An analemma is an image or diagram showing the change in the position of the Sun in the sky, seen from a fixed location on Earth, at the same time every day, over the course of a year.
The north-south component of an analemma results from the change in the Sun’s declination due to the tilt of Earth’s axis of rotation. The east-west component results from the non-uniform rate of change of the Sun’s right ascension, governed by the combined effects of Earth’s axial tilt and orbital eccentricity.
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Because Earth is a sphere moving around the Sun, we can easily see the Milky Way’s center only in certain months. In other months, the Milky Way will be too close to the Sun in the sky, where sunlight will overwhelm and obscure it from view.
Flat-Earthers claim that the Milky Way is visible every night “proves” a flat Earth. In reality, we are inside the Milky Way, and some parts will be visible. However, a specific part of it, like its brighter center, will not be visible every night.
In astronomy, we use a celestial coordinate system to specify the position of celestial objects, like satellites, planets, stars, etc. Each of the coordinate systems has an origin, which can be the observer (topocentric), Earth (geocentric), the Sun (heliocentric), the Moon (selenocentric), or any other location. We choose a specific coordinate origin according to convenience and suitability for the problem at hand.
Some coordinate systems are described as “geocentric,” and flat-Earthers use it as “proof” of geocentrism, or that Earth is stationary and the center of the universe. In reality, it is just the origin of the coordinate. “Geocentric” here means Earth is the origin of the coordinate system. As we live on Earth, a geocentric coordinate is useful for many purposes.
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Planets appear to move near the ecliptic —the line that marks the annual path of the Sun against background stars. From these motions, it is obvious that Venus and Mercury are in motion around the Sun. And the motion of the other planets can only be explained if Earth is in motion around the Sun.
Flat-Earthers claim that Earth is stationary. In reality, from observing the planets’ motion, the most plausible explanation is that all planets, including Earth, are in motion around the Sun.
Anthropocentrism is the belief that human beings are the most important entity in the universe. Real-world evidence does not support many of the anthropocentric notions.
Anthropocentrism can be very emotional. Proponents of pseudoscience —like Flat-Earthers— exploit it to emotionally discredit science. However, scientific knowledge is gained from real-world evidence, not from what we prefer to be true. Science remains true whether or not we believe in it.
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Stellar aberration is the apparent shift of stars about their actual positions, depending on the direction Earth is moving in its orbit around the sun. It occurs because the speed of light is finite; it takes time for light to reach the observer.
Stellar aberration was discovered in 1727 by James Bradley. It was the first direct proof of heliocentrism, that Earth is in orbit around the sun.
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Geocentrism is a superseded description of the universe with Earth at the center. Under geocentrism, celestial bodies all orbited Earth. Geocentrism was the accepted model of the Universe for approximately 18 centuries; before we knew that Earth orbits the Sun —or what we call as heliocentrism.
We often observe flat-Earthers using the arguments for geocentrism as if it supports the flat Earth model. They are wrong. Under geocentrism, the Earth is a sphere, located at the center of the universe. It is not remotely compatible with the flat Earth model, which is an even more archaic understanding of the Universe.
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Flat-Earthers often bring Galileo into the discussion. They treat him as a ‘villain’ who supported the spherical Earth but unable to prove it as he failed to demonstrate the occurrence of stellar parallax.
They are wrong. The Galileo affair was in fact not about the shape of the Earth at all. It was about geocentrism vs. heliocentrism. Everyone involved already knew that the Earth is spherical.
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‘The Principle’ is a pseudoscientific documentary that promotes geocentrism, that the Earth is stationary and the center of the universe. Despite the fact that the film has almost nothing to do with flat-Earth, some flat-Earthers decide to use this film to bolster their beliefs. Because after all, in the flat-Earth model, the Earth is stationary and the center of the universe, right?
This actually gets more complicated than that. We are dealing with two forms of pseudoscience, that sometimes even goes against each other.
Continue reading “‘The Principle’: A Documentary Without Principle”