[JakePhysics]

Hello! My name is Jake, and I am currently working on my PhD in Physics at Purdue University. I am actually writing my thesis paper on gravitation — specifically relating General Relativity and Quantum Gravitation which are two distinct ideas with numerous contradictions.

For a long time, I have always viewed Flat Earthers as ignorant. After listening to some of their views and beliefs, however, I have come to realize that perhaps they are just misinformed and/or confused.

The universe is an incredibly complicated place, filled to the brim with mysteries that humanity may never understand. That being said, it’s understandable that there will be people who question things.

I don’t view Flat Earthers as uneducated, as both Round Earthers and Flat Earthers share the same curiosity! We all just want to understand the universe around us, and I respect everyone who has that drive to learn and seek truth.
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Moving on to the title of this post, I would like to cover something interesting I heard when listening to a Flat Earth livestream.

I noticed that one of the rebuttals that Flat Earthers often bring up, is the idea that the Sun is moving in the universe and how they don’t think this makes any sense. I mean, how could the sun be moving in the universe while the Earth simultaneously revolves around the Sun?Wouldn’t this mean that the Earth would be revolving around the Sun, while also being dragged around by the Sun as it moves in the universe?

This is a very valid point, and for the average person who isn’t incredibly familiar with the principles of gravitation, there is nothing wrong with being skeptical about this! In fact, I think it’s wonderful that people are trying to disprove the common belief. After all, nobody believed Einstein when he published his theory on Relativity since it contradicted everything we thought we knew.

As I am writing my thesis on gravitation, I thought I might answer this question for you all in a way anyone can understand!

Please note, I am going to do my best to explain this while relating to the beliefs of a Flat Earther and will omit as much math as I can.
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One thing that the Flat Earthers agree on, is the fact that other planets and stars are spherical — since we can easily observe them ourselves without the help of the government and private organizations.

Going on this same line of thought, we know that black holes exist because of the picture we have taken of one! Even without the picture, we know that the force of gravity is not a constant throughout the universe since it is common knowledge that our Moon has less of a gravitational attraction than the Earth (this is true even if the Earth is flat since obviously the Moon isn’t crashing into us haha). So, if the gravitational force objects in the universe exert isn’t a constant, then it must also be possible that there must be an object that exerts a gravitational force so large that nothing can escape its pull — including light!

We can (and have) actually physically see that light can be manipulated by gravity. This can be done during any solar eclipse, when the moon passes in front of the Sun. If we use very precise equipment and look at the sun during the eclipse, we can observe that there are stars around it! The stars aren’t actually around the Sun, in fact, they are behind the Sun. We see them because the Sun’s gravity warps the light of those stars just enough to display them around it.

From observation alone, we can also deduce that we live in a spiral galaxy (Milky Way), and that there are millions of other galaxies of all shapes and sizes out there in the universe. We have seen other spiral galaxies, and simply looking at them we see that they have an apparent center. Around the centers, we see a ‘circular’ configuration of billions of stars that looks almost like a vortex, and given enough time we also observe these galaxies to be spinning around the center kind of like a pinwheel. The fact that the galaxies we see are not falling apart and flying everywhere indicates that there must be a force at the center of that galaxy holding all of the stars together.

We know all of this to be true even if we consider the Earth to be flat since we can easily observe these things for ourselves (just be careful if you are trying to look for stars during a solar eclipse).

Continuing on the same line of thought, if we see these stars are being held together in formation (even if you don’t believe the force is gravity) it is evident that there IS a force.

Now, thinking back to the things on Earth, how can we visualize this? Imagine you are standing on a merry-go-round that is spinning, and your shoes are physically glued to the surface of the merry-go-round. As you spin faster and faster, you’ll notice that you will not be flung off of the merry-go-round because your feet are glued to the surface. Instead of flying off, you will feel yourself being held in place by the resistive force of the glue. Your body will be wanting to fly off the edge, however the glue will keep you in place by exerting a force on your feet toward the center of the merry-go-round. The same thing is happening with the stars in these galaxies.

The stars aren’t being flung off in the vastness of space because they are constantly being pulled toward the center of the galaxy as they revolve around it. This attraction must therefore be due to the object at the center of the galaxy. (We believe this to be a supermassive black hole, however I’m explaining this from an observation standpoint alone so nobody makes the argument that since we can’t see anything ourselves, the government is making it up)

From basic physics that has been proved experimentally time and time again here on Earth, we know that if we have a disk that is spinning, and glue 2 objects next to each other at the edge of this spinning disk, they will revolve around the center of that disk with the same angular velocity. Regardless of the position of these two objects on the disk, whether it be up, down, left, right of each other, they will always have the same angular velocity relative to the center of the disk.

