1

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 30, 2019, 12:05:43 PM »

I would love to see you begin with the field equations, incorporate structural mechanics, and derive the condition that planets must form spheres. That would impress me, and it would justify your claim!

In fact, I’d wager you could publish that feat.

And don’t spare the formalism, I can follow it.

If you could follow the formalism you would know what comes out. I don't think you'd be surprised to know that I can't. Not because I think its not true but mostly because I'm not trained in General Relativity. All I know is that its a generalization model of gravity that in a lot of cases linearizes well to Newtons laws of motion but of course if we simplify the math that way I'd suspect you'd argue that it doesn't count?

I mean there are sufficient sources that explain mathematical ways to derive the maximum height of objects: http://quarksandcoffee.com/index.php/2015/10/29/why-are-some-moons-spherical-but-others-are-shaped-like-potatoes/

https://arxiv.org/ftp/arxiv/papers/1004/1004.1091.pdf

And even then I doubt an analytical path without linearization or approximation from the Einstein field equations is possible wouldn't you think>

So if you don't accept that part of the argument (the radius part), then lets go back to my other problem which is equally valid, namely the fact that further south gravity would act under an angle if the flat earth is of finite size. Or it would be infinitely large which I doubt you believe.

2

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 29, 2019, 07:59:45 AM »

By recognising that #1 is incorrect reasoning. Gravity doesn’t mean that a plane will somehow crush itself into a ball. I mean, you own plates, right?

Come now you should know better, plates aren't as massive as planets and likely wouldn't collapse under their own weight.

Interesting observation. Asteroids are bigger than plates, but also apparently not big enough to collapse under their own weight.

What is stopping them from doing so?

In fact, one of the criteria for being classified as a planet is that it must have sufficient mass to gravitationally form a sphere.

Would it do this if it wasn’t rotating?

Lastly, Einstein’s GR does not address this criteria, nor does it explain how a proto-planet does this. There is physics that does, of course, but not GR.

I think you are not understanding what I'm getting at. First of all, the bigger an object gets the 'rounder' it gets due to its own gravity. A plate earth would definitely be of sufficient size so as to NOT stay in the shape of a disk.

Astroids that aren't spherical aren't spherical because they are not heavy enough.

As I said in another post, no Einstein's GR doesn't directly tell you that planets form into spheres but its what happens if you use it. You can derive those conclusions from the equations. Or in other words, if you take the physics of structural mechanics and combine them with GR you can't get away from this prediction.

And even IF the plate had some extra magical material inside it so as to not form into a sphere, under its mass, gravity would tilt the further you go south on a flat disk which we absolutely don't experience so that would also suggest GR to be wrong.

3

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 29, 2019, 07:54:53 AM »

By recognising that #1 is incorrect reasoning. Gravity doesn’t mean that a plane will somehow crush itself into a ball. I mean, you own plates, right?

Come now you should know better, plates aren't as massive as planets and likely wouldn't collapse under their own weight.

Well first it depends on how deep they are but they definitely don't keep their shape as a disk. You'd have to re-explain a lot. Not only does the shape not make sense, the predicted direction of gravity on continents farther from the center would start to point sideways towards the middle the farther you go south. This is true UNLESS the plate is much bigger than the area that we walk on in which case it definitely IS too big to not deform.

4

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 29, 2019, 07:52:05 AM »

By recognising that #1 is incorrect reasoning. Gravity doesn’t mean that a plane will somehow crush itself into a ball. I mean, you own plates, right?

Yes, that's incorrect reasoning....

https://en.m.wikipedia.org/wiki/Haumea
Debatable beast, particularly since it maintains a ring.

Furthermore, gravity does not necessarily work uniformly.

Okay thats just not how it works. An object the size of the proposed flat-earth would definately collapse in on intself due to the proposed functioning of gravity as proposed by Einstein. That is what I was arguing. You can't say: gravity does not necessarily work uniformly. My argument was that IF it works according to Einsteins predictions, a flat earth would be compressed into a spherical ball (or close to a sphere) and since it doesn't either the earth isn't flat or Einsteins predictions is wrong. How am I going wrong here?

You are wrong because Einstein never predicted this. General relativity does not predict the shapes of planets. I am a bit baffled that you think it does. Do you mean to say Newton?

No? The general theory of relativity predicts the curvature of space-time via the Einstein Field equation which is a function of in part the metric tensor which in its term carries the effects of mass and energy inside space. Newtons law of gravity are a low-speed almost-flat approximation of General Relativity.

No. The metric tensor tells you how distances are calculated. The stress energy tensor deals with energy.

Nowhere in the field equations does it say that a planet has to be spherical. That isn’t what the field equations do.

You are right I fucked up there.

