All of Simon_Jester's Comments + Replies

Re: Nanotech That's exactly my point: if nanotech performs as advertised by its starriest-eyed advocates, then interstellar colonization can be done with small payloads and energy is cheap enough that they can be launched easily. That is a very big "if," and not one we can shrug off or assume in advance as the underlying principle of all our models.

What if nanotech turns out to have many of the same limits as its closest natural analogue, biological cells? Biotech is great for doing chemistry, but not so great for assembling industrial machinery ... (read more)

The way you put it does seem to disparage biologists, yes. The biologists are doing work that is qualitatively different from what physicists do, and that produces results the physicists never will (without the aforementioned thousand tons of computronium, at least). In a very real sense, biologists are exploring an entirely different ideaspace from the one the physicists live in. No amount of investigation into physics in isolation would have given us the theory of evolution, for instance.

And weirdly, I'm not a biologist; I'm an apprentice physicist. I still recognize that they're doing something I'm not, rather than something that I might get around to by just doing enough physics to make their results obvious.

This is profoundly misleading. Physicists already have a good handle on how the things biological systems are made of work, but it's a moot point because trying to explain the details of how living things operate in terms of subatomic particles is a waste of time. Unless you've got a thousand tons of computronium tucked away in your back pocket, you're never going to be able to produce useful results in biology purely by using the results of physics.

Therefore, the actual study of biology is largely separate from physics, except for the very indirect route ... (read more)

I wouldn't have assigned much of a prior probability to either of those common sociobiological beliefs, myself. It would hardly surprise me if they were both complete nonsense.

So what do you mean when you say that these beliefs are "standard" or "widely held?" Obviously, I am not a representative sample of the population, so I may have no opinion on a widely held belief. But I'm not aware of strong evidence that these beliefs are widely held, or at any rate are more widely held than the evidence would warrant.

Or, with tongue firmly in cheek, I claim that I'm presenting counterevidence for the common belief that [insert proposition here] is a common belief...

The catch is that complex models are also usually very wrong. Most possible models of reality are wrong, because there are an infinite legion of models and only one reality. And if you try too hard to create a perfectly nuanced and detailed model, because you fear your bias in favor of simple mathematical models, there's a risk. You can fall prey to the opposing bias: the temptation to add an epicycle to your model instead of rethinking your premises. As one of the wiser teachers of one of my wiser teachers said, you can always come up with a function tha... (read more)

From a social psych standpoint, it's very interesting: why do people come up with something, then fail to use it in ways that we would consider obvious and beneficial?

I think a lot of it is hidden infrastructure we don't see, both mental and physical. People need tools to build things, and tools to come up with new ideas: the rules of logic and mathematics may describe the universe, but they are themselves mental tools. Go back to Hellenic civilization and you find a lot of the raw materials for the Industrial Revolution, what was missing? There are a lot ... (read more)

I know of no confirmed historical evidence of wheelbarrows being used until around the time of the Peloponnesian War in Greece, and as I understand it they subsequently vanished in the Greco-Roman world for roughly 1600 years until being reintroduced in the Middle Ages. Likewise, wheelbarrows are not evident in Chinese history until the first or second century AD.

So wheelbarrows are an application of wheels, but they're a much later application of the technology, one that did not arise historically for two to four millennia after the invention of the two o... (read more)

To make this calculation in a MWI multiverse, you still have to place a zero (or extremely small negative) value on all the branches where you die and take most or all of your species with you. You don't experience them, so they don't matter, right? That's a specialized form of a general question which amounts to "does the universe go away when I'm not looking at it?"

If one can make rational decisions about a universe that doesn't contain oneself in it (and life insurance policies, high-level decorations for valor, and the like suggest this is p... (read more)

A machine-phase civilization might still find (3a) or (3b) an issue depending on whether nanotech pans out. We think it will, but we don't really know, and a lot of technologies turn out to be profoundly less capable than the optimists expect them to be in their infancy. Science fiction authors in the '40s and '50s were predicting that atomic power sources would be strongly miniaturized (amusingly, more so than computing devices); that never happened and it looks like the minimum size for a reasonably safe nuclear reactor really is a large piece of industr... (read more)

Your aliens are assigning zero weight to their own death, as opposed to a negative weight. While this may be logical, I can certainly imagine a broadly rational intelligent species that doesn't do it.

Consider the problems with doing so. Suppose that Omega offers to give a friend of yours a wonderful life if you let him zap you out of existence. A wonderful life for a friend of yours clearly has a positive weight, but I'd expect you to say "no," because you are assigning a negative weight to death. If you assign a zero weight to an outcome involvi... (read more)

Good points. However: (1) Most of the cataclysms we see are either fairly explicable (supernovae) or seem to occur only at remote points in spacetime, early in the evolution of the universe, when the emergence of intelligent life would have been very unlikely. Quasars and gamma ray bursts cannot plausibly be industrial accidents in my opinion, and supernovae need not be industrial accidents.

(2)Possible, but I can still imagine large civilizations of people whose utility function is weighted such that "99.9999% death plus 0.0001% superman" is infe... (read more)

To our perspective, this is from (2): all advanced civilizations die off in massive industrial accidents; God alone knows what they thought they were trying to accomplish.

Also, wouldn't there still be people who chose to stay behind? Unless we're talking about something that blows up entire solar systems, it would remain possible for members of the advanced civilization to opt out of this very tempting choice. And I feel confident that for at least some civilizations, there will be people who refuse to bite and say "OK, you guys go inhabit a tiny subs... (read more)

This is my hypothesis (3c), with an implicit overlay of (3a).

Here goes:

Alternate explanations for rarity of intelligence:

3a) Interstellar travel is prohibitively difficult. The fact that the galaxy isn't obviously awash in intelligence is a sign that FTL travel is impossible or extremely unfeasible.

Barring technology indistinguishable from magic, building any kind of STL colonizer would involve a great investment of resources for a questionable return; intelligent beings might just look at the numbers and decide not to bother. At most, the typical modern civilization might send probes out to the nearest stellar neig... (read more)

I dunno. I mean, a lot of horror stories that are famous for being good talk about stuff that can never be and should never be, but that nonetheless (in-story) is. I think it's that sense of a comforting belief about the world being violated that makes a good horror story, even if the prior probability of that belief being wrong is low.

I think you're misreading the story. It's not an argument in favor of irrationality, it's a horror story. The catch is that it's a good horror story, directed at the rationalist community. Like most good horror stories, it plays off a specific fear of its audience.

You may be immune to the lingering dread created by looking at all those foolish happy people around you and wondering if maybe you are the one doing something wrong. Or the fear that even if you act as rationally as you can, you could still box yourself into a trap you won't be able to think you... (read more)

Countercounterevidence for 3: what are the assumptions made by those models of interstellar colonization?

Do they assume fusion power? We don't know if industrial fusion power works economically enough to power starships. Likewise for nanotech-type von Neumann machines and other tools of space colonization.

The adjustable parameters in any model for interstellar colonization are defined by the limits of capability for a technological civilization. And we don't actually know the limits, because we haven't gotten close enough to those limits to probe them yet... (read more)

One thing that caught my eye is the presentation of "Universe is not filled with technical civilizations..." as data against the hypothesis of modern civilizations being probable.

It occurs to me that this could mean any of three things, which only one of which indicates that modern civilizations are improbable.

1) Modern civilizations are in fact as rare as they appear to be because they are unlikely to emerge. This is the interpretation used by this article.

2) Modern civilizations collapse quickly back to a premodern state, either by fighting a v... (read more)