Comment author: Vladimir_Nesov 09 October 2010 09:29:50PM *  3 points [-]

O(log n) stack size is allowed (since normal loop would also take O(log n) just to write down n), but you need to keep each stack frame constant size, not O(log(n)), since otherwise you get O(log^2 n) total space complexity.

Comment author: datadataeverywhere 01 October 2011 04:46:04AM 1 point [-]

I had thought the solution was very simple before you pointed this out. With some difficulty I improved my solution to O(log(log(n)) * log(n)), and it took quite a bit more time for me to get completely constant sized stack frames.

I suspect most people initially come up with the O(log^2(n)) solution and jump next to the O(log(n)) solution without getting stuck in the middle there, but I'm curious if this gave you any problems.

Comment author: datadataeverywhere 14 August 2011 07:14:59PM 6 points [-]

I'd imagine weird timing and chemical interactions being used by the brain as it is an adaptable system and might be able adapt to use them if they turn out to be helpful.

Human designers have every reason to work very hard to make sure they understand their own designs and that they are free from weird issues. Chips aren't designed [by humans] to have strange EM interactions, but sometimes they do anyway and that occasionally gets exploited---not often though. On the other hand, evolution has no such motive, so I imagine that weird edge cases are vastly more important in biological brains. It seems quite possible that whereas only a few NES games are rendered unplayable on emulations with less fidelity, humans brains just won't work at all until we represent most of what happens on a lower level.

However, I hope that's not the case, since if it is, we have that much longer to wait for whole-brain emulation. I also suspect we will still have heuristics that perform adequately at speeds many orders-of-magnitude faster than molecular simulations (and that quantum effects are negligible).

Also please ignore the 3Ghz vs 25Mhz comparison, it perpetuates the myth that computational power is about clock speed and not operations per second and memory bandwidth.

If we were comparing clock speeds, I would be more interested in the 3GHz to 1.79MHz (the actual NES processor, rather than the first emulation) comparison.

Comment author: gwern 11 October 2010 03:22:28PM *  6 points [-]

In the spirit of my memento-mori.sh, I've written a script to sleep randomly 0-10 minutes and take a screenshot & webcam shot. Obviously many of the values are specific to my own computer (such as the names in /proc, where in ~/ the pictures are sent to, and the use of ImageMagick, jpegoptim, and OptiPNG), but it should be easy to adapt to your own computer:

#!/bin/sh
set -e
if grep open /proc/acpi/button/lid/LID?/state > /dev/null
then
CURRENT=`date +%s`;
SLEEP=$(( $CURRENT % 10 ))
TIMEOUT="m"
sleep $SLEEP$TIMEOUT
import -quality 100 -window root png:$HOME/photos/webcam/xwd-$CURRENT.png
fswebcam --resolution 1280x1024 -S 2 -F 3 ~/photos/webcam/$CURRENT.jpg
optipng -o9 -fix `ls -t ~/photos/webcam/*.png | head -1`
jpegoptim -m50 `ls -t ~/photos/webcam/*.jpg | head -1`
fi

This would be called from one's crontab like so:

0,10,20,30,40,50 * * * * ~/bin/bin/sousveillance.sh

My original script ran every hour on the hour, but I discovered that this was so predictable that I was beginning to work-around it by switching to a more kosher good-looking application, and wasn't frequent enough anyway. Hopefully the randomized version will work better.

Comment author: datadataeverywhere 08 August 2011 09:01:45PM 0 points [-]

Thank you for posting this. I want to do almost exactly this, and set up another task running that will zip up all the images and send them off to my referee.

Unfortunately, I haven't gotten this to work. I'm not very familiar with cron, and I don't know how to debug it. My script works as intended when run manually, but halts (dies? I don't know) when run from cron (at import). I haven't managed to get any error reporting, either by redirecting the script output or the import output. I also haven't been able to get import to run directly from cron, even by using absolute paths and no variables. I suspect these are problems you haven't run across, but if you have, I'd appreciate your advice.

Comment author: Michael_Sullivan 26 February 2011 01:24:24PM 0 points [-]

You have to be careful with counterfactuals, as they have a tendency to be counter factual.

In a world in which soldiers were never (or even just very very rarely) deployed, what is the likelihood that they would be paid (between money and much of living expenses) anywhere near as well as current soldiers and yet asked to do very very little?

