The Solar Year

Guo

invented a giant gnomon with a height of 44ft.

Guo Shoujing

, the khan's brilliant Chinese chief astronomer, was given the job of creating the calendar.

Kublai Khan

When conquered China in 1276, the Daming calendar was used.

China

In 1912, adopted the Gregorian calendar.

Emperor Wu of the Han Dynasty

In 100 BCE, _ sets a Chinese calendar based on a solar year.

Julius Caesar

changes the Roman calendar to include a leap day every four years and a year length of 365 days and 6 hours.

Pope Gregory

introduces the Gregorian calendar, a revision of the antiquated Julian calendar, using the same 365.25- day year as Guo's Shoushi calendar.

Ulugh Beg

He used a 164-foot gnomon to determine that the solar year is 365 days, 5 hours, 49 minutes, and 15 seconds long.

Pope Gregory

He introduces the Gregorian calendar, a revision of the antiquated Julian calendar, using the same 365.25-day year as Guo's Shoushi calendar.

100 BCE

Emperor Wu of the Han Dynasty sets a Chinese calendar based on a solar year.

46 BCE

Julius Caesar changes the Roman calendar to include a leap day every four years and a year length of 365 days and 6 hours.

He then decided to impose his authority a new calendar

the Shoushi calendar

1437

Ulugh Beg used a 164-foot gnomon to determine that the solar year is 365 days, 5 hours, 49 minutes, and 15 seconds long.

1582

Pope Gregory introduces the Gregorian calendar, a revision of the antiquated Julian calendar.

Han Dynasty

A 365.25-day solar year was used when it was first formalized in the first century BCE during the .

50

China’s calculations were different. They were ___ years ahead of the West’s calendar.

Kublai Khan

When _ conquered China in 1276, the Daming calendar was used.

1276

Year Kublai Khan conquered China

Daming

When Kublai Khan conquered China in 1276, the _ calendar was used.

Guo Shoujing

the khan's brilliant Chinese chief astronomer, was given the job of creating the Shoushi calendar.

armillary sphere

An is a tool used to simulate the positions of celestial bodies.

water-powered

Guo created a _ version of armillary sphere.

Khanbaliq

Guo's task was to establish an observatory in _ order to measure the length of the solar year.

Wang Chun

Guo started a series of observations to track the motion of the sun throughout the year in collaboration with mathematician _.

29.530593

In 1279, Guo and Wand declared that a month had _ days

365.2524

In 1279, Guo and Wand declared that an actual solar year has days.

Shoushi calendar

The was widely regarded as the most accurate calendar in the world at their time and it continued to be used for 363 years.

1912

China adopted the Gregorian calendar.

gnomon

Guo invented a giant _ with a height of 44ft. This allowed him to measure the angle of the sun with far greater accuracy.