Dennis Rawlins
Encyclopedia
Dennis Rawlins is an American astronomer, historian, and publisher.
In 1996, Ohio State University invited Rawlins to examine the newly recovered diary of Richard E. Byrd, which contained at critical points erased but still legible altitudes observed by sextant
. Rawlins discovered the uncontested fact that these placed Byrd roughly 100 miles (160.9 km) south of where his official report put him at the corresponding times. Rawlins thus concluded that despite navigating successfully for most of the necessary distance, Byrd's effort had also fallen short, and that therefore the Norwegian explorer Roald Amundsen
, fourth claimant to the North Pole, was first to genuinely reach it, on May 12, 1926. Given that Amundsen is undisputed first attainer of the South Pole, Rawlins announced that Amundsen was thus first to each geographical pole of the earth. When in 1973 Rawlins had published this opinion in his Peary book's final chapter, it had appeared extreme; however, that Amundsen has the first verifiable claim to each pole is now the majority opinion among polar experts.
Rawlins's detailed report on Byrd's trip and on the competence of lingering defenses of it was co-published in 2000 by the University of Cambridge
adding the new finding that Byrd's long-suppressed original June 1926 report to the Secretary of the Navy and the National Geographic Society contained alleged raw sextant readings entirely given to 1" precision; it is uncontended that such precision was not possible on Byrd's standard portable sextant and that it contradicts his 1926 diary, where all sextant observations are expressed to half or quarter arc-minute accuracy.
Polar controversies
While studying historical magnetic declination data in polar regions, Rawlins was surprised to find that there were no such data from the 1909 expedition of Robert E. Peary, eventually leading him to become skeptical of Peary's claim to have reached the North Pole. In 1973, Rawlins wrote Peary at the North Pole: Fact or Fiction? (Washington: Luce) which was the first scientific examination of the issue that concluded that neither Peary nor his rival Frederick A. Cook had reached the Pole. The book also revealed since-confirmed evidence that Peary's 1907 claim to have discovered non-existent "Crocker Land" in 1906 was a fabrication. In 1989 Rawlins found that Peary had suppressed his 1909 diary's only explanation of steering poleward, when he read the diary to Congress in 1911.In 1996, Ohio State University invited Rawlins to examine the newly recovered diary of Richard E. Byrd, which contained at critical points erased but still legible altitudes observed by sextant
Sextant
A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight...
. Rawlins discovered the uncontested fact that these placed Byrd roughly 100 miles (160.9 km) south of where his official report put him at the corresponding times. Rawlins thus concluded that despite navigating successfully for most of the necessary distance, Byrd's effort had also fallen short, and that therefore the Norwegian explorer Roald Amundsen
Roald Amundsen
Roald Engelbregt Gravning Amundsen was a Norwegian explorer of polar regions. He led the first Antarctic expedition to reach the South Pole between 1910 and 1912 and he was the first person to reach both the North and South Poles. He is also known as the first to traverse the Northwest Passage....
, fourth claimant to the North Pole, was first to genuinely reach it, on May 12, 1926. Given that Amundsen is undisputed first attainer of the South Pole, Rawlins announced that Amundsen was thus first to each geographical pole of the earth. When in 1973 Rawlins had published this opinion in his Peary book's final chapter, it had appeared extreme; however, that Amundsen has the first verifiable claim to each pole is now the majority opinion among polar experts.
Rawlins's detailed report on Byrd's trip and on the competence of lingering defenses of it was co-published in 2000 by the University of Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
adding the new finding that Byrd's long-suppressed original June 1926 report to the Secretary of the Navy and the National Geographic Society contained alleged raw sextant readings entirely given to 1" precision; it is uncontended that such precision was not possible on Byrd's standard portable sextant and that it contradicts his 1926 diary, where all sextant observations are expressed to half or quarter arc-minute accuracy.
Solar system dynamics
- Starting in 1967 Rawlins consistently contended that PlutoPlutoPluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
is far smaller than one earth-mass, the then generally accepted gravitationally based figure, and that its effects upon Uranus and Neptune must be effectively imperceptible in the observational data of that day. - At this time, he also recovered a lost 1714 observation of Uranus the first addition to the list of pre-discovery planet observations in over a century and the last of Uranus to date.
- In 1970, he extended the E. Brown transformation to discover planetary perturbation's amplitude as a function of distance, graphically and asymptotically.
