ANNOUNCEMENTS

Homework #1 due today at end of class. HW #2 due next Thursday. Homework #1 question #1 and Homework #2 “meridian slice” questions will be discussed in the course of the lecture today.

Observing Projects. Make sure you understand what is required. Help for Projects as follows: Kate Vann (Sundial , Lunar Phases & Lunar Eclipse); Bobby Wallace (Astrology, Horizon Calendar & Eratosthenes); John Stocke (Constellations, Skygazer & Lunar Eclipse).

Watch for announcement of Sundial and Eratosthenes help sessions early next week. LUNAR ECLIPSE: SUN SEPT 27th 6:30pm

UP FOR DISCUSSION TODAY: THE ANNUAL MOTION OF THE SUN

TIME OF DAY AND DATE OF YEAR

• MOTION OF SUN ACROSS SKY DEFINES THE HOURS; NOON WHEN SUN CROSSES THE MERIDIAN. ONE DAY OF 24 HOURS IS TIME BETWEEN SUCCESSIVE MERIDIAN CROSSINGS (IN 24 HOURS EARTH TURNS THROUGH ALL CELESTIAL LONGITUDES)

• MOTION OF SUN THROUGH FULL CYCLE OF ITS CELESTIAL LATITUDES (DECLINATIONS) DEFINES THE YEAR. THE TROPICAL YEAR IS THE NUMBER OF DAYS (365¼ - a bit) BETWEEN SUCCESSIVE CROSSING OF THE CELESTIAL EQUATOR GOING NORTHWARDS (CALLED THE VERNAL OR SPRING EQUINOX). i.e., SPRING TO NEXT SPRING

UNLIKE THE “FIXED

STARS”, THE SUN

CHANGES ITS

CELESTIAL LATITIUDE.

THE CHANGING

AMOUNT OF SOLAR

HEATING AT ANY ONE

MOMENT AND THE

CHANGING NUMBER

OF HOURS AND

MINUTES OF

DAYLIGHT DETERMINE

THE SEASONS.

Sun higher in sky

Greater heat per square

foot

SUMMER

Sun lower in sky

Less heat per square foot

WINTER

At Equinoxes the Poles of

the Earth are pointed in

space perpendicular to the

direction to the Sun

Sun is over the equator and

intermediate between

SolsticesFILM: “A PRIVATE UNIVERSE”

AT MID-LATITUDES:

calendars set by

SUN ON HORIZON OR

SUN ON MERIDIAN

AT LOW LATITUDES

(i.e., in the TROPICS)

THE SUN’S HORIZON

LOCATION CHANGES

LESS AND ALTITUDE

ALONG MERIDIAN

CHANGES VERY LITTLE

SOLSTICES: SUN IS AS FAR

NORTH OR AS FAR SOUTH

AS SUN CAN GET:

CELESTIAL LATITUDE =

+ 23½ o AND – 23½ o.

EQUINOXES: SUN IS ON

THE CELESTIAL EQUATOR

(Celestial latitude = 0). DAY &

NIGHT OF EQUAL LENGTH

OF TIME.

LATITUDE =+23½ O IS CALLED

THE “TROPIC OF CANCER” and

LATITUDE =-23½ O IS CALLED

THE “TROPIC OF CAPRICORN…

IN BETWEEN THESE LATITUDES

ARE THE TROPICS.

THE “FOUR CORNERS OF THE YEAR”: SOLSTICES AND EQUINOXES

MARCH 20 OR 21st : SPRING OR VERNAL EQUINOX (“EQUAL NIGHT TO DAY”)

JUNE 21ST: SUMMER SOLSTICE OR MIDSUMMER {solstice means Sun standing still (on horizon as it sets)}

SEPTEMBER 21st OR 22nd : FALL EQUINOX

DECEMBER 21st : WINTER SOLSTICE

THE “MERIDIAN SLICE”

Has the Celestial

Latitude = terrestrial

latitude @ the zenith

Basis of celestial

navigation to

determine one’s

LATITUDE. Measure

the altitude of the

meridian passage of

fixed stars; i.e., fixed

celestial latitudes

*** WHERE ARE THE “SOLAR ZONES” FOR KEY WEST & THE EQUATOR ?

THE “MERIDIAN SLICE”

Has the Celestial

Latitude = terrestrial

latitude @ the zenith

Basis of celestial

navigation to

determine one’s

LATITUDE. Measure

the altitude of the

meridian passage of

fixed stars; i.e., fixed

celestial latitudes

THE SOLAR ZONE:

AT ANY ONE LOCATION

THIS IS THE FULL RANGE

OF LOCATIONS ALONG

THE MERIDIAN WHERE

THE SUN CAN BE SEEN

DURING THE YEAR. IN

EITHER HEMISPHERE

THE SOLAR ZONE

LOCATES THE SUMMER

(HIGHEST ALTITUDE EDGE

OF SOLAR ZONE) AND

WINTER SOLSTICES. THE

EQUINOX POSITIONS ARE

HALFWAY BETWEEN

THESE TWO EXTREMES.WHICH OF THE ABOVE LOCATIONS ARE IN THE TROPICS?

HORIZON CALENDAR: requires both a foresight

(typically point on horizon) and backsight (location or

stone marker) … { see Observing Project #2}

HOPI of ARIZONA USE A HORIZON, SUNSET

CALENDAR TO SET THEIR WINTER SOLSTICE

CEREMONY…THE SOYAL.

FORESIGHTS AND BACKSIGHTS: For the Hopi the foresight

are points along the mountain horizon; the backsight a specific

location in Walpi, First Mesa of the Hopi.

