passive_fist

Karma: 2,166

passive_fist Dec 28, 2015, 8:19 PM
3 points
in reply to: username2’s comment on: Open Thread, Dec. 28 - Jan. 3, 2016
I might or might not be an example of someone who has done that. I learned to play guitar from scratch at 28 years old. However, I had previously learned to play the piano when I was a teenager, so that might have made it easier. However the two are very different instruments. YMMV.

A lot of the difficulty in picking up a new instrument may just be lack of time. When I was a teenager I was spending 5+ hours a day playing the piano. I am not exaggerating in the least. As an adult it is very hard to find 30 minutes a day of time. It took me about 3 years to become very good at the piano. Another few years would probably have made me even better. This is consistent with the 10,000 hour rule. A naive calculation would conclude that it would take 30 years of practice at 30 min/day to become equally good at the guitar.

passive_fist Dec 28, 2015, 11:52 AM
0 points
in reply to: turchin’s comment on: Global catastrophic risks connected with nuclear weapons and nuclear energy
I realize that it’s a map of risks, I’m just saying the possibilities don’t even remotely fall into comparable levels of risk. “Death from nuclear ICBM” is quite imaginable and possible. Not only that, there was a time when it almost seemed imminent and inevitable. And it could easily become that way again. Whereas “death from cold fusion” is essentially of zero meaningful concern.

Maybe it would be useful if you could attach some kind of crude probabilities to your estimates. I can fill a pdf with items like “death from massive leprechaun attack” but it wouldn’t be a very useful guide.

passive_fist Dec 28, 2015, 2:30 AM
0 points
in reply to: turchin’s comment on: Global catastrophic risks connected with nuclear weapons and nuclear energy
1. Strictly speaking, the only major barrier to development of fission weapons (once the possibility of prompt criticality was realized) was enrichment. Even a simple gun-type bomb design suffices if you want to build a fission weapon, but you have to get the nuclear material first, and that’s where the bulk of the scientific and technological effort in the Manhattan project was focused. Even today, enrichment is still only the major barrier to aspiring nuclear states/groups. Once it was identified that this was the problem that needed to be solved, the scientists quickly came up with a plan on how to tackle it. But there is no plan or pathway to pure fusion weapons. As far as we know, they could be physically impossible. I’m not discounting the possibility of some incredibly secret pure fusion weapon, but if such a weapon existed it would be exceedingly silly to spend billions of dollars on facilities like NIF or the Z machine—and keep in mind that these projects were funded by and do research for the government agencies responsible for nuclear weapons development. What’s the point? (Also, cold fusion does not exist.)
2. Wrong. A country with a sizeable stockpile of nuclear ICBMs can target and kill anyone it wishes. It’s not restricted to just bombing the other superpower.

passive_fist Dec 27, 2015, 9:41 PM
7 points
in reply to: ChristianKl’s comment on: Open Thread, Dec. 28 - Jan. 3, 2016
Again, why does MrMind have that ‘role’?

I think the fact that you say Clarity is ‘farming for karma’ - without any evidence for this claim—may give away what the real problem is.

Anyway, if the issue is just time zones, I’d be fine with, say, agreeing on UT 00:00 Monday for starting an open thread. Or maybe it would just be simpler to have a bot start the thread.

passive_fist Dec 27, 2015, 9:28 PM
12 points
in reply to: ChristianKl’s comment on: Open Thread, Dec. 28 - Jan. 3, 2016
As far as I remember, the only thing that seemed to be ‘agreed on’ was that the open threads should be weekly, starting on Mondays, and anyone could open one if it hadn’t been opened by Monday. I don’t see how Clarity has broken that norm. I don’t see how this is anything other than an attack on Clarity for being a newcomer, and anyone who downvoted this thread should really take a step back and consider what kind of community their downvote is promoting.

passive_fist Dec 27, 2015, 9:09 PM
9 points
in reply to: ChristianKl’s comment on: Open Thread, Dec. 28 - Jan. 3, 2016
So only MrMind is allowed to create open threads? Who gave him this sole authority? When was this decided by the community?