That being said, it makes sense that the velocity of the Earth around the Milky Way is the same as the velocity of the Sun. Which means, if we know the Sun to be ‘revolving’ about the center of our galaxy — assuming our galaxy is no different from the millions of other galaxies in the universe — then it isn’t the Sun that is ‘dragging’ the Earth around in space, it is simply the scenario of the spinning disk in which the Earth and the Sun are the two objects ‘revolving’ at equal angular velocities. So even if the Earth is revolving around the Sun, that will not have any effect on the way it moves in space relative to the center of our galaxy and the linear/angular motion of our Sun.

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I tried my best to explain this in a way Flat Earthers could understand, sorry if some things seem confusing, it’s difficult to explain these things without math.

[Tom Bishop]

I noticed that one of the rebuttals that Flat Earthers often bring up, is the idea that the Sun is moving in the universe and how they don’t think this makes any sense.

I would recommend addressing something in our wiki rather than something random you heard.

[jack44556677]

Hello! My name is Jake, and I am currently working on my PhD in Physics at Purdue University.

Welcome! You sound like you could be ideal to join the discussion and study this subject.

I have [most] always viewed Flat Earthers as ignorant ... [but] perhaps they are just misinformed and/or confused.

That's progress, albeit tiny, in the right direction! Next step, actually considering and objectively evaluating some of these claims in earnest, accepting/recognizing they may well be possibilities and you may well be wrong currently.  I'm sure I don't have to extoll to a physics phd the benefits of devotion to objectivity and the eschewing of bias whenever possible.  Part of that is testing wild (even stupid, to a layman) things, don't you agree?

That being said, it’s understandable that there will be people who question things.

We call those people many names, one of which is scientist.

I respect everyone who has that drive to learn and seek truth.

Earnestly and with the intention to share, yes; I agree.

I would like to cover something interesting I heard when listening to a Flat Earth livestream.

Livestreams. Ooo boy. Fair enough, however you must realize that the views you heard may not be held by anyone here.  The wiki here is an excellent place to begin getting a taste of the multitude of various views and ideas there are out there.

Flat earth research is a slightly different animal/subject than you're formally trained for.  It has no colleges, no textbooks (yet, anyhow), no popes or deans. Flat earth researchers are mostly unaffiliated individuals with, often, wildly differing approaches, views, and conclusions on the subject. Autodidacticism is not optional, and strong independent research skills are required - which sadly, few have.  You, I suspect - ought to have them in some abundance, at least the research ability.

I'm quite interested to hear your perspectives, seeing as gravitation (as taught and understood by the vast majority) is often erroneously seen as a "logical" reason the earth couldn't possibly be any other shape than the one they learned as children.  Even if the earth was a sphere because gravity is real, or (were it true) because nature prefers spheres; The earth (like all physical objects) can only be determined to be spherical one way, and it isn't through persuasive argument (gum flapping) while sitting around. It's by rigorous and repeated measurement alone.

As I am writing my thesis on gravitation, I thought I might answer this question for you all in a way anyone can understand!

Cool.  There is a big difference between knowing something extremely well and being able to share it with others, especially uninitiated/novices.  I'm not sure how many people here are struggling with the concept of reference frames, but I know it is a lot.

Please note, I am going to do my best to explain this while relating to the beliefs of a Flat Earther and will omit as much math as I can.

Like most subjects, belief is across purposes.  Belief has no place in knowledge/fact, least of all scientific.  The "best" researchers in this subject seek to know, and many - like myself (and possibly you as well?) also seek to identify and eliminate belief (a major source for bias) whenever possible.

One thing that the Flat Earthers agree on

"Flat earther" is more or less a derogatory that very few self-ascribe to.  There is no consensus, or uniformity.  There are even some who speculate that the world IS spherical, but much larger than we assume - as well as those that conclude (and sometimes measure!) the earth to be an inverted sphere that we live on the inside surface of.  There is virtually nothing that every one of the individual researchers agree on, even with only minor majority, except perhaps that our conceptions of the worlds shape are or, at least, may be wrong.

Many flat earth researchers speculate that the planets are also flat, but this is due to rationalization/cognitive dissonance of remnant astronomical/cosmological mythology they haven't totally identified and excised (hopefully yet!).  Many more speculate/deduce/conclude that there are no planets at all the way we and hollywood conceive and depict them.

Going on this same line of thought, we know that black holes exist because of the picture we have taken of one!

Ever wonder why that picture was so hyped? Do you know/ have a sense of how much it costs to hype a "picture" like that across the media channels in such a ubiquitous way?  You, the curious scientist, may feel - of course that is front page news! But the rest of us, very much don't.  Why was it so important to show these people this "picture"?  Also, this is not the first "picture" touted of a black hole that made the rounds in a major way through the media outlets.  There is no solid evidence that black holes do or can exist.  I side with einstein on this one, and a select few other things.

then it must also be possible that there must be

Cool phrasing. It sounds like a provisional but is an absolute in disguise! It's possible that there must be - that's tasty rhetoric.

