Fisika

Fisika(tinaBasa Yunaniφυσικός (physikos):natural, tina φύσις (physis):Alam) mangrupaélmuAlam tina jihat nu panglegana.Fisikawanngulik paripolah jeung interaksizatjeunggaya.Hukum fisikaumumna diwujudkeun dina rupa hubunganmatematis.
Fisika raket pisan hubunganana jeungélmu alamséjén, utamanakimia, élmumolekuljeung senyawa kimia nu dibentukna. Kimia mirip pisan jeung fisika, utamana dinamékanika kuantum,térmodinamikajeungéléktromagnétisme. Ngan, ku sabab fénoména kimiawi nu kompléks jeung kacida lobana ngajadikeun kimia salawasna dianggap salaku disiplin nu misah.
Di handap ieu hiji ihtisar sub-widang jeung konsép utama dina fisika, disusul tepus ku ringkesan sajarah fisika jeung sub-widangna.Béréndélan jejernu leuwih lengkep ogé aya.
Catetan: di handap ieu mangrupa ihtisar ringkes tumuwuhna fisika. Pikeun leuwih jéntré, baca artikel utama subjék ieu,Sajarah fisika.
Geus ti jaman baheula manusa nyoba neuleuman paripolah zat: naha apel bet ragrag kana taneuh, naha barang nu béda boga sipat nu béda, jeung saterusna. Ogé ngeunaan karaktermayapada, samodél bentuk Bumi jeung paripolahcelestial objectsamodélpanonpoéjeungbulan. Sababaraha téori geus diajukeun, tétéla lolobana salah. Téori-téori ieu umumna kedal dina istilahfilosofis, teu kungsi dibuktikeun maké uji éksperimén nu sistematis. There were exceptions and there areanachronisms: for example, theGreekthinkerArchimedesderived many correct quantitative descriptions of mechanics and hydrostatics.
Munggaranabad ka-17,Galiléonaratas dipakéna ékspérimén pikeun ngabuktikeun téori-téori fisik, nu jadi ide konci dinamétode ilmiah. Galiléo geus sacara suksés ngarumuskeun jeung nguji sababaraha hasil panalungtikan ngeunaandinamika, utamana HukumInersia. Dina taun1687,Newtonpublished thePrincipia Mathematica, detailing two comprehensive and successful physical théories:Newton's laws of motion, from which ariseclassical mechanics; andNewton's Law of Gravitation, which describes thefundamental forceofgravity. Both théories agreed well with experiment. Classical mechanics would be exhaustively extended byLagrange,Hamilton, and others, who produced new formulations, principles, and results. The Law of Gravitation initiated the field ofastrophysics, which describesastronomicalphenomena using physical théories.
From the18th centuryonwards,thermodynamicswas developed byBoyle,Young, and many others. In1733,Bernoulliused statistical arguments with classical mechanics to derive thermodynamic results, initiating the field ofstatistical mechanics. In1798,Thompsondemonstrated the conversion of mechanical work into héat, and in1847Joulestated the law of conservation ofenergy, in the form of héat as well as mechanical energy.
The behavior ofelectricityandmagnetismwas studied byFaraday,Ohm, and others. In1855,Maxwellunified the two phenomena into a single théory ofelectromagnetism, described byMaxwell's equations. A prediction of this théory was thatlightis anelectromagnetic wave.
In1895,RoentgendiscoveredX-rays, which turned out to be high-frequency electromagnetic radiation.Radioactivitywas discovered in1896byHenri Becquerel, and further studied byPierre CurieandMarie Curieand others. This initiated the field ofnuclear physics.
In1897,Thomsondiscovered theelectron, the elementary particle which carries electrical current in circuits. In1904, he proposed the first modél of theatom, known as theplum pudding model. (The existence of the atom had been proposed in1808byDalton.)
