An exoplanet (UK: /ˈɛk.soʊˌplæn.ɪt/, US: /ˌɛk.soʊˈplæn.ɪt/)[4] or extrasolar planet is a planet outside the Solar System. The first evidence of an exoplanet was noted in 1917, but was not recognized as such.[5] The first scientific detection of an exoplanet was in 1988; it was confirmed to be an exoplanet in 2012. The first confirmed detection occurred in 1992. As of 1 September 2019, there are 4,109 confirmed exoplanets in 3,059 systems, with 667 systems having more than one planet.[6]
There are many methods of detecting exoplanets.  Transit photometry and Doppler spectroscopy have found the most.
In several cases, multiple planets have been observed around a star.[7]
About 1 in 5 Sun-like stars[lower-alpha 1] have an "Earth-sized"[lower-alpha 2] planet in the habitable zone.[lower-alpha 3][8][9] Assuming there are 200 billion stars in the Milky Way,[lower-alpha 4] it can be hypothesized that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included.[10]
The least massive planet known is Draugr (also known as PSR B1257+12 A or PSR B1257+12 b), which is about twice the mass of the Moon. The most massive planet listed on the NASA Exoplanet Archive is HR 2562 b,[11][12] about 30 times the mass of Jupiter, although according to some definitions of a planet, it is too massive to be a planet and may be a brown dwarf instead. There are planets that are so near to their star that they take only a few hours to orbit and there are others so far away that they take thousands of years to orbit. Some are so far out that it is difficult to tell whether they are gravitationally bound to the star. Almost all of the planets detected so far are within the Milky Way. Nonetheless, evidence suggests that extragalactic planets, exoplanets farther away in galaxies beyond the local Milky Way galaxy, may exist.[13][14] The nearest exoplanet is Proxima Centauri b, located 4.2 light-years (1.3 parsecs) from Earth and orbiting Proxima Centauri, the closest star to the Sun.[15]
The discovery of exoplanets has intensified interest in the search for extraterrestrial life. There is special interest in planets that orbit in a star's habitable zone, where it is possible for liquid water, a prerequisite for life on Earth, to exist on the surface. The study of planetary habitability also considers a wide range of other factors in determining the suitability of a planet for hosting life.[16]
Besides exoplanets, there are also rogue planets, which do not orbit any star.  These tend to be considered separately, especially if they are gas giants, in which case they are often counted as sub-brown dwarfs, like WISE 0855−0714.[17] The rogue planets in the Milky Way possibly number in the billions (or more).[18][19]
Nomenclature

The convention for designating exoplanets is an extension of the system used for designating multiple-star systems as adopted by the International Astronomical Union (IAU). For exoplanets orbiting a single star, the designation is normally formed by taking the name or, more commonly, designation of its parent star and adding a lower case letter.[21] The first planet discovered in a system is given the designation "b" (the parent star is considered to be "a") and later planets are given subsequent letters. If several planets in the same system are discovered at the same time, the closest one to the star gets the next letter, followed by the other planets in order of orbital size. A provisional IAU-sanctioned standard exists to accommodate the designation of circumbinary planets. A limited number of exoplanets have IAU-sanctioned proper names. Other naming systems exist.
History of detection
For centuries scientists, philosophers, and science fiction writers suspected that extrasolar planets existed,[22] but there was no way of detecting them or of knowing their frequency or how similar they might be to the planets of the Solar System. Various detection claims made in the nineteenth century were rejected by astronomers. The first evidence of an exoplanet (Van Maanen 2) was noted as early as 1917, but was not recognized as such.[5] The first suspected scientific detection of an exoplanet occurred in 1988. Shortly afterwards, the first confirmed detection came in 1992, with the discovery of several terrestrial-mass planets orbiting the pulsar PSR B1257+12.[23] The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. In February 2018, researchers using the Chandra X-ray Observatory, combined with a planet detection technique called microlensing, found evidence of planets in a distant galaxy, stating "Some of these exoplanets are as (relatively) small as the moon, while others are as massive as Jupiter. Unlike Earth, most of the exoplanets are not tightly bound to stars, so they're actually wandering through space or loosely orbiting between stars. We can estimate that the number of planets in this [faraway] galaxy is more than a trillion.[24]
Early speculations

“This space we declare to be infinite... In it are an infinity of worlds of the same kind as our own.”—Giordano Bruno (1584)[25]
In the sixteenth century the Italian philosopher Giordano Bruno, an early supporter of the Copernican theory that Earth and other planets orbit the Sun (heliocentrism), put forward the view that the fixed stars are similar to the Sun and are likewise accompanied by planets.
In the eighteenth century the same possibility was mentioned by Isaac Newton in the "General Scholium" that concludes his Principia. Making a comparison to the Sun's planets, he wrote "And if the fixed stars are the centres of similar systems, they will all be constructed according to a similar design and subject to the dominion of One."[26]
In 1952, more than 40 years before the first hot Jupiter was discovered, Otto Struve wrote that there is no compelling reason why planets could not be much closer to their parent star than is the case in the Solar System, and proposed that Doppler spectroscopy and the transit method could detect super-Jupiters in short orbits.[27]
Discredited claims
Claims of exoplanet detections have been made since the nineteenth century. Some of the earliest involve the binary star 70 Ophiuchi. In 1855 William Stephen Jacob at the East India Company's Madras Observatory reported that orbital anomalies made it "highly probable" that there was a "planetary body" in this system.[28] In the 1890s, Thomas J. J. See of the University of Chicago and the United States Naval Observatory stated that the orbital anomalies proved the existence of a dark body in the 70Ophiuchi system with a 36-year period around one of the stars.[29] However, Forest Ray Moulton published a paper proving that a three-body system with those orbital parameters would be highly unstable.[30] During the 1950s and 1960s, Peter van de Kamp of Swarthmore College made another prominent series of detection claims, this time for planets orbiting Barnard's Star.[31] Astronomers now generally regard all the early reports of detection as erroneous.[32]
In 1991 Andrew Lyne, M. Bailes and S. L. Shemar claimed to have discovered a pulsar planet in orbit around PSR 1829-10, using pulsar timing variations.[33] The claim briefly received intense attention, but Lyne and his team soon retracted it.[34]
Confirmed discoveries

As of 1 September 2019, a total of 4,109 confirmed exoplanets are listed in the Extrasolar Planets Encyclopaedia, including a few that were confirmations of controversial claims from the late 1980s.[6]  The first published discovery to receive subsequent confirmation was made in 1988 by the Canadian astronomers Bruce Campbell, G. A. H. Walker, and Stephenson Yang of the University of Victoria and the University of British Columbia.[35] Although they were cautious about claiming a planetary detection, their radial-velocity observations suggested that a planet orbits the star Gamma Cephei. Partly because the observations were at the very limits of instrumental capabilities at the time, astronomers remained skeptical for several years about this and other similar observations. It was thought some of the apparent planets might instead have been brown dwarfs, objects intermediate in mass between planets and stars. In 1990 additional observations were published that supported the existence of the planet orbiting Gamma Cephei,[36] but subsequent work in 1992 again raised serious doubts.[37] Finally, in 2003, improved techniques allowed the planet's existence to be confirmed.[38]

