Each episode of the popular science fiction show 'Star Trek' began with a short speech that explained the mission of the Starship Enterprise. That explanation ended with the phrase "...to boldly go where no man has gone before." Imagine how daring it is to carefully watch the sky, then declare that what is commonly believed is incorrect. In times past, that could get you into very serious trouble. Torture, death, or forfeiture of your immortal soul kind of trouble. At least in modern times only the thing dying is bad astronomy, not bad astronomers. With that in mind, I present some of the people who boldly went where no man had gone before.

Aristotle (384 - 322BC)

Aristotle put forward three experimental proofs to show that the Earth was round. He also thought that the Earth was at the center of the universe, and that the Sun, Moon, planets, and stars revolved around it.

Aristarchus (310? - 230? BC)

Aristarchus created a model of the universe that showed the Sun was at the center of all heavenly bodies. In his only surviving work, On the Dimensions and Distances of the Sun and Moon, Aristarchus described a method for estimating the relative distances of the sun and moon from the earth. Although his method was essentially correct, his estimates were wrong because of his inadequate knowledge of mathematics and his lack of accurate instruments.

Claudius Ptolemaeus (Ptolemy) (85 - 165 AD)

Ptolemy published the Almagest an encyclopedia in which he used centuries of Babylonian observations of the motions of the planets to put forth an argument for an Earth centered universe. The ideas of the Ptolemaic system ruled the world of astronomy for 1,500 years. His death marks the end of the classical era of astronomy.

Nicolaus Copernicus (1473 - 1543) Polish

From his early years, Copernicus, whose Polish name was Mikolaj Kopernik, thought that the Sun lay at the center of the system of planets and stars. In 1543 he published On the Revolution of the Celestial Spheres which began the change of humanity's view of the universe. This work met with great hostility from the Church. As a system of prediction, the Copernican view was no more successful than the Ptolemaic.

Tycho Brahe (1546 - 1601) Danish

Brahe made precise, comprehensive astronomical measurements of the solar system and more than 700 stars. The data Brahe accumulated was superior to all other astronomical measurements made until the invention of the telescope in the early 17th century.

He studied law and philosophy at the universities of Copenhagen and Leipzig; at night, however, Brahe busied himself with observing the stars. With no instruments other than a globe and a pair of compasses, he succeeded in detecting grave errors in the standard astronomical tables, and set about correcting them. In 1572 he discovered a supernova in the constellation Cassiopeia.

After Brahe had spent some time traveling and lecturing, Frederick II, king of Denmark and Norway, offered to provide Brahe with funds to construct and equip an astronomical observatory on the island of Hven (now Ven). Brahe accepted the proposal, and in 1576 construction began on the castle of Uranienborg ("fortress of the heavens"), where for 20 years the astronomer pursued his observations. In 1604 another supernova was discovered. The discovery of the 1572 and 1604 supernovas, shattered a cornerstone of Ptolemaic thinking: that the sphere containing the stars was unchanging.

Although Brahe's theory of planetary motion was flawed, the data he accumulated during his life played a crucial role in developing the correct description of planetary motion. Johannes Kepler, who was Brahe's assistant from 1600 until Brahe's death in 1601, used Brahe's data to help him formulate his three laws of planetary motion.

Galileo Galilei (1564 - 1642) Italian

In 1609 Galileo heard of an astonishing invention: by looking through two glass lenses held at a fixed distance from each other and the eye, distant objects could be magnified. By December of 1609 Galileo had built a simple 20 power telescope for himself, and pointed it to the sky. On January 7, 1610 he discovers 3 of Jupiter's moons: Callisto, Europa & Io. On January 13, 1610 Galileo discovers, Ganymede. After publishing his discoveries, the Church, in 1616, warned him to change his views. In 1632 he published Dialogue Concerning the Two Great World Systems. This book, and it's suggestions put Galileo at the mercy of the Holy Office of the Inquisition, where he was accused of heresy. Forced to abandon his views, Galileo lived out his days under house arrest.

Saturn's most distinctive feature is its ring system, was first seen in 1610 by Galileo, using one of the first telescopes. He did not understand that the rings were separate from the body of the planet, so he described them as handles (ansae). The Dutch astronomer Christiaan Huygens was the first to describe the rings correctly.

