Some Simple Questions
• What is the first day of spring?
• How do you mark a date on a sundial?
The facile answers:
-Spring starts on 21 March, the vernal equinox
-Use a declination line
•The real answer is much more complex.
The problem of the unique assignment of a date to
a solar declination changed the course of history!
Calendar Reform?
• The calendar organizes days, months and years
• Our current Gregorian calendar is a poor
approximation, with Spring starting on any of four
days
• A much better calendar was proposed by a Persian
polymath almost 1000 years ago
•This is actually a story of science and
mysticism, history and politics, religion and war,
colonies and empires and the birth of America
God’s Longitude and the
Lost Colony of Virginia
Dr John Dee
Roger Bailey and Fred Sawyer
NASS Virginia 2007
What is the first day of Spring?
• This year, 2007, the Vernal Equinox is 21
March at 00:07 UT
• 2006 20 March 18:26 UT
• 2008 20 March 05:48 UT
• Difference ~5:41
• Date varies from 19 March to 22 March
• Gains almost 6 hours a year, but leaps back a
day ever four years more or less
• Plot the results: Frank King’s as Blob Chart
Spring Equinox
48.00
Hours from 20 March
Leap Year Cycle
24.00
Julian Error
0.00
1990
2000
2010
-24.00
Year
2020
2030
Fitting Days to the Year
• Julian Calendar: 365.25 days per year
–
–
–
–
One leap year in four
Real year is shorter ~365.2422 days per year
Gains almost 8 days per millennium
Out by 10 or 11 days by 1582, 12 by 1752
• Gregorian Calendar: 365.2425 days per year
– Same one leap year in four except centuries are not
leap years unless divisible by four like 2000
– Date of Easter is complex
– Dates can vary for events like the equinox by 4 days
– No 21 March dates for the spring equinox until 2102
Omar Khayyam’s 33 Year Calendar
• Omar Khayyam: Persian polymath
– 11th Century Poet, Philosopher
• “Rubaiyat” quatrains
• Celebrated wine, women and song
• “A loaf of bread, a flask of wine and
thou”
– Mathematician, Astronomer
• 33 Year Calendar cycle
– Divide year by 33
– Leap year if remainder is not zero
and is divisible by 4
– Reduces date spread to 24 hours
– Basis of Persian Jalāli calendar
Is it a Dee Leap Year?
"February will have 29 days whenever the A.D. yearnumber, reduced modulo 33, is non-zero and is
divisible by 4." But dividing by 33 is difficult
Add 1st two digits (centuries) to the 2nd two
2007: 20+07=27 not evenly divisible by 4 – no Leap
1996
1582
Is it a Dee Leap Year?
"February will have 29 days whenever the A.D. yearnumber, reduced modulo 33, is non-zero and is
divisible by 4." But dividing by 33 is difficult
Add 1st two digits (centuries) to the 2nd two
2007: 20+07=27 not evenly divisible by 4 – no Leap
Do twice and subtract 33 or 66 as required
1996: 19+96=115, 1+15=16, divisible by 4 – Leap Year
1582: 15+82=97, 97-66=31, not divisible by 4 - no Leap
Is it a Dee Leap Year?
"February will have 29 days whenever the A.D. yearnumber, reduced modulo 33, is non-zero and is
divisible by 4." But dividing by 33 is difficult
Add 1st two digits (centuries) to the 2nd two
2007: 20+07=27 not evenly divisible by 4 - no Leap
Do twice and subtract 33 or 66 as required
1996: 19+96=115, 1+15=16, divisible by 4 – Leap Year
1582: 15+82=97, 97-66=31, not divisible by 4 - no Leap
1583: 15+83=98, 98-66=32, divisible by 4 – Leap Year
1584: 15+84=99, 99-66=33, not divisible by 4 – no Leap
16th Century Europe
• Religious reformation and counter-reformation
– Lutheran, Huguenot and Anglican north vs Catholic
south, with Orthodox and Moslems to the east
• Renaissance: the birth of Science
– Science indistinguishable from magic
– Astronomy vs Astrology, Newton’s alchemy
– Kepler’s Platonic solids and Harmonia Mundi vs 3 laws
• Exploration and Empires
• Calendar Reform
Pope Gregory’s Calendar 1582
• Gregorian Calendar
Commission 1579-82 was led
by Christopher Clavius S.J.