On 9 January 1992, radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of two planets orbiting the pulsar PSR 1257+12.[23] This discovery was confirmed, and is generally considered to be the first definitive detection of exoplanets. Follow-up observations solidified these results, and confirmation of a third planet in 1994 revived the topic in the popular press.[39] These pulsar planets are thought to have formed from the unusual remnants of the supernova that produced the pulsar, in a second round of planet formation, or else to be the remaining rocky cores of gas giants that somehow survived the supernova and then decayed into their current orbits.
On 6 October 1995, Michel Mayor and Didier Queloz of the University of Geneva announced the first definitive detection of an exoplanet orbiting a main-sequence star, namely the nearby G-type star 51 Pegasi.[40][41] This discovery, made at the Observatoire de Haute-Provence, ushered in the modern era of exoplanetary discovery. Technological advances, most notably in high-resolution spectroscopy, led to the rapid detection of many new exoplanets: astronomers could detect exoplanets indirectly by measuring their gravitational influence on the motion of their host stars. More extrasolar planets were later detected by observing the variation in a star's apparent luminosity as an orbiting planet transited in front of it.
Initially, most known exoplanets were massive planets that orbited very close to their parent stars. Astronomers were surprised by these "hot Jupiters", because theories of planetary formation had indicated that giant planets should only form at large distances from stars. But eventually more planets of other sorts were found, and it is now clear that hot Jupiters make up the minority of exoplanets. In 1999, Upsilon Andromedae became the first main-sequence star known to have multiple planets.[42] Kepler-16 contains the first discovered planet that orbits around a binary main-sequence star system.[43]
On 26 February 2014, NASA announced the discovery of 715 newly verified exoplanets around 305 stars by the Kepler Space Telescope. These exoplanets were checked using a statistical technique called "verification by multiplicity".[44][45][46] Prior to these results, most confirmed planets were gas giants comparable in size to Jupiter or larger as they are more easily detected, but the Kepler planets are mostly between the size of Neptune and the size of Earth.[44]
On 23 July 2015, NASA announced Kepler-452b, a near-Earth-size planet orbiting the habitable zone of a G2-type star.[47]
On 6 September 2018, NASA discovered an exoplanet about 145 light years away from Earth in the Virgo constellation.[48] This exoplanet, Wolf 503b, is twice the size of Earth and was discovered orbiting a type of star known as an “Orange Dwarf”. Wolf 503b completes one orbit in as little as six days due to its close proximity to the star. This exoplanet is relatively close to Earth and its host star shines extremely bright. Wolf 503b is the only exoplanet that can be found near the so-called Fulton gap that is this large. The Fulton gap, first noticed in 2017, is the observation that it is unusual to find planets within a certain mass range.[49][48]
Astronomers who study exoplanets have found thousands of exoplanets in our galaxy. Wolf 503b is so important because of how close it is to Earth, giving it convenient accessibility for extended studies through the Kepler space Telescope. The "orange dwarf” star that Wolf 503b is orbiting is a bright star. Scientist state that orange dwarf stars have a lifespan three times longer than the Sun. Wolf 503b has a strong influence on its orange dwarf host star. Due to Wolf 503b’s large size, it has a gravitational influence on its host star. Under the Fulton gap studies, this opens up a new field for astronomers, who are still studying whether planets found in the Fulton gap are gaseous or rocky.[48]
Candidate discoveries
As of June 2017, NASA's Kepler mission had identified more than 5,000 planetary candidates,[50] several of them being nearly Earth-sized and located in the habitable zone, some around Sun-like stars.[51][52][53]

Methodology

About 97% of all the confirmed exoplanets have been discovered by indirect techniques of detection, mainly by radial velocity measurements and transit monitoring techniques.[57]
Formation and evolution

Planets may form within a few to tens (or more) of millions of years of their star forming.[58][59][60][61][62]
The planets of the Solar System can only be observed in their current state, but observations of different planetary systems of varying ages allows us to observe planets at different stages of evolution. Available observations range from young proto-planetary disks where planets are still forming [63] to planetary systems of over 10 Gyr old.[64] When planets form in a gaseous protoplanetary disk,[65]  they accrete hydrogen/helium envelopes.[66] These envelopes cool and contract over time and, depending on the mass of the planet, some or all of the hydrogen/helium is eventually lost to space.[65] This means that even terrestrial planets may start off with large radii if they form early enough.[67][68][69] An example is Kepler-51b which has only about twice the mass of Earth but is almost the size of Saturn which is a hundred times the mass of Earth. Kepler-51b is quite young at a few hundred million years old.[70]
Eccentricity
Of the many exoplanets discovered, most have a higher orbital eccentricity than planets in the Solar System.  Exoplanets found with low orbital eccentricity, near circular orbits, are almost all very close to their star and are tidally locked to the star. In contrast, seven out of eight planets in the Solar System have near-circular orbits. The exoplanets discovered show that the Solar System, with its unusually low eccentricity, is rare.[71] One theory attributes this low eccentricity to the high number of planets in the Solar System; another suggests it arose because of its unique asteroid belts. A few other multiplanetary systems have been found, but none resemble the Solar System. The Solar System has unique planetesimal systems, which led the planets to have near-circular orbits. The exoplanet systems discovered have either no planetesimal systems or one very large one. Low eccentricity is needed for habitability, especially advanced life.[72] High multiplicity planet systems are much more likely to have habitable exoplanets.[73][74]
Planet-hosting stars

There is at least one planet on average per star.[7]
About 1 in 5 Sun-like stars[lower-alpha 1] have an "Earth-sized"[lower-alpha 2] planet in the habitable zone.[76]
Most known exoplanets orbit stars roughly similar to the Sun, i.e. main-sequence stars of spectral categories F, G, or K. Lower-mass stars (red dwarfs, of spectral category M) are less likely to have planets massive enough to be detected by the radial-velocity method.[77][78] Despite this, several tens of planets around red dwarfs have been discovered by the Kepler spacecraft, which uses the transit method to detect smaller planets.
Using data from Kepler, a correlation has been found between the metallicity of a star and the probability that the star host planets. Stars with higher metallicity are more likely to have planets, especially giant planets, than stars with lower metallicity.[79]
Some planets orbit one member of a binary star system,[80] and several circumbinary planets have been discovered which orbit around both members of binary star. A few planets in triple star systems are known[81] and one in the quadruple system Kepler-64.
General features
Color and brightness

