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simonster

2,428 karma · joined March 14, 2012

email: simon@simonster.com github: https://github.com/simonster
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simonster··on Next Generation MITnet
Previous discussion (where I originally posted this gist): https://news.ycombinator.com/item?id=14150854
simonster··on MIT no longer owns 18.0.0.0/8
Letter to MIT community: https://gist.github.com/simonster/e22e50cd52b7dffcf5a4db2b8e...

tl;dr MIT is selling off half of 18.0.0.0/8 (8 million IPs)

simonster··on Could a neuroscientist understand a microprocessor?
Previous discussion: https://news.ycombinator.com/item?id=11780565
simonster··on LEDs may cause retinal toxicity at occupational domestic illuminance
Another relevant caveat (from http://www.nature.com/eye/journal/v25/n1/full/eye2010149a.ht...) is that "Mice and rats have been shown to have lower thresholds for photic injury than do primates."
simonster··on Grumpy: Go running Python
They've been working on NumPyPy since at least 2011, and to my knowledge it's still not in serious use.
simonster··on Basic Economy Fares Don't Lower Ticket Prices, They Increase Ticket Prices
> Those seats mean that despite paying more than most people on the plane, I'm not stuck in a middle seat most of the time.

The MCE seats also serve this purpose.

> I'm willing to bet that people with similar flying habits to me provide the majority of profit for an airline as well.

Well, because it encourages people like you to keep their "status," and people without "status" now have to pay extra for a regular seat, it probably benefits the airline. But it is another fare class that the airline invented to make more money, much like the basic economy fares discussed in the article.

simonster··on Basic Economy Fares Don't Lower Ticket Prices, They Increase Ticket Prices
There are seats that are not "Main Cabin Extra" but that AA will still charge you for, although less than they would charge you for MCE. Once the free seats are full, your options are to pay extra, or accept what is most likely going to be a middle seat separated from anyone you're traveling with.

My academic institution refuses to pay for any kind of seat upgrades, so from my perspective, the rational response is to fly on another airline. I will probably have to avoid airlines that start "offering" "Basic Economy" fares for the same reason.

simonster··on Why physicists still use Fortran
At least in OpenBLAS, most (all?) of the BLAS routines are C functions that call kernels written in assembly, but many of the LAPACK routines are the Netlib reference Fortran versions.
simonster··on German research institutions boycott Elsevier
Or just make Science OA. Unlike Nature and Cell, it's published by a non-profit (the American Association for the Advancement of Science). In principle, the American government could just give them money to make everything freely accessible. Or the publishers could ask authors to pay publication fees with waivers for those unable to pay, like most OA journals. Since the goal of the AAAS is (at least theoretically) to publish papers and not to make a profit, the fees need not be much higher than other OA journals. Given the average Science paper probably costs something like $1 million to produce, I doubt the authors would balk at paying a few thousand to make their work accessible to everyone.
simonster··on Neurogenesis Deep Learning
Yann LeCun called a technique for pruning weights "optimal brain damage" back in 1990: http://yann.lecun.com/exdb/publis/pdf/lecun-90b.pdf
simonster··on Depression afflicts almost half of STEM graduate students at UC Berkeley (2015)
They used a clinical depression survey (CES-D). The questions were:

1. I was bothered by things that usually don't bother me.

2. I had trouble keeping my mind on what I was doing.

3. I felt depressed.

4. I felt that everything I did was an effort.

5. I felt hopeful about the future. (REVERSED)

6. I felt fearful.

7. My sleep was restless.

8. I was happy. (REVERSED)

9. I felt lonely.

10. I could not "get going."

So yes, it seems like responses to 2, 4, 5, and 10 could have something to do with the nature of the work in addition to students' mental state. But it is also possible that feeling that way about one's work takes a toll on one's mental health. I don't think it's appropriate to conclude anything based on this survey, but it certainly seems to call for further investigation.

simonster··on Heavy Screen Time Rewires Young Mouse Brains, for Better and Worse
On top of that, mice are nocturnal creatures, so they do not ordinarily experience the same constant barrage of visual stimuli that humans do.
simonster··on Academics argue over how many people read and cite their papers (2014)
> Hopefully, someone will figure out how to answer this question definitively, so academics can start arguing about something else.

The reason academics argue about citation counts isn't necessarily that they care, but that, at many institutions, citation counts are directly tied to hiring decisions.

simonster··on The Best Way to Not Get Tenure
A benefit to what? People arguing for years over boring research questions where the evidence clearly favors one viewpoint over another does not benefit anyone except the people involved in the argument, who can ask for more funding to resolve this hotly debated open question.
simonster··on The Best Way to Not Get Tenure
As a student who has participated in some decisions regarding changing courses at my institution, I think classes here are usually bad because no one really cares. It requires tact to say "this course is garbage and you don't care about it anyway; let me handle it" without bruising egos.

But I think it's bullshit to say that not bruising egos is an important skill, especially in science. The kinds of scientists whose egos are easily bruised are the kinds of scientists who Max Planck was talking about when he said "science progresses one funeral at a time." People who refuse to acknowledge constructive criticism unless it's sugar-coated will continue to pursue the same ideas even after others have proved them wrong.