Neptune was very nearly discovered by Galileo. While he was observing the Jupiter system on 28 December 1612 he recorded Neptune as an 8th magnitude star. Just over a year later the same alignment of Neptune and Jupiter occurred and Galileo, on 27 January 1613, recorded two stars in his field of view. One was Neptune and, remarkably, Galileo observed it again the following night when he noted that the two stars appeared to be further apart. 234 years later, in 1846, French astronomer Urbain Jean Joseph Leverrier calculated the existence and position of a new planet. That same year the German astronomer Johann Gottfried Galle 'discovered' Neptune within 1° of that position.

Johannes Kepler (1571 - 1630) German

Kepler in noted for formulating and verifying the three laws of planetary motion. These laws are now known as Kepler's laws.

In 1594, Kepler worked out a complex geometric hypothesis to account for distances between the planetary orbits, orbits that he mistakenly assumed were circular. Kepler later deduced that planetary orbits are elliptic; nevertheless, these preliminary calculations agreed with observations to within 5 percent. Kepler then proposed that the sun emits a force that diminishes inversely with distance and pushes the planets around in their orbits. Kepler published his account in a treatise entitled Mysterium Cosmographicum (Cosmographic Mystery) in 1596. This work is significant because it presented the first comprehensive and cogent account of the geometrical advantages of Copernican theory.

Kepler, in 1600, became the assistant to the Danish astronomer Tycho Brahe in the latter's observatory near Prague. On the death of Brahe in 1601, Kepler assumed his position as imperial mathematician and court astronomer to Rudolf II, Holy Roman emperor. One of his major works during this period was Astronomia Nova (New Astronomy, 1609), the great culmination of his painstaking efforts to calculate the orbit of Mars. This treatise contains statements of two of Kepler's so called laws of planetary motion. The first is that the planets move in elliptic orbits with the sun at one focus; the second, or "area rule," states that a hypothetical line from the sun to a planet sweeps out equal areas of an ellipse during equal intervals of time; in other words, the closer a planet comes to the sun, the more rapidly it moves.

In 1619 he published his Harmonice Mundi (Harmony of the World), the final section of which contained another discovery about planetary motion: The ratio of the cube of a planet's distance from the sun and the square of the planet's orbital period is a constant and is the same for all planets.

At about the same time he began publishing a book that took three years to appear, the Epitome Astronomiae Copernicanae (Epitome of Copernican Astronomy, 1618-1621), which brought all of Kepler's discoveries together in a single volume. Equally important, it became the first textbook of astronomy to be based on Copernican principles, and for the next three decades it was a major influence in converting many astronomers to Keplerian Copernicanism.

The last major work to appear in Kepler's lifetime was the Tabulae Rudolfinae (Rudolfine Tables, 1625). Based on Brahe's data, the new tables of planetary motion reduced the mean errors from 5° to within 10' of the actual position of a planet. Sir Isaac Newton relied heavily on Kepler's theories and observations in formulating his theory of gravitational force.

Johann Bayer (1572 - 1625) German

Bayer published the first star atlas to show the entire celestial sphere in the 1603 and 1627 editions of the Uranometria. His catalogues contained more stars than Brahe's catalogue, and listed the stars by constellation, and brightness. In the Uranometria Bayer indicated the star's brightness by using the greek character a (alpha) to represent the brightest star in the constellation. b (beta) represented the second brightest, and so on. There are however, some exceptions to this 'rule'. He then combined the greek letter brightness designation and the Latin root of the name of the constellation to name the stars. These designations are still in use today. For example, the brightest star in the constellation Centaurus is known as Alpha Centauri.

Bayer's Uranometria is the first among the star atlases which represent the stars around the south pole.

Johannes Hevelius (1611 - 1687) Polish

Hevelius was an accomplished instrument maker and engraver. He made several large telescopes and some of the last large open sighted instruments after designs by Tycho Brahe, for his observatory which he called "Sternenburg" or "Stellaeburg". He also introduced the use of the vernier scale.

Hevelius published the Selenographia, the first detailed maps of the Moon (1647)

Circa 1670, Johannes Hevelius builds a 140-foot telescope.

1687 Publishes Firmamentum Sobiescianum sive Uranographia star atlas as part two of the Prodromus Astronomiae catalog of 1564 stars published in 1690 by Elizabeth Hevelius. He made his own observations for this atlas.

