Förstår inte varför du hakade upp dig på att jag sa att de trodde att jorden var platt på den tiden. Det har ingenting med att göra med vad vi diskuterade från första början, så jag tänker inte spendera tid på det.
Nu, till diskussionen om heliocentrism och geocentrism.
En väldigt bra förklaring till varför man trodde på geocentrismen och ett väldigt bra bevis för heliocentrismen:
The logical proof for the geocentric system was: "Hey. Look outside. Does it look like we're moving? If I let go this apple, does it fly off sideways or does it simply fall at my feet? Wake up! Earth is not moving!"
And as long as it could not be shown that Earth really moved, there was not other "logical" proof. It is what is known as "common sense".
The earliest known proof that Earth really moves is called "aberration of light". But before we get there, we had to find out that light does not get somehwere instantaneously. Light takes time to get somewhere (also not clear with "common sense").
It has been known since the late 16th century, that the speed of light is not infinite. Light took more time to cover longer distances than short distances.
Predictions of phenomena involving Jupiter's satellites had to be corrected for the distance from Jupiter to Earth. When Jupiter was on the other side of the sun (not exactly in conunction, when it is lost in the glare, but a month before or after), the events were always late on the calculated predictions.
When Jupiter was at its closest to Earth, the events were earlier than predicted.
This showed that Jupiter was in orbit around the Sun. It did not prove that Earth was in orbit around the Sun. Maybe Jupiter (and other planets) were going around the Sun, and the Sun was in orbit around a fixed Earth.
It was clear that the difference in distance (the diameter of the Earth's orbit around the Sun OR of the Sun's orbit around Earth) corresponded to 1000 seconds in light-distance. Because the distance itself was not known with great accuracy at the time, meant that astronomers only had a rough idea of the speed of light.
But (this is the important part): they knew that it was fixed and not infinite.
In 1725, James Bradley (Astronomer Royal in UK) noticed a yearly cycle of change in the apparent position of fixed stars. He had hoped that he had discovered parallax (giving a way to measure distances to stars) but he found that all stars were affected.
Finally, astronomers understood that it was the light "coming down" from above, that appeared to be shifted in one direction as Earth moved in that direction.
Same as rain falling when there is no wind; it falls vertically. However, if you travel through such rain in a fast car, the rain will appear to come from in front, instead of appearing vertical. Stop the car, the rain is vertical again. Drive off in another direction and the rain appears slanted from that new direction.
So, as Earth moves around the Sun, the light appears to "fall" from a slight angle. You have to tilt the telescope (really!) by a little more than 20" -- that is, 1/180 of a degree -- in the direction that the Earth moves. For a small amateur telescope, you can't tell. But for the major telescopes (like at Greenwich in England), one could tell the difference. Even back in the mid 1700s.
In fact, it had been reported earlier (Flamsteed 1689) but no one wanted to believe the explanation at the time.
The angle is small because (as we now know), Earth speed of 29.8 km/s is very small compared to the speed of light 300,000 km/s.
Of course, before accepting this explanation, astronomers checked everything else (including the accuracy of all the telescopes involved in the tests).
So, aberration of light shows that the Earth is moving through space and that its direction changes constantly, so that it follows a circle (almost) that is repeated every year.
The speed is known (roughly) from the amount of tilt and the direction is known by the direction of the tilt. Astronomers could tell that the circle (actually, they already knew it was an ellipse, not a circle) was centred on the Sun.
Conclusion, the Earth is in orbit around the Sun.
We already knew that Jupiter was in orbit around the Sun (from the correction that had to be made to its satellite events) and Kepler's calculations showed that planetary positions were much easier to predict if they were considered in orbit around the Sun.
Newton had already given us his theory of gravity (1687). Knowing our speed around the Sun and the (approximate) size of our orbit, astronomers were able to calculate the mass of the Sun. It was... ahem... astronomical.
It then became clear that a "puny" planet like Earth could not hold, in its gravitational grasp, a Sun that was more than 330,000 times more massive.
The Sun was far more massive than anything else in the solar system. Logically (based on the theory of gravitation), the largest mass of a system must be closer to the barycentre of the system.
(We now know that the Sun contains over 90% of the entire mass of the whole solar system).
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PS: At the time of Galileo's trial (well before Newton's theory), the Church's position, that the Earth, not the Sun, was at the centre, was based on the logical fact that the Sun, being made of fire, had to be very light while Earth was known to be very heavy. It was logical that the heavier of the two body be the centre.
That is why one had to wait for the determination of the Sun's mass (using Newton's theory) for the shift in logical conclusion.
http://en.wikipedia.org/wiki/Aberration_… http://en.wikipedia.org/wiki/List_of_sol… Faktum är att när man ska beräkna omloppsbanor och dyl. med hjälp av GEOCENTRISMEN blir det väldigt fel. När Galileo skulle beräkna Jupiter och dess månars omloppsbanor från en
vinkel så blev deras banor väldigt komplexa och ologiska. Av det så började han tänka på att planeterna kretsade kring solen, precis som månarna gör kring planeterna. Dock så var teorin ny och hade vissa brister, brister som inte finns idag men som fortfarande finns hos geocentriska teorier.
Det var också då kyrkan hotade med hårda straff (inkl. dödsstraff) mot folk som gick emot deras tro, dvs tron på den geocentriska världsbilden. Det var DÅ man blev hjärntvättad av något som inte stöddes av någon förklaring alls, inte IDAG.
bevis för det där. Det enda som stödjer det där är religion, att Gud skapade jorden att vara universums centrum. Följer man fysikens grundlagar och gravitation så är det hur ologiskt som helst.