This is a systematic issue. Science is full of people with big egos. When scientist A criticizes scientist B's idea, ideally scientist A would think really hard about scientist B's criticism and either say "yes, you're right" or "no, here's what you're missing" (ideally with experiments). Scientists with big egos don't do this. They reject other scientists' criticism out of hand, and they criticize people based on feelings rather than ideas. The problem is contagious: Scientists with big egos attract more scientists with big egos, since those are the people who continue to believe they are great despite the barrage of nonsensical criticism. And egos tend to grow larger, not smaller, as people rise in rank.

Appropriately weighing others' evaluations of your ideas is really hard. It requires the technical skill necessary to come up with those ideas in the first place; the social skill to distinguish between sycophantic praise and true positive evaluation; and the emotional control to ignore anger or disappointment that might result from negative evaluation and focus on the content instead. In my experience, people who can do these things make much better scientists, and are much better to work with. They are less guarded when brainstorming ideas and more willing to change their minds in the face of superior evidence. But in modern science, there are relatively few incentives that favor accurate self-evaluation, and many that favor persistence above all else. In a world where ~5% of incoming graduate students go on to become tenured professors, people who aren't great and know it (or are great but don't know it) drop out early, and the people looking for positions end up being a combination of great people and mediocre people who think they're great.

simonster··on Julia 0.5 Highlights
The counter reports all heap-allocated memory, not just memory that persists after the function call, and the description in the post doesn't look quite right. The 208 bytes come almost entirely from calling the function from the global scope. Inside a function, there would only be 16 bytes of memory allocated on the heap, for the generator itself (which we desperately want to get rid of, but that is still WIP) and the return value would live in registers or on the stack.
simonster··on Was Microsoft Built on Stolen Goods?
The question is answered here: http://www.embedded.com/electronics-blogs/say-what-/4442498/.... The answer is no, except for the system calls.
simonster··on Promises and pitfalls of applying computational models to mental disorders
> What is your motivation for defending the status quo? My goal for posting was to point out that existing mental health treatments don't work, and that there are promising developments that point to a better model. I didn't share all my references.

My goal is to provide an opinion that balances yours, because there are likely many people in your situation, and I don't think they should give up on existing treatments quite so quickly. I know how it feels to see someone you know and love afflicted by mental illness, and I also know how, if treatment as usual doesn't work, it feels like there must be something out there that can help them if you can only find it. But I'm also a neuroscientist (albeit in a subfield without any connection to the study of mental illness) and I know that scientists really do the best they can, and are generally willing to pursue any route if they think it might lead to a better understanding of their subject of study, or, in the case of mental illness, a treatment that can work better than what's out there today.

> Antipsychotics have been shown again and again to be ineffective over the long term:

I am not qualified to assess this evidence, since I don't have an extensive knowledge of this field nor the time to acquire that knowledge, but here is a Cochrane review incorporating 65 RCTs that shows antipsychotics are effective for maintenance:

http://www.cochrane.org/CD008016/SCHIZ_maintenance-treatment...

It is true that the reduction in the risk of relapse appears to decrease with the duration of the study, which is definitely a disquieting finding and deserves further study, but there was still a reduction in risk in the longest study included (3 years).

simonster··on Promises and pitfalls of applying computational models to mental disorders
The claims you are making are stronger than the claims made by that paper (http://www.sciencedirect.com/science/article/pii/S0149763416...). First, the paper does not claim that cortisol production is related to psychosis. Instead, it measures the degree to which cortisol levels increase immediately upon awakening (cortisol awakening response or CAR), and specifically notes that CAR necessarily related to overall cortisol levels, but suggests that it may be related to hypothalamic-pituitary-adrenal axis function. It finds that CAR is blunted in patients with schizophrenia and first episode psychosis.

However, it is not clear whether the changes in CAR are causal or symptomatic. For example, psychosis might lead to a disrupted wake-sleep cycle, which could then lead to blunted CAR. To determine whether there is a causal effect, you'd need to perform a longitudinal study, measuring CAR in patients who are at first normal but some of whom later go on to develop a psychosis, and show that the CAR differences predate the development of psychotic symptoms, instead of developing later. The paper notes that such longitudinal studies are "clearly needed."

Mental illness is complicated. While it can clearly be explained scientifically, if the answer were easy, we would have found it by now. With that said, existing treatments have been shown to improve outcomes in double-blind placebo-controlled studies, even if we can't fully explain why, and that is why they are used. There are certainly problems with these treatments: They don't work for many patients and they often have undesirable side effects. But overall, we know that they help people, which is why we use them.

