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The truth about Galileo and his conflict with the Catholic Church
Today virtually every child grows up learning that the earth orbits the sun.
But four centuries ago, the idea of a heliocentric solar system was so controversial that the Catholic Church classified it as a heresy, and warned the Italian astronomer Galileo Galilei to abandon it.
Many people believe that Galileo was hounded by the church for almost two decades, that he openly maintained a belief in heliocentrism, and that he was only spared torture and death because his powerful friends intervened on his behalf. But an examination of the fine details of Galileo’s conflict with church leaders doesn’t bear that out, according to English department distinguished research professor Henry Kelly.
In an article published this month in the journal “Church History,” Kelly clarifies some popularly held notions around Galileo’s travails with the church.
“We can only guess at what he really believed,” said Kelly, who for his research undertook a thorough examination of the judicial procedure used by the church in its investigation of Galileo. “Galileo was clearly stretching the truth when he maintained at his trial in 1633 that after 1616 he had never considered heliocentrism to be possible. Admitting otherwise would have increased the penance he was given, but would not have endangered his life, since he agreed to renounce the heresy — and in fact it would have spared him even the threat of torture.”
This year marks the 400th anniversary of the beginning of the Catholic Church’s investigation into Galileo.
(Score: 2) by AthanasiusKircher on Wednesday February 13 2019, @03:31AM (7 children)
You're replying to a troll, but the AC is correct at least in the idea that one could choose whatever frame of reference one wants as a "center." Heliocentrism strictly isn't completely correct as the solar system actually all moves roughly around the center of mass that includes all planets and other bodies as well as the sun. But the contributions of the smaller planets (like earth) are so tiny that they don't matter much. A body like Jupiter on the other hand is significant enough to screw with earth's orbit quite a bit.
Point is that one could choose to model the solar system with earth at the center and all the physics works out in the equations -- no need to turn the universe into solid rock or anything like that.
The thing is, the math for simple models and first-order approximations works a heck of a lot better with the sun treated as "center." But that choice of a frame of reference is arbitrary, meaning there's no reason to say geocentrism(in that sense) is false... only in the sense that the math is ugly.
(Score: 2) by aristarchus on Wednesday February 13 2019, @04:01AM (6 children)
Ockham's Razor has a well known reality bias, and Reality has a well known liberal bias, and Liberals have a well known Heliocentric bias. But it is not just the math. Consider, posit that the Earth does not move. This means not only does the sun orbit the earth once a day, the rest of the Universe does as well. So as an exercise, calculate the velocity of a galaxy that lies, on a radius from the Earth, of 13 Billion light-years, and traverses that circumference in twenty four hours. Possible? Mathematically, perhaps.
(Score: 2) by AthanasiusKircher on Wednesday February 13 2019, @04:44AM (5 children)
Of course it's possible mathematically. It's just computation of apparent motion from the perspective of a given reference frame. In our reference frame, even using standard models of the universe, there are galaxies that are apparently moving apart faster than the speed of light. But that's because space is expanding fast enough between them to give them that apparent motion when viewed from an appropriate third reference point.
You still can't travel through space faster than the speed of light. But your choice of reference frame can easily make you see apparent speeds that are faster. So what? It's just a reference frame (though perhaps an inconvenient one for practical computational purposes).
(Score: 2) by AthanasiusKircher on Wednesday February 13 2019, @04:50AM (4 children)
(Oh, I should qualify all of that to say that obviously various relativistic effects won't be observed with such apparent motion compared to things actually in motion at speeds like that. I'm more asserting this reference frame business from a Newtonian perspective, which is more relevant when talking about comparisons for basic historical models of the solar system.)
(Score: 2) by aristarchus on Wednesday February 13 2019, @06:14AM (3 children)
Well, of course not, since it is physically impossible, unless Einstein was wrong that C is not an actual constant . . . are you seriously suggesting that? Sometimes apparent motion needs to be actual motion to be apparent, just saying. Are we in the same universe here? One that adheres to Cosmic Speed Limits?
(Score: 0) by Anonymous Coward on Wednesday February 13 2019, @06:18AM (1 child)
OMG! Athanasius is fighting aristarchus on cosmology! Do you think that is air you're breathing? His neural-kinectics are way over the line!
(Score: 0) by Anonymous Coward on Wednesday February 13 2019, @05:57PM
It is astronomy not cosmology. You need a better wizard, can't even load a proper dictionary.
(Score: 2) by AthanasiusKircher on Wednesday February 13 2019, @06:34PM
Given that this is what I said in my previous post: "You still can't travel through space faster than the speed of light. But your choice of reference frame can easily make you see apparent speeds that are faster," I hope you'll understand if I go with, "no, I'm not suggesting that, nor have I ever suggested that."
And, as I noted in my previous post as well, you don't need to choose a wacky thing like the earth as your reference frame to observe speeds greater than c. Galaxies are moving apart faster than c due to the expansion of the universe. So what? It doesn't violate Einstein because we understand that we're talking about something different (expansion of the universe) rather than normal travel through space. If you chose a rotating reference frame to model the universe, you'd have to take into account the assumptions you're making, and that will also involve apparent motion greater than c in some situations.
Nah, open your mind. We're talking about mathematical models here. There's no real "center" of the universe -- and if there is one, it's certainly not the Earth *or* the Sun, so this geocentric vs. heliocentric stuff is moot once you start talking about modeling things beyond the solar system.
One can choose a rotating reference frame in physics, and the math will work out. It's not a preferred frame, because it's non-inertial. You just need to assume centrifugal forces exist, etc., but that's because you chose a weird reference frame. You choose a reference frame and try to model the universe rotating around the earth? Yeah, it's gonna require even more contortions, but you could do it.
Your posts seem to presume there's some sort of absolute preferred reference frame somewhere. There isn't. (Pretty sure aether went out about a century ago.) Physics is just a computational model. Motion and forces observed will be dependent on your choice of reference frame.
It would be bloody stupid to try to choose the reference frame of a single person standing on the earth's surface as the center of the universe when trying to think about distant galaxies, because all the calculations would be a lot more complicated, but there's nothing inherently "wrong" with it. Certainly not more "wrong" than choosing the sun as the center of the universe and trying to calculate everything with respect to it (even though it's rotating as well as revolving around the center of the Milky Way, etc.).