- Two papers by Rawlins and Max Hammerton (University of Cambridge) produced upper limits on the gravitationally permissible masses of planets beyond Neptune, showing that exterior planets at probable distances were far from giant, suggesting that the main bodies of the solar systemSolar SystemThe Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
may end at Neptune. which has since been found to be the case. - Pointing to several resemblances of Pluto with TritonTriton (moon)Triton is the largest moon of the planet Neptune, discovered on October 10, 1846, by English astronomer William Lassell. It is the only large moon in the Solar System with a retrograde orbit, which is an orbit in the opposite direction to its planet's rotation. At 2,700 km in diameter, it is...
, Rawlins proposed in 1973 a mass of Pluto which though too high eventually proved to be closest to the truth among all estimates published by astronomers until the mass of Pluto was accurately ascertained in 1978 through newly discovered CharonCharon (moon)Charon is the largest satellite of the dwarf planet Pluto. It was discovered in 1978 at the United States Naval Observatory Flagstaff Station. Following the 2005 discovery of two other natural satellites of Pluto , Charon may also be referred to as Pluto I...
's orbit. - Rawlins and Myles Standish (J. P. L., California Inst. of Techn.) showed in successive papers that the 1613 position of Neptune recorded by Galileo probably did not contradict modern theory.
- Rawlins originated and programmed the standard method of analytically determining the dimensions and axes of the solar tidal ellipsoid produced by the combined gravitation of all the planets, speculating that such analysis might also assist in explaining the behavior of some irregular variable multiple stars.
- Starting in the early 1980s, Rawlins argued that the long history of disagreements over which lunar eclipseLunar eclipseA lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a...
reports from the classical era were valid for gauging secular earth spin behavior was unnecessary, since centuries of untroubled ancient use of the synodic lunar tables surviving in the AlmagestAlmagestThe Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...
showed that they could be employed as an empirical average. He also suggested that the accuracy of the Almagest tables of the synodic motion of MarsMarsMars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
might offer a similar if less sensitive check of modern theory. - Rawlins has noted a peculiarity of the solar system which he contends may contribute to solving its origin; the only two twin pairs of planets are contiguous, relatively close to each other, and their inner members are the only planets that rotate in retrograde; the suggestion follows that MercuryMercury (planet)Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
and PlutoPlutoPluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
(smallest and most eccentric of the traditional solar system's planets) might be escaped satellites respectively of VenusVenusVenus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
and NeptuneNeptuneNeptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...
.
Atmospheric refraction
- In 1979, Rawlins developed and distributed the first non-series formula for computing atmospheric refractionAtmospheric refractionAtmospheric refraction is the deviation of light or other things like humanelectromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of altitude...
from zenith to horizon to one percent relative accuracy His altered argument method of simplifying computation of refraction is now widely adopted. - Soon after, he produced a similar compact formula for RayleighRayleigh scatteringRayleigh scattering, named after the British physicist Lord Rayleigh, is the elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the light. The particles may be individual atoms or molecules. It can occur when light travels through...
extinctionExtinction (astronomy)Extinction is a term used in astronomy to describe the absorption and scattering of electromagnetic radiation by matter between an emitting astronomical object and the observer. Interstellar extinction—also called Galactic extinction, when it occurs in the Milky Way—was first...
. - His further developments of formulas for atmospheric refraction, and for Rayleigh, ozone, and aerosols extinction appeared in the 1990s; later refined by Keith Pickering.
Antiquary and ancient position astronomy
- While attempting (1982–1991) to reconstruct HipparchusHipparchusHipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
's solar and lunar theories, Rawlins showed that the length of the year preserved on the important Babylonian System B astronomical cuneiform text BM55555 was based upon well known Greek solsticeSolsticeA solstice is an astronomical event that happens twice each year when the Sun's apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes...
s and thereby revealed the previously long disputed time of day of Hipparchus's dawn June 26, 135 B. C. E. summer solstice. (Explicitly on the basis of this proposal, BM55555 has since been placed on permanent display at the British Museum.) This permits a rough check upon the modern theory of the Sun's motion independent of eclipses. Likewise for Rawlins's reconstruction of CallippusCallippusCallippus or Calippus was a Greek astronomer and mathematician.Callippus was born at Cyzicus, and studied under Eudoxus of Cnidus at the Academy of Plato. He also worked with Aristotle at the Lyceum, which means that he was active in Athens prior to Aristotle's death in 322...
's dawn June 28, 330 B. C. E. solstice. - While establishing (1987–94) the standard critical edition of Tycho BraheTycho BraheTycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
's catalogue of stars, Rawlins noticed and incorporated the fact that Brahe's data were consistent with virtually zero aerosols on the nights when dim stars were observed, a finding which relates to current debates on environmental degradation trends. This point was tested and made conservatively quantitative by K. Pickering.