In 2013 the color of an exoplanet was determined for the first time. The best-fit albedo measurements of HD 189733b suggest that it is deep dark blue.[82][83] Later that same year, the colors of several other exoplanets were determined, including GJ 504 b which visually has a magenta color,[84] and Kappa Andromedae b, which if seen up close would appear reddish in color.[85]
The apparent brightness (apparent magnitude) of a planet depends on how far away the observer is, how reflective the planet is (albedo), and how much light the planet receives from its star, which depends on how far the planet is from the star and how bright the star is. So, a planet with a low albedo that is close to its star can appear brighter than a planet with high albedo that is far from the star.[86]
The darkest known planet in terms of geometric albedo is TrES-2b, a hot Jupiter that reflects less than 1% of the light from its star, making it less reflective than coal or black acrylic paint. Hot Jupiters are expected to be quite dark due to sodium and potassium in their atmospheres but it is not known why TrES-2b is so dark—it could be due to an unknown chemical compound.[87][88][89]
For gas giants, geometric albedo generally decreases with increasing metallicity or atmospheric temperature unless there are clouds to modify this effect. Increased cloud-column depth increases the albedo at optical wavelengths, but decreases it at some infrared wavelengths. Optical albedo increases with age, because older planets have higher cloud-column depths. Optical albedo decreases with increasing mass, because higher-mass giant planets have higher surface gravities, which produces lower cloud-column depths. Also, elliptical orbits can cause major fluctuations in atmospheric composition, which can have a significant effect.[90]
There is more thermal emission than reflection at some near-infrared wavelengths for massive and/or young gas giants. So, although optical brightness is fully phase-dependent, this is not always the case in the near infrared.[90]
Temperatures of gas giants reduce over time and with distance from their star. Lowering the temperature increases optical albedo even without clouds. At a sufficiently low temperature, water clouds form, which further increase optical albedo. At even lower temperatures ammonia clouds form, resulting in the highest albedos at most optical and near-infrared wavelengths.[90]
Magnetic field
In 2014, a magnetic field around HD 209458 b was inferred from the way hydrogen was evaporating from the planet. It is the first (indirect) detection of a magnetic field on an exoplanet. The magnetic field is estimated to be about one tenth as strong as Jupiter's.[91][92]
Interaction between a close-in planet's magnetic field and a star can produce spots on the star in a similar way to how the Galilean moons produce aurorae on Jupiter.[93]
Auroral radio emissions could be detected with radio telescopes such as LOFAR.[94][95]
The radio emissions could enable determination of the rotation rate of a planet which is difficult to detect otherwise.[96]
Earth's magnetic field results from its flowing liquid metallic core, but in massive super-Earths with high pressure, different compounds may form which do not match those created under terrestrial conditions. Compounds may form with greater viscosities and high melting temperatures which could prevent the interiors from separating into different layers and so result in undifferentiated coreless mantles. Forms of magnesium oxide such as MgSi3O12 could be a liquid metal at the pressures and temperatures found in super-Earths and could generate a magnetic field in the mantles of super-Earths.[97][98]
Hot Jupiters have been observed to have a larger radius than expected. This could be caused by the interaction between the stellar wind and the planet's magnetosphere creating an electric current through the planet that heats it up causing it to expand. The more magnetically active a star is the greater the stellar wind and the larger the electric current leading to more heating and expansion of the planet. This theory matches the observation that stellar activity is correlated with inflated planetary radii.[99]
In August 2018, scientists announced the transformation of gaseous deuterium into a liquid metallic form. This may help researchers better understand giant gas planets, such as Jupiter, Saturn and related exoplanets, since such planets are thought to contain a lot of liquid metallic hydrogen, which may be responsible for their observed powerful magnetic fields.[100][101]
Plate tectonics
In 2007, two independent teams of researchers came to opposing conclusions about the likelihood of plate tectonics on larger super-Earths[102][103] with one team saying that plate tectonics would be episodic or stagnant[104] and the other team saying that plate tectonics is very likely on super-Earths even if the planet is dry.[105]
If super-Earths have more than 80 times as much water as Earth then they become ocean planets with all land completely submerged. However, if there is less water than this limit, then the deep water cycle will move enough water between the oceans and mantle to allow continents to exist.[106][107]
Volcanism
Large surface temperature variations on 55 Cancri e have been attributed to possible volcanic activity releasing large clouds of dust which blanket the planet and block thermal emissions.[108][109]
Rings
The star 1SWASP J140747.93-394542.6 is orbited by an object that is circled by a ring system much larger than Saturn's rings. However, the mass of the object is not known; it could be a brown dwarf or low-mass star instead of a planet.[110][111]
The brightness of optical images of Fomalhaut b could be due to starlight reflecting off a circumplanetary ring system with a radius between 20 and 40 times that of Jupiter's radius, about the size of the orbits of the Galilean moons.[112]
The rings of the Solar System's gas giants are aligned with their planet's equator. However, for exoplanets that orbit close to their star, tidal forces from the star would lead to the outermost rings of a planet being aligned with the planet's orbital plane around the star. A planet's innermost rings would still be aligned with the planet's equator so that if the planet has a tilted rotational axis, then the different alignments between the inner and outer rings would create a warped ring system.[113]
Moons
In December 2013 a candidate exomoon of a rogue planet was announced.[114] On 3 October 2018, evidence suggesting a large exomoon orbiting Kepler-1625b was reported.[115]
Atmospheres

Atmospheres have been detected around several exoplanets. The first to be observed was HD 209458 b in 2001.[117]
KIC 12557548 b is a small rocky planet, very close to its star, that is evaporating and leaving a trailing tail of cloud and dust like a comet.[118] The dust could be ash erupting from volcanos and escaping due to the small planet's low surface-gravity, or it could be from metals that are vaporized by the high temperatures of being so close to the star with the metal vapor then condensing into dust.[119]
In June 2015, scientists reported that the atmosphere of GJ 436 b was evaporating, resulting in a giant cloud around the planet and, due to radiation from the host star, a long trailing tail 14×10^6km (9×10^6mi) long.[120]
In May 2017, glints of light from Earth, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere.[121][122] The technology used to determine this may be useful in studying the atmospheres of distant worlds, including those of exoplanets.
Insolation pattern
Tidally locked planets in a 1:1 spin–orbit resonance would have their star always shining directly overhead on one spot which would be hot with the opposite hemisphere receiving no light and being freezing cold. Such a planet could resemble an eyeball with the hotspot being the pupil.[123] Planets with an eccentric orbit could be locked in other resonances. 3:2 and 5:2 resonances would result in a double-eyeball pattern with hotspots in both eastern and western hemispheres.[124] Planets with both an eccentric orbit and a tilted axis of rotation would have more complicated insolation patterns.[125]

As more planets are discovered, the field of exoplanetology continues to grow into a deeper study of extrasolar worlds, and will ultimately tackle the prospect of life on planets beyond the Solar System.[57] At cosmic distances, life
can only be detected if it is developed at a planetary scale and strongly modified the planetary
environment, in such a way that the modifications cannot be explained by classical physico-chemical processes (out of equilibrium processes).[57] For example, molecular oxygen (O
2) in the atmosphere of Earth is a result of photosynthesis by living plants and many kinds of microorganisms, so it can be used as an indication of life on exoplanets, although small amounts of oxygen could also be produced by non-biological means.[126]  Furthermore, a potentially habitable planet must orbit a stable star at a distance within which planetary-mass objects with sufficient atmospheric pressure can support liquid water at their surfaces.[127][128]
See also

Exocomet– A comet outside the Solar System
Exomoon– Any moon beyond the Solar System
Exoplanetology
Extragalactic planet– Planet that is outside the Milky Way galaxy
Lists of exoplanets
List of exoplanet extremes
List of exoplanet search projects
Lists of planets
Nexus for Exoplanet System Science
Planetary system– Set of non-stellar objects in orbit around a star
Planet Hunters
Ultra-short period planet (USP)
Zooniverse

Notes

Further reading
 ISBN978-0-465-00936-7 (Hardback); ISBN978-0-465-02039-3 (Paperback).
 ISBN978-0-387-95074-7 (Hardback); ISBN978-1-4419-2872-6 (Paperback).
 ISBN978-0-691-14254-8 (Hardcover).

 ISBN978-0-8165-2945-2.
 ISBN978-0-520-23710-0.
 ISBN978-0-9741689-2-0 (Paperback).

 (Paris Observatory)

 (PHL/UPR Arecibo)
– D. Montes, UCM
 at Paris Observatory

What is the most recently discovered solar system in our galaxy?


ThermodynamicsThe classical Carnot heat engine
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Specific heat capacity

c
=

{\displaystyle c=}

T

{\displaystyle T}

∂
S

{\displaystyle \partial S}

N

{\displaystyle N}

∂
T

{\displaystyle \partial T}

Compressibility

β
=
−

{\displaystyle \beta =-}

1

{\displaystyle 1}

∂
V

{\displaystyle \partial V}

V

{\displaystyle V}

∂
p

{\displaystyle \partial p}

Thermal expansion

α
=

{\displaystyle \alpha =}

1

{\displaystyle 1}

∂
V

{\displaystyle \partial V}

V

{\displaystyle V}

∂
T

{\displaystyle \partial T}

Equations
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Table of thermodynamic equations
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Internal energy

U
(
S
,
V
)

{\displaystyle U(S,V)}

Enthalpy

H
(
S
,
p
)
=
U
+
p
V

{\displaystyle H(S,p)=U+pV}

Helmholtz free energy

A
(
T
,
V
)
=
U
−
T
S

{\displaystyle A(T,V)=U-TS}

Gibbs free energy

G
(
T
,
p
)
=
H
−
T
S

{\displaystyle G(T,p)=H-TS}

HistoryCulture

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The history of thermodynamics is a fundamental strand in the history of physics, the history of chemistry, and the history of science in general. Owing to the relevance of thermodynamics in much of science and technology, its history is finely woven with the developments of classical mechanics, quantum mechanics, magnetism, and chemical kinetics, to more distant applied fields such as meteorology, information theory, and biology (physiology), and to technological developments such as the steam engine, internal combustion engine, cryogenics and electricity generation. The development of thermodynamics both drove and was driven by atomic theory. It also, albeit in a subtle manner, motivated new directions in probability and statistics; see, for example, the timeline of thermodynamics.
History

Contributions from antiquity

The ancients viewed heat as that related to fire. In 3000 BC, the ancient Egyptians viewed heat as related to origin mythologies.[1]
In the Western philosophical tradition, after much debate about the primal element among earlier pre-Socratic philosophers, Empedocles proposed a four-element theory, in which all substances derive from earth, water, air, and fire. The Empedoclean element of fire is perhaps the principal ancestor of later concepts such as phlogin and caloric.  Around 500 BC, the Greek philosopher Heraclitus became famous as the "flux and fire" philosopher for his proverbial utterance: "All things are flowing." Heraclitus argued that the three principal elements in nature were fire, earth, and water.

