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Discover the mystery of Stonehenge, a Neolithic monument in England. Learn about its construction, purpose, and significance. Unravel the fascinating history behind this UNESCO World Heritage site.
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WHERE IS STONEHENGE? Stonehenge is in Wessex-- part of central-southern England on Salisbury Plain in Wiltshire (National Grid Reference SU 123 422). • WHAT WAS STONEHENGE USED FOR, AND WHY? These are the most testing questions. Before outlining the most plausible answers in accordance with the facts of the latest archaeological and scientific scholarly research, a summary of the chief features of the monument are introduced. A link to the theory of Stonehenge is then provided near the bottom of this page. • WHEN AND HOW DID STONEHENGE BEGIN? For some 400 years beginning about 2950 BCE the site was little more than a simple circular earthwork, inside of which was a space about 85 metres or some 90 yards in diameter but at the centre of which there appears to have been a simple wooden structure or timber circle. A ring of 56 pits lies close to the circumference of this open space, and according to the argument presented by Cleal, Walker and Montague (1995) every pit formerly held a timber post, thus forming a large-diameter timber circle. The holes left after the decay of the ring of posts are called Aubrey Holes. The Neolithic people later filled these pits with chalk and re-used them for ritual deposits. The major causeway opening to the north-east embraces the direction of the most northerly risings of both moon and sun. Not until about 2550 BCE did construction of a ring of stones commence. There being no natural stone on this part of the chalk plain, the stones had to be imported. • WHENCE? The first choice of stones, called bluestones, came from South-West Wales, 200 km to the west. Between 60 and 80 bluestones arrived, each weighing 3-4 tons, and there was one exceptional stone at 8 tons which was placed near the centre, on the summer solsticial axis, at the focus of the monument. • The later sarsen stones, weighing between 6 and 60 tons each, were dragged about 32 km (20 miles) southwards from near Avebury. Sarsens are the fractured remnants of ancient sandstone beds dating from the Eocene some 26 million years ago. The photograph, taken in the direction of midsummer sunrise, indicates the immensity of the sarsens of the outer ring. The overhead lintel, which weighs about 6 tons, is supported by 25-ton megaliths. • WHEN DID THE STONES ARRIVE ? The bluestones came about 2550 BCE, possibly at a rate of just a few (3 to 6, say) annually. At some point, delivery of the bluestones stopped. This happened before the ring of bluestones had been completed. Fairly soon afterwards, sarsen stones started arriving, and their delivery is presumed to have taken one or two centuries commencing about 2500 BCE. • HOW ? The bluestones were rafted from Wales by sea and river. The sarsens were dragged from the Avebury Hills by haulage teams, probably aided by oxen. The stones were then tipped end-first into pits dug into the sub-surface chalk The lintels for the trilithons were raised on wooden cribs or by using earthen ramps. • BY WHICH ROUTES? (1) The bluestones came along the Bristol Channel, then possibly up the River Avon to Bath and overland to the River Wylye at Warminster; thence to Salisbury and Amesbury via a second River Avon to Stonehenge. A ditch-and-bank avenue from the latter river to the monument likely marks their final journey. An alternative possibility is a sea-crossing via Lundy Island (as suggested by Rodney Castleden) and then around the Cornish Peninsula to the Salisbury Avon. (2) The sarsens went probably south-west from the Avebury Hills to a col near Devizes and West Lavington, and then south and east