Some Simple Questions What is the first day of spring? How do you mark a date on a sundial? The real answer is much more complex. The problem of the unique.

Some Simple Questions

• What is the first day of spring?• How do you mark a date on a sundial?

•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!

The facile answers:-Spring starts on 21 March, the vernal equinox-Use a declination line

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

Roger Bailey and Fred Sawyer NASS Virginia 2007

Dr John Dee

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

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0.00

24.00

48.00

1990 2000 2010 2020 2030

Year

Ho

urs

fro

m 2

0 M

arch

Julian Error

Leap Year Cycle

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.

year-number, 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 two2007: 20+07=27 not evenly divisible by 4 – no Leap

19961582

Is it a Dee Leap Year?"February will have 29 days whenever the A.D.

year-number, 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 two2007: 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. year-

number, 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 two2007: 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 Year1582: 15+82=97, 97-66=31, not divisible by 4 - no Leap1583: 15+83=98, 98-66=32, divisible by 4 – Leap Year1584: 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 vs alt 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

• 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

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Years

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rs f

rom

20

Mar

ch

Julian Error

Century Correction

Gregorian Error

400 Year Correction

Dee's Mod 33 Vernal Equinox

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Year

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rom

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Mar

ch

Combined Blob Chart for Vernal Equinox

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Year

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rom

20

Mar

ch

Gregorian Khayam Dee

God's Longitude 77º West

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28.00

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Years

Equ

inox

Tim

e

Elizabethan Adventurer

Walter RaleighFavorite of the QueenMilitary commanderCharter to colonize Virginia

Columbus 1492

Raleigh 1585 –1589 Roanoke Island

Cabot 1497

Cortez 1520

Cartier 1541

77º W

Exploration of America

Leon 1513

Menendez 1565

Ribaut 1564

Gilbert 1583

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

• 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 isOf Christ's birth yere: and so for ayEche Bissext shall fall little mys,To shew the sun of Christ birth day”.

Evidence for God’s Longitude

•Fixation on moving west a bit from Roanoke •Hariot’s use of 33 year cycle

• 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

Evidence for God’s Longitude

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