Atomism is a central part of today's relationship between thermodynamics and statistical mechanics. Ancient thinkers such as  Leucippus and Democritus, and later the Epicureans, by advancing atomism, laid the foundations for the later atomic theory. Until experimental proof of atoms was later provided in the 20th century, the atomic theory was driven largely by philosophical considerations and scientific intuition.
The 5th century BC, Greek philosopher Parmenides, in his only known work, a poem conventionally titled On Nature, uses verbal reasoning to postulate that a void, essentially what is now known as a vacuum, in nature could not occur. This view was supported by the arguments of Aristotle, but was criticized by Leucippus and Hero of Alexandria.  From antiquity to the Middle Ages various arguments were put forward to prove or disapprove the existence of a vacuum and several attempts were made to construct a vacuum but all proved unsuccessful.
The European scientists Cornelius Drebbel, Robert Fludd, Galileo Galilei and Santorio Santorio in the 16th and 17th centuries were able to gauge the relative "coldness" or "hotness" of air, using a rudimentary air thermometer (or thermoscope). This may have been influenced by an earlier device which could expand and contract the air constructed by Philo of Byzantium and Hero of Alexandria.
Around 1600, the English philosopher and scientist Francis Bacon surmised: "Heat itself, its essence and quiddity is motion and nothing else."  In 1643, Galileo Galilei, while generally accepting the 'sucking' explanation of horror vacui proposed by Aristotle, believed that nature's vacuum-abhorrence is limited.  Pumps operating in mines had already proven that nature would only fill a vacuum with water up to a height of ~30 feet.  Knowing this curious fact, Galileo encouraged his former pupil Evangelista Torricelli to investigate these supposed limitations.  Torricelli did not believe that vacuum-abhorrence (Horror vacui) in the sense of Aristotle's 'sucking' perspective, was responsible for raising the water.  Rather, he reasoned, it was the result of the pressure  exerted on the liquid by the surrounding air.
To prove this theory, he filled a long glass tube (sealed at one end) with mercury and upended it into a dish also containing mercury.  Only a portion of the tube emptied (as shown adjacent); ~30inches of the liquid remained.  As the mercury emptied, and a partial vacuum was created at the top of the tube.  The gravitational force on the heavy element Mercury prevented it from filling the vacuum.
Transition from chemistry to thermochemistry

The theory of phlogiston arose in the 17th century, late in the period of alchemy. Its replacement by caloric theory in the 18th century is one of the historical markers of the transition from alchemy to chemistry.  Phlogiston was a hypothetical substance that was presumed to be liberated from combustible substances during burning, and from metals during the process of rusting.  Caloric, like phlogiston, was also presumed to be the "substance" of heat that would flow from a hotter body to a cooler body, thus warming it.
The first substantial experimental challenges to caloric theory arose in Rumford's 1798 work, when he showed that boring cast iron cannons produced great amounts of heat which he ascribed to friction, and his work was among the first to undermine the caloric theory. The development of the steam engine also focused attention on calorimetry and the amount of heat produced from different types of coal. The first quantitative research on the heat changes during chemical reactions was initiated by Lavoisier using an ice calorimeter following research by Joseph Black on the latent heat of water.
More quantitative studies by James Prescott Joule in 1843 onwards provided soundly reproducible phenomena, and helped to place the subject of thermodynamics on a solid footing. William Thomson, for example, was still trying to explain Joule's observations within a caloric framework as late as 1850. The utility and explanatory power of kinetic theory, however, soon started to displace caloric and it was largely obsolete by the end of the 19th century. Joseph Black and Lavoisier made important contributions in the precise measurement of heat changes using the calorimeter, a subject which became known as thermochemistry.
Phenomenological thermodynamics

Boyle's law (1662)
Charles's law was first published by Joseph Louis Gay-Lussac in 1802, but he referenced unpublished work by Jacques Charles from around 1787. The relationship had been anticipated by the work of Guillaume Amontons in 1702.
Gay-Lussac's law (1802)
Birth of thermodynamics as a science
Irish physicist and chemist Robert Boyle in 1656, in coordination with English scientist Robert Hooke, built an air pump. Using this pump, Boyle and Hooke noticed the pressure-volume correlation: P.V=constant. In that time, air was assumed to be a system of motionless particles, and not interpreted as a system of moving molecules. The concept of thermal motion came two centuries later.  Therefore, Boyle's publication in 1660 speaks about a mechanical concept: the air spring.[2] Later, after the invention of the thermometer, the property temperature could be quantified. This tool gave Gay-Lussac the opportunity to derive his law, which led shortly later to the ideal gas law.  But, already before the establishment of the ideal gas law, an associate of Boyle's named Denis Papin built in 1679 a bone digester, which is a closed vessel with a tightly fitting lid that confines steam until a high pressure is generated.
Later designs implemented a steam release valve to keep the machine from exploding.  By watching the valve rhythmically move up and down, Papin conceived of the idea of a piston and cylinder engine.  He did not however follow through with his design. Nevertheless, in 1697, based on Papin's designs, engineer Thomas Savery built the first engine. Although these early engines were crude and inefficient, they attracted the attention of the leading scientists of the time. One such scientist was Sadi Carnot, the "father of thermodynamics", who in 1824 published Reflections on the Motive Power of Fire, a discourse on heat, power, and engine efficiency.  This marks the start of thermodynamics as a modern science.

Hence, prior to 1698 and the invention of the Savery Engine, horses were used to power pulleys, attached to buckets, which lifted water out of flooded salt mines in England. In the years to follow, more variations of steam engines were built, such as the Newcomen Engine, and later the Watt Engine. In time, these early engines would eventually be utilized in place of horses.  Thus, each engine began to be associated with a certain amount of "horse power" depending upon how many horses it had replaced. The main problem with these first engines was that they were slow and clumsy, converting less than 2% of the input fuel into useful work.  In other words, large quantities of coal (or wood) had to be burned to yield only a small fraction of work output.  Hence the need for a new science of engine dynamics was born.

Most cite Sadi Carnot's 1824 book Reflections on the Motive Power of Fire as the starting point for thermodynamics as a modern science.  Carnot defined "motive power" to be the expression of the useful effect that a motor is capable of producing.  Herein, Carnot introduced us to the first modern day definition of "work": weight lifted through a height.   The desire to understand, via formulation, this useful effect in relation to "work" is at the core of all modern day thermodynamics.
In 1843, James Joule experimentally found the mechanical equivalent of heat. In 1845, Joule reported his best-known experiment, involving the use of a falling weight to spin a paddle-wheel in a barrel of water, which allowed him to estimate a mechanical equivalent of heat of 819ft·lbf/Btu (4.41 J/cal). This led to the theory of conservation of energy and explained why heat can do work.
In 1850, the famed mathematical physicist Rudolf Clausius coined the term "entropy" (das Wärmegewicht, symbolized S) to denote heat lost or turned into waste. ("Wärmegewicht" translates literally as "heat-weight"; the corresponding English term stems from the Greek τρέπω, "I turn".)
The name "thermodynamics", however, did not arrive until 1854, when the British mathematician and physicist William Thomson (Lord Kelvin) coined the term thermo-dynamics in his paper On the Dynamical Theory of Heat.[3]

In association with Clausius, in 1871, the Scottish mathematician and physicist James Clerk Maxwell formulated a new branch of thermodynamics called Statistical Thermodynamics, which functions to analyze large numbers of particles at equilibrium, i.e., systems where no changes are occurring, such that only their average properties as temperature T, pressure P, and volume V become important.
Soon thereafter, in 1875, the Austrian physicist Ludwig Boltzmann formulated a precise connection between entropy S and molecular motion:

