in the absence of any such power bodies move in straight lines. By 1679, Hooke thought gravitation had inverse square dependence and communicated this in a letter to
740:). At large distances from the source (compared to the size of the source), this power is distributed over larger and larger spherical surfaces as the distance from the source increases. Since the surface area of a sphere of radius 160: 167: 1888:
If two stones were placed in any part of the world near each other, and beyond the sphere of influence of a third cognate body, these stones, like two magnetic needles, would come together in the intermediate point,
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it becomes weaker and attenuated at a greater distance or interval, and the ratio of its decrease in strength is the same as in the case of light, namely, the duplicate proportion, but inversely, of the distances .
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Note: Both Kepler and William Gilbert had nearly anticipated the modern conception of gravity, lacking only the inverse-square law in their description of "gravitas". On page 4 of chapter 1, Introductio, of
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Gravity is a mutual affection between cognate bodies towards union or conjunction (similar in kind to the magnetic virtue), so that the earth attracts a stone much rather than the stone seeks the earth.
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Every corporeal substance, so far forth as it is corporeal, has a natural fitness for resting in every place where it may be situated by itself beyond the sphere of influence of a body cognate with it.
1092: 870:, the decrease is still 6.02 dB, since dB represents an intensity ratio. The pressure ratio (as opposed to power ratio) is not inverse-square, but is inverse-proportional (inverse distance law): 573: 459:'s solution for circular motion (motion in a straight line pulled aside by the central force). Indeed, Bullialdus maintained the sun's force was attractive at aphelion and repulsive at perihelion. 1447: 1243:
stating that "the latitude of a uniformly difform movement corresponds to the degree of the midpoint" and used this method to study the quantitative decrease in intensity of illumination in his
1970: 1304:(1605–1694) refuted Johannes Kepler's suggestion that "gravity" weakens as the inverse of the distance; instead, Bullialdus argued, "gravity" weakens as the inverse square of the distance: 1170: 1003: 910: 1834: 724:
of heat “as the point source is magnification by distances, its radiation is dilute proportional to the sin of the angle, of the increasing circumference arc from the point of origin”.
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from the source of that physical quantity. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space.
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which is the resultant of radial inverse-square law fields with respect to one or more sources is proportional to the strength of the local sources, and hence zero outside sources.
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Newton acknowledged Wren, Hooke and Halley in this connection in the Scholium to Proposition 4 in Book 1 (in all editions): See for example the 1729 English translation of the
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In mathematical notation the inverse square law can be expressed as an intensity (I) varying as a function of distance (d) from some centre. The intensity is proportional (see
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acknowledged that Hooke, along with Wren and Halley, had separately appreciated the inverse square law in the solar system, as well as giving some credit to Bullialdus.
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of the particle velocity that is 90° out of phase with the sound pressure and does not contribute to the time-averaged energy or the intensity of the sound. The
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treatment planning, though this proportionality does not hold in practical situations unless source dimensions are much smaller than the distance. As stated in
1224:. General relativity instead interprets gravity as a distortion of spacetime, causing freely falling particles to traverse geodesics in this curved spacetime. 432:
If the distribution of matter in each body is spherically symmetric, then the objects can be treated as point masses without approximation, as shown in the
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of a sphere increases with the square of the radius. Thus the field intensity is inversely proportional to the square of the distance from the source.
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component of the RMS particle velocity, both of which are inverse-proportional. Accordingly, the intensity follows an inverse-square behaviour:
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Williams, E.; Faller, J.; Hill, H. (1971), "New Experimental Test of Coulomb's Law: A Laboratory Upper Limit on the Photon Rest Mass",
243:{\displaystyle {\frac {{\text{intensity}}_{1}}{{\text{intensity}}_{2}}}={\frac {{\text{distance}}_{2}^{2}}{{\text{distance}}_{1}^{2}}}} 1936:
Translation of the Latin quote from Bullialdus' 'Astronomia Philolaica' … is from: O'Connor, John J. and Roberson, Edmund F. (2006)
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is similarly applicable, and can be used with any physical quantity that acts in accordance with the inverse-square relationship.
