Shape of the Earth
The earth is not a perfect sphere because it bulges slightly at the centre and is flattened at the poles.
Proof that the earth is spherical in shape
1. Bedford Level Experiment
- Was carried out in the Bedford Level Canal in England
- Three poles of same length were fixed at intervals of 5km ensuring that same height was present above the water
- When viewed from one end it looked as if the middle pole was slightly higher
2.
Sighting of a ship - On a sea shore we can only see the mast of an approaching ship and as it comes nearer we can see the other parts