Galileo: A Dialog Concerning Two Chief World Systems

12 Jan 2016
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12 Jan 2016
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The Earth, similar to the other planets, revolves about the sun

The model that the Earth similar to the other planets revolves around the sun allows simple and straightforward explanation of all observed phenomena and measurements. 

Proofs - PRO To Topic
Test Statements for Probability Testing
Refutations - CON To Topic
Proofs - PRO to Topic
Refutations - CON to Topic
Test Statements for Probability Testing

Related Topics

Earth revolving offers an explanation for visible phenomena
Overturned by special relativity
Angular Velocity
Other models also explain visible phenomena
Models are not reality
Occam's Razor is probabilistic
There is no proof that other planets orbit the sun
Not supported by experiment
Which experiments refute it?
The topic statement has been edited so this objection no longer pertinent to The topic statement
irrelevant to whether the Earth revolving offers an explanation of all observational measurements
What experiments give results that are inconsistent with the earth rotating?
Dayton C. Miller
George Airy
Implications of similarity
The topic statement needs to be revised to incorporate special relativity
There is evidence of change in the heavenly bodies
The heavenly bodies are unchanging and perfect, as opposed to Earth
Earth is unique from the rest of the universe
Earth cannot share motion similar to that of the heavenly bodies
Earth is filled with generation and corruption, unlike the heavenly bodies
The topic statement doesn't claim the model is true so your objection is moot
Only small parts of Earth change in the Aristotelian sense
As one cannot see evidence of change, the heavenly bodies haven't changed
Limited capability to perceive something does not make such a thing untrue
The Earth, similar to the other planets, revolves about the sun
Visible sunspots move and change
Supernovas show changes in the universe far from Earth
One would notice the Earth's movement
Motion is relative
The Earth's movement about the sun cannot account for the movement of the stars
The Earth rotates upon an axis
Day-night cycle varies over course of a year, especially near poles
Earth rotating resolves discrepancies and simplifies models of the universe
Objects that revolve have longer periods if they have larger orbits
If stars revolve around Earth, their velocities have changed dramatically
Overturned by special relativity
Incorrect execution and not reproducable
irrelevant to whether the Earth revolving offers an explanation of all observational measurements
Overturned by special relativity

Earth revolving offers an explanation for visible phenomena

Michelson-Morley was overturned by special relativity

It is claimed that as the Earth rotates at approximately 1000mph at the equator that this would be detectable by human senses. However, it is not the 1000mph velocity that human senses would be detecting, but the angular velocity. Id does not matter what size roundabout one constructs, an angular velocity equivalent to one revolution per day will not be detectable other than visually.

The Earth-centric model explains visible phenomena.

The sun and moon orbiting the Earth and all other objects orbiting the sun explains visible phenomena.

There may be other models that explain visible phenomena.

The only fully accurate representation of an object or a system is the object or system itself. A model can serve the purpose of providing a simple explanation of

A model can serve the purpose of providing a simple explanation of a known object or system.

A model can explain visible phenomena and enable predictions that can be supported or falsified by new observations. 

While a good model will be durable and its predictions verified, it is still not reality, it is only a model.

Occam's Razor is not a law, it is probabilistic. While it may be that the simplest explanation is LIKELY to be the truth, it may not be.

Some objects orbiting other objects  is simply a model. They are possible explanations of observable phenomena but are not reality. 

A statement that the Earth behaves like other, similar objects rests on the assumption that the behaviour of the other objects is understood.

Imagine a two body experiment where two observers on both objects asserted that their object was stationary and that the other object was revolving about them.

All observers observations could be explained by a model that showed:

- Object A stationary with object B orbiting it,

- Object B stationary with object A orbiting it, or

- Both objects orbiting around a central point, perhaps according to Newton's gravitational theory.

A model that explains observable phenomena is certainly useful but believing that the model is fact is false.

The Earth revolving upon its axis is a model that explains observable phenomena but is not supported by any experiment. In fact, some experiments refute it.

