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eafer

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You think it's nitpicking because you don't care much about truth when it comes to history, and that's perfectly fine. But it's weird to complain about other people's baloney while spreading your own, and I think in his position as a trusted science communicator he should have been more responsible about this stuff.

> Eh, hard to say what is magic and what is not.

I don't think it is? I think there's a difference between the plausible but wrong and the impossible.

I find that the word "magic" is very overused by smart people online as a sort of thought-terminating cliché. It's a vague concept and I'm not always sure what they mean by it.

It's often extremely hard, even for top minds, to tell apart magic and science ahead of time. Think of Einstein mocking quantum physicists for believing in "spooky action at a distance". Of course if you still don't believe in quantum entanglement today then you are being irrational, but that's only because science has (mostly) settled the question, nothing to do with how magical or plausible the concept may sound.

Someone defending astrology will tell you that the gravity of the moon affects their bloodstream like it affects the tides of the ocean. That doesn't hold water if you sit down and do the math of course, but the same is true if you bother to check the dates for events in ancient history.

I actually kinda like Sagan, Cosmos is seriously gorgeous (though Vangelis does a lot of the heavy lifting there). I'm just kinda tired of the whole "Library of Alexandria" myth that comes up constantly around nerdy forums such as this one.

Believing silly nonsense which is still plausible isn't the same category of error as believing in magic.

Eh, hard to say what is magic and what is not. Sagan's beliefs about the ancient world could have been fixed with a five minute conversation with an expert. He just didn't care enough to do that, and for some reason that attitude is common among so-called skeptics when it comes to history.

People like Sagan have a worldview in which we are all either rational robots that only believe in "science", or else silly magic-believers that can't think by themselves. Of course Sagan himself proves that this is wrong: you can be a great scientist while believing a lot of silly nonsense about the ancient world, and about crab evolution apparently.

I think "made up" is fair. I can't know what his process was and everybody makes mistakes, but almost every single thing he said about history was wrong in a way that was convenient to his narrative, and it's not like he ever retracted anything. Surely if he wrote a whole book about dealing with bullshit he could have used that opportunity for some reflection about his past mistakes, now that would have been interesting to read.

It won't be Lebesgue integrable because it won't be measurable. Your function is actually a good (though not rigorous) argument for the existence of non-measurable sets.

yet its integral over any interval is exactly zero

That function doesn't actually have an integral in any sense that I know of. The Riemann integral doesn't work because, for every interval in every possible partition, the function's upper bound will be 1 and the lower bound will be -1.

That's for uniform distributions. We don't know the distribution here, that's part of the problem, but I would expect early cave art to be more sparse and worse preserved.

And milk can get pretty expensive pretty fast in this country: It always come in 1 litre recipients, and the cheapest one (The one that is within the mentioned program) is right now at ~70 pesos (Some 73 dollar cents at the official dollar price, 40 cents at the current rate for the dollar in the back market... but foreigners can hardly get this price for their dollars).

That's actually extremely cheap by international standards, if this source[0] is to be trusted. Of course it seems expensive for most argentinians because wages are also terribly low.

[0] https://www.numbeo.com/cost-of-living/country_price_rankings...

Airyx OS 5 years ago

OK, I thought you meant rust because that's the only other language with chances of getting support inside the Linux kernel right now.

I'm simply disputing your general claim that moving away from C would not help

I never said such a thing, I said we don't know. As always, in theory, there is no difference between theory and practice; in practice, there is.

Airyx OS 5 years ago

If you are thinking about rust, we don't have any data about it in the context of the kernel yet, not even for device drivers. It may prevent some exploitable bugs, but those aren't a big concern for filesystems - otherwise they wouldn't be put inside the kernel at all. The reality is, we don't know if it would help; and given how conservative we all are with our filesystem implementations (for good reasons), it's possible that we never will.

Airyx OS 5 years ago

Shims in the kernel seem a bit anti-social, since all module developers are expected to contribute to the shared core code. Of course it can be done, and it has been done. But I think FUSE is better if all you care about is portability, and you don't mind the heavy performance cost. My module could be ported for FUSE of course, but it's a lot more work than it may seem, the kernel interfaces are too alien compared to a userland library.