CELESTIAL LATITUDE OF THE SUN THROUGH THE

YEAR… SOLSTICES AND EQUINOXES IN GREEN

CONTINUES

RED MARKS SHOW APPROXIMATE LOCATIONS OF “CROSS-QUARTER DAYS”

NOTE “TWO SUNS” PHENOMENON: SUN STAYS CLOSE TO SAME LOCATION

IN SKY OVER MOST OF YEAR: SUMMER SUN AND WINTER SUN

CELESTIAL LATITUDE OF SUN THROUGH THE YEAR…

SOLSTICES AND EQUINOXES IN GREEN

CONTINUES

RED MARKS SHOW APPROXIMATE LOCATIONS OF CROSS-QUARTER DAYS

NOTE “TWO SUNS” PHENOMENON: SUN STAYS CLOSE TO SAME LOCATION

IN SKY OVER MUCH OF YEAR: SUMMER SUN AND WINTER SUN

“Time of changes”

SUMMER SUN

Winter Sun Winter Sun

COLOSSI OF MEMNON

TEMPLE OF

AMENHOTEP III AT

THEBES (1350 BCE…

1200 YEARS AFTER

PYRAMIDS)

ALIGNED WITH

WINTER SOLSTICE

SUNRISE !!

TEMPLE OF

AMENHOTEP III

C. 1350 BCE (1200

YEARS AFTER THE

GREAT PYRAMIDS

AT GIZA

SUN WORSHIP

REPLACED OSIRIS

BITRTH/DEATH/

REBIRTH CULT

SOLAR COURTYARD

ILLUMINATED ONLY

AT WINTER

SOLSTICE DAWN !

NEWGRANGE IN IRELAND

A 5000+ YEAR OLD

PASSAGE TOMB

ALIGNED TO WINTER

SOLSTICE SUNRISE

ONLY AT THE WINTER

SOLSTICE SUNRISE IS

THE INNERMOST

CHAMBER OF THIS

PASSAGE TOMB

ILLUMINATED BY THE

SUN…. An obvious symbol

of rebirth, of the year and so

of humans.

STONEHENGE: EARLIEST ASTRONOMICAL CONSTRUCTION C. 3200 BCE.

WINTER SOLSTICE

SUNSET

QUESTION: WHY WOULD THE WINTER SOLSTICE BE THE ONE WHICH IS MOST CELEBRATED BY

ANCIENT PEOPLES?

1. IT MARKS THE RETURN OF THE LIGHT

2. LESS DAYLIGHT FOR WORKING, MORE TIME FOR PARTYING.

3. IT’S A SILLY, PAGAN THING.

4. AT THE WINTER SOLSTICE, THE DARKNESS OVERWHELMS THE LIGHT. IT’S AN EVIL TIME.

5. SOME ANCIENT PEOPLES WERE WORRIED THAT THE SUN WOULD KEEP GOING SOUTH AND STAY THERE.

QUESTION: WHY WOULD THE WINTER SOLSTICE BE THE ONE WHICH IS MOST CELEBRATED BY

ANCIENT PEOPLES?

1. IT MARKS THE RETURN OF THE LIGHT

2. LESS DAYLIGHT FOR WORKING, MORE TIME FOR PARTYING

3. IT’S A SILLY, PAGAN THING. IN THE OLD ROMAN CALENDAR THE WINTER SOLSTICE WAS ON DECEMBER 25th AND WAS CALLED THE DAY OF THE UNCONQUERABLE SUN ! CHRISTIANS CO-OPTED IT.

4. AT THE WINTER SOLSTICE, THE DARKNESS OVERWHELMS THE LIGHT. IT’S AN EVIL TIME.

5. MANY ANCIENT PEOPLES WERE WORRIED THAT THE SUN WOULD KEEP GOING SOUTH AND STAY THERE.

ANCIENT TRADITION

IS THAT FIRST DAYS

OF SEASONS ARE

THE CROSS

QUARTER DAYS..

e.g., BELTANE (May

Day) is the first day of

summer.

June 21st, the Summer

Solstice is also called

High or Mid-Summer.

We’ll take these

one-by-one.

ALL WERE USED

BY ANCIENT

PEOPLE BUT

TRADITION

DIFFERED IN

DIFFERENT

LOCATIONS AND

CULTURES.

OLDEST KNOWN

SOLSTICE MARKERS IN

THE WORLD: CIRCA

5000 BCE IN SOUTHERN

EGYPT. Site mapped by

CU Professor Emeritus

Kim Malville.

** SHOW VIDEO:

COSMIC AFRICA **

BABYLONIAN/GREEK

SOLUTION WAS TO KEEP

BOTH SUN AND MOON

CYCLES AND INTER-

CALATE BY ADDING AN

ENTIRE 13TH MONTH ON A

SCHEDULE OVER 19

YEARS.

EGYPTIAN SOLUTION

WAS TO ABANDON

LUNAR CYCLE

ALTOGETHER SO THAT

THE YEAR WAS ALWAYS

THE SAME NUMBER OF

DAYS (365) AND MONTHS

(12) BUT MONTHS HAD >

29 0R 30 DAYS.

WHEN ROME BECAME

THE POLITICAL AND

MILITARY POWER IN

EUROPE THE LUNAR

CYCLE WAS ABANDONED

IN FAVOR OF THE

EGYPTIAN SOLAR

CALENDAR.

BY 1600s THE CLERGY

NOTICED THAT EASTER

WAS SLOWLY BECOMING

A WARM-WEATHER

SUMMERTIME FESTIVAL,

NOT THE SPRING

REBIRTH SYMBOLICALLY

REQUIRED…POPE

GREGORY WAS

CONVINCED TO CHANGE

THE CALENDAR AND HE

GOT CATHOLIC

COUNTRIES TO CHANGE

BUT NOT THE

PROTESTANT

ONES…e.g., BRITAIN DID

NOT CHANGE UNTIL

1700s.; Russia in 1900s.