– Jesuit Astronomer
– "Commentarius in Sphaeram
Joannis de Sacro Bosco"
– Led Gregorian calendar reform
• Prime function –Set the
correct date of Easter
• Correct the accumulated
Julian errors 10-11 days
• Khayyam’s 33 year cycle was
presented by Na'amat Allah,
the Syrian Patriarch on the
calendar Commission
Gregorian Calendar Reform
• Promulgated by Pope Gregory in 1582
• Adopted by most Catholic countries in 1584
• Reviewed in England by Dr John Dee, science
advisor and astrologer for Queen Elizabeth
• Dee recommended adoption of a modified
version dropping 11 days rather than 10
• Dee’s secret agenda: Implement the Khayyam 33
year calendar, not stated in his recommendation
• Recommendation not accepted by the Anglican
church even using the 10 day correction
• England remained on the Julian Calendar to 1752
and had to drop 12 days to get in sync
Dr. John Dee: Science and Magic
• John Dee (1527-1609) was a
noted Elizabethan scientist:
astronomer astrologer
alchemist geographer
cartographer and mystic
• Arrested and imprisoned for
“calculating” in 1555
• Science advisor, astrologer
for Queen Elizabeth I
• Traveled widely gathering
intelligence (spying?)
• “The Perfect Art of
Navigation” Taught Drake,
Frobisher, Harriot
Dee’s Secret 33 Year Calendar
History
• Reform the calendar
and drop 11 days to
return spring to 21
March
• Adopt a different
cycle for leap years
• Calendar reform but
with an improvement
over the Gregorian
calendar
vs
alt History
• Reform the calendar but use
the 33 year Khayyam cycle
• Equinox time spread reduced
to < 24 hours
• Simplifies Easter calculations
• Based on life of Jesus, 33
year cycle from year 1
• Defines “God’s Longitude”,
where the equinox is always on
the same day
• Calendars were the same from
1584 to 1620
• “Quod defertur non aufertur”
Gregorian Vernal Equinox
48.00
Gregorian Error
Hours from 20 March
Julian Error
24.00
0.00
1500
1600
1700
1800
1900
2000
400 Year
Correction
Century Correction
-24.00
Years
2100
2200
Dee's Mod 33 Vernal Equinox
Hours from 20 March
48.00
24.00
0.00
1500
1600
1700
1800
1900
-24.00
Year
2000
2100
2200
Combined Blob Chart for Vernal Equinox
Hours from 20 March
48.00
24.00
0.00
1500
1600
1700
1800
1900
Gregorian
Khayam Dee
-24.00
Year
2000
2100
2200
God's Longitude 77º West
28.00
24.00
Equinox Time
20.00
16.00
12.00
8.00
4.00
0.00
1500
1600
1700
1800
1900
Years
2000
2100
2200
Elizabethan Adventurer
Walter Raleigh
Favorite of the Queen
Military commander
Charter to colonize Virginia
Exploration of America
Cartier 1541
Cabot 1497
Gilbert 1583
Raleigh 1585 –1589
Roanoke Island
Ribaut 1564
77º W
Menendez 1565
Leon 1513
Cortez 1520
Columbus 1492
Raleigh’s Virginia 1584
Target 77º W
Raleigh’s Virginia 1585
Raleigh’s Virginia
1586
• Grenville’s re-supply ships
arrived three weeks late
• Roanoke colony was
temporarily abandoned
• Men had returned to
England on Drake’s ships
• Grenville left 15 good men
Raleigh’s Virginia 1587
• Major expedition in 1587 led by John White
• Three ships with 150 colonists including
planters, craftsmen and a few women and
children
• Destination: Chesapeake Bay, at least 50 miles
farther inland (77º?)
