gathaung

Nice. To make your proposed explanation more precise:

Take a random vector on the n-dim unit sphere. Project to the nearest (+1,-1)/sqrt(n) vector; what is the expected l2-distance / angle? How does it scale with n?

If this value decreases in n, then your explanation is essentially correct, or did you want to propose something else?

Start by taking a random vector x where each coordinate is unit gaussian (normalize later). The projection px just splits into positive coordinates and negative coordinates.

We are interested in E[ / |x| sqrt(n)].

If the dimension ... (read more)

Second question:

Do you have a nice reference (speculative feasibility study) for non-rigid coil-guns for acceleration?

Obvious idea would be to have a swarm of satellites with a coil, spread out over the solar system. Outgoing probe would pass through a series of such coils, each adding some impulse to the probe (and doing minor course corrections). Obviously needs very finely tuned trajectory.

Advantage over rigid coil-gun: acceleration spread out (unevenly) over longer length (almost entire solar system). This is good for heat dissipation (no coupling is ... (read more)

Do you have a non-paywalled link, for posterity? I use sci-hub, but paywalls are a disgrace to science.

Also, do you have a nice reference for the bussard ramjet/ramscoop deceleration?

Obvious advantage: A priori you don't need nuclear fusion at all. You use a big em-field for cross-section and use, ultimately, drag against the interstellar medium for both deceleration and energy generation. No deceleration needed in (thinner) intergalactic medium. Entropy gain should be large enough to run mighty heat-pumps (for maintaining high field superconductors and r... (read more)

What are your scenarios for interstellar warfare? The question obviously depends on whatever turns out to be the technically mature way of violent conflict resolution.

Let me propose a naive default guess:

Small technically mature von-neumann probe meets primitive civilization or unsettled system: probe wins.

Small technically mature von-neumann probe meets system with technically almost-mature inhabitants: probe cannot even make problems.

System with dyson swarm + AI: Unassailable on short timescales. Impossible to profitably invade. Maybe sling another star ... (read more)

You should strive to maximize utility of your pattern, averaged over both subjective probability (uncertainty) and squared amplitude of wave-function.

If you include the latter, then it all adds up to normalcy.

If you select a state of the MWI-world according to born rule (i.e. using squared amplitude of the wave-function), then this world-state will, with overwhelming probability, be compatible with causality, entropy increase over time, and a mostly classic history, involving natural selection yielding patterns that are good at maximizing their squared-a... (read more)

It was not my intention to make fun of Viliam; I apologize if my comment gave this impression.

I did want to make fun of the institution of Mensa, and stand by them deserving some good-natured ridicule.

I agree with your charitable interpretation about what an IQ of 176 might actually mean; thanks for stating this in such a clear form.

In Section 3, you write:

State value models require resources to produce high-value states. If happiness is the goal, using the resources to produce the maximum number of maximally happy minds (with a tradeoff between number and state depending on how utilities aggregate) would maximize value. If the goal is knowledge, the resources would be spent on processing generating knowledge and storage, and so on. For these cases the total amount of produced value increases monotonically with the amount of resources, possibly superlinearly.

I would think that su... (read more)

Congrats! This means that you are a Mensa-certified very one-in-a-thousand-billion-special snowflake! If you believe in the doomsday argument then this ensures either the continued survival of bio-humans for another thousand years or widespread colonization of the solar system!

On the other hand, this puts quite the upper limit on the (institutional) numeracy of Mensa... wide guessing suggests that at least one in 10^3 people have sufficient numeracy to be incapable of testifying an IQ of 176 with a straight face, which would give us an upper bound on the N... (read more)

I think a nicer analogy are spectral gaps. Obviously, no reasonable finite model will be both correct and useful, outside of maybe particle physics; so you need to choose some cut-off of you model's complexity. The cheapest analogy is when you try to learn a linear model, e.g. PCA/SVD/LSA (all the same).

A good model is one that hits a nice spectral gap: Adding a couple of extra epicycles gives only a very moderate extra accuracy. If there are multiple nice spectral gaps, then you should keep in mind a hierarchy of successively more complex and accurate mod... (read more)

AFAIK (and wikipedia tells), this is not how IQ works. For measuring intelligence, we get an "ordinal scale", i.e. a ranking between test-subjects. An honest reporting would be "you are in the top such-and-so percent". For example, testing someone as "one-in-a-billion performant" is not even wrong; it is meaningless, since we have not administered one billion IQ tests over the course of human history, and have no idea what one-in-a-billion performance on an IQ test would look like.

Because the IQ is designed by people who woul... (read more)

I recently had a tech-support problem on lw and wanted to post the solution here. Anyone with write permissions on the faq is invited to copy-paste the following there:

Q: I appear to be unable to comment. Once I log in, the comment button vanishes. WTF?

A: Have you verified your email address? Due to spammers, we had to make email verification mandatory before commenting.

Unfortunately, the lesswrong code is currently unable to indicate if your account is still pending email verification. The easiest way to trigger a new attempt at email verification is to go to your account settings and change your email address; then your new email address will immediately receive a new verification mail.

How did the cited studies try to argue causality?

In other words, it is expected that certain behaviour (drug use, "criminal lifestyle") both causes time spent in prison and lowered life expectancy. Just correlating time spent in prison and life expectancy does not cut the cake.

You would need some kind of randomized control group. For example: Suppose the judges responsible for granting parole were assigned on a last-name basis. Different judges have different statistics on granting parole. Then you compare life-expectancy vs last name of delinquents.

I would rather see the doomsday argument as a version of sleeping beauty.

Different people appear to have different opinions on this kind of arguments. To me, the solution appears rather obvious (in restrospect):

If you ask a decision theory about advice on decisions, then there is nothing paradoxical at all, and the answer is just an obvious computation. This tells you that "probability" is the wrong concept in such situations; rather you should ask about "expected utility" only, as this is much more stable under all kind of anthropic arguments.