Announcement

Collapse
No announcement yet.

Antikythera mechanism, 2000 year old machine?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by Bented View Post
    Most technology from the year 2021 would confuse the pants off of anyone in the year 0021.
    If someone in 0020 found a smartphone manufactured in 2020 how would they describe it?
    Magic, I'm quite certain. There is a fitting quote from Arthur C. Clarke for that one: "Any sufficiently advanced technology is indistinguishable from magic."

    Comment


    • #17
      Originally posted by Corbettprime View Post
      In order to make this mechanism, and cut the gears accurately, some type of lathe and milling mechanism would have been required. In addition, I would say the craftsman involved could be considered one of the first MACHINISTS in the world.
      NADA see clickspring
      The shortest distance between two points is a circle of infinite diameter.

      Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

      Southwestern Ontario. Canada

      Comment


      • #18
        Originally posted by eKretz View Post

        Magic, I'm quite certain. There is a fitting quote from Arthur C. Clarke for that one: "Any sufficiently advanced technology is indistinguishable from magic."
        lol ain't it the truth --- and don't forget "witchcraft" and "deviltry" also two honorable mentions...

        one that could get you burned at the stake and the other that could provide the fire to do it...

        Comment


        • #19
          Originally posted by mklotz View Post

          It's perfectly possible to manually mark out and file satisfactory gears - especially so where the gears are only used for positioning and not for power transmission.
          Considering the mathematics involved alone, could someone explain how to lay out the diameter and spacing on the gear, without knowing the value on Pi? Has there been any evidence of files that small and precise ever been found? What other method of forming gear teeth could have been used? In order to make a file, you need a chisel. For both those, you need steel, and the knowledge of how to heat treat it. How would you lay out the spacing for each of the different diameters involved. I'm not not from Missoui, but SHOW ME! The old Greeks were quite proficient at mathematics, but I would like to know how they made those gears,

          Comment


          • #20
            Originally posted by Corbettprime View Post

            Considering the mathematics involved alone, could someone explain how to lay out the diameter and spacing on the gear, without knowing the value on Pi? Has there been any evidence of files that small and precise ever been found? What other method of forming gear teeth could have been used? In order to make a file, you need a chisel. For both those, you need steel, and the knowledge of how to heat treat it. How would you lay out the spacing for each of the different diameters involved. I'm not not from Missoui, but SHOW ME! The old Greeks were quite proficient at mathematics, but I would like to know how they made those gears,
            We don't have proof of everything that once existed --- It's like me asking you show me all that was lost in the great fire of Alexandria and many more examples --- you can't - so you do not really know what once was...

            Comment


            • #21
              As luck would have it, I came across this article today.

              https://nationalpost.com/news/scient...than-a-century
              Location: Saskatoon, Saskatchewan, Canada

              Comment


              • #22
                Originally posted by Arcane View Post
                As luck would have it, I came across this article today.

                https://nationalpost.com/news/scient...than-a-century
                All I can say is that the thing is outdated --- literally and figuratively as it was built when people (the Geeks) thought that everything revolved around the earth so as far as it keeping accurate track of the planets and the sun in relation to us ? --- yeah --- good luck with that --- it obviously missed the "prime mover" --- Galileo set everyone straight on that long after and made this thing look like a cheap alarm clock of some kind --- still very impressive for it's day but lets not get too carried away as it's not going to solve the national dept or anything like that, thanks for listening,,, AKB

                Comment


                • #23
                  Originally posted by Arcane View Post
                  As luck would have it, I came across this article today.

                  https://nationalpost.com/news/scient...than-a-century
                  Good article, but they did call for a lathe being used, also, noticed Clickspring also using a ruler with evenly spaced subdivisions of a standard unit of measurement.

                  Comment


                  • #24
                    Probably turn out to be an engineering equivalent of the Voynich manuscript

                    Comment


                    • #25
                      Originally posted by Bented View Post
                      Most technology from the year 2021 would confuse the pants off of anyone in the year 0021.
                      If someone in 0020 found a smartphone manufactured in 2020 how would they describe it?
                      This is proof that we were visited by aliens.
                      As Mr. Spock would say.......... fascinating !

                      JL.................

                      Comment


                      • #26
                        We have discussed such marking methods here. And it is marvelous what a skilled and DETERMINED person can accomplish with just hand tools. To say that a lathe and milling machine are required to make this mechanism is simply not true.

                        And I would not even include the exception for power transmission. The ancient water wheels used crude gears and they transmitted a significant amount of power. If anything must be excluded it would need to be high speeds and long operational life. Remember that it was the automotive industry that provided the incentive to develop the manufacture of some of the most precise gears. High speeds and long life!



