Internally Second Life calls their countermeasure the "gray goo fence" but I can't find many good descriptions of how it actually works online, except some mentions that the restrictions on how much something can "rez" increase exponentially. This link was the best description of it I could find:
I believe that, since the attack mentioned therein, they've done other things, such as restricting certain scripting functions to trusted people. But folks have been known to find exploits anyhow.
Of course, feel free to correct me if you actually play Second Life. I've only been following news of it from the outside. I've never actually played it.
I've never understood why people are that worried about it with nanomachines, though. We already have gray goo (though much of it, like algae, is green). I mean, most single-celled organisms are capable of that kind of mass replication. And they can be found pretty much everywhere already. I'd be more worried about accidentally engineering a super-virus or whatever than gray goo per se.
It's true that replication is evolution's specialty, but maybe the initial construction of grey goo would require some specialized environment that doesn't naturally occur. Nuclear bomb isn't so complicated that evolution couldn't figure it out, for example, but it didn't and won't anytime soon.
That's kinda true, but there was a natural nuclear reactor: http://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor
Also, the Sun seems to work pretty well.
If course, neither of these evolved though biological mechanisms, though, but they did arise in a natural environment. I find it difficult to imagine circumstances under which evolution would "figure out" a nuclear bomb - ie, I'm agreeing with your point that evolution usually requires a series of gradual refinements rather than a big jump forward.
Also, all a nuclear bomb requires is enough fissionable material in a small enough space that the reaction is run away. I see no reason to suppose that a spot particularly rich in uranium (or other such materials) couldn't get squeezed hard enough to explode, or that a critical mass somehow formed by natural processes (particularly those which put it under very high pressure).
I suspect that the reason we haven't observed this happening is because most of the material is not present in concentrated form and because it decays over time.
But just so you know, people have accidentally assembled critical masses by hand. There's no special magic to it, other than getting a large enough quantity of suitable material in the first place (which is really, really hard). You can read some of the scary things that happened here:
They called it the "demon core" after a few people died working on it.
The nuclear bomb was a needlessly confusing example--I could have just mentioned explosives in general. Evolution is all about weapons, and explosives make for damn good ones, and it's not hard to imagine a realistic organism that uses them, unlike a nuke-wielding organism. Only I'm not sure that no organism uses explosives. I was already wrong once today about what nature can't do!
Maybe we would have multiple species of replicators trying to outcompete each other.
Things like this always make me think of Sam's Archive's "Geocide" page. Which, by the way, points out that this does not in fact bring about the destruction of the Earth: http://qntm.org/destroy
I think they would make it their first order of business to destroy each other, postponing their primary goals in order to make weapons or enlist the help of allies. If they failed at destroying each other, they would reach some kind of peace treaty. Or maybe they would try peace first, realizing that war has too high a chance of wiping them out.
like an microorganism or device designed to impregnate every women on the planet
or maybe people will start modifying their offspring to worship them
my personal favorite are tiny robots that interfere with the unjust use of force worldwide, causing the collapse of most governments
I suppose their memory holds both code and data?
A good reminder for businesses. If your only goal is to dominate the market, it is not a worthy goal.
>In particular, it turns out that developing manufacturing systems that use tiny, self-replicating machines would be needlessly inefficient and complicated. The simpler, more efficient, and more obviously safe approach is to make nanoscale tools and put them together in factories big enough to make what you want.
(note that he explicitly acknowledges the safety risk) and
>The popular version of the grey-goo idea seems to be that nanotechnology is dangerous because it means building tiny self-replicating robots that could accidentally run away, multiply and eat the world. But there’s no need to build anything remotely resembling a runaway replicator, which would be a pointless and difficult engineering task. I worry instead about simpler, more dangerous things that powerful groups might build deliberately - products like cheap, abundant, high-performance weapons with a billion processors in the guidance systems.
This does nothing to diminish the risk of replicators if they are, in fact, created. And there are all sort of possible problems where replicators would be essential. For example, we may want to release replicators into the environment to clean up certain kinds of pollution which can't be easily brought to a central facility.
Drexler thinks we underestimate the difficulty of building run-away replicators. Nature's had 4 billion years and hasn't managed it. Yes, I'm aware of the wheel argument.
Second, you say it is difficult with many failure modes. So was going to the moon. How can you possibly think it's so difficult that it will never get done? In a thousand years?
Third, you cite Drexler to claim that we underestimate the difficulty. (Who underestimates it? Me? The irrational people who Drexler is afraid will take away his funding, or the handful of academics who seriously consider the issue?) The argument for extreme caution does not rely on it being easy to build run-away replicators, only that it is reasonably possible and that the results are catastrophic. Can you really argue with 99% certainty against the feasibility of future technologies without any sort of restriction based on physical law?
Fourth, you say you are aware of the wheel argument...so...what is your reponse? Should we also consider the laser argument? The computer argument? The space-ship argument? Or the argument from any of the nearly countless things that humanity has created in the past 40 years that never existed in the previous 4,000,000,000 that life was around?
I do think it's interesting the amount of anger I encounter whenever I even remotely question one of the Singularitarians' babies. There seems to be more ... emotional attachment ... than is healthy for skeptical inquiry.
I'd very much like to hear what you have to say, because even when I've discussed this with academics who work in nanotech (though I've never spoken to anyone working directly on replicators), I've never heard a better argument than "it's really, really hard".