Why does it even matter who creates an open thread?

passive_fist Dec 23, 2015, 12:08 AM
0 points
in reply to: turchin’s comment on: Global catastrophic risks connected with nuclear weapons and nuclear energy
1. I see what you are talking about now. Flux-compression driven fusion is most likely not going to work (which explains why there has been no serious effort to pursue it). It’s useful to compare it to the Sandia capacitor-powered Z-machine. To achieve fusion you need (a) a lot of energy, delivered in (b) a short amount of time (preferably nanoseconds as the fuel will tear itself apart at timescales much longer than that), in (c) a very small space. The best EPFCG so far has achieved about 100 MJ and 256 MA, but the killer is the time scale, which is on the excruciatingly slow millisecond level. By contrast, the Sandia machine can deliver about 10 MJ and 27 MA on a nanosecond timescale, and is still far from achieving fusion ignition (currently at least two orders of magnitude away). A planned tripling of energy output via a future upgrade is not expected to produce any fusion ignition either. All of this is evidence against the feasibility of EPFCG fusion. To me, it’s damning evidence. A quote in that same page you linked says, “the U.S. Is not known to have and is not developing a pure fusion weapon and no credible design for a pure fusion weapon resulted from the DOE investment”.
2. It’s not true that ICBMs do not have U-238 blankets. Virtually all modern warhead designs use a U-238 pusher/tamper and some also use a U-238 hohlraum (some omit this in favor of other metals, but the U-238 tamper is still there). I see what you are saying about a ‘blackmail weapon’ but I don’t see how this is any different from the existing MAD doctrine (via nuclear ICBMs, which are more dangerous and more cost-effective).

passive_fist Dec 22, 2015, 9:02 PM
0 points
in reply to: turchin’s comment on: Global catastrophic risks connected with nuclear weapons and nuclear energy
1. Fission weapons with arbitrarily small yields are possible, it’s just that you have to sacrifice efficiency. Before the CTBT, tests of < 1 ton yield were routinely carried out as part of hydrodynamic bomb testing. The smallest critical mass for plutonium (assuming an advanced weapon design) seems to be about 2-3 kg, giving a minimum yield of 5-6 kt without losing efficiency (and thus provides a minimum cost bound for a fission weapon). The 10 MJ figure I gave was assuming the smallest possible primary, and a staged design. I think at this point we have a very clear idea of what it would take to make pure fusion weapons work (after all, it is in the highest national security interest to do so) and as I said, all the approaches seem infeasible for now and the foreseeable future.
2. I’m aware of that study. I wouldn’t worry about it; the calculations are extremely optimistic and we don’t even know if a segregated deuterium layer exists in Jupiter at all.
3. I think you are missing the point. The point isn’t whether you could build a SSB (although, as I said, I doubt it would be of much use in a nuclear ICBM era). The point is whether ‘salting’ by cobalt would produce a more dangerous device than you could make with just uranium-238. The answer is: No, in fact a cobalt bomb would be safer than a U-238 device.

passive_fist Dec 22, 2015, 6:20 PM
0 points
in reply to: turchin’s comment on: Global catastrophic risks connected with nuclear weapons and nuclear energy
I understood your justifications and that’s what I was responding to.
1. There are significant technological barriers to pure fusion weapons and fission implosion triggers would always probably be the cheaper option. Laser-initiated fusion is known to be unworkable; experiments have indicated that at least 10 MJ of laser energy—and probably 2 or 3 times that—is required for reliable fusion ignition; this is far beyond the capabilities of current laser technology to produce in a compact way (the NIF is a huge installation and only produces 1.8 MJ of laser energy). Antimatter-triggered fusion might be possible but we are still far from producing the amount of antimatter required (at least a billion atoms; we’ve currently only been able to produce about 100 atoms confined for a few minutes).
2. You mention “Deuterium in lakes and ice has higher concentration” and “Lithium in dry lakes”, referring to Earth. As for Jupiter, I wouldn’t worry too much about it.
3. The Russians are known to put out a lot of misleading information; I would take those reports with a grain of salt (ahem). Fact is, most current bombs have a secondary pusher/tamper made of Uranium-238 and this produces nuclear isotopes that are more dangerous and far more plentiful than a cobalt blanket ever would. I fail to see the point of a ‘stationary doomsday device’ as nuclear ICBMs are far more dangerous (and they already exist).

