A Geocentric theory is an astronomical theory which describes the universe as a Geocentric system, i.e., a system which puts the Earth in the center of the universe, and describes other objects from the point of view of the Earth. The Greek philosophers Aristotle and Plato described such a theory wherein all celestial bodies move on spheres around the earth, the moon on the innermost one and the fixed stars on the outermost one.
Ptolemy invented the most elaborated geocentric system, allowing the planets not only to move on circles around the earth, but using epicycles. By adding further ideas, he was able to predict the motion of the planets quite well. Ptolemy's model was extremely popular from ancient times until the 1600s, as it had better agreement with observation than any alternative. His model was particularly effective at cosmological predictions.
However, during the 1500s and 1600s, alternatives were proposed. The Danish astronomer Tycho Brahe made the most accurate observations possible before the invention of the telescope. These showed discrepancies within Ptolemy's system.
With the invention of the telescope, the observations became more precise, and new phenomena were discovered: In particular, Galileo's use of the telescope to look at the skies revealed that Jupiter had at least four moons, and Venus had phases like the Moon: both phenomena were not predicted by Ptolemy's model.
Johannes Kepler used Brahe's measurements to improve the heliocentric system Copernicus had proposed, showing that planets had elliptical orbits around the sun. When Isaac Newton applied the newly discovered universal theory of gravitation to the data, he used a heliocentric model. By the 1800s, the spectacular successes of Newtonian theory and Maxwell's equations for electromagnetism had convinced practically everyone that the Sun is a preferred frame of reference, and that the laws of physics must be applied in that frame. The geocentric theory was considered to be profoundly mistaken at that time.
Since the advent of relativity theory in the early 1900s, the laws of physics have been written in covariant equations, meaning that they are equally valid in any frame. Heliocentric and geocentric plotting systems are both used today, depending on which allows more convenient calculations.
Galileo never proved that Earth orbits the sun, and modern science acknowledges this. While most are aware that Galileo was forced to recant Heliocentrism by the Inquisition, a lesser-known fact is that he wrote a voluntarily recantation of his own accord, several years later.
Geocentrism and Newton's laws are not necessarily at odds with one another. Even granting that the barycenter of the Solar System is near the sun, it is theoretically possible, assuming a finite universe, for the barycenter of the universe to be centered on Earth. In this way, the entire universe can revolve around Earth, in accord with Newton's laws.
It is generally accepted that neither the Heliocentric nor Geocentric model can be proven or even distinguished merely by astronomical observations. It does seem, however, that a theory may be disproven by a combination of observations and application of physics principles. There does seem to be such an inconsistency within the Heliocentric model relating to the moon's phases. This easily observable astronomical display can be viewed and confirmed by nearly anyone on Earth. They do present a significant problem for the Heliocentric theory in that their duration is predictable and consistently equal throughout the orbit of the moon. Relativity theory states there is no such thing as "speed" because everything is in motion, so there is only relative speed or velocity. Since the sun and moon are the celestial bodies which create the moon's phases and Earth is where we observe them from, it is the relative velocity of these bodies we are concerned with. Heliocentric theory states the Earth orbits the sun at 67,000 MPH and the moon orbits the Earth at 2,288 MPH. Since an object traveling 2,288 MPH cannot overtake and orbit an object traveling 67,000 MPH, we know that the moon's velocity of 2,288 MPH is a relative velocity to Earth. That would make the actual velocity of the moon, or its velocity relative to the sun, 69,288 MPH. VAC=VAB+VBC
When these two bodies are traveling in the same direction, (full moon phase) like cars traveling the same direction on a highway, it's easy to conclude this is how we observe the relative velocity of the moon to be 2,288 MPH. The inconsistency comes when the moon inevitably must change direction during the course of its orbit relative to Earth's orbit. When the full moon and waning gibbous phases end and the moon turns and travels perpendicular to Earth's orbit (around the first quarter moon phase) consistent with relative motion theory, observers on Earth would no longer see a relative velocity of 2,288 MPH, but the actual speed of the moon, 69,288 MPH. (nearly 30X faster than the during the full moon phase) When the moon must turn again to travel in a direction opposite Earth's orbit (new moon phase) observers on Earth would view a relative velocity of (Earth 67,000 MPH) + (moon 69,288 MPH) = 136,288 MPH or nearly 60X FASTER than the full moon phase. As the two pass each other, the moon changes direction again, and thus, its relative velocity changes for observers on Earth back to 69,288 MPH as it enters the last quarter moon phase. Once again it is traveling perpendicular to Earth's orbit. It finally completes its orbit by returning to the full moon phase, and, traveling in generally the same direction as the Earth, gives observers a relative velocity of 2,288 MPH again. The problem with the Heliocentric model is there is no way the moon can exhibit all its phases for the same amount of time while its relative velocity to Earth changes exponentially throughout its orbit. This has never been explained or even addressed by the Heliocentric scientific community.
Scripture Quoted to justify Geocentric Theory
A few Bible quotes use geocentric terms. While secularists and evolutionists attempt to use these quotes to discredit the Bible's hold on science, others dispute this usage, claiming that the usage of the terms is similar to the way people today use terms like "sunrise" and "sunset". In this account, the terminology is not wrong, but merely reflects the observer's view.
- "He has fixed the earth firm, immovable." (1 Chronicles 16:30)
- "Thou hast fixed the earth immovable and firm ..." (Psalm 93:1)
- "Thou didst fix the earth on its foundation so that it never can be shaken." (Psalm 104:5)
- "...who made the earth and fashioned it, and himself fixed it fast..." (Isaiah 45:18)
- "The sun also ariseth, and the sun goeth down, and hasteth to his place where he arose." (Ecclesiastes 1:5)
- "Then spake Joshua to the LORD in the day when the LORD delivered up the Amorites before the children of Israel, and he said in the sight of Israel, Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ajalon. And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hasted not to go down about a whole day." (Joshua 10, 12-13)
- The Accuracy of Galileo's Observations and the Search for Stellar Parallax.
- Le Opere Di Galileo Galilei.
- Faulkner, Danny R. (August 1, 2001). Geocentrism and Creation. Answers in Genesis. Retrieved November 22, 2016.