Category: Gravity

Spirit Level on an Airplane

During cruising, an airplane is practically level. It is flying perpendicular to the direction of gravity. The aircraft is still flying following Earth’s curvature and continuously changes its orientation. However, not only its orientation changing but also the direction of gravity, having the same amount of change. As a result, a spirit level on a flight will not show us the difference in orientation of the airplane due to its motion following the curvature of the Earth.

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Electromagnetism

The electromagnetic force is a type of physical interaction that occurs between electrically charged particles. Electromagnetism is different from gravity. Both phenomena are real but have different characteristics.

Flat-Earthers refuse to accept gravity, and some of them use electromagnetism in place of gravity to explain the various phenomena that are explained by gravity. In reality, electromagnetism has different characteristic from gravity, and cannot explain the various phenomena that are explained by gravity.

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Antipodal Tide

Tides are the result of the variation of lunar gravitational acceleration over all the material of which the Earth is composed. They are not caused by the magnitude of such acceleration exerted on a specific location only.

Flat-Earthers discovered that the position away from the Moon is also having a tide, not just the location where the Moon is directly overhead. Then, they were happy to proclaim that it is a failure of science to explain tides. In reality, tides are the result of the variation of lunar gravity over the entire Earth, not just the magnitude of the lunar acceleration on a single location only.

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Egg and Salt Water

An egg will generally sink in freshwater, but if we pour salt into the water and stir it, then the egg will start to float. The reason is that after salt is added, the density of water increases. However, the relationship between density and if the egg floats or sinks is not a direct causality.

Flat-Earthers claim that the phenomenon “proves” things fall because of density, and that gravity does not exist. In reality, the density of the water determines the magnitude of buoyancy the egg receives. If the buoyancy is higher than the weight of the egg, the egg will float, and vice versa.

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Shell Theorem

Shell theorem is a simplification stating that a spherical body affects external objects gravitationally as though all of its mass were concentrated at a point at its center.

The direction of Earth’s gravity toward the center of the Earth made some flat-Earthers to assume that we think gravity is caused by something in the center, and that our inability to go there “disproves” gravity. They are wrong. Earth’s gravity is the result of the entire mass of Earth. Using the center of the Earth is merely a simplification.

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Vacuum in Space and Earth’s Atmospheric Retention

The Earth retains an atmosphere because gravity pulls air particles toward the center of the Earth. Without something affecting the air —like gravity— air particles would move toward lower pressure, and Earth would lose its atmosphere.

Flat-Earthers claim that Earth should not be able to have an atmosphere because without any barrier separating Earth’s atmosphere and space, it would have been sucked by the vacuum in space. They are wrong. Gravity pulls air and allows Earth to retain an atmosphere.

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The Ball and Water ‘Experiment’

Gravity is the attraction between objects with mass. The higher the mass, the greater is the gravitational attraction. Gravity is not the result of the shapes of the objects.

Flat-Earthers like to perform the ball-and-water ‘experiment.’ They spray water to a ball, then observe the water does not stick to the ball the same way the ocean water curves over the surface of the Earth. They would wrongly conclude that “gravity does not exist.” Gravity does not come from the spherical shape of objects, Continue reading “The Ball and Water ‘Experiment’”

Einstein’s Thought Experiments and Daydreaming

Albert Einstein used thought experiments as a tool for formulating his theories. His theories provided predictions that can be tested in observation and experiments. He did not perform the observation and experiments himself. Others did and confirmed his theories.

Some flat-Earthers dismiss Einstein’s theories —especially those about gravity— on the basis that they are founded on thought experiments and daydreaming. They are wrong. His theories have been repeatedly confirmed by various experiments and observation performed by many others, even to this day.

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Buoyancy

Buoyancy is an upward force exerted by a fluid (liquid or gas) that opposes the weight of an immersed object. Buoyancy happens because the fluid has a pressure gradient. Pressure gradient occurs because the fluid is affected by acceleration, such as the Earth’s gravitational acceleration.

Flat-Earthers makes buoyancy as an “explanations” on how things fall. They are wrong. Without Earth’s gravitational acceleration, buoyancy will not occur.

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Orbital Station-Keeping

A satellite in a high enough orbit can remain operational for a very long time because in space there is practically no air resistance. This is a situation that never occurs in our everyday life. A car requires a constant consumption of fuel to keep running, but a satellite can remain in motion without consuming any fuel because there’s practically no force stopping it.

