Over at the Speculist, Phil Bowermaster understands the points I made in "Yes, the Singularity is the biggest threat to humanity", which, by the way, was recently linked by Instapundit, who unfortunately probably doesn't get the point I'm trying to make. Anyway, Phil said:
Greater than human intelligences might wipe us out in pursuit of their own goals as casually as we add chlorine to a swimming pool, and with as little regard as we have for the billions of resulting deaths. Both the Terminator scenario, wherein they hate us and fight a prolonged war with us, and the Matrix scenario, wherein they keep us around essentially as cattle, are a bit too optimistic. It's highly unlikely that they would have any use for us or that we could resist such a force even for a brief period of time -- just as we have no need for the bacteria in the swimming pool and they wouldn't have much of a shot against our chlorine assault.
"How would the superintelligence be able to wipe us out?" you might say. Well, there's biowarfare, mass-producing nuclear missiles and launching them, hijacking existing missiles, neutron bombs, lasers that blind people, lasers that burn people, robotic mosquitos that inject deadly toxins, space-based mirrors that set large areas on fire and evaporate water, poisoning water supplies, busting open water and gas pipes, creating robots that cling to people, record them, and blow up if they try anything, conventional projectiles... You could bathe people in radiation to sterilize them, infect corn fields with ergot, sprinkle salt all over agricultural areas, drop asteroids on cities, and many other approaches that I can't think of because I'm a stupid human. In fact, all of the above is likely nonsense, because it's just my knowledge and intelligence that is generating the strategies. A superintelligent AI would be much, much, much, much, much smarter than me. Even the smartest person you know would be an idiot in comparison to a superintelligence.
One way to kill a lot of humans very quickly might be through cholera. Cholera is extremely deadly and can spread very quickly. If there were a WWIII and it got really intense, countries would start breaking out the cholera and other germs to fight each other. Things would really have to go to hell before that happened, because biological weapons are nominally outlawed in war. However, history shows that everyone breaks the rules when they can get away with it or when they're in deep danger.
Rich people living in the West, especially Americans, have forgotten the ways that people have been killing each other for centuries, because we've had a period of relative stability since WWII. Sometimes Americans appear to think like teenagers, who believe they are apparently immortal. This is a quintessentially ultra-modern and American way of thinking, though most of the West thinks this way. For most of history, people have realized how fragile they were and how aggressively they need to fight to defend themselves from enemies inside and out. With our sophisticated electrical infrastructure (which, by the way, could be eliminated by a few EMP-optimized nuclear weapons detonated in the ionosphere), nearly unlimited food, water, and other conveniences present themselves to us on silver platters. We overestimate the robustness of our civilization because it's worked smoothly so far.
Superintelligences would eventually be able to construct advanced robotics that could move very quickly and cause major problems for us if they wanted to. Robotic systems constructed entirely of fullerenes could be extremely fast and powerful. Conventional bullets and explosives would have great difficulty damaging fullerene-armored units. Buckyballs only melt at roughly 8,500 Kelvin, almost 15,000 degrees Fahrenheit. 15,000 degrees. That's hotter than the surface of the Sun. (Update: Actually, I'm wrong here because the melting point of bulk nanotubes has not been determined and is probably significantly less. 15,000 degrees is roughly the temperature that a single buckyball apparently breaks apart at. However, some structures, such as nanodiamond, would literally be macroscale molecules and might have very high melting points.) Among "small arms", only a shaped charge, which moves at around 10 km/sec, could make a dent in thick fullerene armor. Ideally you'd have a shaped charge made out of a metal with extremely high mass and temperature, like molten uranium. Still, if the robotic system moved fast enough and could simply detect where the charges were, conventional human armies wouldn't be able to do much against it, except for perhaps use nuclear weapons. Weapons like rifles wouldn't work because they simply wouldn't deliver enough energy in a condensed enough space. To have any chance of destroying a unit that moves at several thousands of mph and can dodge missiles, nuclear weapons would likely be required.
