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Very Wrong Math

charlespetzold.com

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Re: Very Wrong Math

#71

Post by Someone »

munch117 wrote: post #23
seanhunter wrote: post #14

I have seen a very similar (incorrect) argument used to justify the idea of a flat earth. A builder on youtube made the argument (with a similar out of scale drawing of the earth) that if he drops a plumb bob and makes a right angle so he has a straight horizontal line and then goes across that line for a bit and drops another plumb bob, the two lines he has dropped are parallel, "proving" that the surface of the ear…

Ah, but would they actually be parallel on a flat earth? Say the earth is disc-shaped. Then the center of gravity is only directly beneath you if you're standing at the exact center. You get ever-so-slightly not parallel lines, just like on a round earth. The fun part of a disc-shaped earth comes as you move towards the sides, and gravity, still pointing towards the center, makes you stand at an increasingly acute an…

> and gravity, still pointing towards the center, makes you stand at an increasingly acute angle to the surface. The ground beneath you will then appear like one big endless mountainside

That’s why you never hear of people who went to the edge of that dis: they slid down that mountainside, and dropped off :-)

Alternatively, you can postulate that disc to be arbitrarily thick.

That will decrease the deviations. If that’s not enough to make them immeasurable, postulate that the stuff “deeper down” has higher density.

In the limit, just postulate that there’s an enormous black hole millions of light years below the center of the earth.

Flat-earthers probably won’t accept Newton’s theory of gravity, however, so you can make up anything.

Re: Very Wrong Math

#72

Post by eminent101 »

kergonath wrote: post #60
seanhunter wrote: post #49

Earlier quoted context omitted.

Bet you’re fun at parties as they say. I totally understand why simplifying assumptions are helpful in modelling and definitely don’t need you to explain that. It also is a bit ridiculous if you think literally about it which makes it something that is fun to laugh about as here.

Yes, sure, I get the jokes. I just found it puzzling that someone would think it stopped. And I don’t talk about work at parties anyway :)

But nobody in this thread thought it (simplifying assumptions) stopped. You seem to be making an assumption that someone thought that and then posting long explanations that nobody asked for. I read the "P.S." of grand-grand-parent comment as good humor. Nothing there implied that they really thought that simplifying assumptions would/should stop.

Imagine a world where every bit of humor is interpreted literally and then refuted pedantically! What kind of a world would that be?

Re: Very Wrong Math

#73

Post by empath75 »

nkrisc wrote: post #51
munch117 wrote: post #41

Earlier quoted context omitted.

If this mysterious disc-accelerating force also accelerated the people and things on the surface, we'd all be weightless. I guess it must be a pushing force from below. So, who's doing the pushing? I'm thinking a big turtle.

They mean it is actually accelerating constantly. My math might be wrong, but if we were accelerating at 9.8m/s/s for at least 4000 years (roughly as long as we have continuously recorded history and the minimum time “gravity” has been observed) then we ought to currently be traveling through space at over 1,000,000,000,000m/s. Now I’m no physicist, but I reckon that might end up violating causality.

Some of them think that.

The problem with trying to "explain" this is that fundamentally, flat-earthers, to the extent that they could be said to have a coherent world view at all, are usually a kind of occasionalist[1]. They don't _believe_ in natural laws or cause and effect. For the most part, they believe that god is in complete control of all events, and things go down because god wants them to go down. There's no required explanation for _anything_. The sun moves across the sky because god wants it to, and he could stop it or make it go backwards if he wanted it to, etc.

Indeed, that a flat earth is incompatible with physics is part of the appeal of believing in it to begin with. They _want_ to overthrow Newton, because a clockwork universe is incompatible with their belief system.

It's also sort of immune to any kind of argumentation. The result of any experiment is simply that god wants it that way, that they're predictable and testable doesn't _prove_ anything, because you can do an experiment a million times, and god could still cause it to fail any time he wants to. God just doesn't want to argue with Netwon right now, for his own reasons, you see.

