You really need to work on saying what you mean rather than something quite different. You’re causing a lot of confusion. For example when you say “it is possible to notice that you are in a rotating frame”, that causes immense confusion.
And has this ever been observed to be other than c?
Yeah, my apologies. I liberally use imprecise language, especially when talking about physics to non-specialists.
Yup! Here are a couple examples:
They seem to be treating those as anomalies in need of explanation rather than anticipated consequences of relativity.
The anomaly is due to the unknown mechanisms by which the different frames move about to produce the superluminal motions. When these mechanisms are known, the superluminal motion are indeed anticipated consequences of relativity. By the way, this mechanism is now known.
There are more direct evidence of the coordinate speed of light changing, but it’s a bit more technical, which is everytime gravitational redshift were detected. This is because gravitational redshift means that frequency changes. As frequency is 1/time, this means time changes. The coordinate velocity of light is ~(space traveled)/time. So everytime “time” changes, the coordinate velocity also changes.
Actually, on the topic of faster than light motion, wikipedia has a bunch of examples in this page: Faster-than-light - Wikipedia
What is this mechanism? What does “different frames move about” mean?
This just means how to geometrically arrange all the blob, geometry, viewing angle etc in the system to produce the particular frames necessary to produce the superluminal motion.
It’s famous enough to have it’s own wikipedia page now! Superluminal motion - Wikipedia
You can read all the details there.
Blob? You may know what you’re saying, but I certainly don’t. And I still can’t tell what “different frames move about” means either.
The idea here is a galaxy launches a blob of plasma that emits light. From the frame of reference of the Earth, this blob seems to move much faster than c. Of course the blob, in its frame of reference, does not move faster than c, and crucially, no information is transported faster than light in either the blob’s frame or Earth’s frame.
This is analogous to your Alpha-Centauri moving faster than c as seen from a guy that rotates in place. In its own frame of reference, Alpha-Cent does not move faster than c, and no information is transported faster than light in either frames.
I have to go now, so I won’t be able to respond immediately anymore. Thank you for the discussion!
I think you are missing the point. In terms of translation and speed, there is no privileged frame. However, in terms of rotation, there is a privileged frame. We can distinguish between a rotating and non-rotating frame.
Just a quick clarification - I really do have to go. We can distinguish between rotating frame and non-rotating frame due to all the extra forces (e.g. coriolis) that is associated with rotation.
However, a person can claim that these forces are a priori there (i.e. the laws of motion is not simply F=ma, but F=ma+rotational forces), and that they are actually at rest. Epistemologically, I cannot say why that person is wrong.
And again, these are all anachronistic statements. Back in Galileo’s time, there are no force laws. As such, whether objects move this way or that in both Galilean or Tychonic models are both postulated axiomatically.
You will get a real response soon. Your writings are always thoughtful, even when I don’t agree with them. But at the moment, I only have enough time to post a minor correction: my “label”: Frantic Unitarian.
I did not invent the description “Frantic Unitarian”; that was Joshua’s sense of humor. I leave it there as a point of humility.
I look forward to re-reading the details of your posting.
Firstly, I was hoping to spare you the “aggro” from the latter part of this thread.
Back at BioLogos, you and I have already discussed Galileo. And before that we discussed Bruno. And I had to “submit to the superior logic” deployed on poor Bruno’s demise.
Technically speaking, Bruno had a lot of opinions, but he didn’t really have much more than anecdotal evidence. And so that was a problem. But the clincher was not really being able to “read minds” via the charges against Bruno. Secretly, down deep, who knows? Maybe one of the Archbishops really didn’t like the discussion of other worlds. And so I had to hang my head a little… and just watch Bruno “burn for being a heretic” … rather than for being a martyr to science.
But the facts are not the same for Galileo. And while he might have been quite the irritating fellow, I don’t think @PdotdQ has succeeded in confirming one of his earlier assertions, that Galileo was being non-scientific, or emotional, because he couldn’t prove his case.
And that’s when I was goaded into joining this grim thread. I apologize for me, and on @PdotdQ’s behalf as well, that the gyrations within this thread have been at times tedious.
I would certainly never challenge an Astrophysicist (as indicated in PdotdQ’s profile) to say to him that he was insufficiently grounded in the questions at hand. But this didn’t prevent him from grandly deciding (and saying) that I don’t have the history chops to discuss the issues with him.