across the chalkland. • WHAT WAS THE MASTER BUILDING PLAN? The first sarsen stone erected may have been the huge Heel Stone, set outside the monument. Also early were the 4 station stones, placed within the circular ditch near the Aubrey ring. A circle of bluestones was commenced but the stones were dismantled after 60 had been raised. Sarsen circles and U-settings then went up, the dominant feature being the trilithon idea of a 6-ton lintel lying across pairs of 25 to 60-ton uprights. In the final stage, the bluestones were put back, some in a circle, the others on a U-setting. The common axis of all the sarsen stones and the bluestone settings is towards the midsummer sunrise. The sparkling 8-ton bluestone went to the heart and focus of the monument where the rays of the rising sun can fall on it only for a few minutes each year at the time of midsummer solstice. It was a devout, clever people who did this. Who were they? • They were the Ancient Britons, part of a precocious flowering of an early World Culture---and until recently inadequately recognised and ill-understood by us, their inheritors. Their names are unknown. Begun in the agricultural Neolithic Age, Stonehenge was completed in the Early Bronze Age by Beaker folk. At a later date (perhaps towards 1500 BCE) some disaster or systems collapse progressively brought the impressive Megalithic Age to an end, not only here but throughout the whole of Britain and Ireland. Much further east, as in Egypt, Babylonia and the Indus Valley, civilisations continued to flourish, although in Crete towards 1400 BCE a splendid high culture was also nearing its end. • This is a plan of the stones as they were at the end of the final stone-moving phase, nearly 4000 years ago. • There is a ring of bluestones inside the sarsen stone circle; and a U-setting of bluestones inside a U-setting of five enormous sarsentrilithons. The common axis is to the midsummer sunrise. The 8-ton Cult Stone is on the main axis at the focus close to the centre. • For a plausible theory and likely answers as to WHY Stonehenge was designed like this, CLICK HERE. • One of the great trilithon stones has numerous axes carved into it; another has a Mother-Goddess type of image carved in relief; and a third bears a splendid carved image of a distinguished human head facing west. • Concerning the latest news of the STONEHENGE Carvings CLICK HERE
Newgrange • The Megalithic Passage Tomb at Newgrange was built about 3200 BC. The kidney shaped mound covers an area of over one acre and is surrounded by 97 kerbstones, some of which are richly decorated with megalithic art. The 19 metre long inner passage leads to a cruciform chamber with a corbelled roof. It is estimated that the construction of the Passage Tomb at Newgrange would have taken a work force of 300 at least 20 years. Winter Solstice • The passage and chamber of Newgrange are illuminated by the winter solstice sunrise. A shaft of sunlight shines through the roof box over the entrance and penetrates the passage to light up the chamber. The dramatic event lasts for 17 minutes at dawn on the Winter Solstice and for a few mornings either side of the Winter Solstice.
THE EARLY BABYLONIANS OBSERVED THE HEAVENS AND OTHER NATURAL PHENOMENA TO GET CLUES AS TO WHAT THE GODS WERE THINKING. THEY WERE LISTED IN THE “ENUMA ANU ENLIL” – 70 TABLETS WITH 70,000 OMENS. MOST OF THE OMENS CAME FROM OBSERVING THE MOON. • ENUMA ANU ENLIL MEANS “IN THE DAYS OF THE GODS ANU (GOD OF HEAVEN) AND ENLIL (GOD OF THE WIND)
BABYLONIAN CALENDAR • LUNAR CALENDAR (MONTH STARTED AND ENDED WITH NEW MOON) • NINETEEN SOLAR YEARS = 235 [(19X12)+7] LUNAR MONTHS • INTERCALATED (INSERTED) 7 MONTHS EVERY 19 YEARS • 19 YEARS IS CALLED A “METONIC CYCLE” • BABYLONIANS RECORDED DETAILED TABLES (EPHEMERIDES) • THEY KNEW THAT THE SUN’S SPEED THROUGH THE CELESTIAL SPHERE VARIED AND THEY MEASURED IT.
