"OBSERVING THE WORLD WITH NAKED EYE : PART 1"

 

“HOW THEY SAW THE SKY AND WHAT THEY SAW”

                                                                         (By ANISHK YADAV, ENGINEERING STUDENT)     

RARE HIEROPHANY AT STONEHENGE

                               

Isn’t It Soo Good To Just Pick A Spot Away From Bright Lights, Lay On Your Back, And Look Up To The Sky, And Then Just Delve Into The Deep And Endless Ocean Of The Sky Full Of Intriguing Mysteries. As Dante Alighieri, Once Said: "Let Us Not Speak Of Them; But Look, And Pass On."

But Was That The Only Thing What Ancient Astronomers Did, Just Look At The Sky And Unwind Themselves From The World?

The Answer Is A Clear No!, The Sky Was Always Full Of Mysteries And With Mysteries There Comes A Huge Interest For Some People To Find Out What If All Of This Makes Some Sense? What If There Is A Reason Why Sun Is Rising Only From The East? What Are Solstices And Equinoxes? And So On...

All These Answers Were Given By A Simple Study, Known As Archaeoastronomy Today, Which Is Nothing But The Science Of Stars And Stones, How The Ancient Used Stones And Structures To Witness And Understand The Hierophanies.

Today We Explore The Sky With Powerful Instruments And We Know That There Are Millions Of Galaxies In The Universe, Each Containing Billions Of Stars. We Know That The Sun Is Only One Among Billions Of Stars And That It Occupies A Peripheral Position Located In One Of The Branches Of The Milky Way, One Among Millions Of Galaxies. Even though They Didn't Have Our Powerful Instruments, Many Ancient Cultures Acquired A Deep Knowledge Of The Sky As Well. However, The Celestial Bodies Available For The Observations By These Cultures Were Only Those Visible With The NAKED HUMAN EYE, And Their Point Of View Was Always That Of An Observer Who Is Located On An Object – The Earth – Which Is Subject To A Complex Series Of Motions Of Its Own. The Continual Changes In The Sky Observed By Them Were Therefore Due To Apparent Movements. Despite This, Many Ancient Astronomers Devised Ingenious Methods Of Observation And Made Highly Accurate Measurements, Which Were Reflected In The Projects Of Their Monumental Architecture.

Thus, If We Want – As We Do - Understand These Aspects Of Architecture, We Must First Study And Understand Astronomy As They Did: With The NAKED EYE, And From The Earth's Surface. So, Let's Begin With Understanding Some Basic Terminologies And Concepts In This First Part Of This Series.

 

(I) THE CELESTIAL COORDINATES AND THE APPARENT MOTION OF THE SUN

With That Being Said, Coordinates And Motion Of The Celestial Objects Have Always Played A Major Role In Determining Varies Aspects Related To Upcoming Events. The Center Of Mass Of Our Planet Moves On An Ellipse, With The Sun Located At One Focus. The Plane, Which Contains The Sun And The Orbit Of The Earth Is Called The Ecliptic. The Earth’s Axis Is Not Perpendicular To The Ecliptic, But Is Inclined By 23.5°; This Angle Is Called Obliquity. Consider Now A Fixed Observer On The Earth's Surface. The Observer Sees All Heavenly Bodies Move As A Consequence Of His Own Movements, In Particular, The Daily Terrestrial Rotation. We See The Sky As A Spherical Surface, The Celestial Sphere. To Fix A Point On A Sphere, Two Numbers Are Needed, For Instance, Latitude And Longitude On The Earth.