This is when I had to point out that every time I had to check one of his outrageous statements, I had to play “catch up” to see if what you threw-down on the discussion table made sense in view of the background material I could locate on short notice.
In the link @PdotdQ provides, he gives this summation:
I thought this was a pretty unfair assessment. @PdotdQ makes it sound like Galileo was just “making stuff up”.
How do I mean this?
A. As PDQ says himself, instrumentation to detect parallax wasn’t made possible until the 1800s!
“The first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61 Cygni using a heliometer.[6]”
Who knows how long it might have taken if Galileo hadn’t begun his work to improve telescopes for astronomical purposes?
B. As for “one of the theories has a hole” in it, presumably meaning that Galileo mis-calculated the distance between the Earth and the Sun. But Tycho would go on to make his own analysis, and used the conservative premise that the parallax was just small enough to not be noticeable and produced measurements from the sun from there. So rather than a hole in the parallax, the hole that disturbed people was that the stars would be quite massive… much larger than the Earth’s sun. And this point was rejected by geocentrists. On scientific grounds? Hardly.
It seems to be obvious that Galileo continued to press on improving measurements and equipment and observations to continue to gather evidence supporting heliocentrism. This, my good sirs, is the fundamental nature of science.
@PdotdQ presents Galileo like he was Bruno … making stuff as he goes along… with no real science to back him up and so forth.
And what are the Geocentrists doing IN CONTRAST to the purportedly amateur rantings of Galileo? They continued to distance themselves from
Well, one of the things they were doing was finishing the disposal of the old Ptolemaic models! And it was because of what Galileo had uncovered.
Nine years after the death of Galileo, Giovanni Battista Riccioli wrote a seminal work, the New Almagest, which included a very long analysis of the motion of the Earth and/or the Sun!:
To Riccioli the question was not between the geocentric world system of Ptolemy and the heliocentric world system of Copernicus, for the telescope had unseated the Ptolemaic system; it was between the geo-heliocentric world system developed by Tycho Brahe in the 1570s [[29]]
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Nine years a
A substantial portion of the New Almagest (Book 9, consisting of 343 pages) is devoted to an analysis of the world system question: Is the universe geocentric or heliocentric? Does the Earth move or is it immobile? . . .
(Giovanni Battista Riccioli - Wikipedia) in his opinion apparently superseding even Galileo’s Dialogue Concerning the Two Chief World Systems — Ptolemaic and Copernican. Indeed, one writer has recently described Book 9 as “the book Galileo was supposed to write”.[[28]]
[[Too bad that Galileo was compelled to disavow all his belief in heliocentrism!]]
(Giovanni Battista Riccioli - Wikipedia) Within Book 9 Riccioli discusses 126 arguments concerning Earth’s motion—49 for and 77 against.
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Since Copernicus was the first to publish heliocentrism, there’s never been any question about what Galileo’s role was: he was the first to use a telescope to study the night sky, and he used the telescope to produce mathematical and observational evidence that Copernicus was right and that Geocentrism was wrong.
Since the Church defended Tycho’s blend of Geo-Heliocentrism well into the 1800’s, expecting Galileo’s work to be uniformly convince all the world that Heliocentrism alone was correct is just plain “pie in the sky”.
However, the fact that even the Jesuits had to reject Geocentrism and move to Tycho’s theories demonstrates that Galileo’s work was real science, and not just the passionate rantings of a man who had luck on his side:
**"The Aristotelian physics of the time (modern Newtonian physics was still a century away) offered no physical explanation for the motion of a massive body like Earth, whereas it could easily explain the motion of heavenly bodies by postulating that they were made of a different sort substance called aether that moved naturally. So Tycho said that the Copernican system "… expertly and completely circumvents all that is superfluous or discordant in the system of Ptolemy. On no point does it offend the principle of mathematics. **
Yet . . . Tycho took issue with the vast distances to the stars that Aristarchus and Copernicus had assumed in order to explain the lack of any visible parallax. Tycho had measured the apparent sizes of stars (now known to be illusory – see stellar magnitude), and used geometry to calculate that in order to both have those apparent sizes and be as far away as heliocentrism required, stars would have to be huge (much larger than the sun; the size of Earth’s orbit or larger).
