A Landmark in Space - Spacetime Zero

Spacetime Zero is a concept and an event in space and time that is meant to provide a landmark in space, to simplify the use of time on Earth and in space, and to provide an interstellar coordinate system. The speed of the Earth and other entities can be more exactly expressed with regards to a fixed coordinate system in space, where they will have absolute locations in this frame of reference. When considering the subject of timekeeping in the future, with civilizations living in space, on other planets, or going on deep space missions, the current timekeeping methods in place are too Earth-centric. This paper describes the concept of Universal Spacetime, with its center at Spacetime Zero, what benefits it brings, and how it can help future spacefaring civilizations, as well as how it can be used now. It considers the speed of a point on planet Earth and describes: the zero-zero spacetime point – the Spacetime Zero event; universal coordinates; timekeeping; spacetime; spaceflight; the concept of Universal Spacetime, UST; and Greenwich Spacetime, GST.