However, There Is Another Important System Of Coordinates, Which Is Based On The Observer Placed On The Earth Surface: The Azimuth-Altitude Coordinate System. Altitude And Azimuth, In Astronomy, Gunnery, Navigation, And Other Fields, Two Coordinates Describing The Position Of An Object Above The Earth. Altitude In This Sense Is Expressed As Angular Elevation (Up To 90°) Above The Horizon. Azimuth Is The Number Of degrees clockwise from due north (usually) to the object’s vertical circle (i.e., a great circle through the object and the zenith). There Are Two Solstices Attained Because Of The Apparent Motion Of The Sun: The Summer Solstice, The Longest Day Of The Year, And The Winter Solstice, The Shortest One. At The Solstices, The Azimuths Are Attained Once A Year; In All Other Days, Twice A Year. In Particular, When The Sun Rises To The East, Assuming A Declination Equal To Zero, We Have The Two Equinoxes. There Are Two Days Of Zenith Passages At Tropical Latitudes, A Day When The Sun Passes The Zenith And It Sits Directly Overhead An Observer At Noon: The Observer Has No Shadow.

 

(II) THE CONSTELLATIONS AND THE APPARENT MOTION OF THE STARS

There Is An Enormous Number Of Stars In The Universe. However, Only A Very Small Percentage Of Them - But Yet, Many Hundreds - Are Visible, On A Clear Night, With The Naked Eye. To Measure The Brightness Of A Celestial Object As Seen From The Earth, It Is Customary To Use The So-Called Apparent Magnitude. The Apparent Magnitude M Is A Number, Which Is Such That The Brighter An Object Appears, The Lower M Will Be. Clearly, The Sun Has The Lowest Possible Magnitude, About –27. After The Sun, There Are The Moon And Venus. The Brightest Star, Sirius, Has A Magnitude Of –1.46. The Most Brilliant Stars - First Magnitude Stars - Include Canopus And Regil In The Southern Skies And Arcturus, Vega, And Capella In The Northern Ones. Since We Are Interested Only In Naked-Eye Observations, It Is Important To Establish The Human Limit: For A Very Experienced Astronomer In Very Favorable Conditions, The Maximal Magnitude Is Equal To 6, But For Normal People, It Is Around 5. In Any Case, In A Clear Sky, There Are Typically Hundreds Of Stars Below Magnitude 6. It Follows That The Sky Of Our Ancestors When There Was No Pollution And Especially, No Light Pollution, Was Plenty Of Brilliant Stars. Today We Count The Stars In This Way: Each Star Is Identified By A Progressive Greek Letter Plus The Name Of The Corresponding Constellation, Such As 'αUMi' Is Used For α Urase Minoris. Plenty Of Stars, However, Also Have Their Own Individual Names, Many Of Which Derive From Old Traditions. For Instance, The Most Brilliant Star Of The Constellation Lyra, α-Lyrae, Is Vega.

To Understand The Motion Of The Stars, We Have To Realize That Stars Move About Each Other And Also To Us, But That We Cannot Appreciate Such Proper Movements Since They Are Too Slow. So, The Movement Of The Stars As Seen From The Earth Is Only Apparent, Due To The Rotation Of The Earth Itself: Stars Just Circle Around The Celestial Pole. All-Stars, Which Are Sufficiently Near The Pole Are Never Seen To Go Beyond The Horizon In Their Rotation. These Stars Are Termed 'Circumpolar' And Are Visible The Whole Night, Every Night. Egyptians Called Them 'Imperishable', The Stars Which Never Die. Stars Consequently Have An Invisibility Period. This Period Ends With The So-Called Heliacal Rising: This day the star Is Visible For A Few Moments, Low On The Eastern Horizon, While The Sun Is Still Under The Horizon.

HELIACAL RISING

While Watching The Diurnal Sky, It Is Natural To Identify Forms And Images In The Shapes Of The Clouds. Similarly, During The Night, Images Can Be Identified By Joining The Bright Dots Of The Stars. In This Way, A Series Of Stylized Figures, The Constellations, Are Formed. Our Constellations Came Down To Us From The Greeks And The Romans But Originated In The Near East. In This Boundary Stone Of The 12th Century BC, For Instance, We See The Constellations Draco, Leo, And Scorpio. 48 Constellations Were Codified By Ptolemy In The Second Century AD, And Others Were Added In Modern Times.