RELIGIOUS EGYPTIAN CALENDAR • NO GOOD NUMBERING SYSTEM • CALENDAR BROKEN INTO 3 FOUR-MONTH SEASONS BASED ON THE NILE) • FLOODING • SUBSIDENCE • HARVEST • NEEDED TO INTERCALATE A MONTH OCCASIONALLY • INTERCALATION DETERMINED BY THE HELIACAL RISING OF SIRIUS (THE DOG STAR)
ADMINISTRATIVE EGYPTIAN CALENDAR • INTRODUCED CIRCA 3000 BC • TWELVE 30-DAY MONTHS/YEAR • THREE 10-DAY WEEKS/MONTH • ADD FIVE DAYS AFTER THE 12TH MONTH • A ROUGH ATTEMPT TO ADD LEAP YEARS CAME MUCH LATER (CIRCA 239 BC)
ANCIENT GREEK ASTRONOMY • METON • LIVED IN ATHENS AROUND 500 BC • INTRODUCED A CALENDAR • YEAR WAS A SOLAR YEAR (365 DAYS) • MONTH WAS A LUNAR MONTH (29 ½ DAYS) • CALENDAR NOT ACCEPTED BY LOCAL AUTHORITIES • METONIC CYCLE • 19 SOLAR YEARS • 235 LUNAR MONTHS • USED TO PREDICT ECLIPSES AND OTHER CELESTIAL EVENTS
ANCIENT GREEK ASTRONOMY • THALES OF MILETUS (c. 625 BC TO c. 547 BC) • ONE OF THE “SEVEN SAGES OF GREECE” • SOMETIMES CALLED THE “FATHER OF PHILOSOPHY” • FIRST COSMOLOGIST (TRIED TO REASON ABOUT THE NATURE OF THE UNIVERSE RATHER THAN DEPEND ON ASTROLOGY” • BELIEVED THAT WATER WAS AT THE BASE OF OUR EXISTENCE, i.e., “ALL THINGS FOUND THEIR ORIGIN IN WATER” • WELL KNOWN MATHEMATICIAN • REMEMBERED FOR HIS “THALES THEOREM” IN GEOMETRY
ANCIENT GREEK ASTRONOMY • ANAXIMANDER (c. 610 BC TO c. 545 BC) • ALSO FROM MILETUS (PROBABLY KNEW THALES) • ALSO A COSMOLOGIST (ARGUED FROM FIRST PRINCIPLES) • SOMETIMES CALLED “THE FATHER OF COSMOLOGY” • CONSIDERED THE EARTH TO BE A CYLINDER - WE LIVE ON THE END • THE UNIVERSE IS AN ALL ENCOMPASSING FIRE • SEVERAL WHEELS WITH HOLES IN THEM ROTATED AROUND THE EARTH • THE STARS WERE CLOSEST, THE MOON NEXT MOST DISTANT, THE SUN WAS THE FARTHEST AWAY
THE PYTHAGOREANS • SAW A RELATIONSHIP BETWEEN THE HARMONY OF MUSIC AND MATHEMATICAL RATIOS • PHYTHAGORAS CLAIMED TO BE ABLE TO HEAR THE MUSIC OF THE SPHERES • RECOGNIZED THE EARTH AS BEING SPHERICAL • VERIFIED THE IDEA OF A SPHERICAL EARTH BY OBSERVING THAT THE SKY VARIED AS ONE MOVED NORTH AND SOUTH • HIS TEACHING PROMOTED THE IDEA OF A RATIONAL ORDER TO THE UNIVERSE
ANCIENT GREEK ASTRONOMY • ERATOSTHENES (276 BC-194 BC) • BORN IN SYENE (MODERN DAY ASWAN) • MATHEMATICIAN, GEOGRAPHER AND ASTRONOMER • MEASURED THE CIRCUMFERENCE OF THE EARTH • DEVISED A LATITUDE AND LONGITUDE SYSTEM FOR THE EARTH • FRIEND OF ARCHIMEDES • OTHER ACCOMPLISHMENTS • DEVELOPED A WAY TO FIND PRIME NUMBERS – CALLED THE “SIEVE OF ERATOSTHENES” • DETERMINED EARTH-SUN DISTANCE (ONE ASTRONOMICAL UNIT) ALMOST PERFECTLY (804,000,000 stadia, 1 stadion varies from 157 to 209 meter) • DETERMINED EARTH-MOON DISTANCE (OFF BY FACTOR OF TWO) • MEASURED OBLIQUITY OF THE ECLIPTIC TO ACCURACY OF 7 ARC MIN • MAPPED THE ENTIRE KNOWN WORLD
