[Pete Svarrior]

A theory eventually appearing incomplete is not the same as it being wrong.

I'm glad you were the one to say it. I assume you will now drop your criticisms about the exact relation between GR and UA being unknown.

[xenotolerance]

mmk

The exact relation is that they cannot both be true at the same time. It's pretty far from unknown.

and, flat Earth belief is not incomplete, strictly speaking; it is incorrect

[xasop]

Arrogant or not, what I wrote about assumptions is correct. Both of you are making the same error. A theory eventually appearing incomplete is not the same as it being wrong. GR doesn't have a ready explanation for the phenomena listed in Svarrior's link, and Newton's physics were phased out in pieces during the last two centuries because it couldn't deal with fields; at no point were the premises found to be faulty in either case.

That is simply not true, at least in the case of Newton. Newtonian physics predicts that gravity operates instantaneously across all space and that an object can go faster than light simply by accelerating for long enough, both of which are directly contradicted by relativity. That is, it makes incorrect predictions (if you accept relativity, and at least special relativity is not being contested here).

If a theory that makes incorrect predictions does not qualify as incorrect, then what is your metric for correctness?

Parsifal, when you write 'I could just as easily say that Newton's theory of gravity was "conjured out of the bunk aether" because he simply thought about what might cause a large ball to attract smaller objects towards it,' this is child's play. "No, you!"

Yes, I'm glad you noticed that the intent was to demonstrate the childishness of your post.

You're right that just saying UA is bunk doesn't discredit anything because it is indeed consistent with flat Earth belief, but that's not the entire argument I put forward, is it?

It was, unless you're counting your unfounded opinion that the Earth is round and therefore all astronomical observations must align with RET as an argument.

The exact relation is that they cannot both be true at the same time. It's pretty far from unknown.

You have yet to demonstrate that.

and, flat Earth belief is not incomplete, strictly speaking; it is incorrect

Yes, you've already told us that you think the Earth is round. There is no need to place a reminder in every post.

[AATW]

It was, unless you're counting your unfounded opinion that the Earth is round and therefore all astronomical observations must align with RET as an argument.

Amused at the idea that the concept of a round (by which I mean roughly spherical) earth is unfounded.

[xasop]

Amused at the idea that the concept of a round (by which I mean roughly spherical) earth is unfounded.

Your amusement also does not constitute an argument. Do the REers in this thread have any actual physics to present?

[AATW]

Amused at the idea that the concept of a round (by which I mean roughly spherical) earth is unfounded.

Your amusement also does not constitute an argument. Do the REers in this thread have any actual physics to present?

From experience Flat Earthers just run away when proof is presented but go on then. I posted this before and it got ignored. Experiments which demonstrate gravity working:

[StinkyOne]

Amused at the idea that the concept of a round (by which I mean roughly spherical) earth is unfounded.

Your amusement also does not constitute an argument. Do the REers in this thread have any actual physics to present?

Do you? You've posted SR, to which you've contributed nothing, and held it up as some sort of validation of UA. We all know Einstein did not believe in a flat Earth. As far as physics, let's stick with Einstein. GR predicts a massive rotating body will warp space around it. (Frame dragging) This has been experimentally confirmed by the LAGEOS satellites. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4946852/

Further, gravity waves have been detected by the LIGO experiment. 
https://www.ligo.caltech.edu/page/what-is-ligo

What experimental data do you have that shows the Earth is flat beyond some guy not understanding light refraction?

[JohnAdams1145]

Parsifal, your explanations of UA have enlightened me to how it works. From what I understand, UA explains the bulk of the force that we feel on Earth, while gravity contributes to the observed local variations.

However, if one admits that the experiments verifying gravity were not faked/manipulated and have been repeated several times, then what explains the unusally small gravitational force as predicted by UA? These experiments verified that, at least on a small scale, that the gravitational force is proportional to both masses and some constant. Of course, there's an easy way to explain this: not unlike Newtonian mechanics and its relationship with SR, the proportionality is merely a small-scale approximation of effect, and gravity is much less strong than predicted at large scales.

But this would entail completely rethinking the orbital dynamics of the various bodies interacting with one another. I admit I haven't done the calculations myself, but changing the gravitational force between objects orbiting in complicated systems should result in deviations from observed behavior. I guess by denying the given mass values of objects in space and positing new ones one could make everything work out, but then there's another problem: such mass values would be wildly inconsistent with the assertion that stars are big balls of gas with certain densities. So you would have to change the composition of the stars and fudge around with the Ideal Gas Law (maybe say it doesn't hold for high temperatures?) to really make this work. Then you would have to reconcile this with spectral evidence detailing exactly what gases are in the stars. It turns into something really bad.

I also don't see why we have to resort to this kind of physics to disprove Flat Earth. The geometry simply doesn't work out, as anyone can figure out by simply measuring a triangle on the Earth!

