For the Aymara tribe, who lived somewhere in the Andes back in the 21st century, time was linear – the past was forwards, because you could see it, couldn’t you? And the future was obviously behind you. On your back, falling through time, more and more became visible.
When nostalgia for that area of time resurged in the 23rd century, a group of what would have once been called cultists formed the Aymara commune and bought a planet for the purpose.
By the 25th century, the planetary culture had been looking deeper and deeper (or higher and higher, depending on how you see it) into this way of experiencing time. Inevitably, when it came to building their first time machine, they built it to go back into the future, so for anyone who knew more, the vista in front grew bigger; they had more power. The past was always there, and if you wanted to look into it, there were already too many ways of doing it. It wasn’t interesting.
The contraption itself (the first of its kind, I mean – later ones were comparatively sophisticated) was made chiefly out of several belt-and-pulley systems. The traveller – or the rememberer, to use the term the Aymara preferred, to indicate the main purpose of remembering more than anyone else – would be tied up in a girdle, which would be violently pulled into the sky to the height of around 1000 feet at a great speed, and through a large hoop which formed the main travel mechanism, to literally be flung back in time. The first few travellers, it turned out later, died on arrival, mainly because when you arrive in the future, 1000 feet above the ground, with only the clothes on your back for company, it’s difficult to know what to do. Modifications were made later to allow for parachutes.