passive_fist Dec 22, 2015, 9:26 AM
7 points
in reply to: [deleted]’s comment on: Open thread, Dec. 21 - Dec. 27, 2015

A major weakness of the standard Bayesian inference method is that it assumes a problem only has two possible solutions.

This is not true at all.

passive_fist Dec 22, 2015, 12:46 AM
4 points
on: Global catastrophic risks connected with nuclear weapons and nuclear energy
I’d say that the possibility of ‘home made nukes’ is essentially zero unless fissile isotopes become widely available and cheap, and even if all current controls on nuclear materials and technology were lifted, that would still be far from plausible. The US government pays about $1mil to $10mil worth of plutonium-238 for a single nuclear weapon; this is even though the current industrial process for producing plutonium is highly optimized and efficient (the first nuclear test required $1bn worth of fissile material).

‘Home made nuke’ is in the same category of plausibility as ‘home made fighter jet’.

EDIT: There are some other misconceptions in your document as well. Natural fusion ignition (in materials at densities and pressures you could find anywhere on or in the Earth) is physically impossible to trigger via a nuclear explosion; a thermonuclear weapon only works by imploding some quantity of fuel contained inside the device, and this implosion requires very precise and special conditions to carry out.

‘Salted’ bombs are largely a myth; ordinary bombs made out of Uranium-238 (most of the current arsenal) produce far more dangerous radioactive isotopes than a hypothetical cobalt bomb. Most nuclear weapons are already ‘salted.’

passive_fist Dec 21, 2015, 11:43 PM
3 points
in reply to: ChristianKl’s comment on: Open thread, Dec. 21 - Dec. 27, 2015
You could just have a two-dishwasher system where the dishwasher takes the place of the cupboard.

It seems like a robot that automated the task of moving clean dishes into a cupboard would be an idea where the potential benefits, if any, are too small to currently justify the major development effort that would be required. Maybe in the future when AI becomes far more widespread and ‘easy’ to develop.

passive_fist Dec 21, 2015, 11:37 PM
1 point
in reply to: ChristianKl’s comment on: Open thread, Dec. 21 - Dec. 27, 2015
During the 80′s and 90′s a number of firms sprouted up around buying and selling penny stocks via strategies like cold calling.

passive_fist Dec 21, 2015, 9:28 PM
2 points
in reply to: IlyaShpitser’s comment on: Open thread, Dec. 21 - Dec. 27, 2015
You are correct in that surveys of IQ and other intelligence scores consistently show physicists having some of the highest. But mathematics, statistics, computer science, and engineering are the same, and most studies I’ve seen generally see very little, if any, significant difference in intelligence scores between these fields.

‘Rationalist’ isn’t a field or specialization, it’s defined more along the lines of refining and improving rational thinking. Based on the lesswrong survey, fields like mathematics and computer science are heavily represented here. There are actually more physicists (4.3%) than philosophers (2.4%). If this is inconsistent with your perception of the community, update your prior.