• Men left at Roanoke in 1586 had disappeared
• Chesapeake Bay destination abandoned
• Second colony established at Roanoke Island
• White returned to England to obtain more
support and supplies
Raleigh’s Virginia 1588-89
• Spanish Armada attacked England
• Although the Armada was defeated, supply
ships unavailable until too late
• Two small ships set out but did not get to
Virginia
• 1589 no ships and supplies available to White
and London partners
• Frustration for White, disaster for the colony
Lost Colony 1590
• 1590 White and London partners had
difficulty obtaining ships and supplies
• Arrived at Roanoke Island in August
• No signs of life, but evidence of attacks
• “CROATAN” carved in tree: tribe or island?
• Wattes unable to stop and explore Croatan
Island but sailed for West Indies and England
• Roanoke Island colony was Lost!
• Indian hostility, starvation?
Jamestown Colony 1607
• Searches for Lost Colony were delayed until
1607
– Dynasty change in England: King James Stuart
– Raleigh in prison, White and Dee destitute
• New Virginia colonization charter:
– John Smith to Jamestown
– Same secret agenda? Perhaps not, but…
–…
Jamestown Colony 1607
• Searches for Lost Colony were delayed until
1607
– Dynasty change in England: King James Stuart
– Raleigh in prison, White and Dee destitute
• New Virginia colonization charter:
– John Smith to Jamestown
– Same secret agenda? Perhaps not, but…
– Jamestown is at 76º 47’ West
God’s Longitude: Reality Check
• The blob charts show the benefit of mod 33
calendar and the 77º base longitude
• Results depend on inputs: I used
– Year length 365.2424 days and constant
– VE 21 March 1582, 23:58:10
• Dee would have known long term average year
length and date of vernal equinox
• Exact time is difficult to determine
• These inputs are reasonable for Dee’s time
but reality is more complex
Evidence for God’s Longitude
• In Elizabethan times, navigation and
explorations were state secrets
• Ref: “The Secret Voyage of Sir Fancais
Drake” by S. Bawlf
• Dee’s recommendation is a historical fact
– “What is delayed is not abandoned”
– Poetry with 33 year and life of Jesus theme
“But eighty foure, the Pattern is
Of Christ's birth yere: and so for ay
Eche Bissext shall fall little mys,
To shew the sun of Christ birth day”.
Evidence for God’s Longitude
• In Elizabethan times, navigation and
explorations were state secrets
• Ref: “The Secret Voyage of Sir Fancais
Drake” by S. Bawlf
• Dee’s recommendation is a historical fact
– “What is delayed is not abandoned”
– Poetry with 33 year and life of Jesus theme
•Fixation on moving west a bit from Roanoke
•Hariot’s use of 33 year cycle
Evidence for God’s Longitude
• In Elizabethan times, navigation and
explorations were state secrets
• Ref: “The Secret Voyage of Sir Fancais
Drake” by S. Bawlf
• Dee’s writings
– “What is delayed is not abandoned”
– Poetry with 33 year and life of Jesus theme
God’s Longitude:
Truth or Fiction ?
• God’s Longitude is plausible but
speculative … a modern interpretation
• Selected facts support premise but there
were many other more important factors
for English settlement to focus on
Virginia
Washington D.C.
77º
Washington D.C.
Welcome to
God’s Country
77º
Acknowledgements
• Frank King: Inspiration and advice
• Simon Cassidy: original historical and mathematical
research on “God’s Longitude”, web info and advice
• Duncan Steel: publicizing the idea in “Marking Time:
The Quest for the Perfect Calendar” and nominating the
Dee’s Calendar as the greatest invention in two millennia
• Derek Hayes: “Historical Atlas of the United States”
• Samuel Bawlf:“The Secret Voyage of Francis Drake”
• Wikipedia and other web resources for pictures and
historical background information