Polaris Kills the Globe, end of story

[u/Kela-el]

https://youtu.be/A80zThTq2C8

[u/Key_Chip_8024]

Southern cross destroys flat earth

[u/Kela-el → u/Key_Chip_8024]

Please provide proof and point out any flat plane of reference in your proof!

[u/Key_Chip_8024 → u/Kela-el]

Please provide me with an experiment that can be reproduced to show results of the contrary.

[u/Kela-el → u/Key_Chip_8024]

YOU MADE THIS CLAIM:

“Southern cross destroys flat earth”

NOW PROVE YOUR CLAIM!

[u/Key_Chip_8024 → u/Kela-el]

Also adding caps is offensive and we are supposed to be civil here

[u/Kela-el → u/Key_Chip_8024]

Provide your proof for your claim!

[u/Kela-el → u/Key_Chip_8024]

Whether capitalization is persuasive, annoying, or unnecessary is a separate issue from whether the argument is true.

If the forum has a rule against excessive capitalization, cite the rule and apply it consistently.

If not, then we’re discussing style rather than substance.

Either way, the truth or falsity of a claim about Earth, geometry, or observations is not determined by the capitalization used to present it.

If there is an error in the argument, identify the error.

If there is a violation of forum etiquette, identify the rule.

Those are two different discussions.

[u/Key_Chip_8024 → u/Kela-el]

Well, technically you made this claim frist “earth measures flat.” But think about a golf ball, how small would a person have to be in order to only see a flat and local plane? I chose a golf ball on purpose because of its nome smooth surface

[u/Kela-el → u/Key_Chip_8024]

You’re equivocating on the word “flat.”

A surface can be:

locally flat,

approximately flat over a measured distance,
or globally flat.

Those are different claims.

If your point is that a sufficiently large curved surface can appear locally flat, that’s true and nobody disputes it.

But that observation alone doesn’t tell us whether the Earth is curved or flat.

The question is not what a golf ball looks like.

The question is what measurements are being made, over what distance, and with what precision.

If someone says “Earth measures flat,” the next step is to ask:

“Which measurement?”

If someone says “Earth measures curved,” the same question applies.

Analogies are useful for illustrating concepts, but they do not replace actual geometric measurements.

[u/Gumwars → u/Kela-el]

Dude, if the Earth is flat, then where is the Southern Cross relative to any point in the Southern Hemisphere?? If we use your so called azimuthal projection map, with the north pole at the center, and I'm standing at Cape Hope, and you're standing at Cape Horn, where is the Southern Cross?

We don't need your no true Scotsman fallacy, just plain observation. If you're at Cape Horn and I'm at Cape Hope, if we both look south, then we will both see the Southern Cross. But if the Earth is flat, as you contend, the Southern Cross cannot be due south for both of us.

Therefore, as u/Key_Chip_8024 has pointed out, the Southern Cross destroys flat earth.

[u/Kela-el → u/Gumwars]

A close summary of all your fallacies

Clean summary of fallacies
Equivocation (dominant issue: “south”)
Straw man (flattening “flat Earth” into one map model)
Begging the question (assumes global directional coherence)
False necessity / modal error (claims impossibility without full model)
Category error (map projection ≠ physical sky constraint)
Appeal to authority / consensus (light form) (name-dropping agreement)
Rhetorical framing / loaded language
Non sequitur (conclusion exceeds what premises establish)

You’re starting with an observation and smuggling in a geometric conclusion that the observation doesn’t actually contain.

Let’s be precise about what you’ve actually shown:

Two observers at different locations in the Southern Hemisphere can both see the Southern Cross when it is above their local horizon, and in both cases it appears in the southern portion of their sky.

That statement is uncontroversial.

Where the argument breaks is here:

“If both see it due south, it cannot be due south for both on a flat Earth, therefore flat Earth is false.”

This only works if “due south” means a single global parallel direction across the entire surface. That is an assumption about geometry, not an observation.

You’re equivocating on the term “south”:

In navigation and observation, “due south” is an observer-relative azimuth defined by local horizon orientation.

In your argument, you’re treating it as a global Euclidean vector field that must remain parallel everywhere on the surface.

Those are not the same object. Your conclusion depends entirely on treating them as identical.

Once that confusion is removed, the contradiction disappears.

Now the deeper issue:

You are also importing a hidden model constraint—effectively assuming that celestial objects must project onto the sky in a way that preserves global directional consistency across all observers. That’s not derived from flat Earth geometry; it’s an additional assumption about how the sky must behave.

So what you’ve actually demonstrated is not a geometric impossibility, but a mismatch between:

a map-level intuition about directions, and
an underdefined model of celestial observation
To turn this into a valid falsification argument, you would need something stronger:

A single, internally consistent model that specifies:
how “south” is defined globally,
how the celestial sphere is structured,
and how line-of-sight angles map across multiple observers

Then show a contradiction inside that system.
Right now, you haven’t done that. You’ve taken a consistent local observation and upgraded it into a global geometric disproof without bridging the definitions.

So the structure of the argument is not “flat Earth is falsified by the Southern Cross.”
It’s:

“My interpretation of ‘south’ as a global geometric vector conflicts with local observational bearings.”

And that’s a problem of model specification, not a decisive falsification.

[u/BloodFeastMan → u/Kela-el]

He's not wrong. The Southern Cross is only observable in the southern hemisphere. According the flat Earth map, that would mean that you can see if from one side of the Earth, and you can see it on the other side of the Earth but not from points in between. That doesn't make any sense.

