Single Idea 22747

[catalogued under 27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement]

Full Idea

If a ship moves forward and a man carries a rod backwards on it, then it is possible for an object to move without quitting its place.

Gist of Idea

A man walking backwards on a forwards-moving ship is moving in a fixed place

Source

Sextus Empiricus (Against the Physicists (two books) [c.180], II.056)

Book Reference

Sextus Empiricus: 'Against the Physicists/Against the Ethicists', ed/tr. Bury,R.G. [Harvard Loeb 1997], p.239


A Reaction

[summary of a verbose paragraph] The point is that you cannot define movement as change of place (contrary to Russell's proposal!). The concept of a place seems to be relative. Walking on a treadmill.

Related Idea

Idea 14168 Occupying a place and change are prior to motion, so motion is just occupying places at continuous times [Russell]