ANCIENT GREEK ASTRONOMY • PLATO AND ARISTOTLE (LATE 5TH CENTURY BC) • ARISTOTLE IS BETTER REMEMBERED AS MORE OF HIS WRITING SURVIVED • THEY BOTH AGREED THAT THE BASIC ELEMENTS OF THE EARTH WERE COMBINATIONS OF HOT/COLD AND WET/DRY • COLD AND DRY – EARTH • COLD AND WET – WATER • HOT AND WET – AIR • HOT AND DRY – FIRE • ARISTOTLE PROVED THAT THE EARTH WAS SPHERICAL BY OBSERVING THE CURVED SHADOW OF THE EARTH DURING LUNAR ECLIPSE • ARISTOTLE BELIEVED THAT THE HEAVENLY BODIES DIDN’T HAVE TO OBEY THE PHYSICAL LAWS OF THE EARTH AS THEY WERE MADE OF A FIFTH MATERIAL – THE “QUINTESSENCE” • ARISTOTLE BELIEVED THAT THE EARTH WAS FIXED – IF IT WERE ROTATING THINGS WOULD FLY OFF AND AN OBJECT DROPPED FROM THE CROW’S MAST OF A SHIP WOULD FALL INTO THE SEA, NOT ON THE DECK AS IT IS OBSERVED TO DO. • A REAL PROBLEM TO BOTH ARISTOTLE AND PLATO WAS THE MOTION OF THE PLANETS. THE CHALLENGE WAS TO SHOW THAT THEIR MOTION WAS AS REGULAR AS THAT OF THE REST OF THE SKY.
ANCIENT GREEK ASTRONOMY • EUDOXUS OF CNIDUS (400 BC – 347 BC) • CONTEMPORARY WITH PLATO • MATHEMATICIAN • DEVELOPED THE HIPPOPEDE (horse foot)- A SET OF CONCENTRIC SPHERES SET AT DIFFERENT ANGLES AND ROTATING WITH DIFFERENT SPEED TO EXPLAIN RETROGRADE MOTION • THE PATH TRACED OUT LOOKED LIKE WHAT WE NOW CALL THE “ANALEMMA” • PROBLEM WITH THE IDEA OF NESTED SPHERES – IT DIDN’T EXPLAIN THE FACT THAT THE BRIGHTNESS OF THE PLANETS CHANGED DURING THE YEAR AS THEIR DISTANCE CHANGED
ANCIENT GREEK ASTRONOMY • HERACLIDES OF PONTUS (387 – 312 BC) • STUDENT OF PLATO • CREDITED WITH PROPOSING THAT THE EARTH ROTATED ON ITS AXIS, A PROPOSITION NOT ACCEPTED BY ARISTOTLE NOR ANY OF HIS CONTEMPORARIES
ANCIENT GREEK ASTRONOMY • ARISTARCHUS OF SAMOS (310 BC - 230 BC) • MEASURED E-S/E-M DISTANCE RATIO • DETERMINED THE RELATIVE SIZES OF THE MOON AND THE SUN • PROPOSED THAT THE EARTH REVOLVED AROUND THE SUN (PHILOLAUS ALSO BELIEVED THAT) • SELEUCUS OF SELEUCIA (MID 2ND CENT BC) ALSO BELIEVED THAT
APOLLONIUS OF PERGA • LIVED ~200 BC • MATHEMATICIAN – SPECIALIZED IN CONICS • ORIGINATED THE TERMS ELLIPSE, PARABOLA AND HYPERBOLA • DEVISED TWO ALTERNATE WAYS OF EXPLAINING THE VARIATION IN THE SPEED OF THE MOON • OFF CENTER CIRCLE • EPICYCLE