1452: 329:{\displaystyle {\text{intensity}}_{1}\times {\text{distance}}_{1}^{2}={\text{intensity}}_{2}\times {\text{distance}}_{2}^{2}} 1247:(ca. 1349), stating that it was not linearly proportional to the distance, but was unable to expose the Inverse-square law. 659:(1 AU)—an approximate threefold increase in distance results in an approximate ninefold decrease in intensity of radiation. 1947:, The MacTutor History of Mathematics Archive, School of Mathematics and Statistics, University of Saint Andrews, Scotland. 1376: 452: 939: 1109:
is zero outside the source. This can be generalized to higher dimensions. Generally, for an irrotational vector field in
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my supposition is that the attraction always is in duplicate proportion to the distance from the center reciprocall
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return, so the inverse square for both paths means that the radar will receive energy according to the inverse
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narrower spherical surface, as in the wider, thus it is as much more compressed and dense here than there.
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varies inversely with the square of the distance from the source (assuming there are no losses caused by
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Hooke remained bitter about Newton claiming the invention of this principle, even though Newton's 1686
404: 1925: 1937: 1239:, was one of the first to express functional relationships in graphical form. He gave a proof of the 1102: 1755: 1194:. The inherent curvature in these spaces impacts physical laws, underpinning various fields such as 1729: 464: 1623: 1429: 383: 91:, which acts like a canal does for water, or how a gun barrel restricts hot gas expansion to one 1851:"The Archaeology of the Inverse Square Law: (1) Metaphysical Images and Mathematical Practices," 1409: 1187: 1117:, the intensity "I" of the vector field falls off with the distance "r" following the inverse ( 25:
S represents the light source, while r represents the measured points. The lines represent the
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in three-dimensional space, the inverse-square law corresponds to the property that the
736:  be the total power radiated from a point source (for example, an omnidirectional 712:
is the radial distance from the center. The law is particularly important in diagnostic
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each approaching the other by a space proportional to the comparative mass of the other
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imminutionis eadem est, ac luminus, in ratione nempe dupla intervallorum, sed eversa.
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argued that the spreading of light from a point source obeys an inverse square law:
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in the direction of the narrow beam relative to a wide beam in all directions of an
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of the Medicean planets deduced from physical causes] (Florence, (Italy): 1666)
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discussed the inverse-square law and how it affects the intensity of light.
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In Ismaelis Bullialdi astronomiae philolaicae fundamenta inquisitio brevis
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is the attraction between objects that have mass. Newton's law states:
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the earth attracts a stone much rather than the stone seeks the earth"
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The energy or intensity decreases (divided by 4) as the distance
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Kepler is breaking away from the Aristotelian tradition that objects
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The inverse-square law generally applies when some force, energy, or
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Ad Vitellionem Paralipomena, quibus astronomiae pars optica traditur
1337:(1653) and publicized the planetary astronomy of Kepler in his book 1264:
Ad Vitellionem paralipomena, quibus astronomiae pars optica traditur
504:. The deviation of the exponent from 2 is less than one part in 10. 1708: 1691: 1539: 63: 87:
while propagating a signal, certain methods can be used such as a
1524:(1952). "An Unpublished Letter of Robert Hooke to Isaac Newton". 867: 835: 701: 420: 39: 1876:"The true theory of gravity is founded on the following axioms: 1333:(1617–1689) publicized the ideas of Bullialdus in his critique 862:
radiating from a point source decreases by 50% as the distance
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Before Galileo: The Birth of Modern Science in Medieval Europe
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given that the space outside the source is divergence free.
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emanating from the sources and fluxes. The total number of
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Hooke's letter to Newton of 6 January 1680 (Koyré 1952:332).
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fusiore, tanto ergo illie stipatior & densior quam hic.
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Theoricae Mediceorum Planetarum ex Causis Physicis Deductae
1361: 821:{\displaystyle I={\frac {P}{A}}={\frac {P}{4\pi r^{2}}}.\,} 655:); but only 1367 watts per square meter at the distance of 644: 375: 72:
energy expands during both the signal transmission and the
26: 1607:(Cambridge, England: Cambridge University Press, 2002), 1087:{\displaystyle I\ =\ pv\ \propto \ {\frac {1}{r^{2}}}.\,} 640: 568:{\displaystyle F=k_{\text{e}}{\frac {q_{1}q_{2}}{r^{2}}}} 111:) to the reciprocal of the square of the distance thus: 398:) is proportional to the square of the radius, as the 1756:"Dimensionality, symmetry and the Inverse Square Law" 1129: 1035: 971: 948: 923: 878: 769: 512: 258: 170: 117: 50:
stating that the observed "intensity" of a specified
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follows an inverse-square law, as do the effects of
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that the substance of both is of the same density."
