Comment author: Thomas 12 October 2015 04:03:26PM -2 points [-]

What can one expect after this super-task is done to see?

Nothing?

At a meta level, if there were this basic a problem, don't you think it would have already been noticed?

It has been noticed, but never resolved properly. A consensus among top mathematicians, that everything is/must be okay prevails.

One dissident.

https://www.youtube.com/watch?t=27&v=4DNlEq0ZrTo

Comment author: JoshuaZ 12 October 2015 08:34:24PM 3 points [-]

Phrasing it as a "super-task" relies on intuitions that are not easily formalized in either PA or ZFC. Think instead in terms of a limit, where your nth distribution and let n go to infinity. This avoids the intuitive issues. Then just ask what mean by the limit. You are taking what amounts to a pointwise limit. At this point, what matters then is that it does not follow that a pointwise limit of probability distributions is itself a probability distribution.

If you prefer a different example that doesn't obfuscate as much what is going on we can do it just as well with the reals. Consider the situation where the nth distribution is uniform on the interval from n to n+1. And look at the limit of that (or if you insist move back to having it speed up over time to make it a supertask). Visually what is happening each step is a little 1 by 1 square moving one to the right. Now note that the limit of these distributions is zero everywhere, and not in the nice sense of zero at any specific point but integrates to a finite quantity, but genuinely zero.

This is essentially the same situation, so nothing in your situation has to do with specific aspects of countable sets.

Comment author: Thomas 12 October 2015 03:20:04PM 0 points [-]

Yes. It's not the Choice axiom which is problematic, but the infinity itself. So it doesn't mater if ZF or ZFC.

Why do I believe this? It's known for some time now, that you can't have an uniform probability distribution over the set of all naturals. That would be an express road to paradoxes.

The problem is, that even if you have a probability distribution where P(0)=0.5, P(1)=0.25, P(2)=0.125 and so on ... you can then invite a super-task of swapping two random naturals (using this distribution) at the time 0. Then the next swapping at 0.5. Then the next swapping at 0.75 ... and so on.

The question is, what is the probability that 0 will remain in its place? It can't be more than 0, after the completion of the super-task after just a second. On the other hand, for every other number, that probability of being on the leftmost position is also zero.

We apparently can construct an uniform distribution over the naturals. Which is bad.

Comment author: JoshuaZ 12 October 2015 03:25:13PM 8 points [-]

The limit of your distributions is not a distribution so there's no problem.

If there's any sort of inconsistency in ZF or PA or any other major system currently in use, it will be much harder to find than this. At a meta level, if there were this basic a problem, don't you think it would have already been noticed?

Comment author: JoshuaZ 12 October 2015 01:08:32PM 1 point [-]

At least two major classes of existential risk, AI and physics experiments, are areas where a lot of math can come into play. In the case of AI, this is understanding whether hard take-offs are possible or likely and whether an AI can be provably Friendly. In the case of physics experiments, the issues connected to are analysis that the experiments are safe.

In both these cases, little attention is made to the precise axiomatic system being used for the results. Should this be concerning? If for example some sort of result about Friendliness is proven rigorously, but the proof lives in ZFC set theory, then there's the risk that ZFC may turn out to be inconsistent. Similar remarks apply to analysis that various physics experiments are unlikely to cause serious problems like a false vacuum collapse.

In this context, should more resources be spent on making sure that proofs occur in their absolute minimum axiomatic systems, such as conservative extensions of Peano Arithmetic or near conservative extension?

Comment author: CellBioGuy 10 October 2015 12:48:14AM *  1 point [-]

Spreading around gamma ray detectors would have similar advantages.

Comment author: JoshuaZ 10 October 2015 01:08:46AM 2 points [-]

Yes, but there's less reason for that. A big part of the problem with neutrinos is that since only a small fraction are absorbed, it becomes much harder to get good data on what is going on. For example, the typical neutrino pulse from a supernova is estimated to last 5 seconds to 30 seconds, while the Earth is under a tenth of a second in diameter. Gamma rays don't have quite as much of this problem and we can sort of estimate their directional data better.

On the other hand, the more recent work with neutrinos has been getting better and better at getting angle data which lets us get the same directional data to some extent.

Comment author: slutbunwaller 08 October 2014 04:23:56PM *  -1 points [-]

Cryonics and transhumanism are laughably irrational. Guess that's what happens with a cult based on a Harry Potter fanfiction by a dropout

Comment author: JoshuaZ 07 October 2015 07:13:02PM 0 points [-]

You do know that both sets of ideas predate HPMOR, right?

