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Galileo Galilei, Heliocentrism, Geocentrism and the Telescope


Written by Danielle

I have been studying about Galileo(1564-1642).

Who is he you might ask? He was an Italian scientist. You have probably heard that he invented the telescope. Well, he didnʼt. Galileo improved the telescope, but he is often given credit for inventing it. Hans Lippershey (1570-1619) was a Dutch optician and a lens maker who made the first telescope in 1608, which Galileo borrowed the idea, and improved upon it.

Galileo discovered many things about space, with his new telescope. One of them being a belief which made the Church very angry at the time, and Galileo was tried by the Inquisition.

Prior to these discoveries, Galileo had already abandoned the old Ptolemaic astronomy for the Copernican. But, as he confessed in a letter to Kepler in 1597, he had refrained from making himself its advocate, lest like Copernicus himself he should be overwhelmed with ridicule.”

I emailed Ed Babinski that works at Furman University, that has done a lot of writing on the subject of Heliocentrism and Geocentrism, and asked him exactly what it was that made the church so angry, and what it was that Galileo believed.

Galileoʼs telescopes may be obsolete today, but they aided him to discover four of Jupiterʼs moons.

Remembering the difference between Heliocentrism and Geocentrism:

Sun=Helios is Central

Earth=Geo is Central

The Face of Helios, the sun god on a coin from Rhodes dating from 200 BC.

Coin showing the son of Helios as he drives his fatherʼs chariot, believed to be the Sun in Mythology.


From: “ed babinski”
To: Danielle
Sent: Tuesday, January 06, 2004
Subject: Itʼs Danielle —- questions (please answer)

Dear Ed

Itʼs Danielle. I was wondering, did Galileo make the church angry by arguing against Heliocentrism ? or was it Geocentrism?

ED: The church taught that the earth was immovable, hence the name “geo” [for “earth”] centrism. Galileo was impressed by Copernicus, who argued that the sun was immovable, hence the name “helio” [for “sun”] centrism. Copernicus wrote a book that he only allowed to be published after he died, De Revolutionbus Orbium Cælestium (Concerning the Revolutions of the heavenly bodies). He argued that the sun stood still, not the earth.

DANIELLE: Didnʼt Galileo teach the earth went around the sun? Did the church teach that the sun and other things in space go around the earth?

ED: The church taught that the earth was the immovable center of Godʼs creation. (Geo-Centrism).

DANIELLE: Is it true that geo-centrism and helio-centrism are completely opposite beliefs? Right?

ED: Yes, opposites, though Gerardus Bouw is a modern day Biblical GEOcentrist with a Ph.D. in astronomy from Case Western Reserve and argues at his website that the difference between the two views has not been proven by science, because it could all merely be a matter of “perspective.”
Bouw is not the only geocentrist today. Heʼs Protestant, but there are Catholic geocentrists, and Jewish oneʼs as well.

A Better Way To Remember The Difference

The word Helios for Sun comes from Helios the sun god

Helios is the young Greek god of the sun. He is the son of Hyperion and Theia. By the Oceanid Perse, he became the father of Aeétes, Circe, and Pasiphae. His other two daughters are Phaethusa (“radiant”) and Lampetia (“shining”). He had a son, named Phaeton, whom he once allowed to guide his chariot across the sky. The unskilled youth could not control the horses and fell towards his death. Each morning at dawn he rises from the ocean in the east and rides in his chariot, pulled by for horses - Pyrois, Eos, Aethon and Phlegon — through the sky, to descend at night in the west. He sees and knows all, and was called upon by witnesses. The reverence of the sun as a god came from the east to Greece. Helios was worshipped in various places of the Peloponnesos, but especially on Rhodes, where each year gymnastic games were held in his honor. Rhodos was also where the Colossus of Rhodes (the sixth the seven wonders of the ancient world) was built in his honor. This huge statue, measuring 32 meters (100ft), was built in 280 BCE by Charès of Lindos. In the earthquake of 224-223 BCE the statue broke off at the knees. On other places where he was worshiped, there were herds dedicated to him, such as on the island of Thrinacia (occasionally equated with Sicily). Here the companions of Odysseus helped themselves with the sacred animals. People sacrificed oxen, rams, goats, and white horses to Helios. He was represented as a youth with a halo, standing in a chariot, occasionally with a billowing cloak. A metope from the temple of Athena in the Hellenistic Ilium represents him thus. He is also shown on much more recent reliefs, concerning the worship of Mithra, such as in the Mithraeum under the St. Prisca at Rome. In early Christian art, Christ is sometimes represented as Helios, such as in a mosaic in Mausoleum M or in the necropolis beneath the St. Peter in Rome. His attributes are the whip and the globe, and his sacred animals were the cock and the eagle.