1793:"Introduction to Non-Euclidean General Relativity" 1754:Gatzia, Dimitria Electra; Ramsier, Rex D. (2021). 1620: 1164: 1086: 997: 955: 930: 904: 820: 567: 328: 242: 164:It can also be mathematically expressed as : 154: 1992:Sound pressure p and the inverse distance law 1/r 1744: 1669:Ryer,A. (1997) “The Light Measurement Handbook”, 639:For example, the intensity of radiation from the 252:or as the formulation of a constant quantity: 95:in order to prevent loss of energy transfer to a 1998: 1520: 1860: : 391–414 ; see especially p. 397. 759:(power per unit area) of radiation at distance 1874:, Kepler sets out his description as follows: 1849:is from: Gal, O. & Chen-Morris, R.(2005) 1658:Lighting for Film and Television – 3rd Edition 1165:{\displaystyle I\propto {\frac {1}{r^{n-1}}},} 1096: 1845:Translation of the Latin quote from Kepler's 1753: 1685: 1683: 1177: 998:{\displaystyle v\ \propto {\frac {1}{r}}\ \,} 905:{\displaystyle p\ \propto \ {\frac {1}{r}}\,} 700:The fractional reduction in electromagnetic 1956:(Gal & Chen-Morris, 2005), pp. 391–392. 1907:to be in their natural place, that a stone 440:while calculating the gravitational force. 1680: 1490:The History of the Royal Society of London 1969:… (London, England: John Martyn, 1667), 1707: 1083: 994: 952: 927: 901: 817: 578:Light and other electromagnetic radiation 151: 1514: 1249: 20: 1262:In proposition 9 of Book 1 in his book 1182:The inverse-square law, fundamental in 598:or other linear waves radiating from a 1999: 1689: 1492:, … (London, England: 1756), vol. 2, 942:with the instantaneous sound pressure 914:The same is true for the component of 1245:Summa logicæ et philosophiæ naturalis 348:Newton's law of universal gravitation 1987:Damping of sound level with distance 1344:In 1663–1664, the English scientist 1306: 1272: 647:per square meter at the distance of 1692:"Non-Euclidean Newtonian Cosmology" 13: 617:per unit area in the direction of 378:is evenly radiated outward from a 14: 2023: 1980: 1924:… (Paris, France: Piget, 1645), 1605:The Cambridge Companion to Newton 1479:Tycho Brahe to Newton", CUP 1989. 1393:William Thomson, 1st Baron Kelvin 1377:Kepler's laws of planetary motion 842: 488: 1446: This article incorporates 1441: 1329:In England, the Anglican bishop 1216:to the dimensionality of space. 609:More generally, the irradiance, 451:. But Bullialdus did not accept 443:As the law of gravitation, this 369: 1959: 1950: 1930: 1914: 1863: 1839: 1823: 1810: 1785: 1663: 1459:General Services Administration 1650: 1614: 1596: 1579: 1570: 1499: 1482: 1472: 453:Kepler's second and third laws 415: 410: 1: 1696:Classical and Quantum Gravity 1496:; see especially pages 70–72. 1435: 1398:Power-aware routing protocols 7: 1847:Ad Vitellionem paralipomena 1355: 1300:..., the French astronomer 1097:Field theory interpretation 834:is doubled; if measured in 606:(in the same time period). 10: 2028: 1798:. MIT OpenCourseWare. 2018 1645:10.1103/PhysRevLett.26.721 1505:Giovanni Alfonso Borelli, 1227: 1178:Non-Euclidean implications 1121: − 1) power law 727: 492: 102: 1103:irrotational vector field 447:was suggested in 1645 by 1943:30 November 2016 at the 1726:10.1088/1361-6382/ab8437 1690:Barrow, John D. (2020). 