How could ancient people determine the winter solstice was occurring?
score:10
The solstice was determined by observing the shade of the gnomon (a vertical stick on a level ground). Indeed, this is difficult to observe with a good precision. However, if you do this for many years, you obtain a better and better result. For example, suppose that your error is E, and you observe for N years. This gives you the length of the year (the time interval between, say two summer solstices) with error E/N. This principle permitted to determine the length of the year (and other constants in astronomy) with high accuracy.
EDIT. Ptolemy describes the following device for determining equinoxes. A flat metal ring was permanently installed in Alexandria in the plane parallel to the equator. (For this you have to determine the inclination of ecliptic first, then your latitude. All this is done by measuring the sun altitude at noon with a gnomon). At the moment of equinox, both surfaces of the ring will be illuminated by the Sun.
Determination of the moment of a solstice is more difficult and less accurate. But again you measure the altitude of the Sun with the gnomon or a similar device at noon, if the solstice happens at noon, say summer solstice, you will obtain the maximal possible altitude for this place. If the maximum this year is less than the maximum possible altitude, this means that the solstice did not happen at noon, and you interpolate.
All this information is contained in Ptolemy's Almagest. Modern calculations permit to verify the numerical data. They show that Hypparchus and Ptolemy could determine the time of an equinox with 7 hours accuracy and solstice to 12 hours.
Hypparchus and Ptolemy determined the length of the year as 365 days 5 hours 55 min 12 sec. They used observations spanned over 550 years.
See also my answer to a related question:
What knowledge may have been lost at the Library of Alexandria?
More post
- 📝 Were there any local or regional elections in Nazi Germany?
- 📝 What was the currency in use in Palestine shortly before and during WWI?
- 📝 What was German GDP in 1919 in Goldmarks?
- 📝 Have historians attempted to reconstruct the polytheistic Semitic pantheon, dividing it into sub pantheons?
- 📝 How effective were the Mongol siege equipment?
- 📝 Venezuelan crisis of 1902–03: Why is there a Russian flag on the cover of the prominent newspaper 'Le Petit Parisien'?
- 📝 Was there a Norse custom of "one keeps what one defends"?
- 📝 Why did the British not introduce the sterling in India?
- 📝 What are these 2 compartments next to these war chariots?
- 📝 How many people worked to build one Liberty ship?
- 📝 Were there many foreigners fighting during the American civil war?
- 📝 19th century cabins: why were beds off the ground? Or weren't they?
- 📝 Does the Ottoman Empire count as a colonial power?
- 📝 Did Afghanistan make war with Alexander the Great?
- 📝 Was it worthwhile for Britain to side with the USA in the Canada-Alaska border dispute?
- 📝 Did Andrew Jackson kill Dickinson fairly according to the customs of duels at the time?
- 📝 What distinguished the Republican Party of Liberia from the True Whig Party?
- 📝 In Battle of Zama, how did Hannibal's use of war elephants lead to a Roman Victory?
- 📝 Did Japan ever attack Vladivostok in WW2? Why or why not?
- 📝 Why did China decide to support Poland in 1956, but not Hungary?
- 📝 Tolstoy's view of history
- 📝 How to understand the geography of Napoleon's military campaigns?
- 📝 Why did email use develop in tandem with the internet, rather than other technologies?
- 📝 Has a battering ram been used to breach a gate?
- 📝 What is the largest overnight depreciation?
- 📝 Are there any underground cities known except those found in Cappadocia?
- 📝 How long did it take to make a 16th century arrow?
- 📝 Did the US manage to eavesdrop on KMT communications during World War 2?
- 📝 What was so technologically advanced about the snorkel?
- 📝 Did genocide occur in the Football War?
Source: stackoverflow.com
Search Posts
Related post
- 📝 How could ancient people determine the winter solstice was occurring?
- 📝 If salt was scarce and expensive, how did people "salt the earth" to ensure their enemies would stay defeated?
- 📝 How common was it for people to live 80+ years in the 17th century?
- 📝 How extensive and developed was the ancient Kushite (Nubian) horse trade?
- 📝 How was the 1849 "Proclamation to the People of California" announcing the formation of a Constitution communicated to the people?
- 📝 What was the ancient Greeks view on people of African descent?
- 📝 During the Middle Ages, how many people could be fed by fishing?
- 📝 How big was the percentage of white people in the USA who were not against granting the blacks equal rights?
- 📝 How was the Ancient Egyptian name 'God is Gracious' written?
- 📝 How could the 4/5 devaluation of Franc Poincaré in 1928 end the financial crisis France was going through?
- 📝 How democratic was the ancient republic of Rome?
- 📝 How could one understand the essence of Greek mythology and the deep meanings? Understanding the belief system of Ancient Greeks
- 📝 How could a prisoner get lessons to read, write and do mathematics in jail, while innocent people didn't get the basic knowledge in 18th-19th century?
- 📝 How could I determine the value of a a 1921 Yuan Shikai Chinese silver dollar?
- 📝 How can we be sure what the first day of the month was 2000 years ago and how can we determine which years were leap years?
- 📝 How could West Berlin had access West Germany/world while the wall was up?
- 📝 How did people distinguish slaves from free people in Ancient Rome?
- 📝 How did 300,000 people survive the 3 1/2 year siege of Sarajevo?
- 📝 How was Germany able to hold itself together, while Austria-Hungary could not?
- 📝 How do ancient Chinese "mirrors" such as these in the National Museum function?
- 📝 How did the ancient Romans count with their fingers?
- 📝 What led some people to (correctly) believe that there was no land under the ice cap at the North Pole?
- 📝 In the Battle of the Coral Sea, how could two Japanese scouts grossly mis-identify two American ships?
- 📝 How serious was Fermat's statement about the ancients?
- 📝 What was the religion of the Arabic people before conversion to Islam?
- 📝 How many people in the US starved to death during the Great Depression?
- 📝 How and when was the modern company ownership structure invented?
- 📝 How did the ancient Greeks synchronize time?
- 📝 How was the United States able to produce excellent tanks in 1942?
- 📝 How did people deal with ice on the roads during the horse-and-buggy era?