Source: Excerpts from Funk and Wagnalls Encyclopedia, 1950
In 1609 Galileo learned that a telescope had been invented, and he soon built and improved telescopes for astronomical use… he observed mountainous configurations of the moon, the phases of Venus, Jupiterʼs satellites, and the existence of sunspots. He also discovered that the moon shines with reflected sunlight, and that the Milky Way is made up of countless stars. His investigations with the telescope were rewarded in 1610 with an appointment as Professor at the University of Florence and as philosopher and mathematician extraordinary to the grand duke of Tuscany.
Galileo had accepted the Copernican theory of the solar system for some time, but not until his astronomical discoveries gave concrete and visible confirmation of the theory did he take a decided position in its favor, in his Letters on the Solar Spots (1613). The Copernican view of the Solar system, which contradicted the prevailing theory that the earth is fixed and is the center about which the universe revolves, roused theological opposition, and Galileo was admonished by Pope Paul V to relinquish the heretical proposition that the sun is the center of the universe. Galileo promised to obey the Pope, and continued his work in astronomy. In 1630, however, he wrote Dialogue on the Two Chief Systems of the World, in which the Copernican system was brilliantly expounded and defended. This work was condemned by the theologians and its sale was forbidden. Galileo was summoned before the Inquisition at Rome in 1633 and forced to recant his belief that the earth moves around the sun. The legend that Galileo whispered “but it does move”, as he rose from his knees after the renunciation of his views, is probably apocryphal. Galileo spent the remaining eight years of his life working in strict seclusion in Florence… His last telescopic discovery, the moonʼs librations, was made in 1637; later in the same year he became totally blind. … his [Galileoʼs] most substantial contribution was his work in what later became the science of mechanics. Although he did not clearly formulate the relation of force and motion into definite laws, his work implied a knowledge and recognition of the laws of motion as later stated by Newton.

Not all of Galileoʼs experiments were successful. He constructed a water thermometer which was extremely inaccurate. He correctly surmised that air had weight, but made a crude and inaccurate attempt to weigh it… Even these experiments, however, were valuable, for they led the way for other scientists to supply correct solutions for these problems.

Who Invented the Telescope?

Source: Catholic Encyclopedia
Hearing early in 1609 that a Dutch optician, named Lippershey, had produced an instrument by which the apparent size of remote objects was magnified, Galileo at once realized the principle by which such a result could alone be attained, and, after a single night devoted to consideration of the laws of refraction, he succeeded in constructing a telescope which magnified three times, its magnifying power being soon increased to thirty-two. This instrument being provided and turned towards the heavens, the discoveries, which have made Galileo famous, were bound at once to follow, though undoubtedly he was quick to grasp their full significance. The moon was shown not to be, as the old astronomy taught, a smooth and perfect sphere, of different nature to the earth, but to possess hills and valleys and other features resembling those of our own globe. The planet Jupiter was found to have satellites, thus displaying a solar system in miniature, and supporting the doctrine of Copernicus.

Source: Funk and Wagnalls Encyclopedia, 1950 edition

“Telescope: essentially a lens or mirror to form an image of a distant object, together with a microscope to enable the observer to examine this image in detail, or a photographic camera or some form of spectroscopic apparatus.
The invention of the telescope was doubtless accomplished in Holland, but there is some confusion and controversy to be encountered in attempting to determine the original inventor. It seems certain that the instrument was known more or less about Europe, but the honor of its invention is usually given to Galileo, who was the first to describe it and exhibit it in a complete form (May, 1609). To Kepler we owe the discovery of the principle of the astronomical telescope with two convex lenses. This idea was actually employed in a telescope constructed by Father Scheiner (Rosa Ursina, 1630).
The invention of the achromatic object glass by Dolland in 1757-58 and the improvement of optical flint glass, which commenced in 1754, soon made possible the construction of improved telescopes. The discovery of methods of making large disks of flint glass was made by Guinand, a Swiss mechanic, who then became associated with Fraunhofer, and telescopes as large as 10 inches aperture were readily made. His successors made instruments with object glasses 15 inches across.

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