Flat-Earthers claim that satellites cannot stay up there for such a very long time because ‘we never refuel any satellites.’ They are wrong. In space, there is practically no drag, and satellites only need to consume fuel to adjust their speed periodically.

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Newton’s Law of Universal Gravitation

Gravity is a natural phenomenon by which all things with mass or energy are brought toward each other. In 1687, Isaac Newton explained the phenomenon as a force, which was formulated in Newton’s law of universal gravitation.

Flat-Earthers insist that gravity does not exist. But this is only a result of a mere ignorance on how gravity works. Everything in our lives is consistent with what is explained in Newton’s law of universal gravitation.

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Schiehallion Experiment

The Schiehallion experiment was an experiment to determine the mean density of the Earth. It involved measuring the tiny deflection of a pendulum due to gravitational attraction from the mountain of Schiehallion, Scotland. The measured deflection was 11.6″ or 0.003°.

Flat-Earthers claim that it is impossible to demonstrate gravity and that it is evidence gravity does not exist. They are wrong. The Schiehallion experiment was one of the first practical experiments of gravity done on Earth.

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The so-called “Experiment” Done by Flat-Earthers

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We often see flat-Earthers create a ‘miniaturized physical model’ of a real object and present them as ‘proof’ in support of flat-Earth and against spherical Earth. Their M.O. is to observe if the model remotely resembles the actual object in a particular way. If it does, then it is enough for them to conclude the model describe how the real object works.

Conversely, if a real object cannot be miniaturized and still have the same behavior as the original object, they would conclude that the behavior of the original object doesn’t exist.

They would wrongly call creating such models “doing an experiment”.

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The Earth is Spherical and The Nile Never Flows Uphill Anywhere

The Nile never flows uphill, or in other words, ascend to a location farther from sea level anywhere in the Nile basin.

Flat-Earthers often claim that if the Earth is spherical, then the Nile will have to flow uphill to overcome the curvature of the Earth. They are wrong.

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The Earth is Spherical and The Mississippi River Never Flows Uphill Anywhere

The Mississippi River never flows uphill, or in other words, ascend to a location farther from sea level anywhere in the Mississippi River basin.

Flat-Earthers often claim that if the Earth is spherical, then the Mississippi River will have to flow uphill to overcome the curvature of the Earth. They are wrong.

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Neptune and Newton’s Law of Universal Gravitation

Unlike other planets that were found by empirical observation, Neptune was found by mathematical prediction involving Newton’s law of universal gravitation.

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The Hypothesized Graviton and Flat-Earthers’ Zeal to Disprove Gravity

Some flat-Earthers mentioned the fact that graviton —the mediating particle of gravitation— is ‘not yet observed’. They took this fact as ‘proof’ that gravity does not exist.

Often they would triumphantly show us screenshots of the table of fundamental particles they took from Wikipedia and other sources. In the ‘gravitation’ column, they would point out its mediating particle has not been observed yet. And they would conclude that scientists are aware gravity does not exist, and we all have been lied to.

Obviously, they are wrong on all accounts.

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The Earth is Spherical and The Amazon Never Flows Uphill Anywhere

The Amazon never flows uphill, or in other words, ascend to a location farther from sea level anywhere in the Amazon basin.

Flat-Earthers often claim that if the Earth is spherical, then the Amazon will have to flow uphill to overcome the curvature of the Earth. They are wrong.

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Equipotential: a Property of the Surface of Water

Gravity causes water to seek the lowest potential, which can be simplified as the position as close as possible to the Earth’s center of gravity. As a result, the surface of the water will have equipotential surface and form an approximately spherical surface which has the same center as the Earth. Every location along the surface has the same potential.

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Hot Air Balloon and the Force of Gravity

A hot air balloon rises because it has buoyancy. Buoyancy is the upward force that is exerted on the trapped hot air because its density is lower than the surrounding air. If buoyancy is greater than the force of gravity — or the weight of the balloon—, then the balloon will rise.

The basic physics escape most flat-Earthers. To them, the fact that a hot-air balloon rises is an ‘evidence’ that gravity does not exist. They believe things go up or down because of density. They are wrong.

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