Giovanni Cassini (1625 - 1712) Italian

Giovanni Cassini, the most notable observer following Galileo. An Italian who headed the Paris Observatory for many years, Cassini was the first to observe seasonal changes on Mars and measure this planet's parallax (or distance), setting the scale of the solar system for the first time. He was the first to describe the bands and spots on Jupiter, and studied the Jovian moons' orbits. He discovered four moons of Saturn, but is best remembered for first seeing the division (now named after him) between the A and B rings.

1655 discovers Jupiter's great red spot
1665 determines the rotational speeds of Jupiter, Mars, and Venus
1671 discovers Iapetus, moon of Saturn.
1672 Jean Richer and Giovanni Cassini measure the astronomical unit to within 7%
1672 discovers Rhea, moon of Saturn.
1684 discovers Tethys, a moon of Saturn.
1684 discovers Dione, a moon of Saturn.

Christiaan Huygens (1629 - 1695) Dutch

Among his discoveries was the principle (later named after him) that states that every point on the front of an advancing wave is itself a source of new waves. From this principle he developed the wave theory of light.

The telescope invented by him allowed one to distinguish the ring of Saturn, to make astrological observations about the planets, of the nebula of Orion and of the Moon, all reported in Systema Saturnium (1659). In 1655 he discovered Titan, a moon of Saturn. Huygens is also remembered for the invention of the eyepiece which takes its name from him.

In Horologium Oscillatorium (1673) he determined the true relation between the length of a pendulum and the period of oscillation and developed theories on centrifugal force in circular motion that assisted the English mathematician Sir Isaac Newton in formulating the laws of gravity.

Sir Isaac Newton (1642 - 1727) British

Newton developed laws that described how planets orbit the Sun, and a theory on the nature of light, color, and rainbows. In 1671 he built a new kind of telescope that used a mirror to reflect the light it gathered, instead of a lens to refract it. The Newtonian design is still one of the most popular today.

1687 Publishes his Principia.

John Flamsteed (1646 - 1719) British

Flamsteed was the first Astronomer Royal of England. When the Royal Observatory Greenwich was founded in 1675, Flamsteed was made its first director. In 1676 he began a series of observations that, by exposing and correcting the large number of errors in contemporary astronomical tables, helped mark the beginning of modern practical astronomy. His catalog of the fixed stars, Historia Coelestis Britannica (1725), listing over 3000 stars, was larger than any previous star catalog. In this catalog, stars were ordered and numbered in each constellation in increasing right ascension, down to a magnitude limit of about +8.

Flamsteed's lunar observations furnished the data that his contemporary, the English astronomer and physicist Sir Isaac Newton, used to verify his theory of gravity.

Edmund Halley (1656 - 1742) British

Halley first calculated the orbit of a comet. He was made Astronomer Royal in 1720 (-1742), and began an 18-year study of the complete revolution of the moon through its ascending and descending nodes.

Halley's most important scientific paper was Astronomiae Cometicae Synopsis (Synopsis on Cometary Astronomy), begun in 1682 and published in 1705. In this work, Halley applied Newton's laws of motion to all available data on comets and then mathematically demonstrated that comets move in elliptic orbits around the sun. His accurate prediction of the return in 1758 of a comet (now known as Halley's comet) validated his theory that comets are part of the solar system.

Edmund Halley also discovered the proper motion of stars.

Nicolas-Louis de Lacaille (1713 - 1762)

De Lacaille spent two years (1751-53) at the Cape of Good Hope charting the positions of 9766 stars and measuring the shape of the Earth. De Lacaille made careful measurements at the Cape which appeared to show that the shape of the southern hemisphere of the Earth was not the same as the shape of the northern hemisphere - the Earth was slightly pear shaped. His star catalogue was published posthumously in 1763.

Charles Messier (1730 - 1817) French

Messier and his colleague, Pierre Mechain, compiled a list of galaxies, nebulae, and star clusters. Messier was interested in finding comets, and his list catalogs objects that proved not to be comets. Of these, 33 were identified by later observers as galaxies, 55 as star clusters, and 11 as true nebulae; the 4 others are a double star; an asterism; a patch of the Milky Way; and a duplicate observation.

Giuseppe Piazzi (1746 - 1826) Italian

Piazzi established the Palermo Astronomical Observatory in 1790, published a catalogue of the stars (1803, 1814) and discovered and named the first minor planet, Ceres.

