Slide1: A Presentation to Astronomy Ireland
By: David Grennan, 27th February 2006 Slide2: Solar Eclipses - Past, Present, and Future. Eclipse Mythology
Chinese, Hindu, Egyptian, Impact on modern day
science and religion.
Mechanics of Solar Eclipses
Why eclipses occur.
Types of Eclipse.
Phases of an eclipse.
Prominences. Slide3: Solar Eclipses - Past, Present, and Future. Safely Viewing Eclipses Eclipse, March 29, 2006 a guide.
Using computer simulations
Eclipse from Ireland.
Eclipse from Turkey.
Eclipse from Space Future Eclipses
Important Eclipses present – 2030
The 'almost' total eclipse of 2015 from Ireland. Slide4: Eclipse Lore
and Mythology "Nothing there is beyond hope, nothing that can be sworn impossible,
nothing wonderful, since Zeus, father of the Olympians,
made night from mid-day, hiding the light of the shining Sun,
and sore fear came upon men." Archilochus (c.710 - 676 BC) Slide5: Eclipse Lore and Mythology Our ancestors saw eclipses as evil omens, often as portents
of some catastrophic event or a sign from their deities. The earliest recorded eclipse was in China on
October 22, 2134 BC. The two court astrologers to the
Emporer lost their heads because, they had failed to predict it The Babylonians were the first to calculate the regular
intervals at which eclipses occur.
Thales of Miletus predicted a solar eclipse that marked
the beginning of the Greek scientific/philosophic era.
Slide6: Eclipse Lore and Mythology Word eclipse comes from a Greek word, “ekleipsis”
meaning abandonment. There is a story that suggests Christopher Columbus used his
Knowledge of an upcoming lunar eclipse to great effect. Slide7: Ancient China People of ancient China were convinced that eclipses
Occurred because a great dragon (or toad, or dog) was
Devouring the Sun.
They made load noises, banged implements etc to scare
Away the dragon.
As total eclipses can only last a maximum of 7 ½ minutes
There raucous behaviour always had the desired effect. Slide8: Ancient China Han Dynasty (206 BC - 220 AD) Slide9: Hindu Folklore According to Hindu mythology, the eclipse represents
the demons Rahu and Keta locked in celestial combat and
eating the Sun. Slide10: Hindu Folklore The Gods were drinking the elixir of immortality.
The demon Rahu slipped into their midst and stole a sip.
Surya (the sun) and Soma (the moon) reported the incident
to the great deity Vishnu.
Vishnu promptly sought out the impudent Rahu
and lopped off his head.
But having become deathless, Rahu survived and to this day
seeks revenge on the tattletales by devouring them. Slide11: Ancient Egypt The egyptian word for eclipse is ‘Akhet’
King Akhenaten (1356-1338 BC) built his capital according
to the totality path of the solar eclipse of 08/15/-1351.
The Pharaoh named his new residence 'Akhet Aten'.
The name of the city means: 'The Eclipse of Aten'.
The name of the Giza Sphinx was 'Hor in the Akhet‘
Many different ancient egyptian sun cults saw eclipses
Differently. Many refer to a serpent eating the Sun God.
Most however refer to a great hawk stealing RA’s glory. Slide12: Eclipses and Religion Many hindus to this day immerse themselves in holy rivers
And lakes during solar eclipses.
Working during eclipses is considered bad luck.
Muslim tradition holds that the prophet Mohammed,
the founder of Islam, prayed for the duration of an eclipse.
Senior muslim clerics issued an edict forbidding people to
look at the Sun directly because it transgresses Islamic law
to harm oneself.
Druids believe eclipse represents man and woman together. Slide13: Eclipses and Religion Luke 23:44-48 “And it was about the sixth hour, and there
was a darkness over all the earth until the ninth hour. And the sun was darkened, and the veil of the temple
was rent in the midst.”
Some suggest a solar eclipse as an explaination for
The ‘darkness’ however the facts don’t lend credance. Slide14: Mechanics of Solar Eclipses Solar eclipse of
11 Aug 1999
Spacestation. Slide15: Mechanics of Solar Eclipses Todo insert flash file. Slide16: Partial
Eclipse Slide17: Annular Eclipse Slide18: Total Eclipse Although a total eclipse refers to a specific event, the events leading
Up to ‘totality’ and following it also hold much interest. Partial Phase
Totality Slide19: Partial Phase During the partial phase there are many interesting things to note. First Contact.
Eclipse increasing in magnitude.
Creatures settling believing night is imminent
Moons shadow racing from the west(ish).
Slide20: First Contact. The moment when the western limb of the Moon contacts the
Eastern limb of the Sun. First contact is not directly
Visible, however very shortly
Afterwards a little ‘bite’ is
Taken from the Sun. Slide21: Temperature As the eclipse increases in magnitude, the amount of warming
Sunlight reaching us falls.
As the eclipse reaches 70-80% you will begin to feel a noticeable
Coolness as if night were coming. Slide22: Increasing Darkness With the decrease in the area of Sun presented to us
Ambient light levels fall.
Most noticeable in the latter stages of the eclipse.
Video from west Africa showing this dramatically. Slide23: Shadow Bands Caused by distortions in the Earth’s atmosphere and the partially
Eclipsed Sun. Best seen on a pale coloured
Wall or concrete pavement. Slide24: Crescent Shadows Note shadows cast by irregularly shaped objects such as leaves
From trees. Slide25: Crescent Shadows Slide26: Bailys Beads. At this point the only sunlight reaching us is through the undulating
Valleys on the Moons limb. Slide27: Bailys Beads. Slide28: Diamond Ring The chromosphere is visible and the ‘Corona’ is becoming visible.
The very last of ‘Bailys Beads’ is also visible.
Totality is now imminent!!!!!! Slide29: Totality!!!! Slide30: Totality!!!! Slide31: The Hybrid Eclipse. The official explaination! “A hybrid eclipse is a unique type of central eclipse where parts
of the path are annular while other parts are total.
This duality comes about when the vertex of the Moon's umbral
shadow pierces Earth's surface at some points, but falls short
of the planet along other portions of the eclipse path.
The curvature of Earth's surface brings some geographic locations
along the path into the umbra while other positions are more distant
and enter the antumbral rather than umbral shadow.” Fred Espenak Slide32: The Hybrid Eclipse. In practice! Slide33: Safely
Eclipses Slide34: Eclipse Safety Directly looking at the Sun,
even for a short time,
DAMAGE YOU EYESIGHT Slide35: Eclipse Safety Approved solar filter material
Should be used to cover your
Equipment and your eyes
AT ALL TIMES. Slide36: Sunglasses You should choose sunglasses that:
filter out 99-100% of UV rays
protect your eyes
are comfortable to wear
do not distort colors.
Source: Prevent Blindness America. Slide37: How to use Filter Material Slide38: How to use Filter Material Slide39: How to use Filter Material Slide40: Eclipse of March 29th 2006
We will use computer simulations to look at this
Eclipse from different vantage points
Animations created with Starry Night Pro Plus
Software. Slide41: Important Solar Eclipses
Present - 2030