## Archimedes’ Principle and Gravity

Archimedes’ principle states that any object, totally or partially immersed in a fluid, is buoyed up by force equal to the weight of the fluid displaced by the object. Meanwhile, Newton’s law of universal gravitation states that every particle attracts each other with force directly proportional to their masses & inversely proportional to the square of their distances.

Flat-Earthers like to characterize gravity as if it was “invented” to “replace” Archimedes’ principle & that the two are competing theories. In reality, these are two different theories that explain different phenomena. Gravity does not explain anything that Archimedes’ principle explains and vice versa. Gravity does not replace Archimedes’ principle; both are valid and in use today.

## Albert Michelson in “Michelson and the Speed of Light”

In 1881, Albert A. Michelson experimented to prove the existence of aether. Aether was a hypothesized material that fills the region of the universe. Scientists knew light is a form of a wave, and because all other waves require a medium to propagate, they formulated the aether hypothesis, in which light can propagate. However, Michelson’s attempt produced a null result. Michelson concluded that the hypothesis of a stationary aether is erroneous.

In 1960, Bernard Jaffe wrote Michelson’s biography in the book “Michelson & the Speed of Light.” Unscrupulous flat-Earthers quoted a lone paragraph from the book out of the intended context and presented it as if Michelson proved the Earth is stationary.

## Mark Twain’s Fake Quote

The following quote is often attributed to Mark Twain. But there is no evidence Mark Twain ever wrote this phrase, despite the fact his writings were very well-documented.

“It’s easier to fool people than to convince them that they have been fooled”

Flat-Earthers like to use the quote to ridicule & describe those who understand Earth is a sphere. In an ironic twist, by attributing the quote to Mark Twain, these flat-Earthers demonstrate that they are being easily fooled themselves.

## Buzz Aldrin’s Interview with Conan O’Brien

In a talk show, Conan O’Brien (the host) incorrectly said that he watched Buzz Aldrin (the guest) landed on the Moon. Buzz corrected him that what Conan saw was just an animation.

Flat-Earthers wrongly use Buzz’s statement as “evidence” that the landing was fake. In reality, Buzz informed Conan that news broadcasts of the landing used animations to give audiences a visual representation of the landing. They did not go to the moon in advance to set up cameras to report the landing.

## Quote Mined Einstein Statement

In 1922, Albert Einstein gave the speech “How I Created the Theory of Relativity” at Kyoto University. Flat-Earthers took a sentence fragment from his speech and quoted him out of context. It became a hoax as if Einstein believed a stationary Earth.

By reading the entire paragraph to understand the context, it is clear that Einstein did not mean Earth is stationary. He understands that Earth is in motion around the Sun.

## The “Earth is a Realm” Quote Misattributed to Nikola Tesla

The “Earth is a realm” quote is often wrongly attributed to Nikola Tesla in flat-Earth communities and incorrectly regarded as “evidence” that Tesla believed Earth is flat.

Someone wrote pseudoscientific drivel and added an actual quote by Nikola Tesla. Flat-Earthers wrongly assume both statements are by Tesla & it became a hoax claiming Tesla was a flat-Earther.

The quote by Tesla was taken from “The Problem of Increasing Human Energy,” in which Tesla mentioned the word “globe” 12×, “gravity” 4×, “planet” 10×. It is clear Tesla was not a flat-Earther.

## Auguste Piccard, A Scientist Falsely Claimed by Flat-Earthers

In 1931, Auguste Piccard went up in a balloon to an altitude of 15781 m, not far above the cruising altitude of an airliner. At the altitude, Earth’s curvature is still very slight and difficult to see, especially through the small portholes in his chamber.

In a Popular Science interview, Piccard was reported to have said that Earth “seemed a flat disc with an upturned edge.” Flat-Earthers quickly interpreted his statement as if he was telling us Earth is flat. In reality, in another interview, it is clear that he is convinced that Earth is a sphere. In his writings about his expeditions, the word “globe” was also mentioned several times.

## Bedford Level Experiment Confirmed the Curvature of the Earth

In 1870, Alfred Russell Wallace took a challenge from a flat-Earther and successfully confirmed the existence of Earth’s curvature in the Bedford level experiment.

Wallace did the experiment on the Bedford Canal. Wallace fixed a black band on the Old Bedford Bridge and observed it with a telescope from the Welney Bridge 6 miles away. Right in the middle, he placed a pole with two discs on it. The telescope, the top disc, and the black band are at the same height above the water.

From the telescope, both discs were seen above the black band, proving the existence of Earth’s curvature.

## Isaac Newton and the “Hypotheses non Fingo”

Isaac Newton formulated the law of universal gravitation, which adequately explained the motion of all bodies in space known at his time. He also showed it is the same law that is causing everyday objects to fall on Earth.

In his famous phrase “hypothesis non fingo,” Newton stated that he did not know what causes gravity and refused to speculate. Flat-Earthers use it to discredit him. In reality, just because he did not know what causes gravity, it does not mean his law of universal gravitation is wrong.

## Archimedes and the Surface of any Fluid

In the 3rd century BCE, Archimedes of Syracuse wrote what we now call the Archimedes’ principle in his book “On Floating Bodies” using the spherical Earth model.

Flat-Earthers like to misuse Archimedes’ principle as if it supports their claim that Earth is flat. In particular, they abuse Archimedes’ principle as if it is a competing explanation against gravity. In reality, Archimedes and other Greek scientists at the time already knew Earth is a sphere, and he explicitly mentioned it in his writings.

