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.
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.
Continue reading “Sunset, Camera Zooming, and Autoexposure”
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”
During an equinox (March 20 and September 22-23), the Sun is directly above the equator. If we are on the equator, an upright stick will not have a shadow in the middle of the day.
On any other location, the angle between the stick and the direction of sunlight will be the same as the observer’s latitude.
This fact can only occur if the Earth is a sphere, and only if the Sun is very far relative to the size of the Earth.
Continue reading “The Angle of a Shadow During Equinox”
If we were to observe the direction to the Sun over the entire course of the day, on multiple locations on Earth’s surface, and then plot the results on the so-called flat-Earth map; then they would not consistently point to the position of the Sun that is calculated from its location on such map.
This fact happens because the flat-Earth map is not the correct description of the real Earth.
Continue reading “The Direction to the Sun vs the Position of the Sun”
The variation of the temperature at the different times during the day is the result of two primary causes: the difference of the thickness of the atmosphere the sunlight must traverse to reach the surface; and the change of the concentration of sunlight over the same surface area of the Earth.
Flat-Earthers claim that the change in Sun’s distance caused such a difference in temperature and that it can only be explained in a flat Earth. They are wrong.
Continue reading “Temperature Variations at the Different Times During the Day”
Any diagram showing two or more celestial bodies is almost never drawn in the correct scale. The reason is that in most cases, any two celestial bodies are spaced too far away relative to their sizes. It is just not possible to draw them in the correct scale and still effectively describes what we want to explain. We don’t have much choice other than drawing them not to scale.
The perpetrators of flat-Earth disseminate the allegations that the diagrams were drawn not to scale because of evil intentions, and not because of legitimate technical reasons. Some people don’t understand this and fell victim to flat-Earth indoctrination.
Continue reading “Total Lunar Eclipse, Drawn to Scale”
A long time ago, Babylonians carefully maintained records of the occurrence of eclipses and used these records to predict future eclipses. To honor that, in 1691, Edmund Halley named the interval in a cycle of eclipse using a Babylonian unit of time: the “Saros”.
NASA explained the Saros in a web page titled Eclipses and the Saros, and the unscrupulous flat-Earthers were quick to devise a conspiracy theory. They invented the scenario that NASA —a space agency with billions of dollars of a budget— are somehow using ancient technology to predict the occurrences of an eclipse. They are wrong. NASA does not use the Saros Cycle to predict eclipses.
Continue reading “The Saros Cycle and Prediction of Eclipses”
The distance to the Sun was first determined with a good accuracy from worldwide observations of the transit of Venus. A transit of Venus is a phenomenon where Venus passes in front of the Sun. By measuring the time Venus spends crossing in front of the Sun from two or more locations on the surface of the Earth, it is possible to calculate the distance to the Sun.
Flat-Earthers insist that it is impossible to determine the distance to the Sun in the globe model because sun rays are practically parallel. They are wrong. Using simple geometry, the distance to the Sun can be determined from the observations of the transit of Venus.
Continue reading “Determining the Distance to the Sun from the Transit of Venus”
At any given time, there is an equal area of the Earth that is experiencing daytime, and that is having a night time. The reason is that the sun is very far, and it would illuminate a hemisphere of the Earth, and leave the other dark.
If we plot which areas of the Earth that are getting sunlight on an azimuthal equidistant map centered on the north pole, the sun would appear to illuminate a somewhat elliptical area during the northern hemisphere summer, and a lopsided Bat-Signal shaped area during the winter. During the equinox, the sun would appear to illuminate a half-circle area.
Continue reading “Day and Night Areas on a Flat Earth”