Acrux

“Seize that impostor!” Ford screamed. Rority's nobotic robot simulation of Ford smiled. “It won't work, spy. Men, take this... whatever it is to an interrogation booth.”
Ford's eyes widened in terrified horror. “NO!” he screamed, “I'm the real General Ford! Please, no! Galaxy no!” He started shaking, and Rority absentmindedly noted that this was like time travel, where nobots did the actual traveling while making it look to the traveler like he's actually being transported in time. This was cool!
Ever since the supernova had ripped the shrouds of unreality from the underground Earthians' eyes and minds, Rority and other archaeohistorians had been busy studying the early days of their self-imposed nobotic imprisonment. They had found that the earliest time travelers knew they weren't really traveling through time, but were doing so by proxy; living cells never survived the trip, since traveling backwards through time involved speeds greater than the speed of light. Approaching lightspeed was akin to being in the southern hemisphere when the supernova went off. Just getting to Venus from Earth around the sun in a day or two put a strain on the radiation shields.
Of course, time travel was not like interstellar travel. Interstellar travel was accomplished by space and time itself being expanded and contracted. The radiation danger wasn't there.
Rority shook his head... too much stratodoobing, he really shouldn't let his mind wander like that. Now to visit General Washington.
Millions of miles away on the so-called red planet that no one any longer knew how it got its nickname, Colonel Gorn and Gumal were laughing hysterically.
“I'd better call Rority and see how things are going, then I need to talk to Rula,” Gumal said.
Gorn took a hit of Gumal's stratodoober and giggled. “Shame about the speed of light radio lag, how far away is Earth this week?”
“It doesn't matter,” Gumal said. “We have timeceivers. The signal is sent backwards in time as well as forward through space. I'm really incredulous that you fellows don't have this tech.”
“You can travel through time? Really? How do you do that?”
“Speed,” said Gumal. “Time slows down as you go faster. That was pointed out mathematically millions of years ago, 20 or 30 BB. At the speed of light it would seem to a traveler going to Proxima Centauri that they went there instantaneously, while to an observer here or there it would have taken four years, effectively putting them four years into the future. That's how to go forward. The closer you get to the speed of light the slower time goes in the rest of the universe relative to you. To go backward you pass C. Either direction in time, the farther and faster you go in space the farther and faster you go in time.
“Except,” he added, “that you can't go faster than light. Going much past a fraction of lightspeed kills everything in the ship that's alive because of all the redshift radiation, so we do it using nobots as a proxy. So Rority isn't going to be brewing any decent beer unless the nobots can get seeds and spores here with enough undamaged genetic material to recreate them.
“Actual space travel is different; you simply warp space.”
“Simply?” said Gorn, who promptly had another laughing fit. “I love this stratodoober thing, you need to get this tech to the Venusians. Galaxy knows those nasty creatures need to lighten up,” he said. “So, what is your partner's progress?”
“Give me a minute,” said Gumal, standing up. “I gotta pee. Only thing wrong with beer. I'll call Rority while I'm relieving myself... uh, where are your facilities?”
Yes, they still have to pee ten million years in the future. Especially when they've been drinking beer.
Back on Earth, Rula was bemoaning the entire situation. There was timework to be done, and here the two best timers she had were busy dealing with Martians and Venusians, because a protohistorian and an anthropologist were the closest things they had to diplomats.
And what about these so-called “controls”, the Amish? Well, at least they didn't have too much to worry about from them... unless Venusians showed up. She fervently hoped Rority would have no trouble.
Rority was both annoyed and amused. Annoyed with these primitive, violent Venusians and amused at what was going to happen to their leaders. Unknown to Washington, the nobots were streaming into his castle, attaching themselves to every inorganic surface. He would soon have a psychedelic experience that Timothy Leary would have been in awe of.
Rority had liked Leary, even if the old protobastard was batshit insane. Looking in hindsight, he was glad it was a nobotic surrogate and not him that had gone back, since LSD has no effect on nobots, but has a pretty profound effect on animals, including protohumans, humans, controls, Martians, spiders, and Venusians.
But Washington wasn't getting LSD, his trip would be real. It would be a real nobotic simulation.
Washington was eating dinner. He stuck his fork into the wolf meat... or tried. It moved out of the way. Startled, he rubbed his eyes and tried again.
“Please don't hurt me!” the meat begged. Washington snarled and tried again, when a translucent apparition walked through the wall.
“Washington!” it thundered.
“What...” Washington stammered, “what... who... what do you want?”
“I am the ghost of Alpha Crucis. I am what was left when the Acrux collided three hundred and twenty one years ago.”
“What?” Thought Rority. This wasn't supposed to be the program.
“What?” said Washington. “A ghost? What is Atrix? And who was this Mister Crucis?” Washington asked, perplexed.
“Acrux, not Atrix. Acrux was a star in the southern cross, a stellar system south of Venus that you can't see from here. Two artificial neutron stars in the Acrux system collided, destroying Acrux and every planet in the system.
“Two of the planets were settled from your planet half a million years ago, and they were at war with each other five hundred years ago. Both developed stronger and stronger weapons pretty much on the same time frames, and it culminated in both species developing neutron star construction capabilities within months of each other. Each constructed the biggest one possible, and each launched their weapon at the others' planet.
“Of course, the enormous masses of each astronomically tiny but astronomically massive star, meant to swallow the opposition's planet, attracted gravitationally and collided, resulting in a supernova that obliterated the entire Acrux system and sent huge amounts of gamma radiation straight at Sol.”
“Look, whatever you are,” Washington interrupted.
“Silence!” the voice of the nobotic apparition boomed. “Your very existence depends on your listening to me!”
Rority was puzzled; he didn't program that “Acrux” fertilizer into the apparition's speech. It couldn't really be bovine manure, so it must be something from the nobots' network database. He'd have to study this, of course, but later. He had to study Washington's reaction now.
“One planet was named Nuevo Venus, the other's name was Aphrodite,” the nobotic apparition continued. “Your people were both our parents and our executioners, and you executed over half your own population by sending us to Acrux. You are Guerra, as were we.
“Guerra is war. And war is its own enemy and its own executioner. To live by the weapon is to die by the weapon. To wage war is to die, stupid Venusling. Take heed, fool, or you will suicide as we did.”
The apparition vanished. Washington sat there with his mouth hanging open.
Rority laughed, took a toke from his stratodoober, sipped his beer, and began studying whatever it was the nobots were telling Washington. It was going to be a busy night.
He was really enjoying this.