S
=
k
log

W

{\displaystyle S=k\log W\,}

being defined in terms of the number of possible states [W] such motion could occupy, where k is the Boltzmann's constant.
The following year, 1876, chemical engineer Willard Gibbs published an obscure 300-page paper titled: On the Equilibrium of Heterogeneous Substances, wherein he formulated one grand equality, the Gibbs free energy equation, which suggested a measure of the amount of "useful work" attainable in reacting systems.  Gibbs also originated the concept we now know as enthalpy H, calling it "a heat function for constant pressure".[4]
The modern word enthalpy would be coined many years later by Heike Kamerlingh Onnes,[5]
who based it on the Greek word enthalpein meaning to warm.
Building on these foundations, those as Lars Onsager, Erwin Schrödinger, and Ilya Prigogine, and others, functioned to bring these engine "concepts" into the thoroughfare of almost every modern-day branch of science.
Kinetic theory

The idea that heat is a form of motion is perhaps an ancient one and is certainly discussed by Francis Bacon in 1620 in his Novum Organum. The first written scientific reflection on the microscopic nature of heat is probably to be found in a work by Mikhail Lomonosov, in which he wrote:
"(..) movement should not be denied based on the fact it is not seen. Who would deny that the leaves of trees move when rustled by a wind, despite it being unobservable from large distances? Just as in this case motion remains hidden due to perspective, it remains hidden in warm bodies due to the extremely small sizes of the moving particles. In both cases, the viewing angle is so small that neither the object nor their movement can be seen."
During the same years, Daniel Bernoulli published his book Hydrodynamics (1738), in which he derived an equation for the pressure of a gas considering the collisions of its atoms with the walls of a container. He proves that this pressure is two thirds the average kinetic energy of the gas in a unit volume. Bernoulli's ideas, however, made little impact on the dominant caloric culture. Bernoulli made a connection with Gottfried Leibniz's vis viva principle, an early formulation of the principle of conservation of energy, and the two theories became intimately entwined throughout their history. Though Benjamin Thompson suggested that heat was a form of motion as a result of his experiments in 1798, no attempt was made to reconcile theoretical and experimental approaches, and it is unlikely that he was thinking of the vis viva principle.
John Herapath later independently formulated a kinetic theory in 1820, but mistakenly associated temperature with momentum rather than vis viva or kinetic energy. His work ultimately failed peer review and was neglected. John James Waterston in 1843 provided a largely accurate account, again independently, but his work received the same reception, failing peer review even from someone as well-disposed to the kinetic principle as Davy.
Further progress in kinetic theory started only in the middle of the 19th century, with the works of Rudolf Clausius, James Clerk Maxwell, and Ludwig Boltzmann. In his 1857 work On the nature of the motion called heat, Clausius for the first time clearly states that heat is the average kinetic energy of molecules. This interested Maxwell, who in 1859 derived the momentum distribution later named after him. Boltzmann subsequently generalized his distribution for the case of gases in external fields.
Boltzmann is perhaps the most significant contributor to kinetic theory, as he introduced many of the fundamental concepts in the theory. Besides the Maxwell–Boltzmann distribution mentioned above, he also associated the kinetic energy of particles with their degrees of freedom. The Boltzmann equation for the distribution function of a gas in non-equilibrium states is still the most effective equation for studying transport phenomena in gases and metals. By introducing the concept of thermodynamic probability as the number of microstates corresponding to the current macrostate, he showed that its logarithm is proportional to entropy.
Branches of thermodynamics
The following list gives a rough outline as to when the major branches of thermodynamics came into inception:
Thermochemistry - 1780s
Classical thermodynamics - 1824
Chemical thermodynamics - 1876
Statistical mechanics - c. 1880s
Equilibrium thermodynamics
Engineering thermodynamics
Chemical engineering thermodynamics - c. 1940s
Non-equilibrium thermodynamics - 1941
Small systems thermodynamics - 1960s
Biological thermodynamics - 1957
Ecosystem thermodynamics - 1959
Relativistic thermodynamics - 1965
Rational thermodynamics - 1960s
Quantum thermodynamics - 1968
Black hole thermodynamics - c. 1970s
Geological thermodynamics - c. 1970s
Biological evolution thermodynamics - 1978
Geochemical thermodynamics - c. 1980s
Atmospheric thermodynamics - c. 1980s
Natural systems thermodynamics - 1990s
Supramolecular thermodynamics - 1990s
Earthquake thermodynamics - 2000
Drug-receptor thermodynamics - 2001
Pharmaceutical systems thermodynamics – 2002
Ideas from thermodynamics have also been applied in other fields, for example:
Thermoeconomics - c. 1970s
Entropy and the second law

Even though he was working with the caloric theory, Sadi Carnot in 1824 suggested that some of the caloric available for generating useful work is lost in any real process. In March 1851, while grappling to come to terms with the work of James Prescott Joule, Lord Kelvin started to speculate that there was an inevitable loss of useful heat in all processes. The idea was framed even more dramatically by Hermann von Helmholtz in 1854, giving birth to the spectre of the heat death of the universe.
In 1854, William John Macquorn Rankine started to make use in calculation of what he called his thermodynamic function. This has subsequently been shown to be identical to the concept of entropy formulated by Rudolf Clausius in 1865. Clausius used the concept to develop his classic statement of the second law of thermodynamics the same year.
Heat transfer

The phenomenon of heat conduction is immediately grasped in everyday life. In 1701, Sir Isaac Newton published his law of cooling. However, in the 17th century, it came to be believed that all materials had an identical conductivity and that differences in sensation arose from their different heat capacities.
Suggestions that this might not be the case came from the new science of electricity in which it was easily apparent that some materials were good electrical conductors while others were effective insulators. Jan Ingen-Housz in 1785-9 made some of the earliest measurements, as did Benjamin Thompson during the same period.
The fact that warm air rises and the importance of the phenomenon to meteorology was first realised by Edmund Halley in 1686. Sir John Leslie observed that the cooling effect of a stream of air increased with its speed, in 1804.
Carl Wilhelm Scheele distinguished heat transfer by thermal radiation (radiant heat) from that by convection and conduction in 1777. In 1791, Pierre Prévost showed that all bodies radiate heat, no matter how hot or cold they are. In 1804, Leslie observed that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black body radiation. Though it had become to be suspected even from Scheele's work, in 1831 Macedonio Melloni demonstrated that black body radiation could be reflected, refracted and polarised in the same way as light.
James Clerk Maxwell's 1862 insight that both light and radiant heat were forms of electromagnetic wave led to the start of the quantitative analysis of thermal radiation. In 1879, Jožef Stefan observed that the total radiant flux from a blackbody is proportional to the fourth power of its temperature and stated the Stefan–Boltzmann law. The law was derived theoretically by Ludwig Boltzmann in 1884.
Absolute Zero
In 1702 Guillaume Amontons introduced the concept of absolute zero based on observations of gases. In 1810, Sir John Leslie froze water to ice artificially. The idea of absolute zero was generalised in 1848 by Lord Kelvin. In 1906, Walther Nernst stated the third law of thermodynamics.
See also
Conservation of energy: Historical development
History of Chemistry
History of Physics
Maxwell's thermodynamic surface
Timeline of thermodynamics, statistical mechanics, and random processes
Thermodynamics
Timeline of heat engine technology
Timeline of low-temperature technology

Further reading

 - Timeline (1575 to 1980) @ Hyperjeff.net
 - University of Waterloo
 - WolframScience.com
 - Berkeley [PDF]
 - ThermodynamicStudy.net
 - Carnegie-Mellon University
 - In Pictures