HIPPARCHUS • BORN IN NICEA IN 2ND CENTURY BC • OBSERVED FROM RHODES 141 TO 127 BC • ALMOST ALL ORIGINAL DOCUMENTS HAVE BEEN LOST – WHAT WE HAVE ARE RECORDED BY PTOLEMY IN HIS ALMAGEST • THE FIRST TO USE THE BABYLONIAN DATA • COMPILED A LIST OF LUNAR AND SOLAR ECLIPSES • DEFINED A DETAILED ECCENTRIC CIRCLE MODEL FOR THE SUN • MEASURED THE DISTANCE TO THE MOON USING OBSERVATIONS DURING A TOTAL SOLAR ECLIPSE • INTRODUCED THE SEXAGESIMAL SYSTEM TO ASTRONOMICAL OBSERVATIONS • ADOPTED 360 DEGREES IN A CIRCLE • DISCOVERED THE “PRECESSION OF THE EQUINOXES” • GENERATED THE FIRST STAR CATALOG (850 STARS) OF STAR BRIGHTNESS
HIPPARCHUS STAR BRIGHTNESS CATALOG HIPPARCHUS CATALOG MAGNITUDE (m) BRIGHTEST 1 2 3 4 5 FAINTEST 6 1ST MAGNITUDE STAR IS 100X THAT OF A 6TH MAGNITUDE STAR (100)1/5 = 2.5, I.E. EACH MAGNITUDE IS A FACTOR OF 2.5 IN BRIGHTNESS BA/BB = 2.5 (mB –mA) CURRENT VALUES OBJECTMAGNITUDE (m) SUN -26.5 MOON (FULL) -12.5 VENUS -4.7 SIRIUS -1.5 ALDEBARAN 1.0 VISUAL EYE LIMIT 6.0 BINOCULAR LIMIT 10.0 6 INCH TELESCOPE 13.0 200 “ TELESCOPE (CCD) 27.0 KECK 10 M TELESCOPE 30.0 HUBBLE TELESCOPE 30.0
ELLIPTICAL ORBITS • EACH ELLIPSE HAS TWO FOCI WHICH LIE ON THE MAJOR AXIS • IF THE ORBITED OBJECT IS MUCH HEAVIER IT LIES AT A FOCUS • THE SATELLITE MOVES FASTER WHEN IT’S NEAR PERI(HELION)
CLAUDIUS PTOLEMY • LIVED IN ALEXANDRIA DURING THE 2ND CENTURY AD • BEST KNOWN ASTRONOMER/ASTROLOGER OF ANCIENT GREECE • WROTE THE ALMAGEST (THE GREAT COMPILATION) – A 13 VOLUME COMPREHENSIVE ANALYSIS OF ALL GREEK ASTRONOMY UP TO HIS TIME • HE DREW HEAVILY ON ASTRONOMERS WHO PRECEDED HIM • HIS WRITINGS SURVIVED THE FIRE AT THE LIBRARY IN ALEXANDRIA AS THEY HAD BEEN CIRCULATED THROUGHOUT THE GREEK AND ROMAN WORLD • INTRODUCED THE “EQUANT POINT” TO THE CONCEPTS OF EPICYCLE AND DEFERENT INHERITED FROM APOLLONIUS AND HIPPARCHUS • HE DIDN’T REGARD WORK DONE DURING THE THREE CENTURIES PRECEDING HIM WAS OF ANY VALUE SO ANYTHING DONE DURING THAT TIME IS ESSENTIALLY LOST TO US – HENCE “THE DARK AGES OF GREEK ASTRONOMY”
CLAUDIUS PTOLEMY’S EQUANT • EARTH OFFSET FROM THE CENTER • THE “EQUANT” WAS OFFSET FROM THE CENTER AN EQUAL AMOUNT IN THE OTHER DIRECTION. • THE SUN MOVED AROUND THE ORBIT SHOWN AT A CONSTANT ANGULAR RATE AS SEEN FROM THE EQUANT. • TO AN OBSERVER ON THE EARTH THE SUN’S SPEED WOULD VARY • NOTE THAT THE POINTS OF THE EQUANT AND THE EARTH’S LOCATION LOOK A LOT LIKE THE FOCI OF AN ELLIPSE. • HE WAS THE FIRST TO ABANDON THE IDEA OF UNIFORM CIRCULAR MOTION. IT WAS STILL CIRCULAR BUT NOT UNIFORM. ELLIPTICAL MOTION IS NEITHER CIRCULAR NOR UNIFORM.