Heinrich Olbers (1758 - 1840) German

In 1779 he devised a method, still employed by astronomers, for calculating the orbits of comets. (Olbers discovered several comets, the first, named after him, in 1815.) In 1781 he identified Uranus as a planet rather than as a comet, as had previously been assumed. He discovered the asteroids Pallas in 1802 and Vesta in 1807 and first proposed that all asteroids are fragments of a shattered planet that formerly revolved around the sun. He observed, in 1826, that the night sky should be uniformly illuminated if the universe were infinite and homogeneous, with stars in every direction. This observation, called Olbers' paradox, was only resolved with the discovery of the Red Shift, along with the realization that stars have finite lifetimes.

Sir William Herschel (1738 - 1822) German / British

Originally named Friedrich Wilhelm Herschel, he was born in Hannover, Germany. At the age of 19 he went to England, working as a music teacher and organist but devoting all his spare time to astronomy and mathematics. Unable to procure adequate instruments, he constructed and constantly improved his own telescopes.

In 1774, with the aid of his sister Caroline, he began a comprehensive and systematic survey of the heavens.

In 1781 he discovered a new planet, which he named Georgium Sidus in honor of George III, king of Great Britain, but which is now universally called Uranus.

A year later he was appointed private astronomer to the king, a position that enabled him to devote all his time to his astronomic pursuits. He erected a telescope at Slough with a 48-in (1.22-m) mirror and a focal length of 40 ft (12.2 m). Using this telescope, he discovered two satellites of Uranus (Titania & Oberon) (January 11, 1787) and the sixth and seventh satellites of Saturn (Enceladus August 28th, 1789 & ?).

He studied the rotation period of many planets and the motion of double stars, and also cataloged more than 800 double stars. He studied nebulas, contributing new information on their constitution and increasing the number of observed nebulas from about 100 to 2500. Herschel was the first to propose that these nebulas were composed of stars. He was elected to the Royal Society in 1781 and knighted in 1816. He is considered the founder of sidereal astronomy.

Caroline Lucretia Herschel (1750 - 1848) German / British

Herschel was the sister of William Herschel and the aunt of John Herschel. After the French occupation of Hanover in 1757, William escaped to England, where he became a music teacher. In 1766 William became an organist in Bath and, in 1772, Caroline joined him there. After arriving in Bath, Caroline trained as a singer giving successful performances.

In 1787 the Herschel's moved to Old Windsor and King George III gave Caroline a £50 per year salary as assistant to William. William had been appointed astronomer to the King George III five years earlier.

In 1788 the Herschel's moved to Slough. Every night William observed and Caroline recorded his observations. By day Caroline would work on the results obtained by night. She carried out the lengthy calculations necessary to reduce William's data.

In 1798 Caroline submitted to the Royal Society an Index to Flamsteed's observations together with a list of 560 stars which had been omitted.

Caroline returned to Hannover after William's death in 1822. There she completed her catalogue of 2500 nebulae. In 1828 the Astronomical Society awarded her its gold medal for her work.

Friedrich Bessel (1784 - 1846) German

Bessel, a German astronomer and mathematician, best known for making the first accurate measurement of the distance to a star. He established the uniform system for computing star positions that is still in use. From 1821 to 1833 he accurately determined the positions of stars to the ninth magnitude, bringing the number of stars so cataloged to 50,000. His Astronomische Untersuchungen (Astronomical Observations) was published in 1842. Bessel was the first to succeed in determining the parallax and hence the distance of a fixed star, 61 Cygni, thus giving final confirmation to the heliocentric theory that the sun, rather than the earth, is the center of the solar system. He also determined the diameter, weight, and ellipticity, or deviation from the form of a true sphere, of the earth. In the investigation of problems connected with planetary perturbation, he introduced into mathematics the Bessel functions as the solutions of certain differential equations. The functions are of great importance in determining the distribution and flow of heat or electricity through a circular cylinder and in the solution of problems concerning wave theory, elasticity, and hydrodynamics.

William Cranch Bond (1789 - 1859) American

The first director of the Harvard College Observatory. At the observatory, he studied Saturn and, with William Lassell, discovered its moon Hyperion.

John Herschel (1792 - 1871)

Son of Sir William Herschel, first to survey the southern hemisphere's sky, and discoverer of photographic fixer.

