Live data from Hacker News

A student’s desire to get out of a exam led to a compression algorithm

quantamagazine.org

71–80 of 132 posts

Re: A student’s desire to get out of a exam led to a compression algorithm

#71
post #2

missed opportunity to explain how compression and prediction are related, and that the better you can predict the next token the better your compression gets, then your article gets to mention GPT hey

Apparently compression and intelligence are synonymous: https://mattmahoney.net/dc/rationale.html

Synonymous, according to one person, taking a liberal view of a only vaguely related result.

Re: A student’s desire to get out of a exam led to a compression algorithm

#72
post #8

Quanta magazine and all these pop science websites need to be stopped. (Not because popular science is bad, but because they do it badly, and the clickbait is insufferable)

> but because they do it badly, and the clickbait is insufferable

Well, then, who does pop science "right"?

There's no shortage, of course, of 30+ page review articles on every scientific topic imaginable. And if someone has a few days, a freshly minted STEM degree or years of related experience, and a compelling interest in the topic, they can just pick up one of these review articles and go to town.

But that isn't going to fly for the general public, not even close. And not just because of the mathematics, dry passive-voice language, lack of context, times new roman, and gratuitous expert jargon. It's just too much.

So, what do you recommend?

Re: A student’s desire to get out of a exam led to a compression algorithm

#73

Earlier quoted context omitted.

This is why I was flabbergasted by the nonsense internet takeover of HTTPS. You can't cache it. Probably 99% of web traffic is generic public content, but we can't cache any of it, because 1% of it needs to be private. So then people complain "oh but The Illuminati can see what websites I'm going to!" Yeah, and they still can with HTTPS, it's called statistical network traffic analysis. Decades of research papers sho…

Numerous people are currently sitting in jail in Saudi Arabia for having posted tweets critical of the regime under their own names. Without HTTPS, jails around the world would be a lot busier if authorities could see everything that their populace reads online in clear text, in order to build dossiers on who is most likely to be a dissident. I don’t think the kind of traffic analysis you mention works as well as you…

> Numerous people are currently sitting in jail in Saudi Arabia for having posted tweets critical of the regime under their own names. Without HTTPS, jails around the world would be a lot busier if authorities could see everything that their populace reads online in clear text, in order to build dossiers on who is most likely to be a dissident.

Indeed... When one lives in such regimes, to say that appears to be an utter truism.

Re: A student’s desire to get out of a exam led to a compression algorithm

#75

I thought Huffman coding was obsolete, arithmetic coding replaced it. It allows for fractional number of bits per symbol, so is more efficient.

My understanding why arithmetic coding isn't used as much as Huffman coding is because of the patents that IBM had on arithmetic coding. I'm not familiar with any actively used compression algorithm that uses arithmetic coding.

I have explored using arithmetic coding on some data at work (mainly large amounts of XYZ points). My attempts did not work better than standard zip compression.

Re: A student’s desire to get out of a exam led to a compression algorithm

#76

I thought Huffman coding was obsolete, arithmetic coding replaced it. It allows for fractional number of bits per symbol, so is more efficient.

It’s still used in PNG, it is part of the spec.

There’s a trade off, Huffman is relatively fast and easier to get right, and the gains from increased compression may be considered marginal.

This is a classic engineering trade off.

Re: A student’s desire to get out of a exam led to a compression algorithm

#77
post #9

Caches drive the internet. They are orders of magnitude more important than compression. 99.99% of requests hit a local cache. (1) Compression is important too. (1) I worked in a telco. Check it out for yourself!

Is it still? Afaik now with everything HTTPS, caching proxies on the ISP end are completely useless. We instead now see (proprietary?) cache boxes by big players like YouTube and Netflix that ISPs can install in their DCs, but that seems less elegant, even though it gives the content providers much greater control over what, when and how much gets cached. Still, as a smaller fish, without going with cloudflare, there…

How do these cache boxes work? Does the server send them its half of the ephemeral key or something? I can't imagine each isp has a box with a copy of netflix's private key.

Re: A student’s desire to get out of a exam led to a compression algorithm

#78

There was a series of articles on lossless and lossy and compression techniques in, I think, PC Magazine that I read as a kid and made a big impression on me. I didn't, like, end up ready to write code to build Huffman trees or anything, but it did change it from a total black box into a bunch of smaller pieces each of which a mere mortal can understand. The compression rabbit hole can be a rewarding one to go down i…

[deleted]

Re: A student’s desire to get out of a exam led to a compression algorithm

#80

There was a series of articles on lossless and lossy and compression techniques in, I think, PC Magazine that I read as a kid and made a big impression on me. I didn't, like, end up ready to write code to build Huffman trees or anything, but it did change it from a total black box into a bunch of smaller pieces each of which a mere mortal can understand. The compression rabbit hole can be a rewarding one to go down i…

I found their Encyclopedia page[0], but I suspect you meant something better than this?

Any further recollections to help drill down and find it?

- [0]: https://www.pcmag.com/encyclopedia/term/data-compression

Post reply on HN