Transcript Vegetarian: Greco-Roman Warrior Cycle

•Frazer proponed that scientific inquiry [e.g.
Astronomy] sprung from elements of rituals,
religious doctrine/or philosophy, i.e. human
sacrifice (Messianic Monotheism) and dying
gods (Pagan Polytheism) as well as many other
symbolisms and ritualistic practices resulting in
the formation constituting the cognitive
rationalization of the human psyche thus later
culminating to scientific thought.
Rituals (Sympathetic magic/ imitation) +
Religion (Philosophy) = Science
Simply:
Experiment + Results = Scientific Thought
•The Babylonians were the first civilization
known to possess a functional theory of the
planets called, “Venus tablet of
Ammisaduqa” [7th-century BC]. It is the
earliest evidence that planetary phenomena
were recognized as ‘periodic.’
•Pythagoras, [6th and 5th centuries BC]
appeared to have developed his own
independent planetary theory, which
consisted of the Sun, Earth, and Venus (all
planets) revolving around a "Central Fire"
at the center of the Universe.
•In Philolaus's system (Counter-Earth) [6th
and 5th centuries BC], “Moving the earth
from the center of the cosmos and making it
a planet". First coherent system in which
celestial bodies move in circles nongeocentric and non-heliocentric system.
Ammisaduqa tablet
Antichthon (Venus):
Counter-Earth
Pythagoras (Greek)
Venus Deity
•An important calendar for the Maya
was the Venus cycle: A 584-day Venus,
which tracked the heliacal risings of
Venus as the “Morning Star” and
“Evening Star”.
•Dresden Codex: It is a detailed account
of the astronomical observations of the
Mayas
Dresden Codex
Who contributed/or
stimulated the
astronomical pursuits in
science?
A) Ancient Maya Civilization
B) Greco-Roman Society
C) Babylonian Civilization
D) All of the Above
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[Correct Answer]:
D
 Name: Venus
 Aka Morning/Evening Star
 Minimum Distance to the Sun: 108 million km
 Maximum Distance to the Sun: 109 million km
 Discovery – Unknown
 Observed before recorded history
 Hottest planet in the solar system
 Galileo’s discovery of Venus’ phases helped
disprove the geocentric model
 Satellites: Zero
 Period of Rotation About Axis: 243 days
 Retrograde (clockwise)
 Period of Revolution About Sun: 0.62 years
 Venus’ atmosphere consists mostly of
Carbon Dioxide with thick clouds of
Sulfuric Acid
 The atmosphere is so thick that it
traps the small amounts of the sun’s
energy that reaches the surface
 Greenhouse Effect
 The atmospheric pressure on Venus is
about 90 times greater than that of
Earth’s
 Equivalent to 3,000ft below
Earth’s sea level
Carbon Dioxide
Nitrogen
Carbon Monoxide, Argon, Nitrogen,
Sulfur Dioxide, Water Vapor
<1%
4%
96%
 SIMILAR to Earth, Venus has two poles:
North Pole, South Pole
 Vortex – a visible, whirling mass of air
 Think tornado!
 Plural: Vortices
 Vortices have been discovered in both
polar regions
 North Pole – NASA in 1978
 South Pole – ESA in 2006
 For some odd and undiscovered reason,
these vortices circle about two points
 Like an eye of a storm, but two…
 UNLIKE Earth, whose axis of rotation is
tilted at about 23o , Venus’ axis of rotation
is tilted only at about 3o
 Lack of seasons
 Average surface and lower atmosphere
temperature stays nearly the same
throughout the year
 Stays consistent even throughout day
and night
 Average Surface Temp: 730 K
 That’s 457o C or 855o F all the time
 Space probes have found over 1600 major volcanoes
 Very limited data to prove whether the volcanoes are active/extinct
 Very young surface age, due to lack of “wear and tear” from water
or wind
 No long, linear volcanic chains
 No evidence for plate tectonics or subduction zones like Earth
 No evidence for violent eruptions
 Fluid-like lava flow
 Ishtar Terra – continent near North Pole containing four main
mountain ranges
 About the size of mainland USA
 Volcanoes: Sacajawea, Collete, Cleopatra
 Tessera – a shortening of crust created folding, breaking, clumping
of crust
 Shows signs that the surface of Venus may be in motion
MAY 1989- OCTOBER 1994
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Built partially with spare parts from other missions, the Magellan
spacecraft was 15.4 feet long, topped with a 12-foot high-gain antenna.
The spacecraft weighed a total of 7,612 pounds at launch.The high-gain
antenna, used for both communication and radar imaging, was a spare
from the NASA/JPL Voyager mission to the outer planets, as were
Magellan's 10-sided main structure and a set of thrusters.
The command data computer system, attitude control computer and
power distribution units are spares from the Galileo mission to Jupiter.
Magellan's medium-gain antenna is from the NASA/JPL Mariner 9
project.
Magellan was powered by two square solar panels, each measuring 8.2
feet on a side; together they supplied 1,200 watts of power.
Over the course of the mission the solar panels gradually degraded, as
expected.
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Magellan was the first planetary spacecraft to be launched by a
space shuttle when it was carried by the shuttle Atlantis from
Kennedy Space Center in Florida on May 4, 1989.
Atlantis took Magellan into low Earth orbit, where it was released
from the shuttle's cargo bay.
A solid-fuel motor called the Inertial Upper Stage (IUS) then fired,
sending Magellan on a 15-month cruise looping around the sun 11/2 times before it arrived at Venus on August 10, 1990.