Comment author: JoshuaZ 07 October 2015 07:06:18PM 8 points [-]

Slightly crazy idea I've been bouncing around for a while: put giant IceCube style neutrino detectors on Mars and Europa. Europa would work really well because of all the water ice. This would allow one to get time delay data from neutrino bursts during a supernova to get very fast directional information as well as some related data.

In response to comment by [deleted] on Open thread, Oct. 5 - Oct. 11, 2015
Comment author: NancyLebovitz 07 October 2015 06:54:09PM 5 points [-]

I was expecting a rule like bans should be preceded by a warning and a chance to reply.

Comment author: JoshuaZ 07 October 2015 07:00:57PM 4 points [-]

That's a rule I'd strongly support other than in cases of absolutely unambiguous spamming or clear sockpuppets of banned individuals.

Comment author: NancyLebovitz 06 October 2015 02:35:05PM 32 points [-]

I have banned advancedatheist. While he's been tiresome, I find that I have more tolerance for nastiness than some, but this recent comment was the last straw. I've found that I can tolerate bigotry a lot better than I can tolerate bigoted policy proposals, and that comment was altogether too close to suggesting that women should be distributed to men they don't want sex with.

Comment author: JoshuaZ 07 October 2015 06:49:43PM 5 points [-]

While I'm deeply concerned about the possibility that AA has been engaging in vote-gaming which does seem to be a bannable offense, it isn't clear to me that, as reprehensible as that comment is, that it is enough reason by itself for banning, especially because some of his comments (especially those on cryonics) have been clearly highly productive. I do agree that much of the content of that comment is pretty disgusting and unproductive, and at this point his focus on incel is borderline spamming with minimal connection to the point of LW. Maybe it would be more productive to just tell him that he can't talk about incel as a topic here?

Comment author: CAE_Jones 06 October 2015 04:36:54AM 5 points [-]

More charitable hypothesis: The people most likely to notice an advancedatheist comment the quickest downvote. The next wave of people finds the downvoting excessive and upvote in response.

This doesn't really predict -10 to +3 swings, though.

Comment author: JoshuaZ 07 October 2015 06:34:49PM *  2 points [-]

Not only does it not predict such large swings it also doesn't fit with the fact that after such a swing (which occurs rapidly) he then gets a slow downward trend. I pointed this out to the moderators a while ago and so I have a record of how rapid some of the changes were:

http://lesswrong.com/lw/ls5/if_you_can_see_the_box_you_can_open_the_box/c1kf was at -9 within 8 hours of being posted, 12 hours later or so it was at +4. Note that it has now reverted to +0.

http://lesswrong.com/lw/ln8/february_2015_media_thread/bx5u was at -5, then within 24 hours went to +6 and is now +3.

http://lesswrong.com/lw/lli/open_thread_jan_26_feb_1_2015/bw6v was at -8 at 5 PM EST. At 7:10 EST it was at +6. In the same span http://lesswrong.com/lw/lli/open_thread_jan_26_feb_1_2015/bw6w was at -13 and went to +0. After the fact over the next few days, both those comments went into the deep negative. Similarly http://lesswrong.com/lw/lk7/optimal_eating_or_rather_a_step_in_the_right/bvmk was at -4, then went in the same 2 hour time span up to 3 and then went to 2 (so was left alone after that).

Curiously, within the same 2 hour time span as that set of rapid upvoting, two highly negative comments in support of A went through a similar swing with again a slow reversion over the next few days http://lesswrong.com/lw/lli/open_thread_jan_26_feb_1_2015/bw9t and http://lesswrong.com/lw/lli/open_thread_jan_26_feb_1_2015/bw7l

These aren't the only examples, but simply the most blatant

Based on this evidence I assign an extremely high credence that some form of karma abuse is going on with someone using multiple accounts (approximately 90% certain). I assign an 80% chance that this person is doing so deliberately to upvote comments which are seen at odds with "liberal" politics in some form. I assign a slightly over 50% chance that AA is doing this himself. The fact that it took until now for him to address such concerns despite the fact that others have mentioned them is not positive. After AA himself, I assign the next most likely individual to be Eugine for obvious reasons.

Comment author: JoshuaZ 30 September 2015 12:31:25AM 1 point [-]

Another reason for optimism is that it seems that the level of political bias is actually lower today than it was historically. People are better at judging politically controversial issues in a detached, scientific way today than they were in, say, the 14th century. This shows that progress is possible.

Can you expand on what evidence there is for this?

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