The great silence
(i.e. absence of SETI signals from alien civilizations) is perhaps the strongest indicator of all that high relativistic velocities are attainable and that everybody out there knows it.
The sobering truth is that relativistic civilizations are a potential nightmare to anyone living within range of them. The problem is that objects traveling at an appreciable fraction of light speed are never where you see them when you see them
(i.e., light-speed lag). Relativistic rockets, if their owners turn out to be less than benevolent, are both totally unstoppable and totally destructive. A starship weighing in at 1,500 tons (approximately the weight of a fully fueled space shuttle sitting on the launchpad) impacting an earthlike planet at "only" 30 percent of lightspeed will release 1.5 million megatons of energy -- an explosive force equivalent to 150 times today's global nuclear arsenal...
I'm not going to talk about ideas. I'm going to talk about reality. It will probably not be good for us ever to build and fire up an antimatter engine. According to Powell, given the proper detecting devices, a Valkyrie engine burn could be
seen out to a radius of several light-years and may draw us into a game we'd rather not play, a game in which, if we appear to be even the vaguest threat to another civilization and if the resources are available to eliminate us, then it is logical to do so.
The game plan is, in its simplest terms, the relativistic inverse to the golden rule: "Do unto the other fellow as he would do unto you and do it first."...
When we put our heads together and tried to list everything we could say with certainty about other civilizations, without having actually met them, all that we knew boiled down to three simple laws of alien behavior:
- THEIR SURVIVAL WILL BE MORE IMPORTANT THAN OUR SURVIVAL.
If an alien species has to choose between them and us, they won't choose us. It is difficult to imagine a contrary case; species don't survive by being self-sacrificing.
- WIMPS DON'T BECOME TOP DOGS.
No species makes it to the top by being passive. The species in charge of any given planet will be highly intelligent, alert, aggressive, and ruthless when necessary.
- THEY WILL ASSUME THAT THE FIRST TWO LAWS APPLY TO US.
...
Your thinking still seems a bit narrow. Consider several broadening ideas:
- Sure, relativistic bombs are powerful because the antagonist has already invested huge energies in them that can be released quickly, and they're hard to hit. But they are costly investments and necessarily reduce other activities the species could explore. For example:
- Dispersal of the species into many small, hard-to-see targets, such as asteroids, buried civilizations, cometary nuclei, various space habitats. These are hard to wipe out.
- But wait -- while relativistic bombs are readily visible to us in foresight, they hardly represent the end point in foreseeable technology. What will humans of, say, two centuries hence think of as the "obvious" lethal effect? Five centuries? A hundred? Personally I'd pick some rampaging self-reproducing thingy (mechanical or organic), then sneak it into all the biospheres I wanted to destroy. My point here is that no particular physical effect -- with its pluses, minuses, and trade-offs -- is likely to dominate the thinking of the galaxy.
- So what might really aged civilizations do? Disperse, of course, and also not attack new arrivals in the galaxy, for fear that they might not get them all. Why? Because revenge is probably selected for in surviving species, and anybody truly looking out for long-term interests will not want to leave a youthful species with a grudge, sneaking around behind its back...
I agree with most parts of points 2, 3, and 4. As for point 1, it is cheaper than you think. You mention self-replicating machines in point 3, and while it is true that relativistic rockets require planetary power supplies, it is also true that we can power the whole Earth with a field of solar cells adding up to barely more than 200-by-200 kilometers, drawn out into a narrow band around the Moon's equator. Self-replicating robots could accomplish this task with only the cost of developing the first twenty or thirty machines. And once we're powering the Earth practically free of charge, why not let the robots keep building panels on the Lunar far side? Add a few self-replicating linear accelerator-building factories, and plug the accelerators into the panels, and you could produce enough anti-hydrogen to launch a starship every year. But why stop at the Moon? Have you looked at Mercury lately? ...
Dr. Wells has obviously bought into the view of a friendly galaxy. This view is based upon the argument that unless we humans conquer our self-destructive warlike tendencies, we will wipe out our species and no longer be a threat to extrasolar civilizations. All well and good up to this point.
But then these optimists make the jump: If we are wise enough to survive and not wipe ourselves out, we will be peaceful -- so peaceful that we will not wipe anybody else out, and as we are below on Earth, so other people will be above.
This is a
non sequitur, because there is no guarantee that one follows the other, and for a very important reason:
"They" are not part of our species.
Before we proceed any further, try the following thought experiment: watch the films Platoon and Aliens together and ask yourself if the plot lines don't quickly blur and become indistinguishable. You'll recall that in Vietnam, American troops were taught to regard the enemy as "Charlie" or "Gook," dehumanizing words that made "them" easier to kill. In like manner, the British, Spanish, and French conquests of the discovery period were made easier by declaring dark- or red- or yellow-skinned people as something less than human, as a godless, faceless "them," as literally another species.
Presumably there is some sort of inhibition against killing another member of our own species, because we have to work to overcome it...
But the rules do not apply to other species. Both humans and wolves lack inhibitions against killing chickens.
Humans kill other species all the time, even those with which we share the common bond of high intelligence. As you read this, hundreds of dolphins are being killed by tuna fishermen and drift netters. The killing goes on and on, and dolphins are not even a threat to us.
As near as we can tell, there is no inhibition against killing another species simply because it displays a high intelligence. So, as much as we love him, Carl Sagan's theory that if a species makes it to the top and does not blow itself apart, then it will be nice to other intelligent species is probably wrong. Once you admit interstellar species will not necessarily be nice to one another simply by virtue of having survived, then you open up this whole nightmare of relativistic civilizations exterminating one another.
It's an entirely new situation, emerging from the physical possibilities that will face any species that can overcome the natural interstellar quarantine of its solar system. The choices seem unforgiving, and the mind struggles to imagine circumstances under which an interstellar species might make contact without triggering the realization that it can't afford to be proven wrong in its fears.
Got that?
We can't afford to wait to be proven wrong.
They won't come to get our resources or our knowledge or our women or even because they're just mean and want power over us. They'll come to destroy us to insure their survival, even if we're no apparent threat, because species death is just too much to risk, however remote the risk...
The most humbling feature of the relativistic bomb is that even if you happen to see it coming, its exact motion and position can never be determined; and given a technology even a hundred orders of magnitude above our own, you cannot hope to intercept one of these weapons. It often happens, in these discussions, that an expression from the old west arises: "God made some men bigger and stronger than others, but Mr. Colt made all men equal." Variations on Mr. Colt's weapon are still popular today, even in a society that possesses hydrogen bombs. Similarly, no matter how advanced civilizations grow, the relativistic bomb is not likely to go away...
We ask that you try just one more thought experiment. Imagine yourself taking a stroll through Manhattan, somewhere north of 68th street, deep inside Central Park, late at night. It would be nice to meet someone friendly, but you know that the park is dangerous at night. That's when the monsters come out. There's always a strong undercurrent of drug dealings, muggings, and occasional homicides.
It is not easy to distinguish the good guys from the bad guys. They dress alike, and the weapons are concealed. The only difference is intent, and you can't read minds.
Stay in the dark long enough and you may hear an occasional distance shriek or blunder across a body.
How do you survive the night? The last thing you want to do is shout, "I'm here!" The next to last thing you want to do is reply to someone who shouts, "I'm a friend!"
What you would like to do is find a policeman, or get out of the park. But you don't want to make noise or move towards a light where you might be spotted, and it is difficult to find either a policeman or your way out without making yourself known. Your safest option is to hunker down and wait for daylight, then safely walk out.
There are, of course, a few obvious differences between Central Park and the universe.
There is no policeman.
There is no way out.
And the night never ends.
