The 'phases of Venus' do not prove Copernicanism. An oft cited tale that is invalid.
Part of the Galileo myth, which ignores other models and their explanations which are scientifically and mathematically as valid as Copernicanism.
“…Einstein’s theories reveal they may actually slightly favour an Earth- centred model,” and that the only advantage of Copernican theory is it “is more easily falsifiable than Ptolemy’s,” (Kitty Ferguson)
Definitions
Epicycle: Ancient Greek meaning ‘on the circle’, or a circle moving on another circle. This was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets. In particular it explained the apparent retrograde motion of the five planets known at the time.
Deferent: An epicycle is the motion of a planet within a small circle, which in turn moves along a larger circle called a deferent. Both circles rotate clockwise and are roughly parallel to the plane of the Sun's orbit (ecliptic).
Myths
One of the more popular, if apocryphal ‘proof’s of Copernicanism, is the ‘phases of Venus’ argument, first put forward by the irascible, self-promoting Galileo who disbelieved in the veracity of comets, and whose proof of Copernicanism rested on tidal flows. The myth of Galileo and his purported struggle for ‘science’ against an ignorant, unknowing and corrupt Church is dealt with here. Almost none of what is taught about the Galileo ‘travesty’ is valid.
A charge forwarded by the Copernicans was that that Ptolemy’s geo-centric model could not account for the phases of Venus. This is not true. It does not infer that Ptolemy’s model was correct, but it also does not mean that the Copernican model is valid.
Few have examined Galileo’s claims about the phases of Venus with critical scrutiny. The ‘phases of Venus’ argument is more complicated than textbooks present. Science writer and physicist Kitty Ferguson summarises the Galilean argument:
“It was this line of reasoning that Galileo used in 1610, when he studied the planet Venus through his telescope….In the Ptolemaic system, with Venus always between the Earth and the Sun – traveling on an epicycle on a deferent with the Earth as its center – an observer on Earth would never see the face of Venus anywhere near fully illuminated”.2
This then was the crux of the issue. However as given below, the ancients did see Venus lit up in its entirety, its brightness likened to that of the Sun’s.
Where did Venus come from?
Venus, especially in the ancient world, was known as a very bright star. It is often referred to as the ‘morning star’. According to almost every human culture, Venus arrived suddenly, around 1500 BC, in a period known for cataclysmic terrestrial and geological change; and this is why it was worshipped as a goddess. Venus was never worshipped before 1500 BC and this fact is a puzzle for astronomers, historians and anthropologists.
Today Venus is far less ‘bright’ than in the ancient past. It was associated with Lucifer the fallen angel and its brightness was likened to the Sun. Why was this?
Could Venus, pace the Velikovsky heresy (covered in the next 2 posts), have been a new comet or star arriving in splendour, its light dazzling due to its immature and reflective atmosphere? Is this why 95% of Venus is Co2, the demonised and loathed plant food equivalent on Earth, which comprises 4 parts per million in our atmosphere? Is Venus thus constituted because it is new? An excellent compendium of cultural anthropology related to Venus can be read in the hated heretic Velikovsky’s best seller, ‘World’s in Collisions’ reviewed here.
No one knows. But cultural anthropology is clear that Venus was a brilliant star and much brighter in the ancient world, than today. Its surface was lit up and observable.
The ancient Greeks were convinced that Venus was born from the head of Jupiter or Zeus. Maybe Venus was created by an impact on Jupiter, or maybe it entered our solar system and passed by Jupiter and Mars. Most cultures discuss Mars ‘fighting’ with Venus as well. This is never discussed by the ‘science’, though the author notes that Einstein, or more accurately, Einstotle, died with an open copy of Velikovsky’s ‘Worlds in Collison’ on his desk.