## Tesla’s “Scientists Have Substituted” Quote

In the article “Radio Power will Revolutionize the World” in “Modern Mechanix and Inventions” magazine, July 1934 edition, Nikola Tesla stated:

“Today’s scientists have substituted mathematics for experiments and they wander off through equation after equation and eventually build a structure which has no relation to reality.”

Flat-Earthers like to use the quote to discredit science and scientists, unaware that in the article, Tesla mentioned that Earth is a sphere multiple times.

## Allais Effect

The Allais effect is the alleged anomaly of pendulums or gravimeters, which is purportedly observed during a solar eclipse. The effect has not been able to be consistently measured and was most likely caused by experimental error.

Flat-Earthers use the Allais effect to dismiss the result of Foucault’s pendulum. In reality, the Allais effect is still not conclusive. Even if it is true, it only occurs during an eclipse and does not rule out that the pendulum’s precession is due to Earth’s rotation. Not to mention that there is plenty of other evidence that Earth is in motion.

## Fake Moon Rock That Turns Out to Be a Petrified Wood

The Apollo missions brought back moon rocks to Earth. Some of the moon rocks Apollo 11 and Apollo 17 brought back were gifted twice by President Nixon to 135 countries. In the Netherlands, both of these gifts are intact and preserved in a museum. However, there is another unrelated gift, in the form of petrified wood that was mistaken to be a moon rock for several years.

Flat-Earthers use the petrified wood incident to discredit the Apollo missions. In reality, the incident is not related to the two moon rocks that the United States officially gifted to the Netherlands, which are still displayed in Museum Boerhaave, Leiden.

## Gravitational Acceleration in Archimedes’ Formula

Archimedes’ principle states that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid that the body displaces. Today we usually use B =  -ρgV to calculate the buoyant force, where ρ is the fluid’s density, g is the gravitational acceleration, and V is the volume of the displaced fluid.

Archimedes discovered buoyancy earlier than Newton discovered gravity, and flat-Earthers dispute the presence of g in the buoyancy formula. In reality, buoyancy depends on the weight of the fluid, and the distinction between weight and mass only occurred after Newton. Archimedes’ principle still applies, only that we now have a better understanding of what weight is.

## Isaac Newton and the Falling Apple

The fall of an apple inspired Isaac Newton to understand that the same force that brought the apple falling toward the ground also keeps the Moon in motion around Earth. However, his work involved much more than just observing the falling apple.

Flat-Earthers downplay Newton’s contribution as if it was only about the falling Apple and use the episode as a means of ridicule. In reality, Newton’s works were much more than that.

## Nikola Tesla Was Not Erased From History and Modern Education

Nikola Tesla was a very influential physicist, engineer, and inventor. Due to his influences, various things are named after him.

Many conspiracy theories hijack the reputation of Nikola Tesla, including flat-Earth. They claim Tesla was a flat Earth scientist, and his name was deliberately erased from history books and modern education. In reality, Tesla was a genuine scientist, and it is not hard to find out that many things today are named after Nikola Tesla.

## Earthrise in President Nixon’s Oval Office

Earthrise is a photograph of Earth taken from lunar orbit during the Apollo 8 mission, seven months before the first Moon landing by the Apollo 11 mission. President Nixon hung a copy of Earthrise on the wall next to his desk in the Oval Office.

The picture of Earthrise was prominently visible during news coverage of President Nixon’s call with Apollo 11 astronauts on the lunar surface. Flat-Earthers find it strange Nixon already had the photo hung on the wall when the mission was still ongoing. These people are unaware that there are already several Apollo missions before Apollo 11, and Apollo 11 was only the first to land on the Moon.

## James Cook’s Second Voyage

The second voyage of James Cook was commissioned to search for the hypothetical continent Terra Australis in the Southern Pacific Ocean.  He explored the Pacific and Atlantic oceans in the process and proved there is no such continent unless it is over the South Pole itself, which we now call Antarctica.

Some sources stated that Cook traveled over 60000 miles in his second voyage. Flat-Earthers use the figure as Antarctica’s circumference and claim it as “evidence” that Antarctica is much more than a continent. In reality, James Cook explored the vast ocean and did much more than just circumnavigating Antarctica.

## “What is Gravity”

In a StarTalk episode, Neil deGrasse Tyson was given the question “what is gravity?” He quipped “we have no idea” before elaborating more. Flat-Earthers quoted it out of context to discredit Neil and gravity, completely disregarding what Neil explained afterward.

In reality, Neil did provide a very comprehensive answer to the question “what is gravity” but flat-Earthers only gave an emphasis to the “we have no idea” part of his answer, and skipped the rest of his answer.

## “Stuff is Flat”: Incorrect Neil deGrasse Tyson’s Claim About the Observation of Earth’s Curvature

Neil deGrasse Tyson once incorrectly stated that it is still too close to the surface to see Earth’s curvature from the height of Felix Baumgartner’s jump. In reality, we should be able to see it using our eyes.

Flat-Earthers believe people take Neil’s remarks as gospel and use Neil’s incorrect statement to dismiss any observation of Earth’s curvature. However, we have no problem saying that Neil was wrong. It is OK to be wrong as long as we are willing to revise our views when faced with new facts, and we are certain Neil will.