The Jesuit astronomers in Rome were at first unreceptive to Tycho’s system [combining features of both Geocentrism and Heliocentrism]… [the Jesuit…] Clavius, commented that Tycho was “confusing all of astronomy, because he wants to have Mars lower than the Sun.”
However, after [Galileo’s use…] of the telescope showed problems with some geocentric models (by demonstrating that Venus circles the Sun, for example), the Tychonic system and variations on that system became popular among geocentrists…"
Maybe it would help if I took some of the focus off of Galileo for a posting or two. Instead of putting one man on the spot regarding a Cosmology that took 2 centuries to really find its foundation, let’s just look at what the Catholic Church said about Heliocentrism - - until the Holy Mother Church regained its sanity:
""These discoveries were not consistent with the Ptolemeic model of the Solar System. As the Jesuit astronomers confirmed Galileo’s observations, the Jesuits moved toward Tycho’s teachings.
In February 1615, prominent Dominicans including Thomaso Caccini and Niccolò Lorini brought Galileo’s writings on heliocentrism to the attention of the Inquisition, because they appeared to violate Holy Scripture and the decrees of the Council of Trent. Cardinal and Inquisitor Robert Bellarmine was called upon to adjudicate, and wrote in April that treating heliocentrism as a real phenomenon would be “a very dangerous thing,” irritating philosophers and theologians, and harming “the Holy Faith by rendering Holy Scripture as false.”
In January 1616 Msgr. Francesco Ingoli addressed an essay to Galileo disputing the Copernican system. Galileo later stated that he believed this essay to have been instrumental in the ban against Copernicanism that followed in February. According to Maurice Finocchiaro, Ingoli had probably been commissioned by the Inquisition to write an expert opinion on the controversy, and the essay provided the “chief direct basis” for the ban.
In February 1616, the Inquisition assembled a committee of theologians, known as qualifiers, who delivered their unanimous report condemning heliocentrism as “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture.” The Inquisition also determined that the Earth’s motion “receives the same judgement in philosophy and … in regard to theological truth it is at least erroneous in faith.”
Bellarmine personally ordered Galileo to abstain completely from teaching or defending this doctrine and opinion or from discussing it… to abandon completely… the opinion that the sun stands still at the center of the world and the earth moves, and henceforth not to hold, teach, or defend it in any way whatever, either orally or in writing."
— Bellarmine and the Inquisition’s injunction against Galileo, 1616
In March, after the Inquisition’s injunction against Galileo, the papal Master of the Sacred Palace, Congregation of the Index, and Pope banned all books and letters advocating the Copernican system, which they called “the false Pythagorean doctrine, altogether contrary to Holy Scripture” …[ the ] publication remained forbidden until 1758.
Meanwhile, the Catholic Church remained opposed to heliocentrism as a literal description, but this did not by any means imply opposition to all astronomy; indeed, it needed observational data to maintain its calendar. In support of this effort it allowed the cathedrals themselves to be used as solar observatories called meridiane; i.e., they were turned into “reverse sundials”, or gigantic pinhole cameras, where the Sun’s image was projected from a hole in a window in the cathedral’s lantern onto a meridian line.
In 1664, Pope Alexander VII published his Index Librorum Prohibitorum Alexandri VII Pontificis Maximi jussu editus (Index of Prohibited Books, published by order of Alexander VII, P.M.) which included all previous condemnations of heliocentric books.
In the mid-eighteenth century the Catholic Church’s opposition began to fade. An annotated copy of Newton’s Principia was published in 1742 by Fathers le Seur and Jacquier of the Franciscan Minims, two Catholic mathematicians, with a preface stating that the author’s work assumed heliocentrism and could not be explained without the theory. In 1758 the Catholic Church dropped the general prohibition of books advocating heliocentrism from the Index of Forbidden Books.
In spite of dropping its active resistance to heliocentrism, the Catholic Church did not lift the prohibition of uncensored versions of Copernicus’s De Revolutionibus or Galileo’s Dialogue. The affair was revived in 1820, when the Master of the Sacred Palace (the Catholic Church’s chief censor), Filippo Anfossi, refused to license a book by a Catholic canon, Giuseppe Settele, because it openly treated heliocentrism as a physical fact."