The reason the lives of soldiers who are not deployed are extremely low-stress and not particularly difficult is because of deployment. They are being healed from previous deployments and readied for future deployments. In the current environment where soldiers are being deployed for much longer periods with much shorter dwell times, it's very likely that the services are doing everything they can to make the dwell time as low-stress as possible. 3 hours at the gym and 3 hours doing a relatively low-stress job in your field sounds like what a lot of people I know who are "retired" do. It sounds like a schedule designed to make your life as easy as possible while still keeping you healthy and alert, rather than falling into depression.

In a counter factual world where the army was almost never deployed, they would surely be used for some other purpose on a regular basis, police/rescue/disaster relief/etc. or simply be much much smaller, with pay not needing to be as competitive. We've even experienced this to an extent -- during peaceful times, the active duty military shrinks dramatically, and most of our army is in a reserve or national guard capacity, where they have day jobs, and do not get full time pay from the army unless they are called up to active service. This is still to most accounts a pretty good gig (especially if you use it to get free college tuition) even though it can't replace full time work -- as long as you don't get called up.

In fact, I think that's what some of the people my age that I know in the service were expecting when they joined in peacetime. Very rare callups for crucial work they felt obligated to do well for the good of the country or world. Didn't work out that way though.

Comment author: datadataeverywhere 27 February 2011 10:43:29PM 1 point [-]

I agree that this scenario is pretty unlikely; it seems at least possible if there was a high-level policy change that hadn't caught up to military funding and structure, but made active troop deployment very unlikely. Your second to last paragraph disagrees with this; does the US military really shrink that much when we have fewer wars going on?

China seems much more the model of a country with a large military that rarely is deployed, and they do seem to match your description; lots of manual labor, disaster relief, building infrastructure, etc., with less competitive pay. I agree that this is the natural balance for a country that's not engaging in wars on a regular basis.

In fact, I think that's what some of the people my age that I know in the service were expecting when they joined in peacetime. Very rare callups for crucial work they felt obligated to do well for the good of the country or world.

This might not have been true, and probably won't be true even once we get back to peace time, but if it was, it seems like a pretty good reason to join, and follows the OPs intention. Still not my recommendation!

Comment author: WrongBot 06 February 2011 12:26:07AM 0 points [-]

This comment motivated me to update my blog again, which I am quite grateful for. Has that showed up in your RSS?

My earlier blog posts were eaten when I screwed up the transfer of the site to Wordpress. I wasn't terribly happy with them in any case, but you're not the first person to indicate that they were better than I thought.

In response to comment by WrongBot on Eutopia is Scary
Comment author: datadataeverywhere 07 February 2011 07:47:24PM 0 points [-]

It didn't; I'm sure RSS also broke during the site transfer. I re-subscribed, and I suspect everything will work again. The re-subscription at least retrieved your two current posts. I really did find your earlier writings interesting and enjoyable. I'm not sure I necessarily need them reposted (I wouldn't classify them as reference material for re-review), but more like that would be appreciated.

Comment author: MBlume 07 February 2011 01:30:33AM 2 points [-]

Oh. I now feel really quite silly for not having immediately guessed that where there were naturals there would be a Curse of the Gifted.

I've heard really good things about blues -- basically I've heard that swing originates from a cleaned-up version of blues? -- and your comment is tipping me further towards "oh for goodness sake check this out already," so thanks for that ^_^.

In response to comment by MBlume on Eutopia is Scary
Comment author: datadataeverywhere 07 February 2011 07:29:25PM *  0 points [-]

I've heard that blues originates from a dirtied-down version of swing; at least, I think it's genesis is later. I just got back from an all-weekend blues workshop. Campbell and Chris were two of the instructors, and you can get some idea for what it looks like from the videos on their site. You can see that competition blues often looks a lot like (competition) lindy; maybe a little more varied, but a lot slower, fewer lifts and generally lower energy.

In practice (when dancing for a partner rather than for an audience), blues is generally much smaller and closer. Most dances are usually at least partially danced in close embrace, where the chest to chest and inside thigh to outside thigh connections are the main lead---so it can be a very sensual and intense dance. I've noticed a lot of overlap in the poly and blues communities, in that both are heavily populated by very physically affectionate and openly sexual individuals. Not that those attributes make someone poly any more than they make someone a blues dancer, but there is a strong correlation to each.