                        Originally posted by mklotz View Post

                        It's perfectly possible to manually mark out and file satisfactory gears - especially so where the gears are only used for positioning and not for power transmission.
                        Last edited by Paul Alciatore; 03-14-2021, 12:22 AM.
                        Paul A.
                        SE Texas

                        And if you look REAL close at an analog signal,
                        You will find that it has discrete steps.

                        Comment


                        • #27
                          Originally posted by Corbettprime View Post
                          In order to make this mechanism, and cut the gears accurately, some type of lathe and milling mechanism would have been required....
                          Not so. There was a guy about 25 years ago who reproduced the mechanism with only tin snips, a compass and files. I believe that it was a Nova episode.

                          Comment


                          • #28
                            OK, a simple divider with two points can draw a circle. If you take the trouble to select an arbitrary unit of measure, it can also be used to step off the divisions on a ruler.

                            That same divider can be set to a good guess at the size of a gear tooth division on that circle that it drew. And you can step off the number of teeth you want with it. If it comes out even you have your divisions. If it does not come out even, you adjust the guess and step it off again. Repeat until it does.

                            A circular arc is a good approximation of an involute gear's shape. And circles are used for generating cycloidal gears shapes. And those dividers draw circular arcs so they can approximate the shape of a gear's teeth. A bit of math would be needed to find the radius to set the divider to, but there were good mathematicians in ancient times.

                            OK, we have stepped off and drawn the teeth on our first gear. We need a file or some kind of tool to shape the teeth. Abrasive methods first come to mind. Copper or bronze can make a lap that can be embedded with abrasive (sand). Several different ones would probably be needed for roughing and finishing but it is doable. And files can be made with primitive tools. Tools were made from bronze for a long time before steel or even cast iron was common. But small amounts of iron were available from sources like meteorites. Hardening was also worked out, but if you are using a brass alloy for your gears, then hardening of the steel could be less important and may have just been a byproduct of the forming process (heat, hammering, water cooling, etc.) A chisel? Come on man, chisels were one of the very first tools. They were used in both wood and stone work. Bronze was a common material for them and sharpening was done with abrasives, just like today (well, without the electric motor to drive the wheel).

                            So how do we layout the mating gear if we do not use pi? Well, the pitch diameters of two gears are directly proportional to the number of teeth so we only need to scale the pitch circle of the mating gear to that of the first gear that we just made. We were careful to preserve the diameter of that first gear on a scrap of metal or whatever so we use simple geometric methods to scale it whatever size we need for the mating gear. This can be done with a straight edge and compass. Pi is simply not needed.

                            Did I miss anything?

                            PS: They did have a fairly good value for pi. I don't know how far back it goes, but 22/7 (3.1428...) works for most practical things and, with a percentage of error of only 0.04%, it surely would have worked for those ancient mechanisms. Reality check: 0.04% error translates to an error of 0.0004" in a distance of one inch. Dividers can be good, but not that good.



                            Originally posted by Corbettprime View Post

                            Considering the mathematics involved alone, could someone explain how to lay out the diameter and spacing on the gear, without knowing the value on Pi? Has there been any evidence of files that small and precise ever been found? What other method of forming gear teeth could have been used? In order to make a file, you need a chisel. For both those, you need steel, and the knowledge of how to heat treat it. How would you lay out the spacing for each of the different diameters involved. I'm not not from Missoui, but SHOW ME! The old Greeks were quite proficient at mathematics, but I would like to know how they made those gears,
                            Last edited by Paul Alciatore; 03-14-2021, 01:29 AM.
                            Paul A.
                            SE Texas

                            And if you look REAL close at an analog signal,
                            You will find that it has discrete steps.

                            Comment


                            • #29
                              Originally posted by Corbettprime View Post
                              In order to make this mechanism, and cut the gears accurately, some type of lathe and milling mechanism would have been required. In addition, I would say the craftsman involved could be considered one of the first MACHINISTS in the world.
                              Thank You,
                              JR

                              Comment


                              • #30
                                While Clickspring hasn't- and can't, of course- proven that the mechanism absolutely could have been made with period tools, he has gone a long way towards showing it was certainly- perhaps even easily- possible.

                                The mechanism is/was almost certainly the work of a nation-state; that is, a king or emperor or caesar probably commissioned it. And as such it may have cost a considerable amount- in whatever passed for money at the time, in valuable raw materials, in probably-slave labor, care and housing of whoever was the primary inventor/engineer, etc. Basically, very likely today's equivalent to several million.

                                As above, you can do a lot if you throw enough money and manpower at the problem.

                                Doc.
                                Doc's Machine. (Probably not what you expect.)

                                Comment

                                Working...
                                X