Hello, was Heliocentrism adopted because it’s more “logical” or because it solves a problem?
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The problem with geocentrism is you can look at the planets, track their movements and those observations don’t fit a geocentric model. Additionally more discoveries have been made since the adoption of heliocentrism theory that do not fit in a geocentric model.
Geocentrism = everything revolves around the Earth. The earth is the center of the solar system = Wrong
Helocentrism = the sun is the center of the solar system, everything revolves around it.
Literally every modern concept of astronomy would be wildly different if the former were true. All math, plant spacing and star alignments/distances would be different. Gravity would be different. We actually go around the sun because of its immense mass and gravity. If the sun floated around us, the sun would have devoured the system or shot us out into space billions of years ago.
It was adopted because it was adhered more closely to observed reality. It was later replaced by Newtonian mechanics, again because it better matched actual observations. That, in turn, was replaced by General Relativity, once again because it was more true to observations than its predecessor. And whenever someone correctly elucidates quantum gravity, that will replace general relativity.
Physical theories are not adopted because of utilitarian reasons. They are adopted because experiments reveal that the theory is closer to reality than whatever it supplants. There are often many useful things that come about *because* of the new discovery, but the useful things are not the reason for the replacement – they are a consequence of it.
There were a few problems with geocentrism, though they were not major problems for common people. Primarily, the problem was that the planets – which at the time were simply thought of as wandering stars – would appear to dim and brighten randomly, and at times appear to move backwards through the sky. Accurately predicting their movement was an exercise in progressively more complex math. Heliocentrism reduced that all to a single, relatively simple equation.
And while heliocentrism itself doesn’t change much, the continued refinement of theory, observation and re-formulated theory has led to the entirety of the modern scientific revolution.
Because it fits reality? Not sure what this question even means.
Man think earth is center, other man come up with proof that earth cannot be center and that sun is center instead. So sun is center.
Mars looked like it stopped and went backwards in the sky before resuming going forward, called retrograde motion. This is something explained by the fact that earth passes mars while orbiting the sun. It looks like it’s going backwards but instead it’s just us passing Mars by in space
It had been known since Ancient Greek times that the planets didn’t simply travel in circles around the Earth. Instead, they were seen as travelling along “epicycles”, kind of like spirograph shapes. As more celestial bodies were discovered and more detailed measurements of their motion were taken (especially the measurements by Tycho Brahe and his team), these epicycle models became increasingly complicated. The original heliocentric model had the planets travelling in perfect circles around the Sun – this simply wasn’t accurate. But the same new measurements that were causing problems for the geocentric model led to an improved version of the heliocentric model in which the planets have elliptical orbits with the Sun at one of the foci. So now there were two equally accurate models, but one was straightforward and the other was wildly complicated and getting more so over time.
There were various secondary factors too. Observations of comets and of the phases of Venus clearly contradicted certain variants of the geocentric model. Not enough to be a death knell for the whole thing, but enough for various people to recognise that their particular understanding of the planets was wrong and start questioning their astronomical beliefs more broadly. And then the debate was essentially put to rest by Newton outlining a straightforward mechanism that explained why the planets would have elliptical orbits (this is the result you get if you have two bodies attracting each other with a force inversely proportional to the square of the distance between them).
The problem it solves is making the mathematics simpler.
Let’s say you’re a medieval astrologer. Or a mathematician employed by one. If you want to track the position of Jupiter, say, so you can predict whether a war will be successful, then:
* under the heliocentric model, the path follows (roughly) a circle. So does earth’s. And the earth spins, so there’s another circle. It’s easy enough to calculate with circles.
* under the geocentric model, these three circles get combined into one very complicated path. Kind of a circle, but modified by another circle, and then modified by yet another circle. If you had modern algebraic notation, the formula for the path would be very messy, but you don’t have modern algebraic notation; the path is described as a bunch of words, and the geometry is absolutely horribly messy and complicated.
A few centuries later, the maths is simpler still. Just one extremely simple formula, Newton’s gravitational formula, plus some fancy techniques from advanced (for the time) calculus, and every planet’s path can be tracked. But you’re no longer using a heliocentric model – the “centre” is a point *very close* to the centre of the sun, but slightly shifted towards Jupiter.
It would be *possible* to do the calculations from a geocentric perspective, [or any other perspective](https://xkcd.com/123/), but again, the maths is simplest if we use a not-quite-but-almost heliocentric model
When we arrive in the 20th and 21st centuries, we’ve learned that in a very real sense, every physical frame (geocentric, heliocentric, galacto-centric, the-bus–I-ju8st-missed-centric) is equally valid. However, some perspectives make the maths easier than others, and there are perspectives that make the maths ridiculously complicated. Also our gut feeling is still that simpler maths = *really* real.
The most obvious way to tell that planets don’t orbit the earth in any nice way is that they don’t move at a constant speed or direction on the background of stars from day to day. They sometimes move in retrograde from a geocentric point of view.
However, if you look at their positions relative to the sun, you’ll start to see nice patterns that can be explained with much simpler geometry.
Firstly you’ll notice that mercury and venus just oscillate back and forth, never having much angular separation from the sun. This should tell you that these two at least are obviously orbiting the sun. You can use some trigonometry to get their distance from the sun in AU, and you may be able to guess a simple relationship between orbital period and orbit radius using the period of these oscillations and the length of an Earth year – since mercury, venus, and earth all fit this relationship, you might guess that in fact, earth orbits the sun, not the other way around.
You may also fairly easily notice that the brightening of mars, combined with it’s retrograde motion, can be very easily explained by having it orbit the sun beyond earth, but close enough that these effects are significant. You’ll find that it too fits the same relationship between orbital period and distance to the sun.
You can then check Jupiter and Saturn, and find that they orbit a fair bit further out, but still fit the relationship.
The only exceptions you’ll notice are the stars, which seem to behave like a background, not obviously orbiting anything, the moon, which besides from clearly looking very different to the planets, does appears to actually orbit the Earth, and if you look closely (through a telescope), you’ll see the gallilean moons of jupiter, which very clearly orbit jupiter. You’ll also notice that the moons of jupiter fit the same relationship of distance to period relative to each other, but there are seemingly different constants involved when you look at things orbiting the sun, the earth, jupiter, etc.
To really wrap everything up into one single equation, which simultaneously explains the orbits of everything in the solar system AND why apples fall off trees onto the ground, you need a genius like Newton.
Newton basically found that there’s a single universal law for gravity which explains all of Kepler’s laws, gravity on Earth, and provides new relationships between them.
One of the issues with geocentrism that heliocentrism fixed was the existence of epicycles. When viewed from the surface of the Earth, the Moon and Sun have even and continuous motion across the sky. The planets however, have varible speed and often exhibit retrograde motion (where they move backwards through the sky). In a geocentric model one solution was the introduction of epicycles: instead of moving around Earth in rings, the planets orbit in rings-on-rings, like a theme park teacup ride. This motion is complex and proved difficult to explain- no one could come up with a better explanation that “God just likes it that way.” The heliocentrist model eliminated epicycles altogether because the planets are orbiting the Sun in nearly circular orbits, so the bizarre motion is the result of the difference with Earth’s orbit. The simpler planetary motion of the heliocentric model let us develop more comprehensive theories about the motion of bodies in general.
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