But on the last part, sure it doesn't directly tell you that a planet HAS to be spherical but that is the result you get if large heavy objects get too heavy and collapse in on themselves under their own gravity. And maybe they won't collapse into a perfect sphere but they definately don't stay the shape of a disk unless you introduce some extra material that account for the forces that keep its shape which don't exist.

5

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 28, 2019, 04:28:25 PM »

By recognising that #1 is incorrect reasoning. Gravity doesn’t mean that a plane will somehow crush itself into a ball. I mean, you own plates, right?

Yes, that's incorrect reasoning....

https://en.m.wikipedia.org/wiki/Haumea
Debatable beast, particularly since it maintains a ring.

Furthermore, gravity does not necessarily work uniformly.

Okay thats just not how it works. An object the size of the proposed flat-earth would definately collapse in on intself due to the proposed functioning of gravity as proposed by Einstein. That is what I was arguing. You can't say: gravity does not necessarily work uniformly. My argument was that IF it works according to Einsteins predictions, a flat earth would be compressed into a spherical ball (or close to a sphere) and since it doesn't either the earth isn't flat or Einsteins predictions is wrong. How am I going wrong here?

You are wrong because Einstein never predicted this. General relativity does not predict the shapes of planets. I am a bit baffled that you think it does. Do you mean to say Newton?

No? The general theory of relativity predicts the curvature of space-time via the Einstein Field equation which is a function of in part the metric tensor which in its term carries the effects of mass and energy inside space. Newtons law of gravity are a low-speed almost-flat approximation of General Relativity.

6

Flat Earth Theory / Re: Convince me

« on: March 28, 2019, 08:24:39 AM »

I have no idea what #4 is about, do you?

You've never heard of point 4 before?
It's basically this image.

It's often presented as a proof against flat earth by showing curvature. I think there a few threads here somewhere discussing and debating it.

[we don't need that picture to be so huge in every quote ~pete]

Oh I see. Thanks!

I imagine that the response to this is to use vanishing perspective theory to explain that the apparent curvature is actually an optical effect of parallel lines converging in interesting ways as they approach the limit of one’s vision.

I don’t really understand how VPT can simultaneously explain the sinking ship effect and this bridge effect. Maybe somone who is more knowledgable can chime in?

But the problem is that the objects that are proposed to be on a straight line don't converge in ways that would be predicted by the geometry of vanishing points. They already disappear partially under a horizon while not having shrunk to infinitesimal size.

7

Flat Earth Theory / Re: Get the Science Right

« on: March 28, 2019, 08:18:37 AM »

Irrelevant. Objects/events across the surface will, and the light from them will come to our eyes and tell us there is curvature.

You don’t have to live on a black hole to get curvature. You’ve been watching too much Star Trek.

I won't dispute that but from what I understand the person I was responding to was claiming that the light traveling would follow the curve of the earth but I might have misunderstood that.

8

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 28, 2019, 08:17:05 AM »

How does one get around this?

By not deliberately misunderstanding Flat Earth Theory and physics.

I'm not deliberately misunderstanding it. Lets keep it simple at the beginning.

1. If Einsteins theories of relativity is true, the gravitational attraction of matter would crush a flat earth into a sphere.

Do you disagree with that or not? If you don't then what is wrong with:
2. If the earth is flat, Einstein must be wrong.

9

Flat Earth Theory / Re: A question regarding the interconnectedness of physics

« on: March 28, 2019, 08:15:38 AM »

By recognising that #1 is incorrect reasoning. Gravity doesn’t mean that a plane will somehow crush itself into a ball. I mean, you own plates, right?

Yes, that's incorrect reasoning....

https://en.m.wikipedia.org/wiki/Haumea
Debatable beast, particularly since it maintains a ring.

Furthermore, gravity does not necessarily work uniformly.

Okay thats just not how it works. An object the size of the proposed flat-earth would definately collapse in on intself due to the proposed functioning of gravity as proposed by Einstein. That is what I was arguing. You can't say: gravity does not necessarily work uniformly. My argument was that IF it works according to Einsteins predictions, a flat earth would be compressed into a spherical ball (or close to a sphere) and since it doesn't either the earth isn't flat or Einsteins predictions is wrong. How am I going wrong here?

10

Flat Earth Theory / Re: radio waves as reliable straight line

« on: March 27, 2019, 07:16:55 PM »

We know that light diffracts, that it does not travel straight through an edge between different materials and that P900s don't give exact RE or FE results because the light is bending.

Do radio waves have the same problem?

On FE, if I sight something through a telescope and a radar set, could it be in some other position than where it appears due to bending of both radio and light waves in the same way?

