Sextant

According to Aristotle, pre-Socratic philosophers believed in a flat Earth. Galileo overthrew the physics of Aristotle, however it fell to Isaac Newton to bring these threads together and to demonstrate that the laws that governed the heavens were the same laws that governed motion on the surface of the Earth.

In 1742, a paper was discovered in Newtons handwriting describing an instrument consisting of a sector of brass, the arc of which, though only equal to one-eighth part of a circle, is divided into 90°. A telescope is fixed along a radius of the sector, the object-glass being close to the centre and having outside it a plane mirror inclined 45° to the axis of the telescope, and intercepting half the light which would otherwise fall on the object glass.

Before Newton's plan was published the sextant in its present form was invented by John Hadley. A sextant can be used to measure the Lunar distance between the moon and another celestial object in order to determine Greenwich time which is important because it can then be used to determine the longitude.

The WBC theme this week is Philosophy - hope you enjoyed my take on the subject.