ZODIACs AS CONSTELLATIONs

Since The Earth Axis Describes A Circular Cone, The Pole Moves Along A Circle; In A Certain Epoch, It May Or May Not Pass Near The Position Of A Brilliant Star. What We Call The Pole Star Today Is Actually The Specific Star Close To Which The North Pole Is Today; During The First Half Of The Third Millennium BC Another Star, Thuban Of The Constellation Draco, Was The Pole Star, While In The Period In-Between No Pole Star Existed At All: The North Celestial Pole Was In A Dark Zone. By The Way, The South Pole Is always In A Dark Zone, As Its Path Never Intersects A Brilliant Star.

 

(III) SIGHTSEEING WITH THE NAKED EYE

The Attitudes Of Ancient People Towards The Natural Environment And The Landscape Were Often Completely Different From Ours. Two Fundamental Concepts Must Be Borne In Mind. The First Is That The Ancient Man Was A Religious Man, And The Second Is That Religion Was Bound Up With The Natural Cycles And That Natural Cycles Were Bound Up With Power. It Is Essential To Take Account Of Them When Engaged In Fieldwork, And Also, More Simply, When Visiting An Archaeological Site, Because These Aspects Are Visible In The Landscapes. Typically Indeed, The Monuments Studied By Archaeoastronomy Are Immersed In Landscapes That Were Of Special, Sacred Significance For The People Who Built Them. Therefore, It Is Important To Look Around Carefully, Trying To Understand How The Ancient Configuration Of The Surroundings Might Have Been. Furthermore, We Must Try To Imagine The Landscape And The Sky As A Whole, Since It Is In This Way Ancient People Perceived The Cosmos Around Them. Once We Are Sufficiently Acquainted With The Landscape And The Way Monuments Were Placed In It, We Can Search For Alignments: Any Feature Of The Ancient Projects, Which Seems To Point Deliberately Towards A Specific Direction.

RARE VIEW OF TEMPLE OF HATSHEPSUT

Examples Are Axes Of Temple Of Hatshepsut At Deir el Bary, Egypt; Entrances Of Tombs, Like The Tumulus Of Maes Howe In The Orkney Island, Or Main Roads Of Ancient Towns, Like The So-Called Street Of The Death, In Teotihuacan, Mexico, And So On.

STREET OF DEATH, TEOTIHUACAN

Measuring Alignments Is Not Enough, However. We Must Make An Accurate Relief Of The Visible Horizon. In Fact, We Need Both Azimuth And Altitude To Identify The Position Of A Celestial Object, That Is, The Connection. Further, Prominent Features At The Horizon May Be Of Cultural Interest, Such As Sacred Mountains, Special Profiles, Or Other Inter-Related Monuments.

To Measure These, We Can Certainly Use The Following Things:

(i)Magnetic Compass: To Measure Azimuths, We Can Use The Magnetic Compass. Due To The Earth's Magnetic Field, The Compass Aligns In A Direction – Called Magnetic North – Which Is A Rough Indication Of The Geographical North. The Deviation Of The Direction Of Magnetic North To The Geographical North, Or Magnetic Declination, Depends On The Position Of The Observer As Well As On Time.

(ii)Clinometer: To Measure The Altitude Of The Visible Horizon About All The Azimuths Of Interest, We Can Use Another Simple Instrument: The Clinometer. The Clinometer Is Essentially A Goniometer Used Vertically, And As Such, It Allows To Measure Angular Heights. Recall In Fact That A Hill Which Is 100 Meters High, But Is Very Near, Can Block The View Much More Than A Distant Mountain.

 

So Now You’re Ready To Observe The Sky Or Any Other Archaeological Site You Visit With The Naked Eye And With A Clearer Meaning This Time, Like Watching Them As An Archaeoastronomer. For This Part We’ll Wrap It Up Here, In The Next Part We’ll Be Going To Actually See Some Of The Famous Archaeological Sites And How They Are Important And Why. So With That Being Said:

“FOLLOW ME, AS I WOULD LIKE TO GO, SINCE THE CONSTELLATION OF FISHES IS ALREADY DARTING ON THE HORIZON”