1310: 1276: 1188:non-Euclidean geometries 1186:spaces, also applies to 866:is doubled; measured in 465:Giovanni Alfonso Borelli 455:, nor did he appreciate 376:other conserved quantity 1899:Notice that in saying " 1624:Physical Review Letters 1430:Principle of similitude 1405:Inverse proportionality 1266:(1604), the astronomer 1023:sound pressure and the 405:Gauss's law for gravity 384:three-dimensional space 83:To prevent dilution of 1772:10.1098/rsnr.2019.0044 1454:Federal Standard 1037C 1448:public domain material 1410:Multiplicative inverse 1318: 1284: 1259: 1166: 1088: 1019:is the product of the 999: 957: 932: 906: 822: 569: 430: 330: 244: 156: 56:inversely proportional 35: 2007:Philosophy of physics 1922:Astronomia Philolaica 1911:to be with the earth. 1348:was writing his book 1339:Astronomia geometrica 1298:Astronomia Philolaica 1296:In 1645, in his book 1253: 1167: 1089: 1000: 958: 933: 907: 823: 570: 425: 331: 245: 157: 24: 1656:Millerson,G. (1991) 1235:of the 14th-century 1127: 1033: 1013:quadrature component 969: 946: 921: 876: 767: 510: 256: 168: 115: 1920:Ismail Bullialdus, 1732:on 25 February 2020 1718:2020CQGra..37l5007B 1637:1971PhRvL..26..721W 1465:on 22 January 2022. 956:{\displaystyle p\,} 931:{\displaystyle v\,} 664:isotropic radiators 325: 290: 237: 220: 1854:History of Science 1387:Telecommunications 1260: 1254:German astronomer 1241:mean speed theorem 1237:Oxford Calculators 1222:special relativity 1200:general relativity 1162: 1084: 995: 953: 928: 902: 818: 738:isotropic radiator 670:, headlights, and 668:parabolic antennas 613:the intensity (or 565: 457:Christiaan Huygens 403:the point source. 326: 309: 274: 240: 221: 204: 152: 44:inverse-square law 36: 2012:Scientific method 1938:"Ismael Boulliau" 1829:Johannes Kepler, 1760:Notes and Records 1327: 1326: 1302:Ismaël Bullialdus 1293: 1292: 1157: 1078: 1062: 1056: 1047: 1041: 993: 989: 977: 916:particle velocity 899: 890: 884: 812: 784: 680:isotropic antenna 563: 526: 449:Ismaël Bullialdus 400:emitted radiation 394:(which is 4π 313: 298: 278: 263: 238: 225: 208: 197: 189: 177: 149: 141: 131: 125: 121: 52:physical quantity 2019: 1974: 1963: 1957: 1954: 1948: 1934: 1928: 1918: 1912: 1867: 1861: 1843: 1837: 1827: 1821: 1814: 1808: 1807: 1805: 1803: 1797: 1789: 1783: 1782: 1780: 1778: 1751: 1742: 1741: 1739: 1737: 1728:. Archived from 1711: 1687: 1678: 1667: 1661: 1654: 1648: 1647: 1618: 1612: 1600: 1594: 1583: 1577: 1574: 1568: 1567: 1522:Koyré, Alexandre 1518: 1512: 1503: 1497: 1486: 1480: 1476: 1467: 1466: 1461:. Archived from 1445: 1444: 1389:, particularly: 1307: 1273: 1192:hyperbolic space 1171: 1169: 1168: 1163: 1158: 1156: 1155: 1137: 1093: 1091: 1090: 1085: 1079: 1077: 1076: 1064: 1060: 1054: 1045: 1039: 1004: 1002: 1001: 996: 991: 990: 982: 975: 962: 960: 959: 954: 937: 935: 934: 929: 911: 909: 908: 903: 900: 892: 888: 882: 827: 825: 824: 819: 813: 811: 810: 809: 790: 785: 777: 695:square root of 2 574: 