The model of the Earth orbiting the sun predicts parallax.

Some movement is observed in some stars but most stars do not display parallax.

Objects being too far away for their movement due to parallax being visible is conjecture, not proven fact.

Observed movement in objects that move is not consistent with the Earth orbiting the sun.

In short, the prediction of parallax derived from the model of the Earth orbiting the sun is not supported by observation.

The topic statement has been modified to state that the theory the earth similar to the other planets explains all observations simply, getting nothing wrong.

Attempts to define "reality" as different than a simple model that has been tested and makes all correct predictions are thus irrelevant.

Michelson-Morley interferometer experiments

Dayton C. Miller interferometer Experiments

George Airy's stellar aberration experiment

The statement that Earth orbits the sun. just like the other planets implies that the behaviour of the other planets is known.

The other planets revolving about the sun is part of the heliocentric model devised to explain observation, not provable fact, or reality.

Planets orbiting the sun is absolutely true by definition in terms of the heliocentric model, but is not proven fact, or reality outside of the model. Therefore, saying that the Earth orbits the sun, just like the other planets is simply a restatement of 'in the heliocentric model the Earth and the other planets orbit the sun'.

I think at the moment this statement is correctly rated not established. The statement needs to be modified to say something about special relativity else it is simply not true.

Day 2, Sagredo's summary of Day 1. "The [Aristotelian world system] holds the substance of the heavenly bodies to be ingenerable, incorruptible, inalterable, invariant, and in a word free from all mutations except those of situation, and accordingly to be a quintessence most different from our generable, corruptible, alterable bodies."

The topic statement doesn't claim the model is true so your objection is not relevant. The topic statement is tentatively established. The claim  "the model is true"could serve as another truthsift topic but it is not this one.

Overall, the nature of Earth tends more towards permanence than change. Salviati on the first day argues that while some aspects, such as living things, may change and transform, Earth has endured and appears that it will endure far longer, so perhaps it is not so different from the seemingly-unchanging heavens. "For let me ask the Peripatetic if, being of the opinion that celestial bodies are incorruptible and eternal, he believes that the terrestrial globe is not so, but corruptible and mortal, so that there will come a time when, the sun and moon and other stars continuing their existence and their operations, the earth will not be found in the universe but will be annihilated along with the rest of the elements, and I am certain that he would answer, No. Therefore generation and corruption belong to the parts and not to the whole; indeed, to very small and superficial parts which are insensible in comparison to the whole mass. "

Salviati's argument against Simplicio's statement that Earth has changed in ways that we haven't perceived on the moon, and thus the moon hasn't changed in those ways. Salviati argues that it is difficult to measure such changes. "Of the moon???s appearance, I find no more exact description than that some say it represents a human face; others, that it is like the muzzle of a lion; still others, that it is Cain with a bundle of thorns on his back. So to say "Heaven is inalterable, because neither in the moon nor in other celestial bodies are such alterations seen as are discovered upon the earth" has no power to prove anything."

The model that the Earth similar to the other planets revolves around the sun allows simple and straightforward explanation of all observed phenomena and measurements. 

Salviati argues that there is evidence that the heavenly bodies are not unchanging. "Now, getting back to the subject, I say that things which are being and have been discovered in the heavens in our own time are such that they can give entire satisfaction to all philosophers, because just such events as we have been calling generations and corruptions have been seen and are being seen in particular bodies and in the whole expanse of heaven. Excellent astronomers have observed many comets generated and dissipated in places above the lunar orbit, besides the two new stars of 1572 and 1604, which were indisputably beyond all the planets." The Webexhibits Museum which is the source of these translations appends a note to the dates mentioned in the above text adding that supernovas appeared in those years.
For example, if one dropped an object from a great tower, the object would fall to the west of the tower, as Earth would have turned from west to east in the time it took for the object to fall.

