Curvature Analysis: Anacapa Islands from Miramar Beach

General Information

  • Claimed by: bmlsb69
  • Object 1:
    • Name: West Anacapa Island
    • Height: 930 ft (283 m)
    • Distance: 31.63 miles (51 km)
  • Object 2:
    • Name: Middle Anacapa Island
    • Height: 325 ft (99 m)
    • Distance: 31.63 miles (51 km)
  • Object 3:
    • Name: East Anacapa Island
    • Height: 250 ft (76 m)
    • Distance: 31.63 miles (51 km)
  • Observer
    • Location: Miramar Beach, CA, USA
    • Height: 3 ft (1 m)

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Lunar Craters

At any time, the Sun illuminates one half of the Moon and the other half dark. The phase of the Moon is the shape of the sunlit portion of the Moon as viewed by observers on Earth.

The phase of the Moon can never be adequately explained using the flat Earth model. To deal with this inconsistency in their theory, some perpetrators of flat Earth invented an ‘explanation’ that the phase of the Moon is not caused by sunlight. They are wrong. We can observe the Moon very carefully using telescopes of high-zoom cameras, and it will be evident how the lunar craters are lit. And this can only happen if the Moon is sunlit.

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Geocentric Coordinate System Does not Imply Geocentrism

In astronomy, a celestial coordinate system is a system for specifying positions of celestial objects like satellites, planets, stars, etc. The origin of the coordinate can be anywhere, including Earth. If the coordinate system is Earth-centered, we call it a geocentric coordinate system.

Flat-Earthers are often triggered by the term ‘geocentric’. They would search inside astronomy books and scientific journals to find the word ‘geocentric’. If they can find it, they would use the fact as ‘evidence’ of geocentrism, or that the Earth is the center of the universe, and the Sun is revolving around the Earth.

They are wrong. In many cases, the term ‘geocentric’ refers to the origin of a coordinate system. And it has nothing to do with whether the Sun revolves around the Earth or the other way around.

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Circumpolar and Non-Circumpolar Stars

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.

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Sun Path

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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Football Field and ‘Flat-Earth Convergence Experiments’

A properly designed football field does not lie perfectly flat. Its middle portion is slightly raised to promote runoff of excess water. Without it, the field can become muddy & uncomfortable.

Some flat-Earthers conducted the perspective convergence ‘experiment’. They put a camera on the surface of a football field, and record a person walking away across the field. The person started to disappear from his feet first. Because they felt the football field is flat, they took the wrong conclusion that the person disappeared due to ‘perspective’. They were wrong. The field is, in fact, not perfectly flat. If it is perfectly flat, the person would appear fully at the end of the field.

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Countering Gravity

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.

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Earth’s Curvature Calculation

The amount of obstruction of a distant object that is caused by Earth’s curvature depends on:

  1. The distance of the object.
  2. The height of the observer.
  3. The height of the object.
  4. The magnitude of atmospheric refraction.

Flat-Earthers like to use the visibility of a distant object to prove Earth’s curvature does not exist. Very often, they failed to account for observer’s height and atmospheric refraction, or make other mistakes, like unit conversions errors, distance calculation errors, etc. Once all are considered for, and mistakes are fixed, everything will be consistent with spherical Earth.

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Real Photos of the Earth

The first photo showing the entire Earth was taken in 1966 from the spacecraft Lunar Orbiter 1. Since then, there are too many photos showing the whole earth taken from various missions to space.

The advent of computers in the 80s introduced a new technique of generating such pictures. A satellite can be used to take many photos of the Earth from a low orbit, and computers can be used to assemble those pictures into a single photo of the Earth.

Flat-Earthers ‘discovered’ such technique, then they concluded that all pictures of the Earth taken from space are all composites, the results of manipulation or assembled by computers. They are wrong. Just because there were pictures created using such technique, it doesn’t mean there is no genuine picture showing the entire Earth, not composites, not stitched, and were taken from a single shot.

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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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Infrared Vision

When we are unable to see a distant object, then it is due to one of these reasons:

  • Our eyes lack the sufficient angular resolution to recognize the object.
  • Atmospheric condition limits visibility.
  • The object is far enough and obscured by Earth’s curvature.

Some flat-Earthers like to show that a previously unseen distant object can be brought into view using infrared vision. They would take that as ‘evidence’ of the non-existence of Earth’s curvature. They are wrong. Infrared vision can reveal hidden objects caused by visibility limitations, but not ones obscured by Earth’s curvature.

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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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Illuminated Fraction of a Full Moon

A lunar eclipse does not happen every month because the orbit of the Moon is tilted 5.145° to Earth’s orbit around the Sun. And thus, the Earth does not always cast its shadow on the Moon during maximum opposition. Instead, a full moon occurs.

Some flat-Earthers take this as ‘evidence’ that a full moon cannot possibly happen because the geometry does not allow for a 100% illuminated Moon. They are wrong. In reality, a full moon is never 100% illuminated.

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Observations of Sunspots From Multiple Locations on Earth

Sunspots are darker spots on the surface of the Sun. The location where sunspots appear is unpredictable, but the appearance of sunspots is always the same when observed from anywhere on Earth; only the orientation is different on different observer location. Observers on the opposite position on the Earth will see the sunspots reversed. The reason is that the Earth is a sphere. Any two observers on Earth’s surface are not standing on the same plane.

Some flat-Earthers have spatial awareness difficulties and present the difference of the appearance of sunspots as ‘evidence’ the Earth is not spherical. They are wrong. If the Sun were close as in the flat Earth model, we would see the different appearance of sunspots on the different observer location. In reality, everyone on Earth observes the same appearance of sunspots, only with the different orientation that corresponds to the position of the observer.

Astrolabe

Astrolabe is an astronomical instrument for measuring the altitude of the sun or stars, and to determine the solution of various problems in astronomy, time, and navigation. Astrolabe was used from classical antiquity, about 2nd century BC,  until the age of discovery where it was superseded by the more accurate sextant, star charts, and time-keeping devices.

Flat-Earthers claim that astrolabes can only work because the Earth is flat. They are wrong. Astrolabes were designed using the spherical Earth model. To use an astrolabe, a good understanding of the spherical Earth model is required.

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Sunset, Camera Zooming, and Autoexposure

There are videos showing the sun to appear to set, but after the camera is zoomed in, the sun is still above the horizon. The reason is that the camera’s autoexposure system is constantly adjusting the exposure, and in such scenes, there’s a difference in overall brightness before and after zooming in.

Flat-Earthers are taking such videos as ‘evidence’ of a receding sun. They are wrong. This is merely a matter of photography. In reality, the sun is not receding, and it has the same angular size throughout the day.

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Geometry of a Full Moon

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.

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Salar de Uyuni and Other Salt Flats

Salt flats are flat expanses of ground covered with salt and other minerals. Salar de Uyuni in Bolivia is the world’s largest salt flat. Salt flats are visibly very flat, but like every other geology features, they all follow the curvature of the Earth.

Flat-Earthers take the flatness of Salar de Uyuni and other salt flats as ‘evidence’ of a flat Earth. They are wrong. While most salt flats appear flat, they still gradually curve and follow the curvature of the Earth.

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