Yes and it depends on what you are measuring. Radiowaves and light are both waves in the electromagnetic spectrum and for most materials except metamaterials and metals the refractive index of light also applies to radio waves.

The concept of ground waves is an example of radio-waves bending allthough I'm sceptical of their existence since they seem to be equally well explained by reflections off a non-perfect reflecting surface. These 'seem' to predict much better the transition of the path loss exponent from 20dB per decade to 40dB per decade in the far field via a 30dB per decade region which isn't predicted by ground waves but is measured.

A better example would be the refraction of radio waves by the upper atmosphere. Here we very clearly know we can have long range radiowave propagation due to the signals being bend by the gradually varying complex dielectric permeability of the sky.

11

Flat Earth Theory / Re: amateur radio operators

« on: March 27, 2019, 07:09:43 PM »

Some science is very difficult from the Round Earth perspective some science is very difficult from the Flat Earth perspective that just be how it is my man.

Is that how we solve problems? Just stating that its difficult to explain? That sounds to me like just brushing off an obvious problem

12

Flat Earth Theory / A question regarding the interconnectedness of physics

« on: March 27, 2019, 06:50:46 PM »

Hey people, I'm wondering something when I went off and think about the interconnectedness of physics.

In the case that the earth is flat, the following must be true.

1. Gravity as a consequence of mass due to Einsteins theory can't be true because else the flat earth would collapse into a sphere. Thus Einstein's theory of relativity must be false.
2. If Relativity is false then the performed measurements on the effects of the curvature of space and time on light must be false as well.
3. If Relativity is false then there is no longer a good agreement on the interaction of electrostatic forces for moving observers due to length-contraction which means that maxwell's equations are wrong (moving observers looking at moving charges in a neutrally charged wire wouldn't experience any forces because there is not electrostatic force and the static magnetic field due to the flow of charges exerts no force on stationary charges which means that from the perspective of a moving charge moving at equal velocity as charges in a wire, there would be no attracting but repellant force. However, from a stationary observer the moving charge would experience lorentz forces in a stationary magnetic field caused by the moving charge in the wire which leads to contradictions. This problem is resolved by length contraction from the perspective of the moving observer but this isn't allowed since relativity was not true).
4. If maxwell doesn't work then all we know about the interaction between electric charges doesn't work and hence
5. All of chemistry is wrong
6. All of electrical engineering is wrong and thus
7. All modern day computers and electronics work only by accident and not because of the laws of physics
8. All of wireless communication which follows Maxwell's equations is wrong
9. The understanding of all atomic structures is wrong which are all based on the interaction of electric forces and quantum mechanics
10. Our understanding of mechanics is wrong

Basically everything we know about physics is wrong.

How does one get around this?

13

Flat Earth Theory / Re: Get the Science Right

« on: March 27, 2019, 06:37:23 PM »

Well, nothing has to be relativistic here. Minkowski space is, basically, 4-dimensional Euclidean space. It’s flat! So parallel lines will appear to converge.

I you are in a curved spacetime, then parallel lines will not stay parallel, hence they may not appear to converge in the distance.

Just think of the surface of a globe (I know I know). The lines of longitude are parallel at the equator but meet at the poles. This is because a globe’s surface has curvature.

Make sense?

Ah, I didn't see what angle you were going for there. You're absolutely right that in curved spacetime parallel lines would not stay parallel.

That said, the amount of curvature for Earth's mass/size is infinitesimally small. I don't have the calculations with me, but I'd wager that across a whole flat Earth disk there wouldn't be enough curvature to make two parallel lines starting five feet apart actually converge by the other end of the disk, let alone to account for something the size of the Sun. So unless there's something to suggest such a dramatic curvature, I don't think you can suggest perspective on Earth works any differently than it would in perfectly flat space.

Dude, please re-read my previous reply, and then read again what you just wrote. Parallel lines at the equator will meet at the poles. Look at a globe. That is the whole point of longitude lines.

Dramatic is subjective. The curvature of a spherical surface is 2/R^2, which can be derived from Einstein’s field equations. It’s dramatic enough for our purposes here.

You said "parallel lines in curved spacetime won't stay parallel." I agreed with you.

Lines on a globe have nothing to do with lines of perspective unless that globe is warping spacetime enough to bend it into a similar sphere. The Earth has absolutely nowhere near enough mass to do anything like that.

What other connection are you trying to draw between lines of perspective and lines on a globe?

The correct one. The surface of the Earth is a curved surface. Two parallel lines, which begin on the equator, will meet at the poles. That’s it. If you and your pal begin at the equator and walk parallel to each other, then you will meet at the poles.

I frankly do not understand why you think this doesn’t apply to perspective.

Because the earth isn't a black hole and we don't life on its event horizon hence light won't be following its curvature people walking on it will.