Stephen Douglas Kerr (born September 27, 1965) is an American professional basketball coach and former player who is the head coach of the Golden State Warriors of the National Basketball Association (NBA).[1] He is an eight-time NBA champion, having won five titles as a player (three with the Chicago Bulls and two with the San Antonio Spurs) as well as three with the Warriors as a head coach. Kerr has the highest career three-point percentage (45.4%) in NBA history for any player with at least 250 three-pointers made. He also held the NBA record for highest three-point percentage in a season at 52.4% until the record was broken by Kyle Korver in 2010.
On June 2, 2007, the Phoenix Suns named Kerr the team's president of basketball operations and general manager. Kerr helped managing partner Robert Sarver buy the Suns in 2004 and became one of Sarver's trusted basketball advisors. Kerr announced his retirement from the Suns in June 2010. Afterwards, Kerr returned as a color commentator for NBA on TNT until 2014, when he pursued a career in coaching.
On May 14, 2014, the Golden State Warriors named Kerr the team's head coach. On April 4, 2015, with a win over the Dallas Mavericks, Kerr broke the NBA record for the most regular-season wins for a rookie coach. The Warriors went on to win the 2015 NBA Finals, making Kerr the first rookie coach to win a championship since Pat Riley in the 1982 NBA Finals. On April 13, 2016, the Warriors broke the record for the most wins in an NBA season, breaking a record previously held by Kerr's 1995–96 Chicago Bulls. The Warriors returned to the Finals for three straight years, losing in 2016 and winning again in 2017 and 2018.
Early life
Kerr was born in Beirut, Lebanon to Malcolm H. Kerr, an American academic who specialized in the Middle East, and his wife, Ann (Zwicker).[2] He has three siblings.[3] His grandfather, Stanley Kerr, volunteered with the Near East Relief after the Armenian Genocide and rescued women and orphans in Aleppo and Marash before eventually settling in Beirut.[4] Kerr spent much of his childhood in Lebanon and other Middle Eastern countries.  He attended Cairo American College in Egypt, the American Community School in Beirut, Lebanon, and Palisades High School (now Palisades Charter High School) in Los Angeles.
Malcolm Kerr was killed by the Shia Lebanese militia called Islamic Jihad (later, elements of Islamic Jihad formed Hezbollah) on the morning of January 18, 1984 at the age of 52 while he was serving as president of the American University of Beirut.[5][6][7][8] He was shot twice in the back of his head, by gunmen using suppressed handguns, in the hallway outside his office.[3][6][7][8] Kerr was 18 years old at the time, and a college freshman;[5] regarding his father's death, he has said: "Before my father was killed, my life was impenetrable. Bad things happened to other people."[2] The Kerr family sued the Iranian government under the Antiterrorism and Effective Death Penalty Act of 1996.[9] While warming up with the Arizona Wildcats for a game at arch-rival Arizona State in 1988, Kerr had to deal with many ASU Sun Devil fans in the crowd chanting "PLO" and "your father's history."[10][11] Though tearful, Kerr led the Wildcats to victory, scoring 20 points in the first half, making all six of his three-point attempts.[11] The athletic director of Arizona State, Charles Harris, sent a letter of apology to Kerr a few days later.[12]
Kerr graduated from the University of Arizona in 1988 with a Bachelor of General Studies, with emphasis on history, sociology and English.[13][14]
Collegiate career
Minimally recruited out of high school, Kerr played basketball for the University of Arizona from 1983 to 1988. In the summer of 1986, Kerr was named to the USA Basketball team that competed in the FIBA World Championship in Spain. The team was the last American Men's Senior Team composed strictly of amateur players to capture a gold medal. He blew out his knee in the tournament, usually a career-ending injury, forcing him to miss an entire season (1986–87) at Arizona. After returning to the team, Kerr became a fan favorite due to his leadership, his ability to triumph in adversity, and long-range shooting. Virtually every time he got the ball, the Arizona fans would chant "STEEEVE KERRRR." It became a rallying cry. He helped the Wildcats reach the Final Four of the NCAA Division I basketball tournament in 1988 along with fellow All-American teammate Sean Elliott. Kerr also set an NCAA record for 3-point percentage in a season (114–199, 57.3%).
Professional career
Career beginnings
Kerr was selected by the Phoenix Suns in the second round of the 1988 NBA draft. He was traded to the Cleveland Cavaliers in 1989. He spent over three seasons (1989–1992) there and then part of the 1992–93 season with the Orlando Magic.
Chicago Bulls
In 1993, he signed with the Chicago Bulls. The Bulls made the playoffs in the 1993–94 and 1994–95 seasons, but without Michael Jordan's presence for all of 1994 and much of 1995, the team could not advance to the Finals. However, with Jordan back full-time for the 1995–96 season, the Bulls set a then NBA-record of 72–10 and defeated the Seattle SuperSonics in the 1996 NBA Finals.
Kerr played a major part of the Bulls' championship victory in the 1997 NBA Finals against the Utah Jazz. In the final seconds of Game 6 with the score tied at 86, he took a pass from Jordan and hit the title-winner. The Bulls won, earning the franchise's fifth title. Kerr also won the 3-Point Shootout at the 1997 All-Star Game.
In the last minute of Game 2 of the 1998 NBA Finals against Utah, Kerr missed a 3-pointer, grabbed his own rebound and made a pass to Jordan who made a crucial three-point play, putting them in the lead for good. The play helped Chicago win the game and tie the series at 1. The Bulls won the series in 6 games.
San Antonio Spurs
In January 1999, Kerr was acquired by the San Antonio Spurs in a sign-and-trade deal with the Bulls, whereby Chuck Person and a first-round pick in the 2000 NBA draft was sent to Chicago.[15] The Spurs reached 1999 NBA Finals and won their first NBA Championship with a 4–1 series victory over the New York Knicks. Kerr became one of two players to win four straight NBA titles without being a part of the 1960s Boston Celtics dynasty—the other being Frank Saul, who won four straight with Rochester and Minneapolis from 1951–54.[16] Kerr and Saul are also the only two players in NBA history to have won two championships with two different teams in consecutive seasons.[17]
Portland Trail Blazers
Kerr was traded to the Portland Trail Blazers alongside Derek Anderson on July 24, 2001 in a deal that brought Steve Smith to the Spurs. He would remain in Portland for the 2001–02 season, playing in 65 games.
Return to the Spurs
After his brief stint in Portland, he was traded back to San Antonio, along with Erick Barkley and a 2003 2nd-round pick, in exchange for Charles Smith, Amal McCaskill, and Antonio Daniels on August 2, 2002. He supported the Spurs from the bench in nearly every game (75) the following year, in what would be his final season in the league.[18] In Game 6 of the 2003 Western Conference Finals against the Dallas Mavericks, Kerr made four second-half three-pointers that helped eliminate Dallas. The Spurs eventually won the NBA championship by beating the New Jersey Nets in the 2003 NBA Finals, 4–2.
Kerr announced his retirement after the 2003 NBA Finals. He played 910 regular-season games but started only 30 of them, 20 of those games coming in the 1991–92 season. His career totals are: 5,437 points (6 ppg), 1,060 rebounds (1.2 rpg), and 1,658 assists (1.8 apg). He also retired as the league's all-time leader in three-point shooting percentage for a season (.524 in 1994–95) and career (.454).
Post-playing career
Television analyst

