YHK - yet another hacker news clone

You could have invented transformers from memory

316 points speckx 16 hours ago 73 comments

craftkiller 14 hours ago | parent

This article does two things which make it unhelpful for me:

1. It uses math notation. This is a software development site, wouldn't this be much more clear to this audience written as psuedo code instead of a complex series of greek and latin letters?

2. It doesn't step through a concrete example. What is hollow R raised to the (M * d_v) ? Is it a number, a set, a list, a matrix?

To use an example I understand: RAG used to seem complicated to me when only math people were talking about it in math words. For example, let's take a line from wikipedia on embeddings:

> the representation is a real-valued vector that encodes the meaning of the word in such a way that the words that are closer in the vector space are expected to be similar in meaning

What made it clear was learning that generating an embedding is just a function(string) -> list[float], and RAG is just taking a list[float] for your prompt and finding other list[float] that are close to it in your dataset.

So what would make this article more clear, is step through a simplified example of putting a value into a memory store and querying that memory store, showing the actual data structures.

saghm 13 hours ago | parent

> This is a software development site, wouldn't this be much more clear to this audience written as psuedo code instead of a complex series of greek and latin letters

At the risk of stating the obvious, this is a forum where people can post arbitrary links to other sites, some of which might have audiences that might not be "the exact set of people who read Hacker News". I'm not sure you'd be able to make a compelling argument that alexwang.ai is aimed at software developers and no one else.

craftkiller 13 hours ago | parent

Yes, but you need to consider your audience when posting links to this site. For example, if I posted to HN a link to a really good cookie recipe, it wouldn't be a good fit for this site. The author did nothing wrong, but that doesn't make it a good submission to HN.

This article is a bit more of a grey area. It is on a subject that is deeply relevant to this site and I'm sure some HN readers will get value from it. My point is that an even better submission to HN would have been an article on the same topic but written for programmers rather than mathematicians.

saghm 13 hours ago | parent

I'm surprised to this take, because I feel like I see math stuff posted here fairly often, and often with a large number of people commenting on it in substantive ways. Often times the math savvy crowd will even help explain stuff to people like me who are not particularly fluent in advanced math.

craftkiller 13 hours ago | parent

> Often times the math savvy crowd will even help explain stuff to people

Perhaps, but HN apparently is pretty hostile to people explaining why something is not clear and how it could be more clear based on all the downvotes. I'll keep that in mind: "If you don't understand something, shut up!"

SyneRyder 12 hours ago | parent

I think people likely hit an early "break" and "goto xkcd 386" when they saw "this is a software development site" in your comment, without reading the rest of your comment.

Clear explanations are a good thing, but different explanations help people in different ways. Your explanation seems helpful to me, and reminds me of Ben Affleck's explanation in the GQ interview. But Ben Affleck connected it directly to arrays of RGB pixel data, which clicks more with me personally, but probably wouldn't with everyone. It certainly didn't make things any clearer to the interviewer.

saghm 12 hours ago | parent

There's a certain irony in praising clear explanations as a defense of an explanation that needlessly veered into value judgment

SyneRyder 11 hours ago | parent

Well, sure... but it seemed to me that they didn't realize they're posting on Startup News, a news site for founders of startups:

https://news.ycombinator.com/hackernews.html

"... the thing that makes hackers such good startup founders is that they care about more than business. They have intellectual curiosity driving them as well as the desire to make money. So the way to make a news site for startup founders is to make it be about more than just startups. ... If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."

My thought was to show some grace, considering that not everyone's been around here for 20 years or knows that "hacker" doesn't apply only to computer programmers. That was my thinking anyway.

craftkiller 11 hours ago | parent

I had no idea it used to be called Startup News! When I joined in 2012 this site was "essentially /r/programming but for more serious programmers and without jokes"

saghm 12 hours ago | parent

I didn't downvote, and I don't think there's a problem with explaining why something isn't clear. There's a difference between expressing criticism and saying that something doesn't belong here, and which I'd argue is evidenced from the fact that the reaction to my comment critiquing yours doesn't seem to have ruffled many feathers (at least not yet!)

craftkiller 12 hours ago | parent

Not sure I'm understanding you correctly, but it sounds like you're saying that I said that this post doesn't belong here? I said no such thing. I said this article is "unhelpful for *me*" but "deeply relevant to this site" and "some HN readers will get value from it".