Ancient astronomy
In 1976, inspired by the researches of Johns Hopkins physicist Robert Newton, Rawlins began a series of probes of ancient astronomical questions. Among his and his colleagues' findings and contentions:- The Great PyramidGreat Pyramid of GizaThe Great Pyramid of Giza is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact...
was probably oriented ca. 2600 B. C. E. by using at winter solstice the star 10Flamsteed designationFlamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek letters. Each star is assigned a number and the Latin genitive of the constellation it lies in...
iBayer designationA Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...
DraconisDraco (constellation)Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...
(previously unnoticed in the ever accumulating pile of mostly dubious Great Pyramid literature, which Rawlins facetiously calls "the Greater Pyramid"). - Recognizing in two ancient lists of year lengths the oldest surviving data in continued fractionContinued fractionIn mathematics, a continued fraction is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number, then writing this other number as the sum of its integer part and another reciprocal, and so on...
form, Rawlins proposed that these indicate that ca. 280 B. C. E., heliocentristHeliocentrismHeliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...
astronomer Aristarchus of SamosAristarchus of SamosAristarchus, or more correctly Aristarchos , was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe...
discovered precessionPrecessionPrecession is a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle is constant...
over a century before Hipparchus, deriving the same faulty 1° per century estimate later adopted by the heretofore-accepted discovererHipparchusHipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
. - The slim surviving calendar data associated with Aristarchus suggest that he possessed and maybe originated the very accurate so-called Babylonian month (29 days 12 hours 44 minutes 3⅓ seconds) decades before the earliest known cuneiformCuneiformCuneiform can refer to:*Cuneiform script, an ancient writing system originating in Mesopotamia in the 4th millennium BC*Cuneiform , three bones in the human foot*Cuneiform Records, a music record label...
hint of it. - The accuracy of this estimate of the mean month's duration is most convincingly explained by its having been (as stated in Ptolemy's much questioned testimony) computationally based on the uniquely stable eclipse cycle, 4267 synodic months = 4573 anomalisticOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
months, which (dividing by 17) generates the supposedly Babylonian equation 251 synodic months = 269 anomalistic months. - Until the moon is greater than about 3° distant from quarterMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
phase, curvature in its terminatorTerminator (solar)A terminator, twilight zone or "grey line" is a moving line that separates the illuminated day side and the dark night side of a planetary body...
cannot be discerned by the unaided eye, so assuming Aristarchus knew the eye's limits (he is said to have been a student of human vision) his famous 87° elongation for half moon makes more sense as not a precise angle but a lower bound. - AristyllusAristillusAristillus was a Greek astronomer, presumably of the school of Timocharis . He was among the earliest meridian-astronomy observers....
was long chronologically grouped with fellow Alexandrian TimocharisTimocharisTimocharis of Alexandria was a Greek astronomer and philosopher. Likely born in Alexandria, he was a contemporary of Euclid....
(ca. 300 B. C. E.), the other earliest known observer of star declinationDeclinationIn astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
s, and thus mis-dated about forty years early. His date was fixed by least squares to ca. 260 B. C. E., showing that his previously denigrated accuracy was actually among the ancients' best. The same analysis also finds Aristyllus's probable latitude, and shows that his estimate of it was accurate to about 1'. - The successive lunar distances of Hipparchus (ca. 140 B. C. E.), 3144 and 3122½, heretofore investigated withoutHipparchusHipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
satisfactory fit, can both be elicited with trigonometry, using Aristarchus's 87° half moon elongation, and are consistent with a hypothesis of ancient incorporation of heliocentrist astronomical measure. - Recognition of a mean longitude of the Sun computed by Hipparchus for May 2, 127 B. C. E., inadvertently preserved by Ptolemy's careless plagiarismPlagiarismPlagiarism is defined in dictionaries as the "wrongful appropriation," "close imitation," or "purloining and publication" of another author's "language, thoughts, ideas, or expressions," and the representation of them as one's own original work, but the notion remains problematic with nebulous...
. - Recovery of two lost Hipparchus orbits of the Sun's motion, a crude early one and a refined last one.
- Proposing that the central equation of Babylon's System A, 6247 synodic months = 6695 anomalistic months, was based on an eclipse relation about 1010 years long, from just dividing by 2 the 12,494 months elapsed between then contemporary lunar eclipses and corresponding very ancient, now lost Babylonian lunar eclipse reports. Pairs of eclipses thus separated are so infrequent that the only two available to the Seleukid empire which birthed System A were November 23, 1292 versus January 16, 281 and December 5, 1274 versus January 26, 263 B. C. E. The earliest certain System A cuneiform tablet is dated to 263 B. C. E.
