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Alternative galaxies - WAS Antikythera mechanism

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  • #61
    Originally posted by AD5MB View Post
    if antikythera comes into contact with kythera do you get a chemical reaction?
    No chemical reaction what-so-ever, but time does stand still so they were never allowed to touch - they could be played with in the same room and stuff but only under adult supervision...

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    • #62
      Originally posted by J Tiers View Post
      Why only ONE ever made?
      No one knows how many were made- we only know how many have beenfound.

      Since there's so much disagreement on what the device's actual function is, there is a chance that it didn't work right due to some fundamental flaw.

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      • #63
        Originally posted by CarlByrns View Post
        Since there's so much disagreement on what the device's actual function is, there is a chance that it didn't work right due to some fundamental flaw.
        There is no longer any real dissent over what the device's functions were. Enough secrets have been revealed at this point, the mechanism is now pretty well understood. It was used to predict lunar and solar eclipses (down to the hour, also denoting their color), to predict and visually show the position of the 5 known planets at that time revolving around the earth (as the ancient Greeks believed). It also related these events to the Olympic games held at the various Greek island states. As for accuracy, the device is very accurate, even in plotting the moon's extremely complex elliptical orbit along with the orbit of its orbit via two pinned gears on a slot spinning on two offset axes. Probably the most brilliant feature of the entire machine.

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        • #64
          The motion of the Moon is by far the most interesting part. If you plot the motion of the Moon and Earth around the Sun the Moon never circles the Earth. We live on one part of a binary planet system. The Moon and Earth circle the Sun together in nearly the same orbit. The reason it looks like the Moon circles the Earth is simply because the Earth's rotation is not locked to the Moon. The orbit of the Moon is entirely convex around the Sun. Modeling that mechanically is not simple, to say the least, especially considering the mathematical concepts and knowledge required. The device was not constructed by just a skilled machinist. It also involved a brilliant mathematician of the day. Someone like that should have been very well known in the social culture at that time. There should be some trace of written records.
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          • #65
            Originally posted by Machine View Post
            Really? So a person writing down his observations of birds flying is more brilliant than someone who designs and builds a flying airplane? And you do know that the ancient Greeks weren't living in the era of automatic transmissions, cucko clocks, personal computers and television? They were living in antiquity, long before any of the modern inventions and knowledge you were born into and now take for granted. Knowledge that seems "so easy" today, was yesterday's eternal conundrum. The Antikythera mechanism is an incredibly complex machine even for the standards of 1000+ years after its construction. Which themselves wouldn't have been built without the lost and found again legacy of ancient machines like this corroded lump of metal found on the sea floor.

            It's through the work of a million geniuses spanning thousands of years that we have what we have today. Make no mistake, inventing the technology we have today was not easy. What is easy is to look back on what they discovered with the benefit of a priori knowledge, dismiss their state of mind living within their own time, and conclude: "it's just gear ratios"
            So it is not a set of gears? I must have missed something.

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            • #66
              Originally posted by Abner View Post
              So it is not a set of gears? I must have missed something.
              Yes, it's your own Assumed Level of Knowledge, you haven't taken into account the rarity of gears of any kind at the time of this mechanism.

              It's like saying of the Wright Brothers' first test flights at Kitty Hawk "It's just aerodynamics"

              :-)
              If you benefit from the Dunning-Kruger Effect you may not even know it ;-)

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              • #67
                Originally posted by Evan View Post
                The device was not constructed by just a skilled machinist. It also involved a brilliant mathematician of the day. Someone like that should have been very well known in the social culture at that time. There should be some trace of written records.
                It's believed by many of the experts researching the mechanism that Posidonius - a Greek astrologer and philosopher - is the one behind the device...



                ...although others before him made it possible for him to build such a device (including Hipparchus and Archimedes himself). The evidence defining its age and likely origin supports that theory as well. It may have been built under his personal guidance while he was still alive, or it may have been built shortly after his death using his designs and mathematical legacy (although his death is recorded as 50 BC, right around the sinking of the ship carrying the mechanism).

                The Antikythera shipwreck sank around 70-50 BC, as determined by recovered amphoras and dated coins. The evidence found aboard the sunken ship also strongly suggests it came from Rhodes. The Roman orator and statesman Cicero visited Rhodes in 79 BC. From his own journal he describes a mysterious device he had seen during his visit:

                “…orrery recently constructed by our friend Posidonius, which at each revolution reproduces the same motions of the sun, the moon and the five planets that take place in the heavens every day and night. Would any single native doubt that this orrery was the work of a rational being?” {note: an "Orrery" is a mechanical model of the solar system, or of just the sun, earth, and moon, used to represent their relative positions and motions.}

                Pretty compelling - and amazing - evidence Posidonius might be our man. And since his name is similar to posi-traction, which also involves a planetary gearset, I just like him for that alone.