There are undoubtedly better treatments out there, but either they haven't been discovered yet or they haven't been proven to help. There is no nefarious motive behind sticking to the status quo. Researchers know that, if they were to publish a paper showing spectacular results from a treatment with few side effects, it would be great for the people they're trying to help, and also for them and their career. Instead, people stick to the status quo because, historically, alternative treatments have not been as effective.

simonster··on Western-style diet linked to state-dependent memory inhibition
There is no paper. This was a 15 minute oral presentation. It may or may not be interesting work, but it's not at the point where the popular press should be reporting on it.
simonster··on Western-style diet linked to state-dependent memory inhibition
It sounds like this was a conference presentation, which are usually not peer-reviewed in biological sciences, so I would be very careful about drawing any conclusions from it.
simonster··on Why we challenge Microsoft’s battery test
Of course it is. But if you care a lot about battery life, you might wonder if you should use Edge with an ad blocker or Opera, and the provided benchmarks are not very useful for determining which of those options is superior.
simonster··on A 32nm 1000-Processor Array
According to the link, the CM-1 had 16 processors on a chip, but there were a lot of chips (up to 4096 to yield up to 65536 processors). Still, the programming paradigms that were used for the Connection Machine might be useful for the massively parallel chip described here.
simonster··on Could a neuroscientist understand a microprocessor?
This is an interesting idea, and the paper is pretty well thought out. But I think one source of information not sufficiently explored is anatomy, which would help a great deal with the microprocessor, although it seems to help less with the brain. If you have the connectivity of the entire microprocessor (as the authors have determined using microscopy), then you can probably determine that there are recurring motifs. If you can figure out how a single transistor works, then you can figure out the truth tables for the recurring motifs. That takes care of most of Fig. 2. The only question that remains is if you could figure out the larger scale organization.

Anatomy also helps with the brain, but not nearly as much. People are still trying to figure out how the nematode C. elegans does its relatively simple thing even though the full connectome of its 302 neurons was published 30 years ago. But in larger brains, the fact that neurons are clustered according to what they do and projections are clustered according to organization in the places that they project from provides at least some level of knowledge. We are not merely applying Granger causality willy-nilly to random neural activity. We know what's connected to what (at a gross level) and in 6-layer cortex we even have an idea of the hierarchy based on the layers in which projections terminate (which is how Felleman and Van Essen got Fig. 13b in the paper).

OTOH, I think our failure to understand many neural networks at a conceptual level is quite disturbing, and perhaps a sign that the kind of conceptual understanding we seek will be forever beyond our reach. The authors mention this toward the end of the paper, although I think they overstate our understanding of image classification networks; I've never seen a satisfying high-level conceptual description of how ImageNet classification networks actually see. One possibility is that we simply don't have the right concepts or tools to form this kind of high-level description. Another possibility is that there simply is no satisfying high-level way to describe how these networks; there are only the unit activation functions, connectivity, weights, training data, and learning rule. We can find some insights, e.g., we can map units' receptive fields and determine the degree to which different layers of the network are invariant to various transformations, but something with the explanatory power of the CPU processor architecture diagram in Fig. 2a may very well not exist.

I hope that the brain's anatomical constraints provide some escape from this fate. Unlike most convolutional neural networks, the brain has no true fully connected layers, and this may serve to enforce more structure. We know that there is meaningful organization at many different scales well beyond early visual areas. At the highest levels of the visual system, we know that patches of cortex can be individuated by their preferences for different types of objects, and similar organization seems to be present even into the "cognitive" areas in the frontal lobe. It remains to be seen whether it's possible to put together a coherent description of the function of these different modules and how they work together to produce behavior, or whether these modules don't turn out to be modules at all.

simonster··on How Austin Beat Uber
Certainly the situation is ridiculous, but why blame the citizens of Austin instead of Uber, which could allow drivers who are willing to get fingerprinted to drive?
simonster··on Ketamine and Depression: A Breakthrough?
The Nature paper was about isolating a metabolite of ketamine that is not responsible for the intoxicating aspects, but is responsible for the antidepressant activities (at least in mice).
simonster··on Ketamine and Depression: A Breakthrough?
The "antidepressant screens" referred to here are in mice, not humans. The Nature paper is an amazing set of experiments that provide very compelling evidence that (2R,6R)-HNK is responsible for the antidepressant effects of ketamine in mouse models of depression, but Neuroskeptic is right that it's not clear that (2R,6R)-HNK is also responsible for the antidepressant effects of ketamine in humans. We know that mouse models of depression are not necessarily great; SSRIs seem to be more effective in mouse models than they are in humans.
simonster··on Apple Stole My Music
The preceding sentence is:

> Either way, if you’ve used iTunes Match as a convenient way to free up space on your Mac by deleting your own copy of any of your music, don’t cancel your subscription in favor of Apple Music if you want to keep that music DRM free.

Given the reference to freeing up space, it seems like he is talking about the original music files within iTunes and not a backup.

simonster··on Apple Stole My Music
The article you linked to appears to describe something totally different. It says that if you delete your music from your computer, then re-downloading the music through Apple Music will give you DRMed files. But it also says:

> If you haven’t deleted your own copies of your music, then there’s nothing to worry about. If you download onto other devices from Apple Music, those devices will get the DRM versions, but you’ll still have your DRM-free originals.

simonster··on Apple Stole My Music
But other people have posted here and said they enabled Apple Music and their music was not deleted, so clearly this doesn't happen under all circumstances, and this wouldn't be the first time a technical support representative was wrong. This is a pretty extraordinary claim and I'm not really willing to believe everyone loses all their local music when they turn on Apple Music without more data to confirm.
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