A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Universe of the ancient Greeks.
From: Bill B
Date: 2006 Mar 4, 17:40 -0500
From: Bill B
Date: 2006 Mar 4, 17:40 -0500
George wrote: "Bill, it depends on what you mean by "obvious". Try to put yourself in their position." Yes George, hoisted on my own petard there. While I was careful to mention the Rube Goldberg models were bizarre by current thinking, I was indeed guilty of regurgitating the word "obvious" from the former post. Exactly the mindset that inhibits original thought.
Good call. My point was that Aristarchus of Samos was able to think outside the box, and came up with an elegant working model. That model was bizarre for its time as it ignored the "givens" from that and preceding periods. (Unfortunately when we see farther by standing on the shoulders of giants, our perspective is altered by the very act of standing there.) In a broader sense, any argument is only as valid at the premises. If we are tied to a false premise (or giant), the argument is prone to failure. While he was not aware of Newtonian dynamics, observation lead him to a conclusion that became obvious to him, although not supportable by physics at that time. What unknown force(s) was at work keeping the celestial bodies from flying off onto space, likewise earthbound objects, was not know then. To his credit, he did not appear to explain it away using gods or God, angels etc. as movers. The model simply accurately predicted the movements of celestial bodies. As a sidebar, I often wonder why Galileo (other than ego), when freed to write anything by his Pope friend as long as it was understood to be "fiction" chose to attack the hand that freed him. He could just as easily written a book on heliocentricity by stating up front that everyone knew that God made earth the center of the universe, pay that "truth" some lip service; but then state that for the practical purpose of determining movement of heavenly bodies, a simplistic heliocentric MODEL was useful for mortals, and then explain the *model* in detail. In Sumner's case, coincidence caused him for one brief moment to see outside of the box. That box being, "Every good sailor knows his latitude. Combine Ho with latitude and declination and time, and you get longitude." End of story until then. Sumner had good reason at time of his discovery to question the premise, "Every good sailor knows his latitude." Looking back, all the knowledge needed for a celestial LOP was there. (Unlike Aristarchus of Samos, who would have to wait for Kepler, Newton, et al to prove or disprove his thinking.) In the northern hemisphere with a southern declination, a body will rise later at a given longitude the farther north you go. So to get the same Ho as you move north, your longitude must move east for a rising body. Therefore you can have the same Ho anywhere along that path. The question became, "What is that path?" Thinking along the lines of current boxes, I was talking to a Purdue physics friend about the implications of the speed of light not being a constant, but rather a slowly-changing variable. He noted the failure of unification theory, plus that, put a real wrinkle in current models. What new (untestable) theory came along to bridge the gap/fill the void? String theory. Which as a layman seems like it would have the Pythagoreans smiling and chiding, "We told you so, armonia, harmony." How far has man really come in 4,000 years? Heaven is still up, hell is still down. In the colonies these days, supporters of "Intelligent Design" (literal creationism) want that theory taught alongside evolution in the schools. The supporters claim intelligent design is scientific. But how does a scientific supporter reconcile science that dates modern man and the earth as more than days younger than the oldest objects in the universe? Simple, God created super-intelligent aliens in the beginning to take over populating the earth/designing modern man at a later date. How far have we come--really? Bill > Bill wrote, in a thread "Simple celestial navigation in 1897" > > | Currently working though the book Ken mentioned, Arthur Koestler's "The > | Sleepwalkers." (Not, *in my opinion* a light read--he gets you to the edge > | of your seat crying, "But what about" then casually drops it in at the last > | possible moment.) > | > | It did, and does not, come to me as a surprise that the obvious can be > | totally ignored for much longer than a century. In the first stages of > | Koestler's book we go from bizarre models of the solar system/universe (by > | current thinking), to functional models of the solar system (Aristarchus of > | Samos & Herakleides) but continued to ignore the obvious and kept trying to > | pound an elliptical peg into a round, or square, hole for over a 1000 years. > > ====================== > > Comment from George- > > Bill, it depends on what you mean by "obvious". Try to put yourself in their > position. > > It was widely recognised, by the Greeks, that the Earth was indeed spherical, > and approximately half > of it was inhabited. But it was quite obvious, to the Greeks (most of them, > but Aristarchus was an > honourable exception) that the Earth was NOT spinning around. It was stable > underfoot. If you threw > a stone vertically upwards, it came back down in the same place. There was not > a constant, powerful > wind blowing, as there would have been if the Earth's surface was travelling > so fast. Remember, they > had no reason to know that the atmosphere was finite, giving way to empty > space; there was no > concept of such empty space. And they had no notion of Newtonian dynamics. > > Ptolemy, in the early pages of his "Almagest", in about 200 AD, considers the > arguments for and > against motion of the Earth, and decides that indeed the Earth is stationary > at the centre of the > Universe. I doubt if many of us would have argued otherwise, if we had found > ourselves in the same > situation, in the same state of knowledge. > > Indeed, Copernicus laboured under many of the same handicaps that the Greeks > did, but had the vision > to set the counter-objections to one side, in favour of the simplicity of the > planetary motions that > resulted if motion of the Earth, around its axis and around a fixed Sun, was > contemplated. > > George. > > contact George Huxtable at email@example.com > or at +44 1865 820222 (from UK, 01865 820222) > or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.