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                • #68
                  Originally posted by Abner View Post
                  So it is not a set of gears? I must have missed something.
                  Sure it is. And your computer is just a pile of sand and metal ore.

                  What have you invented lately? What have you brought to the table that no one else has in human history? If nothing of value - why?

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                  • #69
                    So it is not a set of gears? I must have missed something.
                    Yes, exactly as Machine said. Any skilled machinist could make one, even with simple tools. Design one? That is a very different story.
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                    • #70
                      Originally posted by Evan View Post
                      The motion of the Moon is by far the most interesting part. If you plot the motion of the Moon and Earth around the Sun the Moon never circles the Earth.
                      Are you telling us that the moon does not orbit the earth?

                      We live on one part of a binary planet system.
                      Very few astronomers would consider the earth and moon to be a binary planet system.

                      The Moon and Earth circle the Sun together in nearly the same orbit. The reason it looks like the Moon circles the Earth is simply because the Earth's rotation is not locked to the Moon. The orbit of the Moon is entirely convex around the Sun. Modeling that mechanically is not simple, to say the least, especially considering the mathematical concepts and knowledge required. The device was not constructed by just a skilled machinist. It also involved a brilliant mathematician of the day. Someone like that should have been very well known in the social culture at that time. There should be some trace of written records.
                      Modeling that motion is actually quite easy -- a bicycle wheel mounted horizontally on a merry-go-round does it nicely. (As kids, we had a "Spirograph" that could map out similar orbital motions on paper.)

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                      • #71
                        Of all the planets and moons in the solar system, Pluto and Charon are the two which resemble each other the most closely. They are almost the same size, and they are very close together. They are so close together that they orbit the center of mass between them, and the center of mass goes around the sun. Pluto and Charon are so close that they may even share an atmosphere. Molecules may be drawn off Pluto and turn to solids on the surface of Charon.

                        The only other planet and moon in the solar system which could be a double planet are the Earth and the Moon.
                        http://www.windows2universe.org/plut...ry_planet.html

                        "the center of mass goes around the sun" Exactly what happens with Earth and Moon. The barycenter is nearly outside the Earth (average a little over 0.7). The Moon used to be a lot closer and at that time it was a full binary system.
                        Last edited by Evan; 02-05-2017, 12:59 PM.
                        Free software for calculating bolt circles and similar: Click Here

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                        • #72
                          Originally posted by Evan View Post
                          http://www.windows2universe.org/plut...ry_planet.html

                          The only other planet and moon in the solar system which could be a double planet are the Earth and the Moon.
                          The International Astronomical Union (IAU) isn't on board with that.

                          "the center of mass goes around the sun" Exactly what happens with Earth and Moon. The barycenter is outside the Earth.
                          The Earth-Moon barycenter is well within the earth.

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                          • #73
                            Yes, I have modified my response. I was also thinking of the null gravity point. That is well outside the Earth.
                            Last edited by Evan; 02-05-2017, 01:05 PM.
                            Free software for calculating bolt circles and similar: Click Here

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                            • #74
                              Originally posted by Evan View Post

                              "the center of mass goes around the sun" Exactly what happens with Earth and Moon. The barycenter is nearly outside the Earth (average a little over 0.7). The Moon used to be a lot closer and at that time it was a full binary system.
                              The International Astronomical Union (IAU) does not consider the Earth-Moon system to be a binary planet system, however, there are two common proposals for the definition of a binary system:

                              Proposal 1. The center of mass (barycenter) lies outside both bodies. The Earth-Moon system fails this as the barycenter is located within the Earth.

                              Proposal 2. The mass ratio of the objects is close to 1:1. The Earth-Moon system fails this as the ratio is about 81:1.

                              The fact that the Moon used to be closer is irrelevant, and it doesn't alter the failure to meet the criteria of either proposed definition.

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                              • #75
                                In terms of the orbits it still works like a binary planet. Just look at a plot of the orbits. As I said, the Moon's orbit is fully convex. Also, if the Moon were a separate body it would be considered a full planet.

                                There is plenty of disagreement in the astronomical community including on the definition of Pluto. I have been following astronomy all my life.
                                Last edited by Evan; 02-05-2017, 04:02 PM.
                                Free software for calculating bolt circles and similar: Click Here

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