Johann Gottfried Galle (1812 - 1910) German

Galle was the observer who first saw Neptune in 1846. Galle is also noteworthy for having been Encke's assistant, and he's one of the few astronomers ever to have observed Halley's Comet twice -- dieing two months after the comet passed perihelion in 1910.

William Lassell (1799 - 1880) British

1846 discovers Triton, moon of Neptune.

1851 discovers Umbriel and Ariel, moons of Uranus.

Giovanni Schiaparelli (1835 - 1910) Italian

Born in Savigliano, NW Italy. He studied at Berlin and at Pulkova, Russia, and became director of Brera Observatory, Milan. He discovered the link between meteor showers and comets, observed double stars, discovered the asteroid Hesperia, and termed vague linear features on Mars as ‘canali‘.

Alvan G. Clark, Jr. (1832 - 1897)

1862 Discovers Sirius' white dwarf companion. Friedrich Bessel had proposed the existence of an unseen companion in 1844.

Maria Mitchell (1818 - 1889) American

In October 1847, she discovered a telescopic comet, an accomplishment that brought her international recognition. The following year she became the first woman elected to the American Academy of Arts and Sciences.

Sir William Huggins (1824 - 1910) British

Sir William, made the first photographic spectrum of a comet (1881 III) and discovers the cyanogen (CN) emission at violet wavelengths, which caused near mass hysteria 29 years later as the Earth passed thru the tail of Halley's Comet.

J. Norman Lockyer (1835 - 1920)

Discoverer of the element helium in 1868. Lockyer was making visual spectroscopic studies of the sun (helios) when he attributed unknown absorption lines to the new element, not "discovered" on earth until 1891. Helium is the second simplest and most abundant element in the universe after hydrogen.

Lockyer is also known as the Father of Archeo-astronomy; he was among the first to propose scientifically that Stonehenge was an astronomical observatory and that the Egyptian pyramids and great medieval Christian cathedrals were built along important astronomical orientations.

Asaph Hall (1829 - 1907)

August 11, 1877 Discovers Deimos, moon of Mars.

August 17, 1877 Discovers Phobos, moon of Mars.

Edward Emerson Barnard (1857 - 1923) American

Barnard is known for his achievements in astrophotography and for his discovery of comets, nebulas, Amalthea (a moon of Jupiter, in 1892), and the nearby star named for him. He determined, through painstaking photography, that the dark regions of the Milky Way are actually dark clouds of dust and gas.

Henrietta Leavitt (1868 - 1921) American

Leavitt's work made possible the first accurate determination of extragalactic distances. While working at the Harvard College Observatory on a survey of Cepheid variable stars (stars the luminosity, or brightness, of which varies in an extremely regular manner) she discovered (1912) that the Cepheids having the greatest average brightness also had the longest periods of variation. When, in 1913, the Danish astronomer Ejnar Hertzsprung accurately estimated the distances of a few Cepheids, the distances of all Cepheids could be calculated from Leavitt's period-luminosity correlation. This method of distance determination greatly increased the scientific knowledge of the physical universe.

George Ellery Hale (1868 - 1938) American

While Hale was still in college, his father built the Kenwood Physical Observatory, a small observatory near Chicago containing 12-inch refracting telescope. Hale used the observatory for original research and in 1889 invented the spectroheliograph, a device used to study the surface of the sun. In 1908, Hale discovered that sunspots have magnetic fields.

Hale conceived and helped design the first giant reflecting telescope. The instrument, a reflector with a 200-in (5.08-m) mirror, was installed at Mount Palomar Observatory near San Diego, California, in 1948. It was named the Hale Telescope in his honor. His writings include The Study of Stellar Evolution (1908) and Beyond the Milky Way (1926).

Henry Norris Russell (1877 - 1957) American

Russell was an astrophysicist noted for his work on stellar evolution. Born in Oyster Bay, New York, Russell obtained his Ph.D. from Princeton University in 1900 and taught there from 1905 to 1947, also serving as its observatory's director (1912-47). After 1921 he was associated with Mount Wilson Observatory, as well. From pioneering research on binary stars and stellar parallaxes, Russell developed a theory (1913) of stellar evolution that served to displace older concepts. He went on to do important work on the spectra of elements in stars and to determine the abundance of various gases in the sun's atmosphere. Combined with the independent work of Danish astrophysicist Ejnar Hertzsprung, the kind of graph he developed by plotting the absolute magnitudes of stars against their spectral types became known as a Hertzsprung-Russell diagram.