In 2003, Kerr became a broadcast analyst for Turner Network Television (TNT), offering commentary alongside renowned analyst Marv Albert. During his tenure, he performed a segment sponsored by Coors Light called Steve's Refreshing Thoughts in which he brought up interesting facts in NBA history. This segment continued through sponsorship, and became known as Steve Wonders,  sponsored by Sprint. In the same time period, Kerr also contributed to Yahoo! as an NBA commentator.
He has provided his voice for the in-game commentary of EA Sports video games NBA Live 06, NBA Live 07, NBA Live 08, NBA Live 09 and NBA Live 10 with Albert. He has also provided his voice as a color analyst for NBA 2K12, NBA 2K13, NBA 2K14 and NBA 2K15. He remains a commentator in NBA 2K15 despite becoming the Golden State Warriors coach for the 2014–15 season several months prior to the game's release.
Kerr left broadcasting in 2007 to work as a general manager for the Phoenix Suns, but it was confirmed on June 28, 2010 that he would return as an NBA analyst for TNT starting with the 2010–11 NBA season. Since 2011, Kerr has also called the NCAA Men's Division I Basketball Championship on Turner Sports and CBS, teaming up with lead broadcasters Jim Nantz and Clark Kellogg for the First Four and Final Four games, and with Albert in other rounds.
Kerr was a regular contributor to the website Grantland from 2011 until it closed in 2015.
Phoenix Suns front office
On April 15, 2004, Kerr was announced as a member of a potential group of buyers that would acquire his old team, the Suns, from Jerry Colangelo for $300 million. He became part of Suns management, acting as a consultant.[19][20] During the 2006 NBA All-Star Weekend, he was a member of the San Antonio team that won the Shooting Stars Competition.[21]
On June 2, 2007, Kerr announced his departure from his broadcasting position at TNT and his commentating position at Yahoo! to assume duties as the general manager of the Phoenix Suns beginning with the 2007–2008 season. On February 6, 2008, reports surfaced that Kerr was planning to trade Suns forward Shawn Marion and guard Marcus Banks to the Miami Heat in exchange for Shaquille O'Neal, which he did. The Suns were eliminated by the San Antonio Spurs in five games in the first round of the playoffs.
On December 10, 2008, Kerr continued to remake the Suns roster by trading away Boris Diaw, Raja Bell, and Sean Singletary to the Charlotte Bobcats in exchange for Jason Richardson, Jared Dudley, and the Bobcats' 2010 second-round draft pick, which was used to draft Gani Lawal of Georgia Tech.[22] On June 25, 2009, Kerr traded O'Neal to the Cleveland Cavaliers for Ben Wallace, Sasha Pavlovic, a future second-round draft pick and cash.
On May 5, 2010, the Suns wore Los Suns jerseys in Game 2 against the Spurs to be united against the controversial Arizona immigration law. Kerr himself compared the law to Nazi Germany.[23]
On June 15, 2010, Kerr stepped down as president and general manager of the Suns, but still owned a 1% share of the Suns' organization that he kept until 2014.
Head coaching career
Golden State Warriors (2014–present)

On May 14, 2014, Kerr reached an agreement to become the head coach for the Golden State Warriors, succeeding Mark Jackson.[24][25] Kerr coached in the 2014 Summer League for the Warriors. During the 2014–15 season, the team's offense employed elements of the triangle offense from his playing days in Chicago under Phil Jackson, the spacing and pace of Gregg Popovich in San Antonio, and the uptempo principles Mike D'Antoni and later Alvin Gentry used in Phoenix when Kerr was the GM.[26][27]
After the Warriors beat the Houston Rockets to win their 14th consecutive game, Kerr became the first coach to start his career with a 19–2 record.[28] This beat out Al Cervi and his 18–2 start with the Syracuse Nationals. On December 10, 2014, Kerr became the first NBA rookie head coach to win 21 of his first 23 games.[29] He was named the head coach of the Western Conference team for the 2015 NBA All-Star Game after Golden State had the best record in the conference.[30] On April 4, the Warriors beat the Dallas Mavericks 123–110 to clinch home-court advantage throughout the playoffs, and Kerr got his 63rd win of the season to become the highest winning rookie head coach in NBA history, passing Tom Thibodeau and his 62 wins with the Chicago Bulls in the 2010–11 season. In the NBA Coach of the Year voting, Kerr was runner-up to Mike Budenholzer.
The Warriors ultimately finished with one of the best regular seasons in NBA history, and the greatest in the team's 69-year history. Golden State ended with an overall record of 67–15, becoming the 10th team to win 67 or more games in a single season. It was the first time the Warriors had ever won as many as 60 games in a season; their previous high was 59 in the 1975–76 season. The Warriors also ended with a 39–2 home record, which is tied for the second best home record in NBA history. The Warriors were first in defensive efficiency for the season and second in offensive efficiency, barely missing the mark that the Julius Erving–led Sixers achieved by being first in both offensive and defensive efficiency. They became the first team in NBA history to have two win streaks over 15 at home (18 and 19).
In the opening round of the playoffs against the New Orleans Pelicans, Kerr led the Warriors to their first four-game playoff sweep since the 1975 NBA Finals. Afterwards, the team surpassed the Memphis Grizzlies (4–2, in the second round). Down 2–1 in the series, Kerr made an unconventional adjustment in Game 4 to leave the Grizzlies' Tony Allen open and have his defender, center Andrew Bogut, guard the interior. His strategy was lauded after Allen, Memphis' best wing defender, was benched and limited to 16 minutes after missing wide open shots.[31][32][33] The Warriors then defeated the Houston Rockets (4–1, in the Western Conference Finals), making the NBA Finals for the first time in 40 years.
The Warriors faced the Cleveland Cavaliers in the Finals. Kerr and rival coach David Blatt were both in their first season as NBA head coaches, and this was the first time a pair of rookie head coaches faced each other in the NBA Finals since the NBA's first year of existence, in 1947 with Eddie Gottlieb of the Philadelphia Warriors and Harold Olsen of the Chicago Stags competing.[34] After the Warriors went down 2–1 to Cleveland, Kerr started swingman Andre Iguodala in place of Bogut, jump-starting their stagnant offense for a 103–82 road win that evened the series. It was Iguodala's first start of the season, and the small unit came to be known as the Death Lineup. After the game, Kerr admitted to lying to the press in response to pregame questions about potential changes to his starting lineup.[35] The Warriors went on to win the championship in six games, defeating the Cavaliers, 4–2, in the series, to give Kerr his sixth championship and first as a head coach.
After the first two days of the defending champion Warriors' training camp, Kerr took an indefinite leave of absence to rehabilitate his back, which had caused problems since the 2015 NBA Finals.[36] Around this time, assistant coach Luke Walton assumed Kerr's coaching duties. Kerr missed all of 2015 and most of January 2016, although technically the NBA credited Walton's win-loss record to Kerr.[37] Kerr said "I think it's ridiculous", when asked about getting all of Walton's wins.[38] On January 22, 2016, Kerr returned to coaching after missing 43 games, but warned he might need to miss games occasionally if there was a recurrence of the headaches and pain related to the spinal fluid leak that sidelined him. The Warriors went 39–4 with interim coach Luke Walton.[39] The Warriors went 34-5 after Kerr returned to coaching. Golden State broke the 1995–96 Chicago Bulls 72–10 record by winning 73 games.[40] Kerr became the first person in NBA history to be a part of 70-win teams as a player and head coach. He was named 2015–16 NBA Coach of the Year.[41] Kerr would lead the Warriors to the 2016 NBA Finals where they would again face the Cleveland Cavaliers. The Warriors lost in seven games.
On November 20, 2016, the NBA announced that Kerr had been fined $25,000 for public criticism of officiating during a radio interview with KNBR 680 on November 17.[42] Kerr missed time during the 2017 playoffs due to recurring back issues.[43] Associate head coach Mike Brown has acted as acting head coach during periods of Kerr's absence, and Brown continued head coaching into the playoffs leading the Warriors to a 12–0 record in the postseason. Kerr returned for the 2017 NBA Finals where he led the Warriors to victory over the Cleveland Cavaliers in five games. The Warriors finished the playoffs with a 16–1 record, the best postseason winning percentage in NBA history.[44] Kerr is the fourth coach in NBA history to win two championships in his first three seasons of coaching. Kerr won his third championship as a head coach when the Warriors defeated the Cleveland Cavaliers in the 2018 NBA Finals in four games to give Kerr his eighth championship of his career.
Kerr is third on the Warriors' all-time wins list behind Don Nelson and Eddie Gottlieb, and only Nelson has won more games in the West Coast portion of Warriors history.
Personal life
He married Margot Kerr, his college sweetheart, in 1990. They have three children: Nick, Maddy and Matthew.[45]
Since the conclusion of the 2016 U.S. presidential election, Kerr has been critical of Donald Trump and his election victory. In an interview following the election, Kerr voiced the opinion that Trump's rise to power was based on insults against women and minorities. He compared Trump's campaign performances and the crude responses of his supporters to The Jerry Springer Show. Although he expressed hope that Trump would be a good president, he made clear his "disgust" with Trump's disrespectful public discourse and his disappointment with the election results.[46]
Kerr has been a strong supporter of gun control.[47]
Career statistics

LegendGPGames playedGSGames startedMPGMinutes per gameFG%Field goal percentage3P%3-point field goal percentageFT%Free throw percentageRPGRebounds per gameAPGAssists per gameSPGSteals per gameBPGBlocks per gamePPGPoints per gameBoldCareer high

NBA
Regular season

Playoffs

College

Coaching record

LegendRegular seasonGGames coachedWGames wonLGames lostW–L %Win–loss %PlayoffsPGPlayoff gamesPWPlayoff winsPLPlayoff lossesPW–L %Playoff win–loss %

See also

List of NBA players with most championships

Career statistics and player information from
 on IMDb

Who is head coach of the Golden State Warriors?