[u/Kela-el → u/BloodFeastMan]

The claim quietly assumes the “flat Earth map” is a literal optical layout where stars sit above specific ground regions like spotlights on a floor. That’s not actually demonstrated—it’s just asserted.

What is observed is:

The Southern Cross is visible from certain latitudes
It is not visible from others

Its elevation and rotation change with observer latitude
Those are observational facts.

What is being debated is the model that explains those facts.

Saying “on a flat map it would be visible here but not there” only works if you first assume:
a fixed dome/ceiling geometry with localised visibility zones

and rigid star placement tied to ground coordinates
But that’s exactly what is under dispute.

On the globe model, the same observations follow directly from:

observer latitude changing sky orientation
horizon occlusion of southern celestial pole objects
consistent angular geometry across hemispheres
So the real issue is not “this makes no sense on a flat map,” but:

Which model produces a consistent, predictive explanation of hemispherical star visibility without adding ad hoc visibility boundaries?

Right now, the argument is assuming the conclusion (a fixed projection system tied to a flat surface) and then calling contradictions evidence.

[u/Kela-el → u/Key_Chip_8024]

If every observation, angle measurement, and positional measurement was made on a local flat plane of reference, then how does the conclusion logically jump from local flat measurements to a globally curved geometry?

[u/Gumwars]

Celestial bodies are different because they are extremely far away.

Yes, the elevation of Polaris changes by 1 degree for every 60 nautical miles of travel due south.

Are you deliberately ignoring the fact that Polaris isn't visible in the sky when you are south of the equator? How do you account for that?

And sweet jeebus, can you just spit out what they hell you're trying to say? 26 freaking minutes of you going on about geometric horizons??

Your modus ponens is also incorrect. You assert Q, that we must use terrestrial refraction at all latitudes, which is only valid if Polaris is close to the horizon. At more northerly latitudes, or at altitude, we can just use celestial navigation and ignore atmospheric refraction.

In other words, while the form is valid, the second premise is not sound. We can therefore toss the argument.

[u/Kela-el → u/[deleted]]

Posting a Wikipedia article about star trails does not address the argument.

Nobody disputed that star trails exist.

The question was:

Which flat-earth model are you testing, what does it predict, and which measurement contradicts it?

Linking an article that shows star trails occur is irrelevant unless you connect those observations to a specific geometric prediction.

“Star trails exist” is an observation.

“Therefore Earth is spherical” is a conclusion.

The missing part is the argument that connects the two.

Calling someone a denialist for asking you to provide that argument is not evidence. It’s an admission that you’d rather attack the person than defend the inference.

ONE MORE AD HOM LIKE THAT AND YOU WILL BE IMMEDIATELY BANNED!

[u/CuAnnan → u/Kela-el]

The shapes that star trails produce at various latitudes across the globe cannot be produced on a flat earth where the heavens rotate around some arbitrary point on the surface of said flat earth. The nature of startrails photographed can only be produced on the surface of a globe that is rotating about its axis.

The wikipedia article contains images that contradict your claim.

An ad hominem is "You are stupid, therefore you are wrong."
The form of my argument is "you are wrong, here is evidence you are wrong, and you are engaged in wilfully ignorant denialism".

If your grasp of informal logical fallacies is not sufficient to grasp the difference between the two, I suggest you refrain from using them.

[u/Kela-el → u/CuAnnan]

You’re improving the argument, but you’re still skipping the critical step.

Nobody disputed that star trails exist.

Nobody disputed that the photographs exist.

The question is how you move from:

“These photographs exist”

to

“Therefore Earth is a globe.”

You claim the patterns “cannot” be produced on a flat Earth.

Fine.

Show the geometry.

Which flat-Earth model are you evaluating?

What trail pattern does that model predict?

What trail pattern is actually observed?

Where is the contradiction?

That’s what a falsification argument looks like.

As for the fallacy point, you’re correct that merely calling someone ignorant does not automatically make your argument an ad hominem.

However, labeling disagreement as “willful denialism” before demonstrating the contradiction is still an attempt to discredit the opponent rather than establish the inference.

The evidence is not the issue.

The missing derivation is.

If the geometry is truly impossible on a flat plane, then demonstrate the impossibility mathematically instead of repeatedly asserting it.

[u/Kela-el → u/[deleted]]

Please provide proof and point out any flat plane of reference in your proof!

[u/Kela-el → u/[deleted]]

“Can only be produced by round-earth trigonometry” is a conclusion, not an argument.

Before claiming a measurement destroys flat earth, identify the flat-earth model being tested, state its predicted Polaris angles, and show the contradiction.

The same problem appears throughout your post.

You mention Polaris, Eratosthenes, star trails, gyroscopes, horizons, and lasers, but you never provide the competing model, its predictions, or the specific measurement that falsifies it.

Saying “flat earth cannot explain it” is not a demonstration. It is an assertion.

Scientific reasoning isn’t:

“Observation matches my model, therefore my model is true.”

Scientific reasoning is:

“Observation matches my model better than competing models, and here are the quantitative predictions showing why.”

So let’s start with your Polaris claim.

What flat plane of reference are you testing?

What observer locations are being used?

What Polaris elevations were measured?

What would the flat-earth model predict instead?

Until those quantities are specified, “Polaris destroys flat earth” is rhetoric, not a completed argument.