Here's an interesting (and fun) experiment to check that Earth isn't flat. You'll need an airplane and a very accurate compass. Head due West for 50 miles. Then head due North for 50 miles. Now turn to where you started (ensure that you won't miss!). Record the angle turned in your notebook. When you arrive where you started, record the angle from due West in your notebook. If you sum all of the angles in the triangle, they don't add up to 180 degrees 

In fact, they add up to more than 180 degrees, proving that the Earth has a curve to it (and not the weird one).


Now as for things that I haven't seen an FEer explain (and I apologize if it's on the Wiki; I've tried my best to read it):
The "shielding" aspect of UA -- what's the physical mechanism behind this and can this be quantified? Also wouldn't that planets/stars in space have halves that shield the other halves, yielding some interesting math? I presume that the math could eventually work out, unless some other Round Earther can prove it wrong to me.

https://en.wikipedia.org/wiki/Schuler_tuning. This is used in virtually all software written for inertial navigation systems. Without it, they would deviate drastically. Current inertial navigation systems are rather accurate (still pretty poor) and can be used on things like ballistic missiles. Why would inertial navigation systems include something that shouldn't exist per FE theory?

The Foucault Pendulum. I'm aware of the page on the Wiki. Dr. Samuel Birley Rowbotham clearly has no idea what he's talking about as numerous Foucault pendulums have been built with differing materials and many in climate-controlled environments. They all confirm one another. I've seen one in a museum. One cannot attribute this to simple environmental conditions. As for the second part, Mach's principle is misinterpreted. It's a general heuristic about making physical laws relating the stars to us -- by observing the motions of the stars, we can perhaps conclude something about our frame. You can see this in GR where the metric tensor (spacetime) is affected by matter. It says nothing about the stars' gravitational pull moving the Foucault pendulum (which would be totally inconsistent with the idea of a weak gravitational force!).  One should note that there is a current debate about the idea of "absolute rotation"; this has little to do with a Foucault pendulum or FE.

Seismic science. I'm not familiar with this topic, but it seems that seismologists determine the composition of the interior of the Earth by examining reflected seismic waves. You'll need to discredit their observations.

Pictures by amateurs and commercial ventures. Rockets work in space (that's a fact and if you want to debate that, I suggest you read up on physics). The ability of them to get to space is consistent with Newton's laws. There have been pictures taken of the Earth that clearly show that it is round. Many different types of cameras have been sent up, including those without a fish-eye lens. They have verified that the Earth is round.

[Tom Bishop]

As for the second part, Mach's principle is misinterpreted. It's a general heuristic about making physical laws relating the stars to us -- by observing the motions of the stars, we can perhaps conclude something about our frame. You can see this in GR where the metric tensor (spacetime) is affected by matter. It says nothing about the stars' gravitational pull moving the Foucault pendulum (which would be totally inconsistent with the idea of a weak gravitational force!).  One should note that there is a current debate about the idea of "absolute rotation"; this has little to do with a Foucault pendulum or FE.

Mach says that the pendulum is attracted to all of the masses of the universe.

https://books.google.com/books?id=kvGt2OlUnQ4C&lpg=PA207&ots=wFVg2aWiGf&dq=mach's%20principle%20pendulum&pg=PA207#v=onepage&q=mach's%20principle%20pendulum&f=false

Read through the above page. According to Mach's Principle the pendulum needs to somehow "sense" the presence of all of the masses of the universe.

Any act of apparent attraction is called "gravitation," which is different than "gravity". Gravitation is more of a general analogy to the word  "attraction" without any specific underlying mechanism implied. Hence, the gravitation of the stars pulls the pendulum.

[JohnAdams1145]

Tom, yes I understand what Mach said. Unfortunately, he doesn't mean that the distant stars explicitly attract the pendulum with gravity. He's talking about this in the context of the debate about absolute rotation and effectively a debate about how we should frame our physical laws. A central principle of relativity is that all inertial observers are equivalent. So speed doesn't matter. In effect, in SR, if I'm flying on a plane, I can assert that I'm stationary (and everything else is moving) and all of the physical laws will perfectly describe the situation with that assumption. Now the debate is on whether we can say the same of rotation; if we observe the stars rotating around us, can we form physical laws that take that into account while retaining the principle that there is no "privileged" reference of rotation? Can I say that I'm not rotating and then relate the apparent motion of the stars to me? This is what he means by "sense". Mach does not say that the Foucault pendulum is actually physically forced by the stars or that the stars exert any appreciable force in the Newtonian sense on us.

Currently, our physical laws fully describe most macroscopic phenomena, but they're not elegant in that they require a non-rotating frame of reference. Once you throw rotation in, you get all sorts of fictitious forces (which themselves are derived from a non-rotating frame of reference).