1: https://en.wikipedia.org/wiki/Occasionalism

Re: Very Wrong Math

#74

Post by plagiarist »

jbeninger wrote: post #57
nkrisc wrote: post #51

Earlier quoted context omitted.

They mean it is actually accelerating constantly. My math might be wrong, but if we were accelerating at 9.8m/s/s for at least 4000 years (roughly as long as we have continuously recorded history and the minimum time “gravity” has been observed) then we ought to currently be traveling through space at over 1,000,000,000,000m/s. Now I’m no physicist, but I reckon that might end up violating causality.

Nah, when you move that fast, further acceleration stops increasing speed and starts squishing time instead, so you asymptotically approach C. So I guess what I'm saying is I see absolutely no problem with the flat earth arguments?

We should see this as all the celestial bodies traveling "down" at relativistic speeds by now. Unless maybe they are also experiencing 1 G in the same direction as us in addition to whatever other accelerations.

Re: Very Wrong Math

#76

Post by cratermoon »

lukan wrote: post #53
tempestn wrote: post #29

Earlier quoted context omitted.

Depends what causes things to stick to the flat Earth. IIRC flat earthers have various explanations for gravity, including the disc continuously accelerating upward; in that case you'd experience the same force everywhere on it.

The theological argument I recently heard is, the creator just made up and down. And things move down. But it is not gravity.

"A wizard did it"

Re: Very Wrong Math

#77

Post by microtonal »

aja12 wrote: post #15
kubb wrote: post #9

Curious, does the air being thinner affect flight time?

From what I've learned reading AdmiralCloudberg's plane crashes analysis [1]: altitude heavily matters in fuel consumption. Jet planes use a lot less fuel at a higher altitude, up to the point that a plane on the verge of running out of fuel at a medium altitude might manage to squeeze in 50 or 100 more miles of flight by climbing 5000 feet, even accounting for the increased fuel consumption during climb. I guess tha…

I’m confused, isn’t turbofan a type of jet engine?

https://en.m.wikipedia.org/wiki/Turbofan

Did you mean turboprop?

Re: Very Wrong Math

#79

Post by jerf »

seanhunter wrote: post #14

I have seen a very similar (incorrect) argument used to justify the idea of a flat earth. A builder on youtube made the argument (with a similar out of scale drawing of the earth) that if he drops a plumb bob and makes a right angle so he has a straight horizontal line and then goes across that line for a bit and drops another plumb bob, the two lines he has dropped are parallel, "proving" that the surface of the ear…

"We joke about LLMs hallucinating but I'm not convinced we are so superior when we are outside our personal "training data"."

In all seriousness one of the things about LLMs that most impress me is how close they get to human-style hallucination of facts. Previous generations of things were often egregiously and obviously wrong. Modern LLMs are much more plausible.

It's also why they are correspondingly more dangerous in a lot of ways, but it really is a legitimate advance in the field.

I observe that when humans fix this problem, we do not fix it by massive hypertrophy of our language centers, which is the rough equivalent of "just make the LLM bigger and hope it becomes accurate". We do other things. I await some AI equivalent of those "other things" with interest; I think that generation of AI will actually be capable of most of the things we are foolishly trying to press hypertrophied language centers into doing today.

Re: Very Wrong Math

#80

Post by [deleted] »

kurthr wrote: post #4
BalinKing wrote: post #2

Related Wikipedia article: https://en.wikipedia.org/wiki/String_girdling_Earth#Implicat... . The takeaway is that the extra length of the arc is likely much smaller than one would intuitively expect. The problem is usually framed like so: If you wrapped a rope around the earth, how much more rope would you need to add so that it would be 1 meter above the ground at all points? The answer is only 2π meters!

The only issue I see with this is that as a classic physics trope, we've approximated the earth as a sphere. If, instead we approximate it as a fractal... then the distance is infinite, or at least highly dependent on the thickness of the rope! The error in the original is assuming that the radius is proportional to the height above the earth (Earthradius=0?).

[deleted]
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