- Among indications of Hipparchus's early use of spherical trigonometrySpherical trigonometrySpherical trigonometry is a branch of spherical geometry which deals with polygons on the sphere and the relationships between the sides and the angles...
are his climataClimataThe climata were the ancient divisions of the inhabited portion of the spherical Earth by parallel circles centered on the Pole...
, his tables for parallaxParallaxParallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
, and a 1994 proposed solution of the long-vexing source of atypical randomness of fractional endings of the southern longitudes in Hipparchus's stellar catalogue. - There is a hitherto submerged problem with Otto Neugebauer's and other panBabylonianists' long reigning conventional belief that Ptolemy mis-attributed the extremely accurate equation 5458 synodic months = 5923 draconiticOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
months to Hipparchus instead of to decliningBabylonBabylon was an Akkadian city-state of ancient Mesopotamia, the remains of which are found in present-day Al Hillah, Babil Province, Iraq, about 85 kilometers south of Baghdad...
Babylon's astrologers, since the only explicitly dated cuneiform tablet computationally based upon this ratio is from 103 B. C. E., which is after Hipparchus. - The 5458 month equation in question could have been found by dividing 5/2 into the large apogee-perigee eclipse relation 13,645 synodic months = 14,807½ draconitic months, which is 14,623½ anomalistic months long or about 1103 years. Exceptionally, one of Hipparchus's few surviving eclipse records, January 27, 141 B. C. E., will work with this equation. The equation is cited to him by Ptolemy, and Hipparchus is the only astronomer known ever to have used an apogee-perigee eclipse relation (half integral in anomaly); but no record survives today of the required prior eclipse of November 13, 1245 B. C. E. or indeed of any other eclipse even nearly this ancient.
- The planetary data of PlinyPliny the ElderGaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
are inconsistent with geocentric astronomy but compatible with heliocentric astronomy. - Elementary and undisputed chronological evidence shows that Ptolemy's adoption of his orbital parameters was not based upon his purported empirical justification of them.
- Persistent doubts of the -7.5° remainder for the 4267 month eclipse relation (see above) underlying the canonical ancient tables of the moon's mean motion are found to be based upon previous investigators' failure to use the appropriate anomalistic yearYearA year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....
when computationally checking it. - Ptolemy's remarkably accurate last lunisolar equation (ca. 160 C. E.), 8523 MetonicMetonic cycleIn astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...
years = 105,416 synodic months, is consistent to its full high precision with having been intelligently based upon the 781 sidereal year cycle by which eclipses return to the same star. - To explain Ptolemy's final equation, 3277 synodic months = 3512 anomalistic months, Rawlins resorted to proposing that it was based upon dividing by 5 an eclipse cycle that is longer than any ever considered as used by ancient Greek astronomers, 16,385 months or about 1,325 years. Parallel to the 13,645 month Rawlins proposal cited above, umbraUmbraThe umbra, penumbra and antumbra are the names given to three distinct parts of a shadow, created by any light source. For a point source only the umbra is cast.These names are most often used to refer to the shadows cast by celestial bodies....
l eclipses recorded by Ptolemy in his era happen to have occurred 16,385 months after prior umbral eclipses, e. g., those of July 11, 1201 B. C. E. and June 12, 1190 B. C. E.; but there are no surviving records of the much earlier events. - Though Rawlins's calculations are not disputed, most historians do not accept that eclipse data as early as 1292-1190 B. C. E. were known to the hypothesized classical era discoverers of eclipse cycles 1010, 1103, and 1325 years long. They are certain that there is no significance in the coincidence that all three of Rawlins's unambiguous cyclic reconstructions (directly from centuries-separated classical data) via ancients' standard methodology, point to their use of eclipse data from the same slice of time, the 13th century B. C. E.
- Generalizing beyond these still quite controversial cyclic hypothese, Rawlins proposed in 2002 the inclusive theory that all mean motions adopted by genuine ancient astronomers (moon and planets, as well as the Sun's sidereal motion) were based upon the simple, reliable, and anciently well attested method of observing and counting integral cycles. When Rawlins in 1980 first questioned centuries of orthodoxy on this issue by imperfectly proposing that all five planets' Almagest mean motions were based on cycles, the idea continued for over 20 years to be not acceptable to historians. In 2003 its truth became undisputed, following A. Jones's unexpected discoveries.
- Rawlins was also long involved in the now concluded controversy over the origin of the star catalogueStar catalogueA star catalogue, or star catalog, is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some...
in the Almagest, discovering strong mechanical and statistical evidence that Hipparchus was the catalogue's primary observer, as had been obvious to most astronomers since Brahe's 1598 accusation that Ptolemy had usurped it.
