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The New Coffee Room

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  3. Sagan: Ancient Greeks showed the earth is round.

Sagan: Ancient Greeks showed the earth is round.

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  • jon-nycJ Offline
    jon-nycJ Offline
    jon-nyc
    wrote on last edited by
    #5

    The first (and best) half of Max Tegmark’s book ‘Our Mathematical Universe’ explores the history of human knowledge about the universe and covers in great detail some of the early experiments of the ancient Greeks. It’s a truly fascinating read.

    "You never know what worse luck your bad luck has saved you from."
    -Cormac McCarthy

    1 Reply Last reply
    • KlausK Offline
      KlausK Offline
      Klaus
      wrote on last edited by
      #6

      If you want to use this experiment to calculate the circumference of the earth, I think it would matter that one city is south or north of the other. Otherwise, how can you be sure that you measure at the same time of the day without any sun-independent time measuring device?

      1 Reply Last reply
      • jon-nycJ Offline
        jon-nycJ Offline
        jon-nyc
        wrote on last edited by jon-nyc
        #7

        THere's a detail Sagan missed.

        Syene is on the Tropic of Cancer. It was known that the obelisk cast no shadow at noon on the summer solstice. So Erasthenes simply measured the angle in Alexandria when the shadow was at its shortest on the solstice.

        "You never know what worse luck your bad luck has saved you from."
        -Cormac McCarthy

        1 Reply Last reply
        • jon-nycJ Offline
          jon-nycJ Offline
          jon-nyc
          wrote on last edited by
          #8

          By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?

          As implausible-but-true facts go, it's right up there with the English having ruled the world.

          "You never know what worse luck your bad luck has saved you from."
          -Cormac McCarthy

          Doctor PhibesD 1 Reply Last reply
          • jon-nycJ jon-nyc

            By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?

            As implausible-but-true facts go, it's right up there with the English having ruled the world.

            Doctor PhibesD Offline
            Doctor PhibesD Offline
            Doctor Phibes
            wrote on last edited by
            #9

            @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

            By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
            As implausible-but-true facts go, it's right up there with the English having ruled the world.

            Your time is coming, McTwatface

            I was only joking

            jon-nycJ brendaB 2 Replies Last reply
            • CopperC Offline
              CopperC Offline
              Copper
              wrote on last edited by
              #10

              https://www.amazon.com/Longitude-Genius-Greatest-Scientific-Problem-ebook/dp/B003WUYE66/ref=sr_1_1?crid=3JVFBOUFUEEKL&keywords=longitude&qid=1659112814&sprefix=longitude%2Caps%2C126&sr=8-1

              The dramatic human story of an epic scientific quest and of one man's forty-year obsession to find a solution to the thorniest scientific dilemma of the day--"the longitude problem."

              Full of heroism and chicanery, it is also a fascinating brief history of astronomy, navigation, and clockmaking, and opens a new window on our world.

              58430b22-9b9d-45f5-a27a-d40447139be2-image.png

              jon-nycJ 1 Reply Last reply
              • CopperC Copper

                https://www.amazon.com/Longitude-Genius-Greatest-Scientific-Problem-ebook/dp/B003WUYE66/ref=sr_1_1?crid=3JVFBOUFUEEKL&keywords=longitude&qid=1659112814&sprefix=longitude%2Caps%2C126&sr=8-1

                The dramatic human story of an epic scientific quest and of one man's forty-year obsession to find a solution to the thorniest scientific dilemma of the day--"the longitude problem."

                Full of heroism and chicanery, it is also a fascinating brief history of astronomy, navigation, and clockmaking, and opens a new window on our world.

                58430b22-9b9d-45f5-a27a-d40447139be2-image.png

                jon-nycJ Offline
                jon-nycJ Offline
                jon-nyc
                wrote on last edited by
                #11

                @Copper I read that years ago. My father gave it to me.

                "You never know what worse luck your bad luck has saved you from."
                -Cormac McCarthy

                1 Reply Last reply
                • bachophileB Offline
                  bachophileB Offline
                  bachophile
                  wrote on last edited by
                  #12

                  Good book longitude.

                  And another thought, did they take into account daylight savings time.? Could have thrown the whole experiment off by one hour and then where would we be. With a crooked globe.

                  1 Reply Last reply
                  • Doctor PhibesD Doctor Phibes

                    @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                    By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                    As implausible-but-true facts go, it's right up there with the English having ruled the world.

                    Your time is coming, McTwatface

                    jon-nycJ Offline
                    jon-nycJ Offline
                    jon-nyc
                    wrote on last edited by
                    #13

                    @Doctor-Phibes said in Sagan: Ancient Greeks showed the earth is round.:

                    @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                    By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                    As implausible-but-true facts go, it's right up there with the English having ruled the world.

                    Your time is coming, McTwatface

                    That’s MISTER McTwatface to you, pal.

                    "You never know what worse luck your bad luck has saved you from."
                    -Cormac McCarthy

                    1 Reply Last reply
                    • Doctor PhibesD Doctor Phibes

                      @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                      By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                      As implausible-but-true facts go, it's right up there with the English having ruled the world.

                      Your time is coming, McTwatface

                      brendaB Offline
                      brendaB Offline
                      brenda
                      wrote on last edited by
                      #14

                      @Doctor-Phibes said in Sagan: Ancient Greeks showed the earth is round.:

                      @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                      By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                      As implausible-but-true facts go, it's right up there with the English having ruled the world.

                      Your time is coming, McTwatface

                      That's Twaty McTwatface, sir.

                      Doctor PhibesD 1 Reply Last reply
                      • brendaB brenda

                        @Doctor-Phibes said in Sagan: Ancient Greeks showed the earth is round.:

                        @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                        By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                        As implausible-but-true facts go, it's right up there with the English having ruled the world.

                        Your time is coming, McTwatface

                        That's Twaty McTwatface, sir.

                        Doctor PhibesD Offline
                        Doctor PhibesD Offline
                        Doctor Phibes
                        wrote on last edited by
                        #15

                        @brenda said in Sagan: Ancient Greeks showed the earth is round.:

                        @Doctor-Phibes said in Sagan: Ancient Greeks showed the earth is round.:

                        @jon-nyc said in Sagan: Ancient Greeks showed the earth is round.:

                        By the way, do you guys know any greeks? Isn't it shocking that they used to be brilliant?
                        As implausible-but-true facts go, it's right up there with the English having ruled the world.

                        Your time is coming, McTwatface

                        That's Twaty McTwatface, sir.

                        I was trying not to be overly offensive. I know Jon’s a bit sensitive

                        I was only joking

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