add flat earthers to the group on the right.

Earth’s Curvature Calculation.The amount of obstruction of a distant object caused by Earth's curvature depends on object distance, observer height, object height & atmospheric refraction. #flatearth #researchflatearth #flatearthsociety

What do you want to know?.

Real Photos of the Earth.The existence of composite Earth photos is not proof all Earth photos are composites. There are many real photos showing the entire Earth that were taken in a single frame,.#flatearth #researchflatearth #flatearthsociety

does anyone know what happened to @RocketRagnar? he used to regularly post useful information about navigation etc. but it seems his account no longer exists.

Orbital Station-Keeping.A satellite does not need to be constantly refueled. In space, there's practically no drag. A geostationary satellite needs speed adjustment (Δv) of only 182 km/h per year. #flatearth #researchflatearth #flatearthsociety

The infamous flat-earth personality here in Indonesia —who names himself 'bossdarling'— is a little too successful. People fall victim to his drivel every day. We call these new victims "fresh graduates".

Infrared Vision.Infrared vision might reveal objects beyond visibility limitations but will never reveal objects obstructed by Earth's curvature. #flatearth #researchflatearth #flatearthsociety

Newton's Law of Universal Gravitation.Gravity causes two objects with mass m1 and m2 to have the force F toward each other. We call the force of gravity resulting from the mass of Earth as 'weight'. #flatearth #researchflatearth #flatearthsociety

Illuminated Fraction of a Full Moon.Flat-earthers think the lunar orbit does not allow a full moon to occur & an eclipse should occur instead. They are wrong. A full moon is almost never 100% illuminated. #flatearth #researchflatearth #flatearthsociety

Observing the ISS from ISS Transits.ISS transit is where the ISS passes in front of the Sun or the Moon, and is relatively easy to capture. This can be used to show flat-Earthers that satellites really exist. #flatearth #researchflatearth #flatearthsociety

so, what can we do on a flight to prove globe earth and disprove flat earth & related hoaxes? I can think of:. 1. measuring the dip of the horizon (easy).2. confirming that GPS works (easy).3. confirming horizon curvature (medium).4. measuring eotvos effect (hard). anything else?.

Observations of Sunspots From Multiple Locations on Earth.The appearance of sunspots is identical from anywhere on Earth, only with the different orientation. This proves spherical Earth & the Sun is very far.#flatearth #researchflatearth #flatearthsociety

one of the most extreme cases of cognitive dissonance involving #flatearth happens when any Muslim flat-earther is being told he actually performed his rituals using the results from spherical earth calculations, and practically wouldn't be able to do so otherwise.

Astrolabe.An astrolabe consists of rete: a star chart, centered on NCP using the stereographic projection; & mater: marks the boundary of visible stars. It cannot possibly work in a flat earth. #flatearth #researchflatearth #flatearthsociety

Sunset, Zooming, and Autoexposure.There are videos showing sunset, but after zooming in, the sun is shown above the horizon. The reason is that the camera's autoexposure system is adjusting the exposure. #flatearth #researchflatearth #flatearthsociety

A strong earthquake+tsunami hit Sulawesi several hours ago. Predictably (and sadly), flat-earthers & conspiracy types here are already making noises in social media telling people the disaster was not natural but artificial, using HAARP or bomb as "explanation".

Geometry of a Full Moon.Some flat Earthers claim if Earth is a sphere, then a full moon should only be visible at midnight. This is simply a spatial visualization problem. #flatearth #researchflatearth #flatearthsociety

a local flat earther "experiment". "proving" the moon is shaped like a frying pan.

Salar de Uyuni.Salar de Uyuni and other salt flats are visibly very flat, but they are not perfectly flat. Their surface follows the curvature of the Earth, like every other surface features on Earth. #flatearth #researchflatearth #flatearthsociety

Angle of a Shadow During Equinox.During an equinox, the angle of a shadow produced by sunlight at noon is the same as observer's latitude. This can only happen if the Earth is a sphere & the Sun is very far. #flatearth #researchflatearth #flatearthsociety