Sagredo and Salviati both give multiple arguments for the relativity of motion. Here is one of Sagredo's from day 2. "Suppose, then, that an artist had used this pen to draw on a piece of paper, starting when the ship left port and continuing until it reached Alexandretta. [...] As far as the artist was concerned, his drawing would have been exactly the same if the ship had never moved; and yet the only trace of the pen's very long journey would be those lines drawn on a sheet of paper. [...] In the same way, since the Earth is moving, the motion of the falling stone actually extends over several hundred or even several thousand braccia [...] . But that part of its motion which is common to the stone, the tower, and us is imperceptible to us, as if it did not exist; the only part of its motion which we can observe is the part in which neither we nor the tower participate, which is the stone's motion as it falls down the height of the tower." https://books.google.com/books?id=9-1whP_STloC&pg=PA288 

The distant stars appear to revolve around the Earth. If the earth revolved around the sun, the stars might appear to move a little, but they would not appear to be revolving around Earth.

On why areas closer to the poles have different day and night cycles compared to the equator:

"Next you may see how of all parallels, only the great circle CD is cut into equal parts by the boundary of light IM, the others above and below this all being cut into unequal parts. Of the upper ones, the semidiurnal arcs (which are those in the part of the earth lighted by the sun) are greater than the seminocturnal ones, which remain in the dark. The contrary happens for the remainder which are beneath the great circle CD toward the pole B; of these, the semidiurnal arcs are smaller than the seminocturnal. Also you may see quite plainly that the differences of these arcs go on increasing as the parallels become closer to the poles, until the parallel IK stays entirely in the lighted part, and its inhabitants have a twenty-four-hour day without night. In contrast to this the parallel LM, remaining all in the dark, has a night of twenty-four hours without day."

It's a little small, but here is the picture referred to: http://www.webexhibits.org/calendars/imagesFolder/dartmouth/7.3.fig6.gif 

If the stars are very distant from Earth and revolve around Earth or a point near to it, they would have a very slow orbit. Kepler had shown this for the planets in his third law, "The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit," and one didn't have to trust Kepler to verify this, as the periods of the motion of the planets were well known. "This order is such that the greater orbits complete their revolutions in longer times, and the lesser in shorter; thus Saturn, describing a greater circle than the other planets, completes it in thirty years; Jupiter revolves in its smaller one in twelve years, Mars in two; the moon covers its much smaller circle in a single month. And we see no less sensibly that of the satellites of Jupiter (stelle, Medicee), the closest one to that planet makes its revolution in a very short time, that is in about forty-two hours, the next, in three and a half days; the third in seven days and the most distant in sixteen. And this very harmonious trend will not be a bit altered if the earth is made to move on itself in twenty-four hours. But if the earth is desired to remain motionless, it is necessary, after passing from the brief period of the moon to the other consecutively larger ones, and ultimately to that of Mars in two years, and the greater one of Jupiter in twelve, and from this to the still larger one of Saturn, whose period is thirty years?it is necessary, I say, to pass on beyond to another incomparably larger sphere, and make this one finish an entire revolution in twenty-four hours. "
Some stars have visibly changed their position over hundreds and thousands of years. Thus, some stars that were near the equator in the past have moved towards the poles. Now they rotate a lesser distance then when they were at the equator. "Not only will the size of the circles and consequently the velocities of motion of these stars be very diverse from the orbits and motions of some others, but (and this shall be the fifth difficulty) the same stars will keep changing their circles and their velocities, since those which two thousand years ago were on the celestial equator, and which consequently described great circles with their motion, are found in our time to be many degrees distant, and must be made slower in motion and reduced to moving in smaller circles. Indeed, it is not impossible that a time will come when some of the stars which in the past have always been moving will be reduced, by reaching the pole, to holding fast, and then after that time will start moving once more; whereas all those stars which certainly do move describe, as I said, very large circles In their orbits and are unchangeably preserved in them."

Michelson-Morley was overturned by special relativity

The experiments of Dayton C. Miller where criticized for incorrect execution and could not be reproduced, even involivng newer laser measurements, etc.

irrelevant to whether the Earth revolving offers an explanation of all observational measurements

Michelson-Morley was overturned by special relativity