[ WP ] The Earth does not rotate . One side always faces the sun and is in continual daylight . The other side is in eternal night . Cultures on both side develop around this .

Wow, crazy but I actually wrote a story to more or less the same prompt a while ago ( not Earth but same premise ). Here it is ( bit long, sorry ): 
 
 
 **Life Sentence** 
 
 
 A sudden and uncomfortable quiet resonated throughout cell block F. The deafening roar of the abrupt silence was so startling that the hair on Warden Myloch ’ s arms stood at attention. “ Why ’ d he stop? ” Myloch barked at one of the assigned guards who ’ d just arrived to tail him for that shift. Myloch had never bothered to learn his name. Nor anyone else ’ s for that matter. 
 
 
 The anonymous guard attempted to stammer out a response, but the inexplicable cessation of the raucous cacophony that continuously emanated from cell F-2358 left the guard trembling and speechless in the face of his fearsome superior officer. His face was pale and gaunt from the long shifts, like most of the guards at the First Akronos Colony Penitentiary. Myloch ignored his sputtering inferior and took off to cell F-2358, walking at a pace so brisk that the other guards assigned to his detail accelerated to a light jog just to keep up behind him. Myloch glanced at the cardiometer on his wrist that measured the remaining heartbeats in his shift. Only 11,000 beats in, Myloch thought to himself. It ’ s going to be a long one. 
 
 
 In all his shifts at the Akronos ColPen, never once had Warden Myloch heard the pounding and screeching that rang out from cell F-2358 stop. Myloch had been there almost as long as Prisoner F-2358, who had been sentenced to serve a billion-heartbeat prison sentence, a punishment reserved only for murderers. The prisoner had begun early on in his sentence to drum noisily on the walls of his cell, eventually evolving into a complex rhythm assumedly meant to occupy the seemingly endless time spent in the perpetual twilight of this damned planet. However, the slow ticking of Prisoner F-2358 ’ s sentence gradually infused his beats with a sickness, an expression of his deteriorating mind. The once mildly pleasant rhythmic pounding devolved into a discordant racket of screeching and body slapping that didn ’ t even stop during Prisoner F-2358 ’ s brief and seldom naps. The guards weren ’ t sure if he actually slept, or merely rested his eyes. 
 
 
 Myloch held a bloodshot and fearsome eyeball to the retina scanner adjacent to the mysteriously silent prisoner ’ s cell, unblinking as the harsh light inspected his eye. The door buzzed loudly to alert the guards of its opening, then quickly slid up to reveal the cramped cell. Prisoner F-2358 ’ s grotesque body lay face-down and unmoving on the bare concrete floor, the cardiometer on his outstretched arm repeatedly blinking an error message. 
 
 One of the guards behind Myloch entered the dim cell and read the cardiometer. “ 318,532,110 beats left. The poor bastard was getting close. ” 
 
 Another nameless gray-suited guard turned to one of his associates. “ What do you think did him in? ” 
 
 “ Looks like Ole ’ Howler just ran out of time. The heart was bound to go one of these days the way he was carrying on. ” 
 
 “ He was probably going to make it out of here in record time with the way he screamed. I ’ m sure it kept his ticker pumping double time. ” 
 
 Myloch stared blankly at the prostrate body, which occupied nearly the entire space of the cement cell. Paperwork and bureaucratic bullshit just waiting to happen. He ran a callused hand through his thinning hair. “ Alright, quit dicking around here you little chicken shits, ” he barked. “ Let ’ s get this son of a bitch out of here. ” 
 
 “ You don ’ t want to wait for a coroner? ” one of the guards somehow dared ask. 
 
 “ That won ’ t be necessary. ” Myloch swiveled on one heel and headed down the hall to continue his shift ’ s rounds. 38,576 beats left in the shift. He would be counting every one. 