When objects move fast enough, they will be invisible to the naked eye. How fast something needs to move to be unnoticeable varies based on its size, but for an object a meter long it's about 1,100 mph, approximately Mach 1. There is no reason why engines could not eventually be developed that propel person-sized objects to those speeds and beyond. In this very exciting post, I list a few possible early-stage products that could be built with molecular nanotechnology that could take advantage of high power densities. Google "molecular nanotechnology power density" for more information on the kind of technology a superintelligence could develop and use to take over the world quite quickly.
A superintelligence, not being stupid, would probably hide itself in a quarantined facility while it developed the technologies it needed to prepare for doing whatever it wants in the outside world. So, we won't know anything about it until it's all ready to go.
We'll still be stuck in the blue region while superintelligences develop robotics in the orange and red regions and have plenty of ability to run circles around us. There will be man-sized systems that move at several times the speed of sound and consume kilowatts of energy. Precise design can minimize the amount of waste heat produced. The challenge is swimming through all that air without being too noticeable. There will be tank-sized systems with the power consumption of aircraft carriers. All these things are probably possible, no one has built them yet. People like Brian Wang, who writes one of the most popular science/technology blogs on the Internet, take it for granted that these kind of systems will eventually be built. The techno-elite know that these sorts of things are physically possible, it's just a matter of time. Many of them might consider technologies like this centuries away, but for a superintelligence that never sleeps, never gets tired, can copy itself tens of millions of times, and parallelize its experimentation, research, development, and manufacturing, we might be surprised how quickly it could develop new technologies and products.
The default understanding of technology is that the technological capabilities of today will pretty much stick around forever, but we'll have spaceships, smaller computers, and bigger televisions, perhaps with Smell-O-Vision. The future would be nice and simple if that were true, but for better or for worse, there are vast quadrants of potential technological development that 99.9% of the human species has never heard of, and vaster domains that 100% of the human species has never even thought of. Superintelligence will happily and casually exploit those technologies to fulfill its most noble goals, whether those noble goals involve wiping out humanity, or maybe healing all disease, aging, and creating robots to do all the jobs we don't feel like doing. Whatever its goals are, a superintelligence will be most persuasive in arguing for how great and noble they are. You won't be able to win an argument against a superintelligence unless it lets you. It will simply be right and you will be wrong. One could even imagine a superintelligence so persuasive that it convinces mankind to commit suicide by making us feel bad about our own existence. In that case it might need no actual weapons at all.
The above could be wild speculation, but the fact is we don't know. We won't know until we build a superintelligence, talk to it, and see what it can do. This is something new under the Sun, no one has the experience to conclusively say what it will or won't be able to do. Maybe even the greatest superintelligence will be exactly as powerful as your everyday typical human (many people seem to believe this), or, more likely, it will be much more powerful in every way. To confidently say that it will be weak is unwarranted -- we lack the information to state this with any confidence. Let's be scientific and wait for empirical data first. I'm not arguing with extremely high confidence that superintelligence will be very strong, I just have a probability distribution over possible outcomes, and doing an expected value calculation on that distribution leads me to believe that the prudent utilitarian choice is to worry. It's that simple.
Remember, most transhumanists aren't afraid of superintelligence because they actually believe that they and their friends will personally become the first superintelligences. The problem is that everyone thinks this, and they can't all be right. Most likely, none of them are. Even if they were, it would be rude for them to clandestinely "steal the Singularity" and exploit the power of superintelligence for their own benefit -- possibly at the expense of the rest of us. Would-be mavericks should back off and help build a more democratic solution, a solution that ensures that the benefits of superintelligence are equitably distributed among all humans and perhaps (I would argue) to some non-human animals, such as vertebrates.
Coherent Extrapolated Volition (CEV) is one idea that has been floated for a more democratic solution, but it is by no means the final word. We criticize CEV and entertain other ideas all the time. No one said that AI Friendliness would be easy.