A circumpolar star is a star, as viewed from a given latitude on Earth, that never sets below the horizon due to its apparent proximity to one of the celestial poles. Circumpolar stars stay up there in the sky, even during the day.
Flat-Earthers claim the Earth is stationary because the same stars are always visible in the sky. They are wrong. Only circumpolar stars are always in the sky. There are others that are not circumpolar. Some are only visible during certain times in a year.
Continue reading “Circumpolar and Non-Circumpolar Stars”
In the Northern hemisphere, the Sun appears to move to the right. In the Southern hemisphere, it appears to move to the left. During sunrise and sunset, the path of the Sun forms an angle that roughly corresponds to the latitude of the observer. This phenomenon occurs because observers on the different locations on Earth’s surface is not standing on the same plane.
The path of the Sun observed from many different locations on Earth’s surface is evidence of spherical Earth. This observation cannot possibly occur on a flat Earth.
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Gravity is not the only force. There are other forces, too. Multiple forces can simultaneously affect a single object. Forces can counteract gravity, making an object move against the direction of gravity. Such facts do not disprove gravity.
Flat-Earthers take the fact there are objects that move against the direction of gravity as ‘evidence’ of the non-existence of gravity. They are wrong. There are forces other than gravity affecting the object, having the opposite direction from gravity, with at least the same magnitude.
Continue reading “Countering Gravity”
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.
Continue reading “Newton’s Law of Universal Gravitation”
Some people are confused that a full moon is visible all night, and think if the full moon is the result of the opposition of the moon from the sun, then a full moon should be visible only at midnight.
Flat-Earthers who have such spatial visualization problem take a step further and use it as ‘evidence’ that the Earth is not a sphere. They are wrong. The full moon phenomenon can easily be explained in the spherical Earth model.
Continue reading “Geometry of a Full Moon”
We cannot travel to another location by hovering inside a helicopter and wait for the Earth to rotate below us until we are above our destination. The reason is the phenomenon of inertia.
Flat-Earthers claim that we cannot do such a thing as ‘proof’ of a motionless Earth. They are wrong. When on the ground, the helicopter itself is already moving at the same velocity as Earth’s surface.
Continue reading “Helicopter and Earth’s Rotating Motion”
There are several models explaining the figure of the Earth. These models vary in the way they are used, in their complexity and in the accuracy with which they represent the size and shape of the Earth. These models are sphere, ellipsoid, and geoid.
Flat-Earthers often take the existence of these multiple models as evidence of disagreement among scientists, and that the shape of the Earth is still in contention. They are wrong. All these models are valid models, only with different complexity and accuracy.
Continue reading “The False Dilemma of the Figure of the Earth”
Most combustion engines work with oxygen from Earth’s atmosphere as its oxidizing agent in the combustion process. But in the case of rockets, there’s no oxygen in space. It would have to bring the oxidizer in addition to its fuel or use monopropellant which doesn’t require an oxidizer.
Flat-Earthers claim rockets should not be able to work in space because there’s no oxygen in space. They are wrong. The lack of oxygen in space is merely an engineering problem which is not impossible to solve. Rockets are engineered to carry its oxidizer or utilize monopropellant which does not require an oxidizer.
Continue reading “Rockets and the Lack of Oxygen in Space”
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”.
Continue reading “The so-called “Experiment” Done by Flat-Earthers”
Drag is a force acting opposite to the relative motion of an object moving with respect to a surrounding fluid. The higher the density of the fluid, the higher the magnitude of the drag.
Flat-Earthers claim that it is impossible for satellites to have such high speed. Usually, they would compare the speed of satellites to something like the SR-71 Blackbird, which holds the record as the fastest aircraft. They are wrong. At the altitude where satellites reside, the air density is several magnitudes smaller compared to near the surface, and thus, the drag experienced by satellites is also several magnitude smaller.
Continue reading “Drag”