PTOLEMY’S EPICYCLES • PTOLEMY HAD TO INTRODUCE THE CONCEPT OF EPICYCLE TO EXPLAIN THE MOTIONS OF THE PLANETS. • PARTICULAR PROBLEM WAS THE RETROGRADE MOTION OF THE SUPERIOR PLANETS • HIS USE OF NONUNIFORM MOTION DID NOT SURVIVE THE BASIC PHILOSOPHIC REQUIREMENT THAT ALL HEAVENLY MOTIONS BE UNIFORM. • COPERNICUS’ HELIOCENTRIC SYSTEM USED UNIFORM MOTION, HENCE IT REQUIRED EPICYCLES • HIS LUNAR MODEL WORKED EXCEPT THE EPICYCLE WAS SO LARGE THAT THE DISTANCE TO MOON VARIED FROM 33 TO 64 EARTH RADII. THAT WOULD CAUSE THE APPARENT SIZE OF THE MOON TO CHANGE BY ABOUT 50%. • SOME MODELS HAD SEVERAL EPICYCLES ON EPICYCLES
PTOLEMY’S MODEL OF THE SOLAR SYSTEM • NOTE THAT MERCURY, VENUS AND THE SUN REVOLVE AT THE SAME RATE • HE CONCLUDED THAT THE RADIUS OF THE UNIVERSE WAS ABOUT 20,000 EARTH RADII • ACTUAL DISTANCE TO THE SUN IS ABOUT 23,000 EARTH RADII
PTOLEMY’S POSTULATES • THE EARTH IS FIXED AT THE “CENTER” OF THE CELESTIAL SPHERE • THE CELESTIAL SPHERE IS LARGE WITH RESPECT TO THE EARTH • THE STARS RISE AND SET AS THE RESULT OF THE ROTATION OF THE CELESTIAL SPHERE • THE EARTH IS SPHERICAL • RETROGRADE MOTION IS DESCRIBED BY EPICYCLES
JULIAN CALENDAR • BEFORE THE TIME OF JULIUS CAESARTHERE WERE 355 DAYS PER YEAR (12 LUNAR MONTHS) • EXTRA MONTHS WERE INTERCALATED ABOUT EVERY THREE YEARS • INTERCALATED MONTHS WERE INSERTED PRETTY MUCH ON THE WHIM OF THE PRIESTS OF THEIR RELIGIONS • POLITICAL COLLUSION COULD GET A MONTH INTERCALATED INTO YOUR ADMINISTRATION • DURING THE TIME OF THE SECOND PUNIC WARS AND DURING THE CIVIL WARS INTERCALARY MONTHS WERE OFTEN OMITTED • FOR EXAMPLE, CAESAR CROSSED THE RUBICON ON JAN. 10, 49 BC BUT THE CALENDAR WAS SO FAR OFF THAT IT WAS MID-AUTUMN • THE YEAR 46 BC WAS GIVEN 445 DAYS (EFFECTIVELY THREE INTERCALARY MONTHS), INSERTED AFTER THE SEVENTH MONTH QUINTILIS (LATER NAME JULY AFTER JULIUS CAESAR) • HE INTRODUCED THE CONCEPT OF ADDING A LEAP DAY TO FEBRUARY EVERY FOUR YEARS BRINGING THE LENGTH OF THE CALENDAR YEAR TO 365.25 DAYS • INITIALLY JANUARY AND FEBRUARY WERE NOT CONSIDERED TO BE NAMED MONTHS AS THEY OCCURRED IN THE WINTER • THE FIRST MONTH OF THE OFFICIAL CALENDAR WAS “MARTIUS”, NAMED AFTER THE ROMAN GOD MARS. IF A WAR WAS IN PROGRESS, AT THE ONSET OF WINTER, EVERYONE WENT HOME. THE WAR WAS RESUMED IN MARCH WHEN SPRING CAME, HENCE THE NAME. • THERE’S DISPUTE ON HOW APRIL, MAY AND JUNE GOT THEIR NAMES BUT THE LAST SIX MONTHS OF THE ORIGINAL JULIAN CALENDAR WERE SIMPLY NUMBERED FOR THE LATIN NUMBERS FIVE THROUGH TEN. • IN 8 BC SEXTILIS WAS RENAMED AUGUST AFTER AUGUSTUS CAESAR DIED.