The animus
The Venus moon-phase story was used in the 19th century to take a hammer to the Church and claim that Christianity was ‘anti-science’. This is odd considering that Galileo was Catholic and funded by the Church. In one of the worst books of anti-science propaganda ever issued, Andrew White, in A History of the Warfare of Science with Theology in Christendom, piles absurdity on top of apocrypha to falsify his claim that Galileo had ‘proven’ Copernicanism. He proved no such thing:
“Ten years after the martyrdom of Bruno the truth of Copernicus’s doctrine was established by the telescope of Galileo. Herein was fulfilled one of the most touching of prophecies. Years before the opponents of Copernicus had said to him, ‘If your doctrines were true, Venus would show phases like the moon.’ Copernicus answered: ‘You are right; I know not what to say; but God is good and will in time find an answer to this objection.’ The God-given answer came when, in 1611, the rude telescope of Galileo showed the phases of Venus”.3
Copernicus’ early model was incorrect in many ways. It relied on circular orbits, not elliptical, and upon Aristotle’s crystalline spheres to keep planets in their orbits. It was Kepler the conniver, not Galileo, who corrected this. Copernicus’ model also employed almost double the epicycles of Ptolemy’s model, including complicated ‘epicyclets’ to explain retrograde motions. Copernicus’ model was not simpler, nor more ‘correct’ than that of Ptolemy’s.
The propaganda
In most science textbooks or online fora, the drawings used to illustrate the truism of heliocentricity as it attempts to explain the phases of Venus, are not to scale and incorrect. The distances and size of orbits in their drawings do not reflect the actual distances and orbits.4 This is rather vital.
Without accurate scales the diagrams prove nothing, except perhaps a bias against Ptolemy. Ptolemy, of course, had the same problem, but he did not know the actual distance to the Sun or Venus (or at least the purported distance we use today, which is unsupported by Euclidean calculations). This means that for Ptolemy’s description of Venus’ orbit, an epicycle is placed between the Sun and the Earth rather than outside the Sun. This gives the appearance that Venus will never have different phases.
False claims
Using the same logic, modern heliocentrists often accuse Ptolemy of having the moon come too close to the Earth, and thereby appeal to this lopsided orbit as convincing evidence to discredit his system. For example, Stephen Hawking asserts the following:
“Ptolemy’s model provided a fairly accurate system for predicting the positions of heavenly bodies in the sky. But in order to predict these positions correctly, Ptolemy had to make an assumption that the moon followed a path that sometimes brought it twice as close to the earth as at other times. And that meant that the moon ought sometimes to appear twice as big as at other times! Ptolemy recognized this flaw, but nevertheless his model was generally, although not universally accepted. It was adopted by the Christian church as the picture of the universe that was in accordance with scripture, for it had the great advantage that it left lots of room outside the sphere of fixed stars for heaven and hell”.5
The above claim is typical of the absurdity that passes for ‘The Science’.
Hawking, or whoever wrote his books, made the above remarks without noting that Ptolemy’s model was neither absolute in its distances nor ever adjusted to make it correct. The writer, whether Hawking or the group behind him, additionally implies that the Catholic Church knew of Ptolemy’s alleged error yet had an ulterior motive for insisting that his model be preserved. In reality, Ptolemy’s model could be adjusted, it was adjusted, and it did show similar accuracy as the heliocentric model.
Copernican accuracy?
Before Kepler’s improvements to the heliocentric model, Copernicus’ system was no more accurate than Ptolemy’s, and Copernicus used more epicycles than Ptolemy. As Copernicus’ model was improved over time, so were the results of calculations to track the orbits of the planets. The same kind of corrections could have been made to the Ptolemaic model to improve its accuracy, including corrections to account for the phases of Venus. There is an equivalency in mathematics and processes which are usually disregarded.
For example, the distance to the Moon, and the phases of Venus could have been made as prominent and precise as they appear in the improved Keplerian model if, instead of Ptolemy’s circles:
(a) the planetary orbits are made into elliptical paths around the Sun;
(b) the Sun’s orbit around the Earth is made a deferent and the epicycle’s radius is made equal to the actual scalar distance between the sun and planet;
(c) the Sun’s motion is placed in one epicycle and the planets’ epicycles are centred on the Sun;
(d) the Earth is lined up with respect to the stars rather than with respect to the Sun.
All four solutions would make the paths cycloidal with respect to the Earth and all will account for the phases of Venus. Option (c) is essentially the model proposed by Tycho Brahe. As astronomer Gerardus Bouw notes:
“Even astronomers and historians who should know better claim that Galileo’s discovery that Venus exhibits moon-like phases disproved the Ptolemaic model. All that Galileo’s observations actually meant insofar as the Ptolemaic model was concerned, was that the radii of the epicycles were much larger than had previously been suspected; and all that Kepler’s elliptical orbits meant to the Ptolemaic model was that two of the epicycles could be combined into one ellipse”.6
For Galileo and early Copernicans, the phases of Venus, and the supposedly great distances involved in the travels of Venus in the sky, intimated that Venus must orbit the Sun, and therefore, the Earth would follow suit. Neither conclusion was proven of course.