Ancient geography
From 1979 to the present, Rawlins has intermittently pursued ancient geographical investigations. Results:- Verified, sharpened, and expanded the data base and fit of Aubrey Diller's important 1934 discovery that StraboStraboStrabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...
's list of Hipparchus's climata (longest day correlated to latitude) are based upon spherical trigonometry in the earliest period to which this branch of mathematics can be traced. - Discovered and refined a potential common solution to both erroneous ancient earth circumferences, 29000 and 21000 statute miles (the two values used successively by Ptolemy and other ancient mathematicians), suggesting that the former was based upon observations of mountaintop dip or light-house distance visibility, the latter upon multiple sunsets, thus both were corrupted by horizontal light rays' curvature which is 1/6 of the Earth's curvature.
- Calculated to 1' precision that EratosthenesEratosthenesEratosthenes of Cyrene was a Greek mathematician, poet, athlete, geographer, astronomer, and music theorist.He was the first person to use the word "geography" and invented the discipline of geography as we understand it...
's serious errors for obliquityAxial tiltIn astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...
and for the latitudes of Alexandria and Rhodes could all three be explained as arising from one source, his use of an asymmetric gnomonGnomonThe gnomon is the part of a sundial that casts the shadow. Gnomon is an ancient Greek word meaning "indicator", "one who discerns," or "that which reveals."It has come to be used for a variety of purposes in mathematics and other fields....
for his famous altitude of the noon sun at the summer solstice. - Showed that Strabo's chart of the Nile river is consistent with being the earliest surviving map in spherical coordinates.
- Restoring an ancient scribal error in which 105 ("cv") feet was misread as 100 vnciae ("c v"), Pliny's "circuli" are solvable as a Roman linear fit to an ancient climata table for a Mediterranean interval of latitudeLatitudeIn geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s (Greenwich centenary symposium, 1984) - The list of cities' equinoctialEquinoxAn equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator...
ratios of a gnomon's height to its shadow's length given by VitruviusVitruviusMarcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....
is a fit within approximately 1' to a climata table. - The Giza pyramids, AmarnaAmarnaAmarna is an extensive Egyptian archaeological site that represents the remains of the capital city newly–established and built by the Pharaoh Akhenaten of the late Eighteenth Dynasty , and abandoned shortly afterwards...
's Great Aten Temple, KarnakThebes, EgyptThebes is the Greek name for a city in Ancient Egypt located about 800 km south of the Mediterranean, on the east bank of the river Nile within the modern city of Luxor. The Theban Necropolis is situated nearby on the west bank of the Nile.-History:...
, and Biga Island (legendary sacred tomb of Osiris) lie upon latitudes equal to unit fractions of a circle, respectively 1/12, 1/13, 1/14, and 1/15 which if not a coincidence might imply early Egyptian realization that the earth is round. Rawlins's only venture into the speculative area of archaeoastronomy.
- In 2006, DIO Editor Dennis Duke published online Indiana University classicist-philologist Aubrey Diller's edition of the final portion of Ptolemy's "Geographia", book eight, in which sites are purposefully positioned by hours, not degrees as in books 2 through 7. Appended is an afterword by Rawlins, to whom Diller had bequeathed the manuscript.
- Rawlins soon after posted (2006 and 2007) the results and theories that had arisen during his own researches into the "Geographia":
- Redating Marinus of TyreMarinus of TyreMarinus of Tyre, was a Greek geographer, cartographer and mathematician, who founded mathematical geography.-Biography and historical context:...
, Ptolemy's cited source for the bulk of the work. - Tyre is absent from book 8, so Marinus did not author that distinct portion of the "Geographia".
- The traditional equation of the Blessed Islands with the Canary Islands is suspect, since the earliest extant maps of the "Geographia" show islands at 0° longitude that are much more consistent with the location of the Cape Verde Islands.
- Primary cities' "Geographia" latitudes show errors many times larger than ancient astronomers' knowledge of their geographical latitudes because the former were computed by spherical trigonometry from astrological manuals' crudely rounded climata.
- Sign errors in latitude are proposed as the cause of ancient maps' elimination of the Pacific Ocean.
Publishing controversy
In the 1980s, Rawlins had a dispute with Michael Hoskin, editor of the Journal for the History of Astronomy, over the quality and equity of refereeing standards at the J. H. A.. Rawlins in 1991 founded his own journal, DIO, the International Journal of Scientific History. Since founding DIO, Rawlins has used its pages both as an outlet for work and as a forum to lampoon his rivals.External links
- http://www.dioi.org/cot.htm DIO online, a compendium of several hundred of Rawlins's contributions.
- Starbaby by Dennis Rawlins, originally published in Fate Magazine, October 1981