100 years of General Relativity 

(November 2015)

Masses create dips in the space-time fabric which act as trajectories

A theory necessary for a 10km correction of a GPS signal: The spacetime of a satellite is less warped by the Earth's mass than the spacetime on the surface of the Earth

BBC iWonder

http://www.bbc.co.uk/guides/zs7d2p3

Excerpt/

"This is the main idea of general relativity and was summarised by the American physicist John Wheeler who said: "

'Matter tells space how to curve. Space tells matter how to move."

Note: Drop a big ball on a fabric: it creates a dip. Drop a smaller ball nearby: it will move on the trajectory of the fabric dip. 

Interactive also from http://www.bbc.co.uk/guides/zs7d2p3.

"Ultra-precise atomic clocks in the satellites run 45 millionths of a second faster per day than clocks here on the ground, deep in Earth's gravitational well."

"If those millionths of a second weren't taken into account when the satellite signals were synced, your GPS coordinates would be out by more than 10 kilometres."

http://www.abc.net.au/news/2015-11-25/einstein-general-relativity-100-years-on/6968370

Tweets