Since Bob wants to post a re-hashed video version of popsci's top 10 list I'll just bump this ancient post I made that debunks it all.
...
1. The Moon
2. Ships and the Horizon
3. Varying Star Constellations
4. Shadows and Sticks
5. Seeing Farther from Higher
6. Ride a Plane
7. Look at Other Planets
8. The Existence of Timezones
9. The Center of Gravity
10. Images from Space
Source: http://www.popsci.com/10-ways-you-can-prove-earth-is-round <--- DEBUNKED!1. The Moon Over the Flat Eartha) The Moon and the Sun in the sky at the same time during a lunar eclipse (this also proves the existence of the black sun).
b) The wrong side of the Moon occulted during an eclipse.
c) The cooling effects of Moonlight prove it's not reflected sunlight.
d) The distance to the Moon as measured by a sextant using plane trigonometry is ~3000 miles.
e) Stars are sometimes visible through the Moon.
f) Clouds are sometimes visible behind the Moon.
g) The NASA Moon landing is a proven hoax.
2. Ships and the Flat HorizonWhen a ship disappears beyond the horizon it's due to perspective and having traveled past the vanishing point.
3. Seeing Starsa) The north star Polaris is visible south of the equator as far as the tropic of Capricorn; impossible on a spherical Earth.
b) Airy's Failure experiment proves the Earth is stationary.
4. Sticks and Shadows Will Break their Skull and Bonesa) A sundial made from a stick that casts a shadow and used to determine solar time proves the heliocentric model is impossible by revealing the path of the Sun through the sky.
b) The example given by two sticks casting shadows à la Eratosthenes can be easily explained by a geocentric flat Earth.
5. You Can See Farther from Higher on a Flat EarthYou can see father from higher up due to perspective as the vanishing point distance is a function of elevation of the eye/camera from the ground.
6. Ride a Plane Over the Planea) An airplane can fly in a circle over the circular face of the flat Earth without stopping.
b) The windows in an airplane are curved and distort the image you see creating the illusion of a curved horizon.
c) Flight paths make no sense on a globe but make perfect sense on a flat Earth.
d) There's no GPS tracking of airplanes in the southern "hemisphere" proving GPS is actually Earth based.
e) Flight times don't jive with distances traveled in the southern "hemisphere".
f) Gyroscopic compasses on-board airplanes prove the Earth is flat.
7. Observation of Other Planetsa) Observation of planets shows them to be lights in the sky.
b) Close observation of planets by amateur astronomers with telescopic equipment reveals images that contradict those provided by NASA and the establishment, especially those of Venus.
c) Computer simulation of planetary orbits based on the heliocentric model results in chaos.
8. Flat Earth Time Zonea) The Sun rises and sets due to perspective; emerging from and disappearing into the vanishing point at the horizon. This results in the various timezones during its circular orbit above the flat Earth.
b) If the Earth were a rotating sphere completing one revolution every 24 hours the Sun would be over head at midnight every ~180 days.
9. Density Not Gravitya) An object that's denser than air will fall.
b) An object that's lighter than air will rise.
10. Images Not From Spacea) Images taken by amateurs with balloons all show a flat horizon that rises to eye/camera level and a Sun with a hotspot under it.
b) All NASA/establishment photos are taken at high altitude with a wide angle fisheye lens or are fake/CGI/composites.
c) Satellites are a hoax; GPS is achieved via cell towers, satellite TV signals are bounced off the dome and all international data is transmitted via undersea cables.