By Early Modern Englishmany nouns were capitalized, and the earth became and often remained the Earth, particularly when referenced along with other heavenly bodies.
The greek way — BC The very first person to determine the circumference of the earth was Eratosthenes, in sometime around BC. It all started when he was peacefully reading something at the library of Alexandria.
He read that in a city, Syene, little far away from Alexandria, people observed something different on a particular day summer solstice.
At noon, the vertical columns did not cast any shadows at all.
For some reason Curiosity, it is! At Alexandria, he reproduced the conditions on the same day, a year later. He found that his stick did cast a shadow at an angle of 7.
He intuitively confirmed that this could only happen if the earth was round. Being a mathematician, he applied simple geometry and extended an imaginary line from both the locations towards the center of the earth, forming an arc sector with an angle of 7.
He then only needed to find the distance arc length between Alexandria and Syene to determine the circumference of the entire circle Earth.
He simply paid a guy to measure that distance between the two cities for him. The distance was found to be km No, the unit was not kilometers back then… It was stadia! With a very simple geometry and an intuitive mind, he calculated the circumference of the earth close enough to the modern values.
Experiment Requirements Before I begin, understand that this is a fun experiment and we are going to do it with everyday objects that includes the internet.
To begin, all you need is a clear day, vertical stick, and a friend or friends far away from you, preferably on the same meridian. Data Collection Choose a day, say September 25,and a way to synchronize up with your friend.
Besides, using a camera would be cool, as you can record it and do it in an accurate way with more data points for better results. My Hometown, Annur — After plugging all the recorded data into an excel sheet, I got a cute plot like this.
So now, I have the shadow length for different time sets. With the shadow length and the actual length of the object, now I could get the angle that the sun rays make with the sticks at both the locations. This is what I have calculated so far. Approximate illustration of the sun ray angles and the position of the sticks on September 25, When you extend an imaginary line vertically towards the center of the earth from both the sticks, they will meet exactly at the center, as we have assumed that the earth is a perfect sphere.
However, the date is September 25 missed the equinox by two days and the sun is overhead somewhere at 0. So I simply extended the lines outward of my position to form a triangle and found out the angle between my place and Russia.
All I need is the distance between the two locations. So I sent a pigeon to the Russian location and found that the distance it took by air to reach the spot is km. Compensating for the terrain, I added up 40 km Though, I assumed that the earth is a perfect sphere, this compensation could give me better results, as the earth is not a perfect sphere.
Hence, the approximate distance would be km. This feels awesome even with the data that I have simulated. I would actually like to do it with some friends soon and try something challenging like finding the longitude too. Latitude is actually easy to find if you have an almanac by your side.
The difference would give me my longitude. Now, go find friends across the globe and start your experiments. This post was first published on September 27, I am the creator of Geekswipe. I love writing about Physics and Astronomy. I am now creating Swyde.For example, when Eratosthenes, the Greek guy who invented the word and science of geography, looked into a well at noon, he calculated a way to measure the diameter of the earth.
The radius of Earth at the equator is 3, miles (6, kilometers), according to NASA's Goddard Space Flight Center. However, Earth is not quite a .
Measurement of the Earth's circumference a Study in Source Analysis. A Thesis Submitted for the Degree of Master of Arts at the University of Otago. Dunedin, New Zealand. Pfeiffer, Rudolf ().
|The greek way – 240 BC||In lieu of an abstract, here is a brief excerpt of the content: Figuring a Blind Spot in the Romantic Tradition Laura Gribbin bio Among the key words that Emily Dickinson returns to in her poetry—Eternity, Death, Arc, Crescent, Circuit—few have received as much attention or been as difficult to elucidate as her idiosyncratic use of Circumference.|
|June 2006 (Volume 15, Number 6)||This Month in Physics History June, ca. But they had no idea how big the planet is until about B.|
|Chapter 4 LAB Activity: Eratosthenes and the Earth's Circumference Answers - SchoolWorkHelper||Measured Length, arc EF: By making this assumption, that means all the sun rays running along the surface of the earth become nearly parallel.|
History of Classical Scholarship From the Beginnings to the End of the Hellenistic Age. Oxford: Clarendon alphabetnyc.com for: Sieve of Eratosthenes, Foundation of Geography.
Calculating the Circumference of Earth using circumference of the Earth. Use the data in proportion to calculate the polar circumference of the Earth.
Analysis Have students compare results, noticing differences between groups, and between equatorial and polar. Ancient Measurements of the Circumference of the Earth. 1. The reconstruction of the system of ancient lineal units allows to confirm the conclusion of French scholars of the eighteenth and early nineteenth centuries that the ancients had achieved a most accurate calculation of the circumference of the earth and that this calculation had been performed earlier than Greek times.
Using two assumptions Eratosthenes was able to measure the circumference of the earth; 1) the earth is round and 2) the sun’s rays are parallel.
His results concluded that the earth was: , stadia (about 46, km), is quite close to modern measurements.