In1905, Einstein formulated the théory ofspecial relativity, unifying space and time into a single entity,spacetime. Relativity prescribes a different transformation betweenreference framesthan classical mechanics; this necessitated the development of relativistic mechanics as a replacement for classical mechanics. In the regime of low (relative) velocities, the two théories agree. In1915, Einstein extended special relativity to explain gravity with thegeneral theory of relativity, which replaces Newton's law of gravitation. In the regime of low masses and énérgies, the two théories agree.
In1911,Rutherforddeduced fromscattering experimentsthe existence of a compact atomic nucleus, with positively charged constituents dubbedprotons.Neutrons, the neutral nucléar constituents, were discovered in1932byChadwick.
Beginning in1900,Planck,Einstein,Bohr, and others developedquantumthéories to explain various anomalous experimental results by introducing discrete energy levels. In1925,Heisenbergand1926,SchrödingerandDiracformulatedquantum mechanics, which explained the preceding quantum théories. In quantum mechanics, the outcomes of physical méasurements are inherentlyprobabilistic; the théory describes the calculation of these probabilities. It successfully describes the behavior of matter at small distance scales.
Quantum mechanics also provided the théoretical tools forcondensed matter physics, which studies the physical behavior of solids and liquids, including phenomena such ascrystal structures,semiconductivity, andsuperconductivity. The pioneers of condensed matter physics includeBloch, who créated a quantum mechanical description of the behavior of electrons in crystal structures in1928.
DuringWorld War II, reséarch was conducted by éach side intonuclear physics, for the purpose of créating anuclear bomb. The German effort, led by Heisenberg, did not succeed, but the AlliedManhattan Projectréached its goal. In America, a téam led byFermiachieved the first man-madenuclear chain reactionin1942, and in1945the world's firstnuclear explosivewas detonated atTrinity site, néarAlamogordo,New Mexico.
Quantum field theorywas formulated in order to extend quantum mechanics to be consistent with special relativity. It achieved its modérn form in the late1940swith work byFeynman,Schwinger,Tomonaga, andDyson. They formulated the théory ofquantum electrodynamics, which describes the electromagnetic interaction.
Quantum field théory provided the framework for modérnparticle physics, which studiesfundamental forcesand elementary particles. In1954,YangandMillsdeveloped a class ofgauge theories, which provided the framework for theStandard Model. The Standard modél, which was completed in the1970s, successfully describes almost all elementary particles observed to date.
As of2003, reséarch is progressing on a large number of fields of physics.
Incondensed matter physics, the biggest unsolved théoretical problem is the explanation forhigh-temperature superconductivity. Strong efforts, largely experimental, are being put into making workablespintronicsandquantum computers.
In particle physics, the first pieces of experimental evidence for physics beyond theStandard Modelhave begun to appéar. Foremost amongst this are indications thatneutrinoshave non-zeromass. These experimental results appéar to have solved the long-standingsolar neutrino problemin solar physics. The physics of massive neutrinos is currently an aréa of active théoretical and experimental reséarch. In the next several yéars,particle acceleratorswill begin probing energy scales in theTeVrange, in which experimentalists are hoping to find evidence for thehiggs bosonandsupersymmetric particles.
Théoretical attempts to unifyquantum mechanicsandgeneral relativityinto a single théory ofquantum gravity, a program ongoing for over half a century, has yet to béar fruit. The current léading candidates areM-theoryandloop quantum gravity.
Manyastronomicalphenomena have yet to be explained, including the existence ofultra-high energy cosmic raysand theanomalous rotation rates of galaxies. Théories that have been proposed to resolve these problems includedoubly-special relativity,modified Newtonian dynamics, and the existence ofdark matter. In addition, the cosmological predictions of the last several decades have been contradicted by recent evidence that theexpansion of the universe is accelerating.
TingaliMasalah nu teu bisa dipeupeuskeunpikeun "fuller treatment" tina subjek ieu.
See the definition ofphysical.
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