"a far future" is correct and usable in written English.
You can use it when you are referring to a period of time that is significantly different from the present day. For example, "Scientists predict a far future where global warming has led to catastrophic results."
It is hard to spend time at Bostrom's institute without drifting into reveries of a far future.
*** Dune is set in a far future, where warring noble houses are kept in line by a ruthless galactic emperor.
An unusual exercise, more akin to an exposition of the English authors poetics, this book is composed of long Socratic essays set in a far future that oddly resembles the ancient past.
Frank Herbert's Dune features a far future version of a religion that is inspired by Islam, a galaxy which is driven by religious precept, a messiah who assumes the role with reluctance and is essentially martyred in consequence.
Eve takes place in a fictional galaxy in a far future, where humanity has splintered into four competing factions, the theocratic Amarr, the militaristic Caldari, the liberal Gallente and the rebel Minmatar.
Missions are played out on Earth, and specifically (at least, in the Alpha) a far future Russia, where the only artifacts of Soviet power are the tank turrets poking from the verdant overgrowth.
The LAGR Learning Appliedd to Ground Robots) project aims to change the way the robot sees its environment, first by splitting it into a near, immediately navigable area and a far, future-navigable area.
This teenager witnesses the last spark of civilisation being snuffed out on a far-future Hawaii.
"I'll show you the ropes," he told her in half-mocking reference to the possibility of her return to a far-future world.
"The album is based around the idea of a far-future Earth, where the sun has expanded to the size of a red giant and our extinction is imminent," explains Lovett cheerfully.
It's a compulsively readable, life-affirming tale told in direct, lambent prose, and Chait does a masterful job of juxtaposing a traditional African setting with a convincing depiction of a far-future alien society.