Imagine a nursing home that serves steak every day. One resident says "this food isn't helpful to me because I no longer have teeth to chew it. Wouldn't this be better for everyone if we had soup?". They're not suggesting outlawing steak, after all some people will get value from it. They suggesting a way to better serve the entire population of the nursing home.

Nevermark 12 hours ago | parent

Not understanding something isn’t the issue.

Also not an issue: the quality of the article.

Expect to be challenged by content here. Everybody is from time to time. Asking for a mathy analysis to drop the math, fundamentally misunderstands the value of the math.

craftkiller 11 hours ago | parent

I'm not suggesting they drop any math. I'm suggesting they drop the math notation. As programmers, we spend 8+ hours per day reading code. Expressing the same math but in the syntax of code would make it accessible to more people on this site. It's like speaking in someone's native tongue instead of their 2nd language. I can read and mostly understand a news article written in French but it is going to take a lot of time and effort. If a news article is written in English I could read it quickly and easily. Both languages are presenting the same information, it is just a matter of how it is presented.

HN is a site for programmers (or specifically "hackers"). Posting an article to a site for programmers in math notation is like posting a French article to an English message board. Some people will be able to read it with varying levels of difficulty, but wouldn't it be better to post an English version of the same information so everyone can read it easily?

pestatije 10 hours ago | parent

the poster and the writer are different entities... only the writer influences the poster, not the other way around...now the poster saw value for HN readers and thats why it ended here.. with this logic your position doesn't make sense

Nevermark 5 hours ago | parent

The article was elevated as relevant by HN readers, not forced on them.

As an isolated wish, your ideas might be reasonable.

But framing them as necessary HN values, as a critique, as ideas others should conform to, you are not being sensible or reasonable.

mdp2021 3 hours ago | parent

"hackers" = "resourceful".

> If you don't understand something

Ask, but if you advance weak ideas be prepared to be hit - and be glad about it, you are advised to revise the weak ideas.

ergonaught 12 hours ago | parent

I see plenty of things shared here that don’t fit your preconception of what is a fit for a site you don’t operate.

soulofmischief 9 hours ago | parent

Have you considered that you are simply not the audience that Alex or speckx had in mind? It would be healthy to recognize this simple fact and move on while letting the intended audience (Hi! Longtime HN member for over a decade!) enjoy it.

craftkiller 8 hours ago | parent

"If you don't understand something, shut up!"

Got it. Stay classy HN.

soulofmischief 8 hours ago | parent

Please do not put words in my mouth. Did I say to shut up? I said to move on, since this is clearly stressing you out, and additionally because you are ostracizing other members of the community who are just fine with this content. This isn't Harrison Bergeron, the community as a whole does not have to cater to your own intellectual shortcomings. There is no need for sarcasm or snark.

craftkiller 6 hours ago | parent

> I said to move on

They're the same thing on an internet forum. There is no space to move through, so while in the physical world "move on" is different from "shut up", on an online forum they both mean exactly the same thing: "don't say anything".

And yes, this is stressing me out. I took the time and effort to think about and explain how this post could reach a wider audience on hackernews, citing an example from my own learning experience, and nearly everyone has attacked me for it. The original article was clearly meant to explain/educate. You'd think "here's how you can do that for more people" would be useful feedback.

soulofmischief 6 hours ago | parent

You are welcome to shout at the clouds all day. I'm not asking you to shut up, I'm telling you I think it's worth moving on, internally. I'm trying to explain why you would be better served by accepting that you're not the only member of the community. It's easy to forget that other people don't think the same way you do; Bram Moolenaar himself chastised me over this once and I took it to heart.

The thing is, there are fundamental issues with your post. You said, "if I posted to HN a link to a really good cookie recipe, it wouldn't be a good fit for this site", which is wrong; Hackers might be interested in cookies. The site guidelines state,

   On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.

  Off-Topic: Most stories about politics, or crime, or sports, or celebrities, unless they're evidence of some interesting new phenomenon. If they'd cover it on TV news, it's probably off-topic.
If that cookie recipe is really good, I'm curious! Cooking is something many hackers love to do.