By the way, if you assert that the Foucault pendulum is precessed by gravitation, then you need to quantify how much. On one hand, FE theorists say that gravity is much weaker than the current scientific understanding to allow for the variations in gravitational attraction on the Flat Earth (and UA to make the bulk of our weight), but on the other, if you assert that the distant stars have an appreciable effect on the Foucault pendulum, gravity has to be obscenely strong to allow for such distant objects to affect the pendulum. If you posit that the gravity that makes gravitational variation on Earth is a completely different physical effect than the gravitation on the Foucault pendulum, then you've just introduced a 3rd form of invisible force (UA, gravitation #1 -- orbits and spherical celestial bodies, gravitation #2 Foucault pendulum), which does make FE consistent with the Foucault pendulum, but isn't terribly convincing. You'd also have to explain why the second form of gravitation doesn't follow the usual inverse-square law (otherwise it would be cataclysmic near the star).

FE has made me think about Mach's principle a bit. Typically, the rotation of the stars is attributed to the Earth's rotation (which it is), but is there a way to prove to FE theorists that the Earth is round with some physical law that relates external rotating bodies (such as the stars) to us on the Earth without invoking a rotating Earth (which instantly causes disagreement)? Well, that hasn't happened.

[ShowmetheProof]

It was, unless you're counting your unfounded opinion that the Earth is round and therefore all astronomical observations must align with RET as an argument.-Parfisal

You are very wrong.  The RE has many theories that are thought of as facts supporting it, while the FE is the group that is unfounded.  You run away from the facts we present you with, you have never done any experiments of your own to support your theory even when presented multiple times with the idea of launching a CubeSat, and the closest you have gotten to doing a single thing to support TFE is when a Limo driver/self-taught rocket scientist tried to use a steam-powered rocket into the air to prove you guys right.  Your theory of UA is completely untrustworthy, because the reason we're not going past the speed of light is the theory of relativity.  It is Einstein's(RE) generalization of a principle from Galileo(RE).  If they got some major theories right and the largest theory ever wrong they are inconsistent.  Trustworthiness requires consistency.  Not only do we have to say that Einstein and Galileo are untrustworthy, but we must consider UA, and therefore TFES with it, untrustworthy. 

[Trolltrolls]

UA can be debunked by simply realizing the 9.81 figure changes along earths surface and with altitude.

It’s accounted for in FET.

I see. I must have missed that lecture. Could you please bring me up to speed here?

I'm also still waiting for it. It sure does take a long time to cook something up.

[JohnAdams1145]

FE doesn't offer so much an explanation as a stop-gap measure. The variations are due to some unexplained "gravitation" (not gravity as Tom Bishop has been so meticulously pointing out) force that also arises between certain objects. In essence, the variations of the gravitational field along with accepting UA imply that there is some other mysterious force influencing us. Sound a lot like the criticism of the scientific method that Tom Bishop keeps alluding to (start with a theory and make stuff up to support it).

ShowMeTheProof -- UA is compatible with Einstein's theory of SR if the entire universe accelerates with us. Unfortunately, it has plenty of other problems (did I mention that, in addition to UA, Tom Bishop essentially has implied that 2 forms of gravitation exist, none of which are gravity?).

I should make a partial list of the established science that FE throws out the window (a lot of which has been replicated numerous times down here on Earth without the need for spaceships):
- Gravity
- Rockets work in space (they do, and if you want to debate it, you don't understand how they work)
- Measuring distances on Earth (cable ships, plane rides, everything)
- Seismology
- Nuclear physics (particularly that dealing with fusion)

All because some people decide that everything has to be the way it seems at first glance (the Earth looks flat, so it must be flat; the horizon looks flat, so it must be flat; I see the Earth accelerate toward me, so it that's how it must work; rockets don't make much sense, so they can't possibly work; rockets move very fast, which is impossible; I don't understand how a "1000 mph" spinning Earth could work, so it must be impossible), when all of these have very obvious explanations when looked at from a science perspective.

[ShowmetheProof]

I wasn't saying that it wasn't compatible.  I was saying it would render Einstein, Galileo, and TFES untrustworthy.

[xenotolerance]

That is simply not true, at least in the case of Newton. Newtonian physics predicts that gravity operates instantaneously across all space and that an object can go faster than light simply by accelerating for long enough, both of which are directly contradicted by relativity. That is, it makes incorrect predictions (if you accept relativity, and at least special relativity is not being contested here).

If a theory that makes incorrect predictions does not qualify as incorrect, then what is your metric for correctness?

That is basically my metric for correctness. I disagree with your interpretation of Newton's predictions, as Newton's model does not include the variables or knowledge necessary to even make those predictions as you state them. It is more fair to describe them as assumptions - assumptions they were, though Newton wasn't strictly aware that he was making them given the knowledge available in his time, and those he knew about were consistent with the knowledge that was. This is why I refer instead to completeness, and describe Newton as incomplete rather than incorrect. F = ma is an incomplete equation, and makes assumptions that break down for quanta and in gravity wells, but you can accurately predict stuff with it all the same. F = 2ma is strictly incorrect, and attempting to predict anything with it would fail dramatically regardless of any assumptions.

Using these terms, I would describe flat Earth belief as incorrect, as the Earth is not flat. Universal acceleration assumes the Earth is flat, but this assumption is at odds with current common knowledge and observations, so I describe this theory as incorrect.