From all of this it is safe to assume that the average LW’er is ‘very smart’, and that LW contains a mini-community of rationalist scientists. One data point: Me. I have a PhD in engineering and I’m a practising scientist. Maybe I should have phrased my initial comment as: “It might be better if the intersection of rationalists and scientists were larger.”

passive_fist Dec 21, 2015, 9:08 PM
4 points
in reply to: IlyaShpitser’s comment on: Open thread, Dec. 21 - Dec. 27, 2015
It could be that the attitude/belief that theoretical physicists are far smarter than anyone else (and therefore, by implication, do not need to listen to anyone else) is part of the problem I’m outlining.

passive_fist Dec 21, 2015, 8:01 PM
7 points
on: Open thread, Dec. 21 - Dec. 27, 2015
Last week was a gathering of physicists in Oxford to discuss string theory and the philosophy of science.

From the article:

Nowadays, as several philosophers at the workshop said, Popperian falsificationism has been supplanted by Bayesian confirmation theory, or Bayesianism...

Gross concurred, saying that, upon learning about Bayesian confirmation theory from Dawid’s book, he felt “somewhat like the Molière character who said, ‘Oh my God, I’ve been talking prose all my life!’”

That the Bayesian view is news to so many physicists is itself news to me, and it’s very unsettling news. You could say that modern theoretical physics has failed to be in-touch with other areas of science, but you could also make the argument that the rationalist community has failed to properly reach out and communicate with scientists.
What links here?
- pianoforte611's comment on Open Thread, Dec. 28 - Jan. 3, 2016 by [deleted] (Dec 31, 2015, 12:40 AM; 0 points)

passive_fist Dec 21, 2015, 3:28 AM
1 point
in reply to: Lumifer’s comment on: Estimate the Cost of Immortality

Did they provide their own food

Indeed they did. This is mentioned in the report.

In fact cash-grant villages were more likely to grow their own food than control villages. A large part of the cash grants were spent on procuring better seeds and upgrading their livestock. Cash-grant villages were also more likely to undertake productive economic activity like starting businesses.

They did undertake trade with other villages, if they wanted to.

However all this is, basically, injection of a bit of capital into a very very poor village and it does not tell us much about what would happen in a more advanced society with the basic income that is, presumably, sufficient to live on.

I think the fact that you say this hints at what may be the crux of the problem. Sure, cultural and socioeconomic differences are a huge factor, but believe it or not, ‘advanced societies’ do have poor people, and lots of them, and experiments like these hint that a universal basic income cannot simply be dismissed as ‘eliminating incentives and leading to mass starvation.’

UBI is obviously not going to do much for rich people.

passive_fist Dec 21, 2015, 3:07 AM
3 points
in reply to: Lumifer’s comment on: LessWrong 2.0
At some point, yes. Kindergarten is actually a great metaphor. If you’re five, and you run out of the kindergarten, you hit a bus and die.

You can either talk about politics in the way people currently do it—a way completely removed from any sort of disciplined, rational type of thinking—or not talk about it at all. It seems that a community dedicated to refining the art of human rationality should strive not to jump head-first into the current but to refine rationality to the point where our brains are capable of discussing politics rationally.

We are far from that point.

passive_fist Dec 21, 2015, 12:43 AM
−1 points
in reply to: Lumifer’s comment on: LessWrong 2.0

which is usually argued about in much more sophisticated terms than “Yay magenta, boo teal”.

It’s not the sophistication of the arguments that is the problem. The problem is making arguments objective, rigorous, and grounded in experimental observation. I would not mind ‘yay magenta, boo teal’ as long as it were followed by a rational and rigorous justification. Unfortunately, making rational arguments in politics is extremely difficult. However, because of the mind-killing effect, the people making such arguments usually don’t see it that way—they perceive their arguments as extremely rational and common-sense, unable to see why others view the arguments as nonsense. They are unable or unwilling to follow their arguments through with the enormous level of evidence that’s required.

passive_fist Dec 21, 2015, 12:27 AM
0 points
in reply to: Lumifer’s comment on: Estimate the Cost of Immortality

Sigh. Let me quote myself from upthread:

It works for small communities which mooch off larger societies

Not at all. It’s clear that you didn’t even look at the examples. A lot of those examples were largely self-contained. For instance, the one in Madhya Pradesh was done on a set of villages that provided their own food and necessities.