Walter Baade (1893 - 1960) German / American

A German born U.S. astronomer, educated at the University of Göttingen, whose studies of stars in the Andromeda galaxy led him, in the 1950's, to double the common estimate of the size and age of the universe. Begun at Mount Wilson Observatory in 1931, these studies established two major types of stars: the younger, hotter, Population I type and the older, cooler, Population II. In his career in Germany prior to 1931, Baade discovered the asteroids Icarus and Hidalgo.

Jan Hendrik Oort (1900 - 1992) Dutch

Oort is noted for his determination that the earth's galaxy, the Milky Way, rotates, and for his contributions to comet theory. Oort, with his colleagues, established the Milky Way's rotation in the 1920s; they also worked out the mass of the galaxy and the distance of its center from the sun. Oort pioneered in Dutch radio astronomy. He proposed in 1950 that a cloud of cometary material surrounds the solar system at an enormous distance, a concept now generally accepted.

Albert Einstein (1879 - 1955)

By 1911 Einstein was able to make preliminary predictions about how a ray of light from a distant star, passing near the Sun, would appear to be bent slightly, in the direction of the Sun. This effect is now used in a technique called gravitational lensing to examine deep space objects that are hidden by foregound objects.

1916 his famous General Theory of Relativity is presented.

May 29, 1919 - measurements made during a total eclipse of the sun agreed with predictions made on the basis of Einstein's General Relativity theory. This was General Relativity's first scientific test. The curvature of spacetime due to the sun's mass (which we normally think of as gravity) "deflects" the light coming from stars beyond the sun, causing their apparent position to be different from when they're not near the sun on the celestial sphere. You can only observe stars near the sun's limb, where the effect in most pronounced, during an eclipse. (This ignores what radioastronomers can do nowadays.) Interestingly, Newton's theory of light and gravitation also predicts an angular deflection, but the amount is only half that of General Relativity.

Ejnar Hertzsprung (1873 - 1967) Danish

Hertzsprung pioneered in the study of the birth and death of stars. Hertzsprung published his first major papers on the existence of giant and dwarf stars while working at a private observatory. He worked out the general relationships between stars' spectral types, temperatures and true brightness. His work, combined with the independently produced work of astronomer Henry Norris Russell, resulted in the epochal Hertzsprung-Russell diagram of types of stars.

Edwin Hubble (1889 - 1953) American

Hubble proved the existence of large star systems, or galaxies, far outside the Milky Way. In 1923, he discovered Cepheid variable stars in galaxy M-31. After 1948 he also supervised the research conducted with the 200-in (508-cm) telescope at Palomar Observatory. Hubble is also known for his classification of extragalactic systems. His later discoveries concerning galactic motions and distances helped to substantiate the theory of the expanding universe.

Gerard Peter Kuiper (1905 - 1973) Dutch / American

His achievements include measurement of the diameter of Pluto, the discovery of satellites of Uranus (Miranda 1948) and Neptune (Nereid 1949), and the detection of carbon dioxide on Mars. In the 1960s Kuiper served as chief scientist for the Ranger spacecraft crash-landing probes of the moon.

Clyde Tombaugh (1906 - 1997) American

Tombaugh discovered Pluto, the outermost planet in our solar system, in 1930. During his planet search, at the Lowell Observatory, Tombaugh photographed 65 percent of the sky and spent 7,000 hours examining about 90 million star images. Besides Pluto, his discoveries included six star clusters, one cloud of galaxies, one comet and about 775 asteroids.

Stephen Hawking (1942 - ) British

Hawking, a theoretical physicist, best known for his attempts to unite general relativity theory with quantum mechanics and for his integrally related contributions to cosmology. Much of his work has dealt with the black hole concept. His research indicates that general relativity, if true, supports the big bang theory of the creation of the universe. It further suggested that the big bang arose from a singularity, or a point of infinite distortion of space and time. He later refined this concept by viewing all such scientific theories as secondary attempts to describe a reality in which concepts such as singularities have no meaning, and where space and time form a closed surface without boundary. He wrote A Brief History of Time (1988). Hawking has made these important contributions to science while battling amyotrophic lateral sclerosis, an incurable disease of the nervous system.