Presentation on theme: "Ancient Astronomy Unit 1.1"— Presentation transcript
Slide1
Ancient Astronomy
Unit 1.1
1
Slide2
Ancient Astronomy
Many ancient cultures took a keen interest in the changing nighttime sky. The records and artifacts that have survived until the present make that abundantly clear.
2
Slide3
Ancient Astronomy
But unlike today, the major driving force behind the development of astronomy in those early societies
was probably neither scientific or religious. Instead, it
was practical.
3
Slide4
Ancient Astronomy
Seafarers needed to navigate their vessels, and farmers had to know when to plant their crops.
In a real sense, human survival depended on knowledge of the heavens.
4
Slide5
Ancient Astronomy
The ability to predict the arrival of the seasons, as well as other astronomical events, was a highly prized guarded skill.
5
Slide6
Ancient Astronomy
In the previous unit, we saw that the human brain’s ability to perceive patterns in the stars led to the invention of constellations as a convenient means of labeling regions of the celestial sphere.
6
Slide7
Ancient Astronomy
The realization that these patterns returned to the night sky at the same time each year met the need for a practical means of tracking the seasons.
7
Slide8
Ancient Astronomy
Widely separated cultures all over the world built elaborate structures, to serve
,
at least in part,
as primitive calendars.
8
Slide9
Ancient Astronomy
Often the keepers of the secrets of the sky enshrined their knowledge in myth and ritual, and
these astronomical sites were also used for religious ceremonies.
9
Slide10
Ancient Astronomy
Perhaps the best-known such site is Stonehenge,
located on Salisbury Plain in England.
This ancient stone
circle dates from the
Stone Age.
10
Slide11
Ancient Astronomy
Researchers believe it was an early astronomical observatory of sorts, like a kind of three dimensional calendar or almanac
, enabling its builders and their descendants to identify important dates by specific celestial events.
11
Slide12
Ancient Astronomy
Many of the stones are aligned so that they point towards important astronomical events.
12
Slide13
Ancient Astronomy
For example, the line joining the center of the inner circle to the so-called heel stone, set off some distance from the rest of the structure points in the direction of the rising Sun on the summer solstice.
13
Slide14
Ancient Astronomy
Other alignments are related to the rising and setting of the Sun and the Moon at other times of the year.
This is to within a 1° accuracy.
14
Slide15
Ancient Astronomy
While some of Stonehenge’s purposes remain uncertain and controversial, the site’s function as an astronomical almanac seems well established.
15
Slide16
Ancient Astronomy
Although Stonehenge is the most impressive and the best preserved, other stone circles, found all over Europe, are believed to have performed similar functions.
16
Slide17
Ancient Astronomy
Many other cultures are now known to have been capable of similarly precise accomplishments.
17
Slide18
Ancient Astronomy
The Big Horn Medicine Wheel in Wyoming is similar to Stonehenge in design although it is simpler in execution.
Its alignments with the rising and setting Sun and with some bright stars indicate that the Plains Indians were familiar with the nighttime sky.
18
Slide19
19
Slide20
Ancient Astronomy
There is also the Caracol
temple, built by the Mayans around on the 1000 AD on the Yucatan peninsula, which was more sophisticated than Stonehenge.
20
Slide21
Ancient Astronomy
Its many windows are accurately aligned with astronomical events,
such as the sunrise and sunset at the solstices and the equinoxes and the risings and settings of the planet Venus.
21
Slide22
Ancient Astronomy
Astronomy was more than mere academic interest to the Mayans,
Caracol
was also the site of countless human sacrifices, carried out when Venus appeared in the morning or evening sky.
22
Slide23
23
Slide24
Ancient Astronomy
The ancient Chinese also observed the heavens.
Their astrology attached particular importance to “omens” such as comets and “guest stars”.
They kept careful and extensive records of such events.
24
Slide25
Ancient Astronomy
Twentieth century astronomers still turn to the Chinese records to obtain observational data recorded during the Dark Ages when turmoil in Europe halted the progress of Western science.
25
Slide26
Ancient Astronomy
Perhaps the best known guest star was one that appeared in 1054 AD and was visible in the daytime sky for many months.
We now know that the event was actually a supernova.
26
Slide27
https://www.youtube.com/watch?v=Bw-NtS3lM9w
27
Slide28
Ancient Astronomy
It left behind mass that is still detectable today.
The Chinese data are a prime source of historical information for supernova research.
28
Slide29
Ancient Astronomy
A vital link between the astronomy of ancient Greece and that of medieval Europe was provided by astronomers in the Muslim world.
29
Slide30
Ancient Astronomy
For six centuries, from the depth of the Dark Ages to the beginning of the Renaissance,
Islamic astronomy flourished and grew preserving and augmenting the knowledge of the Greeks.
30
Slide31
Ancient Astronomy
Many of the mathematical techniques involved in trigonometry were developed by Islamic astronomers in response to practical problems.
31
Slide32
Ancient Astronomy
Astronomical terms such as “zenith” and “azimuth” and the names of many stars all bear witness to this extended period of Muslim scholarship.
32
Slide33
Ancient Astronomy
Astronomy is not the property of any one culture, civilization, or era.
The same ideas, the same tools, and even the same misconceptions have been invented and reinvented by societies all over the world.
33
Slide34
Ancient Astronomy
Astronomy came into being because people believed that there was a practical benefit in being able to predict the positions of the stars.
34
Slide35
Ancient Astronomy
Ultimately, the need to understand where we came from and how we fit into the cosmos is an integral part of human nature.
35
