1. The distance between the N&S poles is est 12.000km.
2a) To notice any difference BY WALKING that distance that would take years, it would have to be based upon the observation of sunrise & sunsets, as well as moonrise & moonset based upon the start of the journey.
2b)While such may not dissipate the observation of a globed Earth & may perhaps even lend credence that that Earth is the centre of Universe whereby the Sun & Moon revolves around, the fact remains in mathematical sciences taught since primary schools - the tangent - calculation of a straight line against a circle.
2c)Based upon the mathematical calculation of a tangent - l = √(d² - r²), it would take you to walk 4.8km before you can notice the curvature of planet Earth, eg - from Bishan to Novena.
Worse, as you will be travelling either by foot -eg 3km/hr or by car 60km/hr upon a REVOLVING planet Earth which revolves at 107, 826.05km per hour it would seemed that you are walking straight forever....
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