572: 571: 566: 564: 562: 561: 552: 551: 550: 541: 540: 530: 528: 527: 524: 335: 333: 332: 327: 324: 319: 314: 311: 305: 304: 299: 296: 289: 284: 279: 276: 270: 269: 264: 261: 249: 247: 246: 241: 239: 236: 231: 226: 223: 219: 214: 209: 206: 203: 198: 196: 195: 190: 187: 184: 183: 178: 175: 172: 161: 159: 158: 153: 150: 148: 147: 142: 139: 133: 129: 123: 122: 119: 2027: 2026: 2022: 2021: 2020: 2018: 2017: 2016: 1997: 1996: 1983: 1978: 1977: 1964: 1960: 1955: 1951: 1945:Wayback Machine 1935: 1931: 1919: 1915: 1872:Astronomia Nova 1868: 1864: 1844: 1840: 1828: 1824: 1815: 1811: 1801: 1799: 1795: 1791: 1790: 1786: 1776: 1774: 1752: 1745: 1735: 1733: 1688: 1681: 1668: 1664: 1655: 1651: 1631:(12): 721–724, 1619: 1615: 1601: 1597: 1584: 1580: 1575: 1571: 1519: 1515: 1504: 1500: 1487: 1483: 1477: 1473: 1451: 1442: 1440: 1438: 1425:Square–cube law 1367:Antenna (radio) 1358: 1323: 1315: 1295: 1289: 1281: 1268:Johannes Kepler 1256:Johannes Kepler 1230: 1180: 1145: 1141: 1136: 1128: 1125: 1124: 1115:Euclidean space 1099: 1072: 1068: 1063: 1034: 1031: 1030: 1017:sound intensity 981: 970: 967: 966: 947: 944: 943: 922: 919: 918: 891: 877: 874: 873: 845: 805: 801: 794: 789: 776: 768: 765: 764: 730: 580: 557: 553: 546: 542: 536: 532: 531: 529: 523: 519: 511: 508: 507: 497: 491: 418: 413: 372: 320: 315: 310: 300: 295: 294: 285: 280: 275: 265: 260: 259: 257: 254: 253: 232: 227: 222: 215: 210: 205: 202: 191: 186: 185: 179: 174: 173: 171: 169: 166: 165: 143: 138: 137: 132: 118: 116: 113: 112: 105: 17: 12: 11: 5: 2025: 2015: 2014: 2009: 1995: 1994: 1989: 1982: 1981:External links 1979: 1976: 1975: 1965:Robert Hooke, 1958: 1949: 1929: 1913: 1862: 1838: 1822: 1809: 1784: 1766:(2): 333–347. 1743: 1702:(12): 125007. 1679: 1662: 1649: 1613: 1595: 1578: 1569: 1540:10.1086/348155 1534:(4): 312–337. 1513: 1498: 1488:Thomas Birch, 1481: 1470: 1469: 1437: 1434: 1433: 1432: 1427: 1422: 1417: 1415:Distance decay 1412: 1407: 1402: 1401: 1400: 1395: 1384: 1382:Kepler problem 1379: 1374: 1369: 1364: 1357: 1354: 1325: 1324: 1316: 1291: 1290: 1282: 1233:John Dumbleton 1229: 1226: 1210:John D. Barrow 1179: 1176: 1161: 1154: 1151: 1148: 1144: 1140: 1135: 1132: 1098: 1095: 1082: 1075: 1071: 1067: 1059: 1053: 1050: 1044: 1038: 988: 985: 980: 974: 951: 926: 898: 895: 887: 881: 853:sound pressure 844: 843:Sound in a gas 841: 816: 808: 804: 800: 797: 793: 788: 783: 780: 775: 772: 748: = 4 729: 726: 722:Fourier theory 691:stage lighting 579: 576: 560: 556: 549: 545: 539: 535: 522: 518: 515: 495:Electrostatics 493:Main article: 490: 489:Electrostatics 487: 438:center of mass 417: 414: 412: 409: 371: 368: 323: 318: 308: 303: 293: 288: 283: 273: 268: 235: 230: 218: 213: 201: 194: 182: 146: 136: 128: 104: 101: 80:of the range. 