Archibald Campbell, 1st Duke of Argyll, 10th Earl of Argyll (25 July 1658 – 25 September 1703) was a Scottish peer.
Biography
The eldest son of Archibald Campbell, 9th Earl of Argyll and Mary Stuart, daughter of James Stuart, 4th Earl of Moray, Campbell sought to recover his father's estates (by gaining King James II's favour). However, after failing to do so, he supported William and Mary's quest for the throne; this important support led to the monarchs returning his father's estate. Also, he was made a Privy Councillor. He was William's chief Scottish advisor, and was colonel-in-chief of the Earl of Argyll's Regiment of Foot, that was involved in the 1692 massacre of the MacDonalds of Glen Coe, but took no part in any of its field operations. He was made a duke in 1701.
On 12 March 1678, he married Elizabeth Tollemache (daughter of Elizabeth and Sir Lionel Tollemache, 3rd Baronet at Edinburgh, Scotland. Elizabeth's stepfather John Maitland, 1st Duke of Lauderdale was a dominant figure in Scottish politics of the era. They had three children, born at Ham House outside London:
John Campbell, 2nd Duke of Argyll (10 October 1680 – 4 October 1743)
Archibald Campbell, 3rd Duke of Argyll (June 1682 – 15 April 1761)
Lady Margaret Campbell (2 June 1690 – 1742), m. Michael Woods.
The 1st Duke of Argyll is buried at Kilmun Parish Church.


The list of North Carolina hurricanes includes 413known tropical or subtropical cyclones that have affected the U.S. state of North Carolina. Due to its location, many hurricanes have hit the state directly, and numerous hurricanes have passed near or through North Carolina in its history; the state is ranked fourth, after Florida, Texas, and Louisiana, in the number of cyclones that produced hurricane-force winds in a U.S. state.[2][3] Hurricanes in North Carolina history are responsible for over $11billion in damage (2008USD) and almost 1,000total fatalities.
Climatology
As to statistical hurricane research between 1883 and 1996 by the North Carolina State Climatology Office, a tropical cyclone makes landfall along the coastline about once every four years. An estimated 17.5percent of all North Atlantic tropical cyclones have affected the state.[4] Additionally, the remnants of a few Pacific tropical cyclones struck the state.[5] Cape Hatteras is most affected by storms within the state, though Cape Lookout and Cape Fear are also regularly affected; the increased activity in three areas is because it protrudes from elsewhere along the Atlantic coastline.[4] After Southern Florida, Cape Hatteras has the lowest return period, or the frequency at which a certain intensity or category of hurricane can be expected within 86mi (139km) of a given location, in the country.[6] As the Outer Banks are a narrow strip of low-lying land, hurricanes occasionally leave portions of the land partially or fully submerged.[7] Additionally, the remnants of inland tropical cyclones have produced flooding and landslides in the state's western region.[8]
Tropical cyclones have affected North Carolina in every month between May and December; about 35percent of the storms struck the state in September, and 80percent affected the state between August and October, which coincides with the peak of the hurricane season. The earliest storm to affect the state was Subtropical Storm Andrea on May 7, 2007, and the latest was a tropical storm that moved across the Outer Banks on December 2, 1925. The strongest storm to strike the state was Hurricane Hazel on October 15, 1954, which made landfall as a Category 4 hurricane on the Saffir–Simpson Hurricane Scale.[9]
Pre-1900

The list of North Carolina hurricanes before 1900 encompasses 139tropical cyclones that affected the U.S. state of North Carolina. Collectively, cyclones in North Carolina during the time period resulted in over 775direct fatalities during the period. Seven cyclones affected the state in the 1893 season, which was the year with the most tropical cyclones devastating the state during the time period. From the beginning of the official Atlantic hurricane record in 1851 to 1899, there were 12years without a known tropical cyclone affecting the state.
Historical data prior to 1700 is sparse due to lack of significant European settlements along the coastline; the few storms listed are largely records from Roanoke Colony and later the Province of Carolina. Modern meteorologists believe early storms were tropical cyclones, though due to the time period confirmation is impossible.[10] One theory explaining the disappearance of Roanoke Colony suggests a hurricane destroyed the village, though there is no evidence to prove the theory. It is considered unlikely due to lack of damage to a fence around the village, on which the villagers left an inscription.[11]
1900–1949

Between 1900 and 1949, 75tropical cyclones or their remnants affected the state. Collectively, cyclones in North Carolina during that time period resulted in 53total fatalities during the period, as well as about $328million in damage (2008USD). Tropical cyclone affected the state in all but nine seasons. In the 1916 season, five storms affected the state, which was the season with the most storms devastating the state. The strongest hurricanes to affect the state during the time period were the 1933 Outer Banks hurricane and the 1944 Great Atlantic Hurricane, which produced winds of Category3 status on the Saffir–Simpson Hurricane Scale within the state.[2] The 1933 Outer Banks hurricane was the deadliest hurricane in the state during the time period, which killed 21people.[12] The remnants of a hurricane in 1940 dropped heavy rainfall in the state, which caused over $150million in damage (2008USD) from flooding and landslides.[13]
1950–1979

A total of 79tropical or subtropical cyclones affected North Carolina between 1950 and 1979. Collectively, cyclones during the time period resulted in 37total fatalities during the period, as well as about $3billion in damage (2008USD). A cyclone affected the state in every year during the time period, and in three seasons a total of five cyclones assailed the state. The strongest hurricane to hit the state during the time period was Hurricane Hazel, which struck the state as a Category4 hurricane on the Saffir–Simpson Hurricane Scale. Hazel was both the costliest and deadliest cyclone during the period, causing over $1billion in damage (2008USD) and 19deaths.[14] Most storms affected the state in September, though cyclones lashed the state between May and October.
1980–Present

The period from 1980 to the present encompasses 120tropical or subtropical cyclones that affected the state. Collectively, cyclones in North Carolina during the time period resulted in over $10billion in damage (2010USD), primarily from hurricanes Fran and Floyd. Additionally, tropical cyclones in North Carolina were responsible for 77direct fatalities and at least 44indirect casualties during the period. Eight cyclones affected the state in the 1985 season, which was the year with the most tropical cyclones striking the state. Every year included at least one tropical cyclone affecting the state.
The strongest hurricane to hit the state during the time period was Hurricane Fran in 1996, which struck near Wilmington as a Category3 hurricane on the Saffir–Simpson Hurricane Scale; Hurricane Emily in 1993 brushed the Outer Banks also as a Category3 hurricane.[2] The deadliest hurricane during the period was Hurricane Floyd in 1999, which caused 35fatalities and record–breaking flooding in the eastern portion of the state.[15][16] Hurricane Irene hit the Outer Banks on August 27th 2011 as a Category 1, making it the first of its kind to make landfall since Hurricane Ike in 2008.
North Carolina major hurricanes
The following major hurricanes either made landfall on the state or brought winds of Category 3 status to the state. Storms are listed since 1851, which is the official start of the Atlantic hurricane database.[2]

Deadly storms
The table lists hurricanes by death tolls of over 20fatalities. Direct deaths are those that are directly caused by the storm passage, such as drownings or deaths from being struck by windblown objects. Indirect deaths, which are not included in the toll of Hurricane Floyd, are those that are related to the storm, but not directly from its storm effects. Due to lack of data, many early hurricanes have overall death tolls that do not specify indirect or direct.

See also

Climate of North Carolina
Geography of North Carolina
Hazard mitigation in the Outer Banks
List of United States hurricanes
List of wettest known tropical cyclones in North Carolina
List of Atlantic hurricanes

What is the deadliest hurricane to hit North Carolina?