A solid-fuel motor on Magellan then fired, placing the spacecraft
in orbit around Venus.
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Magellan's initial orbit was highly elliptical,
taking it as close as 182 miles from Venus and
as far away as 5,296 miles.
Magellan was in a polar orbit, meaning that the
spacecraft moved from south to north or vice
versa during each looping pass, flying over
Venus's north and south poles.
Magellan completed one orbit every 3 hours, 15
minutes.
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During the part of its orbit closest to Venus, Magellan's radar
mapper imaged a small section of the planet's surface
approximately 10 to 17 miles wide.
At the end of each orbit, the spacecraft radioed back to Earth a
map of a long ribbon-like strip of the planet's surface captured on
that orbit.
Because of the images taken from Magellan, scientists were able to
determine that Venus itself rotates once every 243 Earth days.
As the planet rotated under the spacecraft, Magellan collected
strip after strip of radar image data, eventually covering the entire
globe at the end of the 243-day orbital cycle.
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By the end of its first such eight-month orbital cycle between
September 1990 and May 1991, Magellan had sent to Earth
detailed images of 84 percent of Venus's surface.
The spacecraft then conducted radar mapping on two more eightmonths cycles from May 1991 to September 1992. This allowed it
to capture detailed maps of 98 percent of the planet's surface.
The follow-on cycles also allowed scientists to look for any
changes in the surface from one year to the next. In addition,
because the "look angle" of the radar was slightly different from
one cycle to the next, scientists could construct three-dimensional
views of Venus's surface. As pictured in the next slide.
Maxwell Montes, the planet's highest mountain at 6.6 miles above the average
elevation, is the bright feature in the lower center of the image.
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During Magellan's fourth eight-month orbital cycle at Venus from
September 1992 to May 1993, the spacecraft collected data on the
planet's gravity field.
During this cycle, Magellan did not use its radar mapper but
instead transmitted a constant radio signal to Earth.
If it passed over an area of Venus with higher than normal gravity,
the spacecraft would slightly speed up in its orbit.
This would cause the frequency of Magellan's radio signal to
change very slightly due to the Doppler effect, and example
would be that the pitch of a siren changes as an ambulance passes.
Thanks to the ability of radio receivers in the NASA/JPL Deep
Space Network to measure frequencies extremely accurately,
scientists could build up a detailed gravity map of Venus.
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At the end of Magellan's fourth orbital cycle in May 1993, flight
controllers lowered the spacecraft's orbit using a technique called
aerobraking.
This maneuver sent Magellan dipping into Venus's atmosphere
once every orbit; the atmospheric drag on the spacecraft slowed
down Magellan and lowered its orbit.
After the aerobraking was completed between May 25 and August
3, 1993, Magellan's orbit then took it as close as 112 miles from
Venus and as far away as 336 miles.
Magellan also circled Venus more quickly, completing an orbit
once every 94 minutes.
This new, more circularized orbit allowed Magellan to collect
better gravity data in the higher northern and southern latitudes
near Venus's poles.
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After the end of that fifth orbital cycle in April 1994, Magellan began a
sixth and final orbital cycle, collecting more gravity data and conducting
radar and radio science experiments.
By the end of the mission, Magellan will have captured high-resolution
gravity data for an estimated 95 percent of the planet's surface.
In September 1994, Magellan's orbit was lowered once more in another
test called a "windmill experiment." In this test, the spacecraft's solar
panels were turned to a configuration resembling the blades of a
windmill, and Magellan's orbit was lowered into the thin outer reaches of
Venus's dense atmosphere.
Flight controllers then measured the amount of torque control required to
maintain Magellan's orientation and keep it from spinning.
This experiment gave scientists data on the behavior of molecules in
Venus's upper atmosphere, and lent engineers new information useful in
designing spacecraft.
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On October 11, 1994, Magellan's orbit is scheduled to be lowered a final
time.
This experiment was to test the spacecraft to see how much torque
will be needed to keep the spacecraft from spinning on its axis.
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Within two days after that maneuver, the spacecraft is expected to
become caught in the atmosphere and plunge to the surface.
Although much of Magellan would be vaporized, some sections are
expected to hit the planet's surface intact.
Magellan was the first planetary spacecraft to be terminated intentionally.
De Silva, Shan. "Venus | Volcano World." Large Shield Volcanoes | Volcano
World. Oregon Space Grant Consortium, 1995. Web. 30 Jan. 2014.
Frazer, James George. The Golden Bough. 198 Madison Avenue: Oxford
University Press, 1994. Paperback 1998.
Huffman, Carl, "Philolaus", The Stanford Encyclopedia of Philosophy (Summer
2012 Edition), Edward N. Zalta (ed.), URL =
<http://plato.stanford.edu/archives/sum2012/entries/philola
us/>.
Miles, Susanna W, "An Analysis of the Modern Middle American Calendars:
A Study in Conservation." In Acculturation in the Americas. Edited by
Sol Tax, pp. 273–84. Chicago: University of Chicago Press, 1952.
Nelson, John. Space, Stars, Mars, Earth, Planets and More - NASA Jet Propulsion
Laboratory. Jet Propulsion Laboratory, n.d. Web. 30 Jan. 2014.
Russel, Randy. "Venus." Windows to the Universe. National Earth Science
Teachers Association, n.d. Web. 28 Jan. 2014.