48:scientific law 15: 9: 6: 4: 3: 2: 2024: 2013: 2010: 2008: 2005: 2004: 2002: 1993: 1990: 1988: 1985: 1984: 1972: 1968: 1962: 1953: 1946: 1942: 1939: 1933: 1927: 1923: 1917: 1910: 1906: 1902: 1898: 1894: 1892: 1885: 1884: 1880: 1877: 1873: 1866: 1859: 1855: 1852: 1848: 1842: 1836: 1832: 1826: 1819: 1816:John Freely, 1813: 1794: 1788: 1773: 1769: 1765: 1761: 1757: 1750: 1748: 1731: 1727: 1723: 1719: 1715: 1710: 1705: 1701: 1697: 1693: 1686: 1684: 1676: 1675:0-9658356-9-3 1672: 1666: 1659: 1653: 1646: 1642: 1638: 1634: 1630: 1626: 1625: 1617: 1610: 1606: 1599: 1592: 1588: 1582: 1573: 1565: 1561: 1557: 1553: 1549: 1545: 1541: 1537: 1533: 1529: 1528: 1523: 1517: 1510: 1509: 1502: 1495: 1491: 1485: 1475: 1471: 1468: 1464: 1460: 1456: 1455: 1449: 1431: 1428: 1426: 1423: 1421: 1420:Fermi paradox 1418: 1416: 1413: 1411: 1408: 1406: 1403: 1399: 1396: 1394: 1391: 1390: 1388: 1385: 1383: 1380: 1378: 1375: 1373: 1370: 1368: 1365: 1363: 1360: 1359: 1353: 1351: 1347: 1342: 1340: 1336: 1332: 1322: 1317: 1314: 1309: 1308: 1305: 1303: 1299: 1288: 1283: 1280: 1275: 1274: 1271: 1269: 1265: 1257: 1252: 1248: 1246: 1242: 1238: 1234: 1225: 1223: 1217: 1213: 1211: 1207: 1205: 1204:string theory 1201: 1197: 1193: 1189: 1185: 1175: 1172: 1159: 1152: 1149: 1146: 1142: 1138: 1133: 1130: 1122: 1120: 1116: 1113:-dimensional 1112: 1108: 1104: 1094: 1080: 1073: 1069: 1065: 1057: 1051: 1048: 1042: 1036: 1028: 1026: 1022: 1018: 1014: 1010: 1005: 986: 983: 978: 972: 964: 949: 941: 924: 917: 912: 896: 893: 885: 879: 871: 869: 865: 861: 858: 854: 850: 840: 837: 833: 828: 814: 806: 802: 798: 795: 791: 786: 781: 778: 773: 770: 762: 758: 755: 751: 747: 743: 739: 735: 725: 723: 719: 715: 711: 707: 703: 698: 696: 692: 688: 683: 681: 677: 673: 669: 665: 660: 658: 654: 650: 646: 642: 637: 635: 631: 627: 624: 620: 616: 612: 607: 605: 601: 597: 593: 589: 585: 575: 558: 554: 547: 543: 537: 533: 520: 516: 513: 505: 503: 502:Coulomb's law 496: 486: 484: 483: 477: 475: 471: 466: 462: 458: 454: 450: 446: 441: 439: 435: 434:shell theorem 429: 424: 422: 408: 406: 401: 397: 393: 389: 386:. Since the 385: 381: 377: 370:Justification 367: 365: 361: 357: 353: 349: 345: 341: 336: 321: 316: 306: 301: 291: 286: 281: 271: 266: 250: 233: 228: 216: 211: 199: 192: 180: 162: 144: 134: 126: 110: 100: 98: 94: 90: 86: 81: 79: 75: 71: 67: 65: 61: 57: 53: 49: 45: 41: 32: 28: 23: 19: 1967:Micrographia 1966: 1961: 1952: 1932: 1921: 1916: 1908: 1904: 1900: 1895: 1890: 1887: 1882: 1881: 1878: 1875: 1871: 1865: 1857: 1853: 1846: 1841: 1830: 1825: 1817: 1812: 1800:. Retrieved 1787: 1775:. Retrieved 1763: 1759: 1734:. Retrieved 1730:the original 1699: 1695: 1665: 1657: 1652: 1628: 1622: 1616: 1604: 1598: 1586: 1581: 1572: 1531: 1525: 1516: 1507: 1501: 1489: 1484: 1474: 1463:the original 1453: 1439: 1350:Micrographia 1349: 1346:Robert Hooke 1343: 1338: 1334: 1328: 1319: 1311: 1297: 1294: 1285: 1277: 1263: 1261: 1244: 1231: 1218: 1214: 1208: 1190:, including 1181: 1173: 1123: 1118: 1110: 1100: 1029: 1024: 1006: 965: 913: 872: 863: 846: 831: 829: 760: 756: 749: 745: 741: 733: 731: 718:radiotherapy 709: 705: 699: 684: 676:antenna gain 661: 638: 610: 608: 600:point source 581: 506: 498: 480: 478: 473: 470:Isaac Newton 461:Robert Hooke 442: 431: 426: 419: 395: 388:surface area 380:point source 373: 344:vector field 337: 251: 163: 106: 82: 78:fourth power 68: 43: 37: 18: 16:Physical law 1494:pages 68–73 1372:Gauss's law 714:radiography 687:photography 619:propagation 588:illuminance 421:Gravitation 416:Gravitation 411:Occurrences 366:phenomena. 