You also criticized the article for... using math notation... and wrongly assumed that other engineers on this site who also are interested in mathematics, like Alex Wang, would rather dispense with the compact notation and instead deliver pseudocode. This is entirely the author's prerogative, just as it's your prerogative to skip it and move on, or even criticize it. But you cannot get upset when your criticism is then itself critically evaluated, or claim others are being hostile for examining the content of your comment just as you did the content of the article. I know you weren't being hostile in your criticism, and I'm not aiming to be hostile in mine.

> You'd think "here's how you can do that for more people" would be useful feedback.

Sure! What this mostly comes down to is your misunderstanding of the breadth of our community, and the site guidelines. You truly did mean well, and I also mean well here, even if I am being blunt. The rest of your comment was fine and I don't take issue with the general sentiment.

fc417fc802 1 hour ago | parent

> You also criticized the article for.

> What this mostly comes down to is your misunderstanding of the breadth of our community

Actually I think it's the people responding to him that aren't being sufficiently careful to read what he actually wrote and to understand the message he was attempting to convey. Granted he could have done a better job communicating (case in point, this very conversation) but that's often going to be the case.

It seems like people are interpreting it in a hostile manner when from my perspective the core of it is both actionable and reasonable feedback for anyone attempting to explain a technical topic. Both of the original points (using mathematical notation and failing to step through concrete examples) are each things that will alienate a decent chunk of any potential audience. In fact the former is one of my primary complaints about wikipedia articles on math adjacent topics.

mdp2021 4 hours ago | parent

> software development site ... you need to consider your audience when posting links to this site ... a link to a really good cookie recipe ... for programmers

That is really your interpretation only - and it directly clashes with the explicitly intended: "intellectually curious" (which will be, if not polymaths, at least open).

Of course an intellectual curiosity space hosted around the world of startup enterprises will attract membership of people with experience in engineering.

If you check the submissions, it should be immediately evident that there is no closure.

fc417fc802 1 hour ago | parent

> For example, if I posted to HN a link to a really good cookie recipe, it wouldn't be a good fit for this site.

Going to have to disagree with you here. That would very much depend on the particulars of and circumstances surrounding the recipe. This is a site for anything that would interest the typical hacker (whatever that actually is) after all.

CamperBob2 13 hours ago | parent

Send the link to Claude or your favorite alternative, and cut-and-paste your comment into the box, and you'll get exactly what you want.

andai 12 hours ago | parent

Upvoting you for this is quite fair. Mathematicians do seem to suffer from the Feldspar Problem:

https://xkcd.com/2501/

>It's easy to forget that the average person probably only knows the formulas for Olivine and one or two Feldspars

That being said the llm is indeed the universal translator — the babelfish supreme — and is excellent at translating whatever you want into pseudocode in your language of choice.

bluegatty 11 hours ago | parent

Those are valid bits of feedback to make an articel more accessible, but it's totally fine and apprpriate as it is

aDyslecticCrow 11 hours ago | parent

I guess you're not the target audience for this article then.

This is pretty approachable maths, and explain really well. I've seen far worse in programming language theory papers, which would qualify as "software development" in my mind. There are plenty of users of this forum that would find this paper useful and interesting, with sufficient math background to read it to boot.

msisk6 10 hours ago | parent

Well, you could tell your AI of choice to read the article and explain the math. I did that with ChatGPT and it helpfully translated a lot of it into Python for me.

kccqzy 8 hours ago | parent

The author has a link to the actual code behind the blog post. https://github.com/KeAWang/associative-memory-blog/blob/main...

plaguuuuuu 7 hours ago | parent

Wait, you're saying that mathematics isn't useful to software engineers?

You should give it a go.

craftkiller 6 hours ago | parent

That is not an accurate read of my post. My post was about two things:

  1. The notation used
  2. The lack of concrete examples
I'm not saying they should remove any of the content, just put it in a form more accessible to us. For example, I can read and mostly understand a news article in French, but it will take a lot of time and effort. If it was written in English, it would be easy for me to read. The two news articles have exactly the same content, one is just written in a form easier for me to understand.

Well putting this article in math notation without defining any of the data structures behind it, that's not like putting the article in French, it's like putting the article in Japanese. I can't understand any of it. Some Japanese speakers on this site are saying "I don't understand the problem, just learn Japanese." which is pretty much the least constructive comment they could make.

mrandish 7 hours ago | parent

FWIW, I found the idea of interference-to-signal ratio as a way to think about memory capacity to be intuitive and was really interested in getting a better sense of how models increase capacity, until it hit the first math notation formula. My disconnect was based on the approachable tone of the intro, from which I assumed it would be a more generally accessible article.

