The DFH doesn't claim that the aliens would be "god-like" per your definition. They just have a first-strike capability and motive to use it. Could be a low risk-tolerance for coexisting with other aliens. Or something else. Either way, you don't have to suspend disbelief because you're arguing with a strawman you created.
jonathankoren|3 years ago
At 1% the speed of light, it will take 10 million years just see if you hit anything on the other side of Milky Way. If you have to wait 10 million years, why do you even care? You'll be extinct, as will your target.
Even if you do decide chuck a dinosaur killing sized boulder (which, really is probably the smallest you'd want to use), you'd have expend 4.5 * 10^23 joules just to accelerate it. That's equivalent of all the solar radiation that hits the Earth over five days. That's a huge lift for even a supposed Kardashev I civilization. It's something more practical for a Kardashev II civilization. Although to be fair, the practical threshold is probably somewhere between I and II. And let's be clear here. If you're dismantling planets to build mirrors, you're Galacticus.
Anyway, how would the decision to throw a rock across the galaxy even work? A civilization obtains Kardashev II, and immediately starts looking for Kardashev Is or earlier, and starts tossing rocks at them, just in case they don't go extinct in 10 million years, and somehow don't also become a Kardashev II in the next 10 million years, because as soon as they do, they're going to hit you with a rock in 20 million years? To put that in perspective, 20 million years ago was when apes and monkeys split on the evolutionary tree. 10 million years ago was when humans and apes split. At this point, you might as well toss a rock at every planet that has a biosignature, because 10 million years is a long time. Better keep tossing rocks in that direction, in case something else evolves. Maybe you better toss a planet at it, just be sure. That's only 2.19 * 10^37 joules, or 200 years of the sun's output. Shit. You better be Kardashev III. Wait! We know there aren't any Kardashev IIIs in the observable universe! Double shit!
If this casually genocidal Kardashev II civilization exists on the far side of the Milky Way, and wanted kill humanity, they'd be looking at homo erectus. They'd have wait another 100,000 years just to get a radio signal, and then what? Throw the rock immediately, and hope that in the ensuing 10 million years humanity hasn't learned how to redirect a relativistic rock? Or maybe they just threw the rock without even waiting for the radio signal, and it's on its way right now! Maybe the asteroid that hit 65 million years ago was a warning shot! Maybe they were trying to kill off a potential Silurian civilization before it even got really started, and ironically spawned us!
This strains credulity.
linkdink|3 years ago