When looking at the comparisons between the geocentric theory vs heliocentric theory concepts, we find that there are two very different ways to look at the universe. In the geocentric theory, the Earth is essentially the center of the universe. The sun and other planets rotate around the Earth, giving us our day and night. In the heliocentric theory, the Earth rotates around the sun and this is a mechanism that is found throughout the rest of the universe.
The geocentric theory was developed in the early centuries of our BC modern calendar. For more than 1,000 years, it would dominate scientific thinking until astronomers and scientists could offer “proof” of the validity of the heliocentric theory. Today the idea that the Earth orbits the sun is what is generally accepted by the scientific community.
What Is the Scientific Evidence of the Geocentric Theory?
When people asked for scientific evidence that showed the geocentric theory was the correct model of the universe, there were three general key points that were made.
- The Earth had to be the center of the universe (or at least the Solar System) because all things fall to the surface of the planet. This included objects that originated in space.
- The motion of the stars, moon, sun, and the planets of our solar system could be explained by the perfect circles in the geocentric models of Ptolemy.
- People are unable to feel the Earth move, which meant that the rest of the universe was likely moving around the planet instead.
The reason why these three key points remained scientific facts for more than 1,000 years was because there was no observed parallax of the stars. Those who supported geocentric theory stated that if no observed parallax was possible, then it discredited the validity of heliocentric theory. This was despite of the fact that critics of geocentric theory have existed since at least 200 BC when Aristarchus proposed that the Earth had to rotate around the sun due to the sheer size of the sun itself.
Ptolemy, about 4 centuries after Aristarchus, recognized that it would become necessary for the geocentric theory to be able to explain the motion of the heavenly bodies in a logical, scientific way. One of the methods that was used to solve the problem of orbits that were not pure circles was to include what he called “retrograde loops.”
This would help to explain why sometimes planets appeared to be moving “backward” in relation to an observer’s position on Earth. His terms of retrograde and prograde are still used today even though the heliocentric theory is considered to be proven and that planetary bodies have orbits that are more of an elliptical shape than a perfect circle.
It is an effect that occurs because when we look at the sky from our planet, the sun, moon, and stars appear to travel in a westerly direction. This is referred to as diurnal motion. Yet when a satellite orbits the planet, it can appear to be traveling in an easterly direction even though it is orbiting in the same direction as the sun, moon, and stars.
This effect occurs because the orbit of the satellite is faster than the rotation of the planet itself. There is one natural satellite, the moon Phobos for Mars, that offers a similar effect. Today we understand that the Earth rotates and this motion can be explained by the actual orbital effect of other satellites.
For those looking at geocentric theory, however, it was an ancient puzzle that would actually give us the word “planet.” The word comes from the Greek word for “wanderer.”
How Heliocentric Theory Was Proven to Be Correct
The initial concept of heliocentric theory placed the sun at the center of the universe. As we were able to peer deeper into space, however, we recognized that each star had the potential to be its own sun with planets that would orbit them. We saw that potential solar systems could orbit around their own central core. That galaxies could rotate around another center.
So the heliocentric theory applies throughout the entire universe. There is not necessarily a single center of the universe because it is continuing to expand, but several central points where orbits and rotation can be achieved.
It would not be until the 1500s when the mathematics of the heliocentric theory would be presented by Nicolaus Copernicus. Others, including Kepler and Galileo, would make observations that would support the Copernican Revolution in terms of Earth’s placement in the universe.
To counter the final argument that a parallax had not been observed, Friedrich Bessel proved that the parallax of a star was greater than 0 by measuring the parallax of star 61 Cygni in the mid-1800s. Vega and Alpha Centauri were also measured by Friedrich Struve the same year that Bessel provided his findings.
It would take a series of steps in the 1700s and 1800s for the heliocentric view to become widely accepted by the scientific community. The principle of relatively, for example, rules out the idea that our planet remains at a state of perpetual rest. Mach’s principle considers rest with respect to distant masses having special properties of velocity, which removes any centrism argument for either the sun or the Earth.
Is the Geocentric Theory Obsolete?
In the 1900s, Menachem Mendel Schneerson wrote that if the theory of relativity was being accepted as a scientific principle, then it would make the geocentric theory become obsolete. The theory of relativity encompasses the special and general relativity theories that were proposed by Albert Einstein.
Schneerson suggested that if two bodies in space are in motion that is relative to each other, then it would be impossible from a scientific standpoint to determine which object was rotating around the other. Not only would this idea then make the geocentric theory obsolete, but it would also make the heliocentric theory become obsolete as well.
This would be because it would be impossible to determine the stationary status of an object. Without at least some examination of this component, it would be an unscientific statement to say that Earth rotates around the sun or even that the sun rotates around the Earth. In some ways, it could even be argued that each planetary body rotates around each other, providing support to each orbital movement.
Some have suggested that not only is our solar system rotating around the sun, but that our sun is rotating around its own central nexus. This creates more movement through our universe than we even realize today. Several models have been suggested or offered to help explain or show how that movement could be taking place.
One of the most popular models places the solar system into the shape of a vortex instead of a relative circle. Could the heliocentric model be just as boring and incorrect to the vortex model as the geocentric theory was to the heliocentric theory so many years ago? Only time and additional observations and discoveries will help us to understand the full truth of our universe, solar system, and how we really live on this pale blue dot of ours.
What Geocentric Theory vs Heliocentric Theory Means Today
Because geocentric theory has been effectively disproven as a possibility for the state of the universe, it has become a term to refer to calculations that involve the Earth in some way. In such a system, the center-of-mass frame of the planet is therefore described as being geocentric, while a heliocentric frame is used to calculate velocity or angular momentum.
Using what we have discovered to be fact, we use heliocentric data today to be able to calculate the source of mechanical energy of a planet, asteroid, or other body in relation to how it moves around the sun. Smaller bodies can gain higher levels of heliocentric velocity because of the effects of gravity, while larger bodies, such as a planet, will have a heliocentric velocity that remains constant.
Through these measurements, if a constant velocity alters for some reason, it indicates that there has been a change in the mass of the body, the star it rotates around, or some other alteration has occurred within that solar system to affect its orbit.
The geocentric theory vs heliocentric theory debate may have been laid to rest more than a century ago and then confirmed with the discovery of other galaxies, but that doesn’t mean the ideas that were generated from such a debate have no meaning today. Ptolemy’s work, for example, to explain planetary movement helped us to refine our understanding of how real orbits operate.
As we take another trip around the sun, we’re experiencing heliocentric theory in its base form. Take a moment to appreciate that fact, even if something seems to be moving in the wrong direction when you look up into the sky.