{"id":9988,"date":"2024-03-04T01:44:34","date_gmt":"2024-03-03T23:44:34","guid":{"rendered":"https:\/\/uni-mag.gr\/?p=9988"},"modified":"2024-05-13T10:59:43","modified_gmt":"2024-05-13T07:59:43","slug":"greenwich-or-the-ball-of-time","status":"publish","type":"post","link":"https:\/\/www.uni-mag.gr\/en\/greenwich-or-the-ball-of-time\/","title":{"rendered":"CAPTAIN GG: GREENWICH OR BALL OF TIME"},"content":{"rendered":"\n
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Kid A:<\/strong> I know very well, I don’t often feel like eating fish. Now I want to try fish and chips!<\/p>\n\n

Mr. A:<\/strong> Fish and chips?<\/p>\n\n

Kid A:<\/strong> Exactly. What did I say? Fried fish and fries.<\/p>\n\n

Dafni<\/strong>: So to add a little color to your plate, you don’t need anycolored salad?<\/p>\n\n

Kid A:<\/strong> Let’s get the green mushy peas too.<\/p>\n\n

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Captain GG:<\/strong> I know a restaurant with the best fish and chips. Shall we go?<\/p>\n\n

Mom<\/strong>: Where are we going this time?<\/p>\n\n

Captain GG:<\/strong> We’re going to England, which has the best fish and chips. It is a great opportunity to go to the Greenwich observatory as well. We’ll all find out what that red ball above the observatory is doing. As a captain, I always need to know exactly where my ship is.<\/p>\n\n

Dad<\/strong>: So, you need to know how to calculate the longitude and latitude of where you are. Does the red ball help?<\/p>\n\n

Captain GG:<\/strong> We learned to find latitude in my sundial story.<\/p>\n\n

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CAPTAIN GG: Sundial<\/em><\/figcaption><\/figure>\n\n
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Mr. A<\/strong>: Then we used the sextant to calculate the angle \u03c6. This is the latitude of a place.<\/p>\n\n

Dafni<\/strong>: We found that the latitude of Greece is approximately +40\u00b0 North.<\/p>\n\n

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Captain GG:<\/strong> Now, we’ll see how we find the longitude (\u03bb) of a place.<\/p>\n\n

Kid A:<\/strong> I learned at school that Greece is located approximately between 20\u00b0 and 30\u00b0 East. <\/p>\n\n

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The meridians of the Earth. The prime meridian is marked in black, which is the one that passes through Greenwich. Greece is two meridians east of Greenwich. All meridians east of Greenwich are marked in blue. Accordingly, those to the west of Greenwich are in red. The figure above is from www.daskalosa.eu<\/a><\/em><\/p>\n\n

Kid A:<\/strong> In this figure above, our Earth is like a big orange.<\/p>\n\n

Daphne<\/strong>: The black line is the Greenwich meridian.<\/p>\n\n

Mr. A<\/strong>: Each slice of the orange is 15\u00b0.<\/p>\n\n

Dad<\/strong>: Sit down and see how we can explain this 15\u00b0.<\/p>\n\n

Mr. A<\/strong>: Easy. The whole circle is 360\u00b0. It takes 24 hours for the Earth to rotate. So, 1 hour is 360\u00b0 : 24 = 15\u00b0.<\/p>\n\n

Dafni<\/strong>: A slice of orange is 1 hour or 15\u00b0.<\/p>\n\n

Mom<\/strong>: That is, from England to Greece is two slices of orange. The difference between them is 2 hours or 30\u00b0.<\/p>\n\n

Captain GG:<\/strong> So, to calculate \u03bb we need to know exactly what time it is. The red ball of Greenwich drops exactly at 13:00, as shown in the next video.<\/p>\n\n

Captain GG<\/strong>: Right, that’s when all the ships compare their timers.<\/p>\n\n

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