Airyx OS 5 years ago

C being a shitty language that does not force or even encourage programmers to handle errors

I don't see where this is coming from. Most of the world's top filesystems are written in C, and they work just fine. Maybe other languages could get better results, but it's hard to say with so little data.

implementation knowledge about file system technology is generally stuck in the 1990s

If you are talking about me, that might be true, I'm relatively new to this and still learning. But there's definitely people out there with some serious "implementation knowledge". And tools like xfstests did not exist in the 1990s, that makes a huge difference.

Airyx OS 5 years ago

I don't think I can, I'm using gpl code from other parts of the kernel. I'm not sure I would want to either, I put a lot of work into this and the gpl gives me more of a feeling of ownership.

That said, there's nothing stopping you or anyone else from reworking my code into a (gpl-licensed) FUSE driver. I don't think it's a straightforward task, but it can definitely be done.

Airyx OS 5 years ago

The main problem is simply that people really really really don't like losing their data after they saved it to disk. A simple app that corrupts its in-memory state once a year is probably acceptable. A filesystem that corrupts its on-disk state once a year is pure garbage. You basically need to aim for zero bugs.

How hard this is, it depends on the filesystem. Something like FAT, for example, is pretty much designed for ease of implementation, with few edge cases. Modern filesystems are not like that at all, the data structures are very complicated, so they must be extremely well tested before they are good enough to use. That would probably require an fsck to check for subtle inconsistencies; in the case of APFS you can use mine, but it's still very incomplete. Apple's published fsck is not very thorough.

As an example of the kind of problems to expect, I recall a bug in the Linux HFS+ driver. If you had a drive with lots of short filenames and lots of long filenames, and you started deleting the short filenames, eventually you would lose half of your files. This kind of things happen because HFS+ has variable-length keys in the index nodes of its trees, so deleting a record may trigger a complicated cascade of node splits. APFS inherited this feature, and it was very annoying to implement.

But HFS+ is very well documented; APFS is not, and that doesn't help.

Airyx OS 5 years ago

Oh, I wasn't trying to diss FreeBSD. It would probably have been better to write my driver for fuse to make it portable, but it's too far along at this point.

Airyx OS 5 years ago

compatible with macOS filesystems (HFS+ and APFS)

How far along is this? I think she's underestimating how hard it is to implement a modern filesystem that won't eat users' data. I've been working on a Linux APFS driver[0] for several years, and it's not fully functional yet. It's a pity that she is working with FreeBSD, or it could have been of use to her.

[0] https://github.com/eafer/linux-apfs-rw

Sure, but there's plenty of starving people in Argentina as well, not all the country is as wealthy as Buenos Aires. So the question is, why do they come here instead of going to a bigger chinese city? My guess is that they already have a support network here. That's why many of them end up working in the same businesses, such as running small supermarkets.

I don't think you should get downvoted, it's a good question. I live in Buenos Aires, and there is definitely a general perception that the country is hopeless. But for some reason we do get a fair share of immigrants from more prosperous countries such as South Korea and China. There's also a lot of people coming in from Africa, mainly Senegal from what I've heard.

SEEKING WORK | Argentina | Remote

Email: hn.eafer@gmail.com

I'm a programmer, most familiar with C on Linux and Win32. I'll be happy to start a project from scratch, or to help support any old codebase. For a sample of my work please see rdrview [1], a small command line tool that found some success here on Hacker News; or [2], a naive filesystem implementation I've been working on.

My current rate is 20 USD/hour. For what it's worth, I have a background in math.

[1] https://github.com/eafer/rdrview

[2] https://github.com/linux-apfs

SEEKING WORK | Argentina | Remote

Email: hn.eafer@gmail.com

I'm a programmer, most familiar with C on Linux (both userland and the kernel) and Win32. I'll be happy to start a project from scratch, or to help support any old codebase. For a sample of my work please see rdrview [1], a small command line tool that found some success here on Hacker News; or [2], a naive filesystem implementation I've been working on.

My rate is 20 USD/hour, and I don't expect to be paid until I have something to deliver. For what it's worth, I have a background in math.

[1] https://github.com/eafer/rdrview

[2] https://github.com/linux-apfs