We can (and have) actually physically see that light can be manipulated by gravity.

No, this is a mistake/lie that they teach us.  There is no experimental validation (scientific support) of that statement whatsoever. Experimentally, light's path can only be altered by direct interaction with matter.  You may argue pedantically and irrelevantly for diffraction, but please do not unless you feel you must.

This attraction must therefore be due to the object at the center of the galaxy.

Incorrect.  What you have there is merely a speculative hypothesis (at best), which now needs experimental validation or refutation.  This is, fundamentally, why astronomy is largely pseudoscience mythology and not science.  It (largely) cannot and does not adhere to the scientific method, and ergo is not a part of science.

We believe this to be a supermassive black hole

Correct!  But don't you know that belief has no place in knowledge/fact, least of all scientific?  Why are you believing in things, and why are small children (most who will never be astronomers) being taught these beliefs as "facts" under the guise of science when they are not?

I tried my best to explain this in a way Flat Earthers could understand, sorry if some things seem confusing, it’s difficult to explain these things without math.

You'll be more effective if you answer questions you are asked, address/respond to content found here (not a random podcast with some people claiming - or you have mistaken - to speak for "flat earthers"), or pipe in to an existing conversation with a clarification / your perspective if you think it edifying and/or clarifying.

There is much I wish to discuss with you, on the other hand - but like you on the other side of the keyboard I simply do not know where to begin.  Talk of gravitational lensing and black holes being a hoax is fun, and important, but somewhat tangential to the discussion at hand.  At the end of the day it is a research challenge.  Can you validate the existence of either of those things scientifically/experimentally, and can anyone? The answer to both questions is no, but you may not have put the research hours in to determine that adequately for yourself yet.

I think any discussion about science should start out with some agreement on functional definition of terms for the purposes of the discussion.  I find that the working definitions for science, scientific method, hypothesis, and experiment are at the core of science and discussion thereof.  I have found that most people, including many scientists, have incorrect or broken (not working) definitions and so I think we should start here - assuming you are interested in discussing this topic!

What are your (personal/working) definitions for the following words? I will include my, working/functional, definitions.

Science : That which adheres rigorously to the scientific method (with the caveat of natural law which is established solely through rigorous and repeated measurement), and colloquially to the body of knowledge which that method produces.

Scientific Method : (has many fringes, but the bones are)
1. Observe a phenomenon.
2. Hypothesize a cause for the observed phenomenon.
3. Experimentally validate, invalidate, or neither (when it really borks) the hypothesis.

Hypothesis : (There are MANY more criteria here for a VALID hypothesis, but this is the core)

A speculation on the cause of an observed phenomenon and the expected influence of manipulating that cause on the observed phenomenon for the sole purpose of being experimentally validated/refuted (ideally).

Experiment :

A procedure which validates or invalidates a hypothesis by establishing a causal link (ideally) between a hypothesized cause/IV/Independent Variable that you manipulate and the hypothesized effect/DV/Dependent Variable that you only monitor.

I have found that with the correct working definitions you can begin to discern science from pseudoscience (including the belief mentioned above) masquerading as it.

[SteelyBob]

I think any discussion about science should start out with some agreement on functional definition of terms for the purposes of the discussion.

Hi Jack. I think your definitions are pretty good really, although we clearly disagree on the fundamental issue at stake here. One important addition I’d suggest is the importance of a well-framed hypothesis. A good hypothesis needs to be ‘falsifiable’, meaning that you need to be able to define what it would take to prove it wrong.

Interestingly, FET is actually quite a good hypothesis, in that it is readily falsifiable - it is easy to describe what might cause you to conclude that the world is, in fact, not flat. This, however, doesn’t make it correct. The problem, I think, is that many FET proponents simply ignore anything that might falsify the hypothesis. Examples include, but aren’t limited to, the behaviour of navigation gyroscopes, the changing elevation of stars with changing latitude, the constant angular size of star constellations as they move around the sky and the different behaviour of the surface wind in the two hemispheres (Buys Ballot’s law). All these things robustly falsify FET, nobody on these forums ever really addresses any of them, and the wiki is hopelessly vague and woolly on these matters.

As an aside, you said:

Experimentally, light's path can only be altered by direct interaction with matter.

Gravity’s influence on light was settled in the 1950s - Einstein’s work on this was falsifiable, like all good theories, but the Pound-Rebka experiment, and every subsequent repetition, showed beyond doubt that he was spot on.