Ellipticals
Ptolemy and his successors did contemplate adding elliptical orbits to the model.
“A glance at the orbit of Mercury in the Ptolemaic system…shows a similar egg-shaped curve staring into one’s face” (Koestler The Sleepwalkers, pp. 80-81).
In 1080, the Spanish-Muslim astronomer Al-Zarqali (aka Arzachel) became quite famous for his Toledan Tables, the forerunner of the Alfonsine Tables (published in 1252 A.D.), of planetary positions. Originally written in Arabic, only two Latin translations have survived. Along with his six astrolabes, the Toledan Tables reveal Al-Zarqali was aware of the improvements available to the Ptolemaic system by means of elliptical orbits, but at this time in history, deference to the perfect circle which was based on Aristotle’s description of the cosmos, was simply too strong to be overcome.
The preference to support Aristotelian cosmology over the more complicated heliocentric model, was always a complaint of the ‘Enlighteners’, with their ‘Dark Age’ propaganda, men with little understanding of history, who conveniently forgot that the telescope, an invention which took some 200 years to manufacture with enough quality to observe stellar details, was entirely a school-men phenomenon and was unavailable to the ancients.
However, the Ptolemaic system did explain the phases of Venus and could be modified to save the phenomena.
a. The Ptolemaic theory left six free parameters that had to be fixed by guesswork.
b. No violence was done to the essentials of the Ptolemaic theory by fixing these in such a way that the deferents of Mercury and Venus were taken equal to the Earth-Sun distance and the deferents of the superior planets to their actual distances from the Sun.
c. This means that the geometrical arrangement of the Copernican system (when treated as here in the zero-eccentricity approximation) is exactly reproduced, the only difference being that in one system the earth is at rest, in the other the Sun.
d. This in fact is the system which Tycho Brahe proposed. As far as astronomical observations are concerned, the Tychonic system, which is a special case of the Ptolemaic one, is kinematically identical to Copernicus’s except in its relation to the distant stars.7
In other words, the phases of Venus are not proof for the heliocentric system.
Bottom Line
The phases of Venus don’t prove heliocentricity. The fact that Ptolemy did not know the distances between planets was compensated by the fact that his system incorporated six variables to account for such unknown quantities, thus making his model very pliable to what would actually be observed in the future. These parameters are common in modern software code, when you are trying to future-proof a program.
In reality, Copernicus was influenced by many non-scientific factors, and he chose not to make those adjustments. As a committed Platonic-Pythagorean Sun worshipper, Copernicus did not want to amend Ptolemy’s model to fit the observations. As astronomer Ivan King understood it:
“In a single phrase, the God-centered outlook of the Middle Ages had been replaced by the man-centered outlook of the renaissance. The change had flowed over every aspect of human activity”.8
Copernicanism is a philosophical choice not a scientific fact. It might be right, it might be wrong. It is just a theory.
All hail.
Sources
1 Kitty Ferguson, Measuring the Universe, 1999, p. 106.
2 Kitty Ferguson, Measuring the Universe, 1999, p. 106.
3 Andrew White, A History of the Warfare of Science with Theology in Christendom, 1907, p. 130.
4 Ferguson, Ibid., pp. 92-93.
5 Stephen Hawking and Leonard Mlodinow, A Briefer History of Time, 2005, pp. 9-10.
6 Gerardus Bouw, Geocentricity, 1992, pp. 309-310.
7 Julian B. Barbour, Absolute or Relative Motion, Vol. 1, The Discovery of Dynamics, Cambridge University Press, 1989, pp. 224-225, italics his.
8 Ivan R. King, The Universe Unfolding, 1976, p. 126.
You wrote: " though the author notes that Einstein, or more accurately, Einstotle, died with an open copy of Velikovsky’s ‘Worlds in Collison’ on his desk." Where is the source for that? Looking at his sad face all these years I often wondered if he actually believed the plagiarized, speculative, never tested, nonsense that made him a "genius". Just imagine if all the idiots in the world proclaim you as such. It would be intolerable. It would be like being King Midas.