Comment author: Vladimir_Nesov 04 February 2011 05:42:59PM 1 point [-]

Is this a MWI concern? I have observed the money with probability 1. There is no probability distribution.

No, it's a UDT concern. What you've observed is merely one event among other possibilities, and you should maximize expected utility over all these possibilities.

Comment author: datadataeverywhere 04 February 2011 06:32:58PM 0 points [-]

I'm really not trying to be obtuse, but I still don't understand. The other possibilities don't exist. If my actions don't affect the environment that other agents (including my future or other selves) experience, then I should maximize my utility. If, by construction, my actions have the potential of impacting other agents, then yes, I should take that under consideration, and if my algorithm before I see the money needs to decide to one-box in order for the money to be there in the first place, then that is also relevant.

I'm afraid you'll need to be a little more explicit in describing why I shouldn't two-box if I can be sure that doing so will not impact any other agents.

I probably don't need to harp back on this, but the only other reason I can see is that Omega is infallible and wouldn't have put the money in B if we were also going to take A. If we two-box, then there is a paradox; decision theories needn't and can't deal with paradoxes since they don't exist. Either Omega is fallible or B is empty or we will one-box. If Omega is probabilistic, it is still in our best interest to decide to one-box before hand, but if we can get away with taking both, we should (it is more important to commit to one-boxing than it is to be able to break that commitment, but the logic still stands).

That is, if given the opportunity to permanently self-modify to exclusively one-box, I would. But if I appear out of nowhere, and Omega shows me the money but assures me I have already permanently self-modified to one-box, I will take both boxes if it turns out that Omega is wrong (and there are no other consequences to me or other agents).

Comment author: Vladimir_Nesov 04 February 2011 01:36:34PM 2 points [-]

If the box is transparent, and we can see the money, we simply don't care what Omega says. As long as we trust that the bottom won't fall out (or any number of other possibilities), we can make our decision because our information (about which universe we are in) is not incomplete.

In transparent Newcomb's, you're uncertain about probability of what you've observed, even if not about its utility. You need Omega to make this probability what you prefer.

Comment author: datadataeverywhere 04 February 2011 04:04:53PM *  0 points [-]

Is this a MWI concern? I have observed the money with probability 1. There is no probability distribution. The expected long-run frequency distribution of seeing that money is still unknown, but I don't expect this experiment to be repeated, so that's an abstract concern.

Again, if I have reason to believe that (with reasonable probability) I'm being simulated and won't get to experience the utility of that money (unless I one-box), my decision matrix changes, but then I'm back to having incomplete information.

Likewise, perhaps pre-committing to one-box before you see the money makes sense given the usual setup. But if you can break your commitment once the money is already there, that's the right choice (even though it means Omega failed). If you can't, then too bad, but can't != shouldn't.

Under what circumstances would you one-box if you were certain that this was the only trial you would experience, the money was visible under both boxes, and your decision will not impact the amount of money available to any other agent in any other trial?

Comment author: ciphergoth 03 February 2011 01:32:09PM 2 points [-]

I think P(X|E) - P(X) is the wrong measure - should be the log likelihood ratio log(P(E|X)) - log(P(E|NOT X))

Comment author: datadataeverywhere 03 February 2011 02:36:56PM 1 point [-]

I was feeling uncomfortable about that myself.

In all likelihood, I shouldn't be using probability at all, because probability theory doesn't capture cause and effect well. Thinking back, what I should have said is just that rationalists are more likely to adopt polyamory than polyamorists are likely to adopt rationalism. The actual ratios of each are less relevant.

Comment author: Eneasz 02 February 2011 11:50:20PM 1 point [-]

I think it may. I'm still not convinced that MWI universes differ in any appreciable way at the macro level. It may be that every other instance of me lived an identical life except with slightly different atoms making up his molecules.

But in either case, I prefer maximizing meme-similar persons, not gene-similar ones, so my actions are self-consistent regardless. I'm acausally trading with an entity other than Azathoth.

Comment author: datadataeverywhere 03 February 2011 12:29:18AM 1 point [-]

I followed you until

I'm acausally trading with an entity other than Azathoth.

which entity are you trading with? We haven't gone back to talking about Prometheus, have we?

I might like to increase the number of meme-similar persons in my universe, but I don't really care about meme-similar persons in universes that can't influence mine. Even this is something I feel relatively weakly about. It's also just a personal difference in values, and I can reason pretending I share yours.

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