The earth is flat

Since making an argument for ones statement seems to have gone out of fashion, I'll just lay down my own. 1.(a) Lunar eclipses: During lunar eclipses, the projected shadow of the earth on the moon is always rounding. If the earth were flat, then this projection will not always be circular (we would see clear evidence of a line if a flat earth were true). (b) If you travel north or south a significant distance, you will see a different set of stars at night. This will not happen on a flat surface. This indicates that the Earth's surface curves away and downward from wherever you stand. This is also apparent from a ship moving away over the horizon, hull disappearing first - or moving towards over the horizon, tallest point visible first. (c) If the Earth was flat then satellites would soon crash to ground as they require a constant equality between gravitational force experienced from a spherical object and their speed to maintain an orbit. Likewise calculating any slingshot from orbital travel would be rendered impossible, calculating re-entry would also be rendered as such. (d) The times at which sunrise, sunset, the rising and setting of stars, and eclipses are seen to occur differ at different longitudes. This would be true on a spherical Earth but not on a flat Earth. 2. Eratosthanes (long time dead) measured the angle of the sun at noon in Alexandria, Egypt, and in Syrene. Finding the difference in the angles and knowing the distance between the two points, the circumference of the Earth was calculated fairly accurately. Similarly simultaneously one can measure the length of the shadows cast by identical poles perpendicular to a flat surface that is tangential to the earth's radius at various, distant locales. If indeed the earth is spherical, then the shadows should all vary in length from one distant location to another (which they do!). This means that the angle at which the parallel rays of sunlight struck each pole varied from one location to another. If the earth is flat, then it would be expected that the lengths of the shadows would be equal when measured concurrently, since the rays of sunlight that strike the earth are parallel. They are however not identical. The variance can only be explained reasonably in a way that's congruent with angles that indicate a spherical surface. 3. If you climb higher, you can see further. On top of a large building, or in an airplane, you can see things that are invisible *below the horizon* when you are on the ground. Even on a flat unobstructed plain, one is able to watch the Sun set, and at the point when the Sun is falls just below the horizon, climb/fly quickly up and see the Sun again. 4. (a) Tides: If the Earth were flat, then there would be no tides, because the tides depend on there being a substantial distance between the near and far sides of the Earth, from the point of the Moon and Sun. (b) Think of the mass being concentrated at a point in the centre of the earth. Gravity acts outward perpendicular to the source. Gravity acts, therefore, *radially* out from the centre of the earth. Since the force of gravity is roughly the same everywhere on the globe, it equates that the Earth must be spherical. Equally, if the Earth was not spherical, there would be marked differences in atmospheric pressure and significantly different sea levels across hemispheres. 5. How can it be noon and midnight simultaneously? An impossibility with a flat Earth, not so with a spherical one. Keep in mind the size of/distance from the sun here. :) 6. The South Pole has been located exactly. On a given day at this point, the sun is lower in the sky than anywhere else on earth, because the South Pole is the *southernmost* point. No insuperable ice wall has been discovered in Antarctica (assuming you are running with the standard flat Earth model). No photos from space are apparent of such a thing. 7. Seasons: A flat Earth model conflicts with the evidence that the solar angle oscillates by the same amount at every latitude. On a flat Earth, the angle would oscillate less at high latitudes than at low latitudes. http://www.astrosociety.org... 8. Finally for now, the ubiquitous images of Earth from space in these debates. http://www.nasaimages.org... http://www.nasaimages.org... http://www.nersc.gov... http://www.svs.net...