2001:Categories 1709:2002.10155 1591:at page 66 1436:References 1107:divergence 1009:near field 634:scattering 630:absorption 592:irradiance 340:divergence 31:flux lines 1971:page 227: 1587:Principia 1331:Seth Ward 1196:cosmology 1184:Euclidean 1150:− 1134:∝ 1058:∝ 979:∝ 886:∝ 860:wavefront 857:spherical 849:acoustics 799:π 754:intensity 626:wavefront 623:spherical 584:intensity 482:Principia 364:radiation 307:× 297:intensity 272:× 262:intensity 188:intensity 176:intensity 127:∝ 120:intensity 93:dimension 89:waveguide 74:reflected 1941:Archived 1926:page 23. 1835:page 10. 1609:page 204 1564:41626961 1556:13010921 1356:See also 1341:(1656). 1025:in-phase 940:in-phase 938:that is 666:such as 662:For non- 643:is 9126 621:), of a 352:electric 312:distance 277:distance 224:distance 207:distance 140:distance 64:distance 1802:30 July 1777:30 July 1736:30 July 1714:Bibcode 1633:Bibcode 1228:History 1101:For an 1007:In the 728:Example 702:fluence 651:(0.387 649:Mercury 103:Formula 62:of the 58:to the 46:is any 40:science 1820:(2012) 1673:  1562:  1554:  1548:227384 1546:  1202:, and 1061:  1055:  1046:  1040:  992:  976:  889:  883:  851:, the 752:, the 708:where 672:lasers 604:energy 392:sphere 362:, and 130:  124:  97:bullet 85:energy 60:square 1909:seeks 1796:(PDF) 1704:arXiv 1560:S2CID 1544:JSTOR 1450:from 1011:is a 855:of a 657:Earth 645:watts 615:power 611:i.e., 596:light 594:) of 428:them. 390:of a 360:sound 356:light 342:of a 70:Radar 42:, an 1905:seek 1886:... 1804:2023 1779:2023 1738:2023 1677:p.26 1671:ISBN 1660:p.27 1552:PMID 1527:Isis 1362:Flux 732:Let 716:and 689:and 586:(or 582:The 463:and 338:The 27:flux 1768:doi 1722:doi 1641:doi 1536:doi 1021:RMS 847:In 763:is 744:is 685:In 641:Sun 636:). 632:or 590:or 472:: 445:law 382:in 54:is 38:In 2003:: 1973:"" 1858:43 1856:, 1764:75 1762:. 1758:. 1746:^ 1720:. 1712:. 1700:37 1698:. 1694:. 1682:^ 1639:, 1629:26 1627:, 1589:, 1558:. 1550:. 1542:. 1532:43 1530:. 1457:. 1206:. 1198:, 963:: 868:dB 836:dB 750:πr 682:. 653:AU 476:. 358:, 354:, 99:. 1893:. 1806:. 1781:. 1770:: 1740:. 1724:: 1716:: 1706:: 1643:: 1635:: 1611:. 1593:. 1566:. 1538:: 1160:, 1153:1 1147:n 1143:r 1139:1 1131:I 1119:n 1111:n 1081:. 1074:2 1070:r 1066:1 1052:v 1049:p 1043:= 1037:I 987:r 984:1 973:v 950:p 925:v 897:r 894:1 880:p 864:r 832:r 815:. 807:2 803:r 796:4 792:P 787:= 782:A 779:P 774:= 771:I 761:r 757:I 746:A 742:r 734:P 710:r 706:r 559:2 555:r 548:2 544:q 538:1 534:q 525:e 521:k 517:= 514:F 396:r 322:2 317:2 302:2 292:= 287:2 282:1 267:1 234:2 229:1 217:2 212:2 200:= 193:2 181:1 145:2 135:1 109:∝

Index


flux
flux lines
science
scientific law
physical quantity
inversely proportional
square
distance
Radar
reflected
fourth power
energy
waveguide
dimension
bullet

divergence
vector field
Newton's law of universal gravitation
electric
light
sound
radiation
other conserved quantity
point source
three-dimensional space
surface area
sphere
emitted radiation

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