To be clear, I have no problem with math people conveying math stuff with math notation but it seemed like the type of article which, even if it will get into notation, first at least explains "the main idea of it" without notation, then expands with notation as necessary when fleshing details or implementation.

planckscnst 5 hours ago | parent

What made it not useful to you likely makes it much more useful for me.

Fortunately, LLMs can work wonders in adapting content to be more accessible to a wide variety of audiences. Just give it a link and feed your exact post to it. It will be able to translate it into pseudocode and provide examples.

sailfast 13 hours ago | parent

This is a really interesting article! While I can’t profess to understand all the math it is a great way to demonstrate it.

I recall awhile back hearing someone ask whether intelligence was actually the same or similar to “compression” or storing all of this knowledge in weights - IE the ability to create something from reason or weights or relationships / connections. This article makes it even more interesting!

yhjc2692 9 hours ago | parent

For anyone interested, here is a recent 3Blue1Brown series on "Compression is Intelligence": https://www.youtube.com/watch?v=l6DKRf-fAAM

(For anyone not familiar with 3B1B, it's a YouTube channel that visualizes intriguing math concepts to explain them intuitively!)

361994752 12 hours ago | parent

Who? Me?

andai 12 hours ago | parent

See also:

NNCP: Lossless Data Compression with Neural Networks (2019)

https://news.ycombinator.com/item?id=27244004

https://bellard.org/nncp/

yoz-y 12 hours ago | parent

Would be nice if articles defined the requirements to be a “you”.

mathisfun123 12 hours ago | parent

why?

arcanemachiner 12 hours ago | parent

Because I'm an idiot.

mllev15 5 hours ago | parent

Yeah I was lost by the second tweet

layer8 11 hours ago | parent

https://en.wikipedia.org/wiki/Generic_you

yoz-y 10 hours ago | parent

This is actually useful. I didn’t know that generic “you” meant “one”. I always interpreted it as “you the reader” and felt desperate once a week when reading articles like these.

NikolaNovak 10 hours ago | parent

I love seeing helpful people create this moment :)

https://xkcd.com/1053/

wk_end 9 hours ago | parent

As a native English speaker, I interpret it as “you the reader”. Or maybe I should say, I don’t intuit any material difference between “you the reader” and “any given reader” or “one”. I think your original comment is a good critique of the headline.

mdp2021 4 hours ago | parent

It is an abstraction: "you" immediately, but not just you specifically, hence any abstract "objected" person (even the first person taken reflectively as a mental instance).

satvikpendem 3 hours ago | parent

Interesting. Are you a native English speaker? You in the general case is used quite a lot and I wouldn't be able to handle every single article or reference using that to mean to refer to me specifically.

fc417fc802 1 hour ago | parent

But it does? It's generic, meaning you the reader are fully interchangeable with other possible subjects. At least that's the connotation it carries for me, and for what it's worth I'm a native speaker. If the reader (ie the target audience from the author's perspective) isn't interchangeable then I'd expect some other article to be used (ex they, the relevant professional, an interested party, etc).

zahlman 9 hours ago | parent

That said, the audience for this is still pretty niche.

(Even the audience for, say, 3b1b's explanation of what a transformer is, is niche.)

penguin_booze 2 hours ago | parent

The 'you' this article--and other articles like this--mentions, doesn't definitely include you, nor me, nor people like us.

Recently, Jensen Huang reportedly said he doesn't know where he lives (the address) with a straight face. This 'you' situation here is kind of like the Jensen situation: neither party understands what it's like to be the other party.

vatsachak 12 hours ago | parent

Great article. My favorite fact about "transformers as a hopfield network" is that transformers are so good at memorizing that they only need one step to find a suitable memory as opposed to multiple steps for a vanilla hopfield network

kooi 12 hours ago | parent

Goodness, someone posts a great article which IMO accessible math, and people get upset.

If you think that is crazy, ohh boy, just wait til you see all the other papers underlying LLMs, AI, and optimization in general.

I appreciate this post because starting from linear algebra is the correct way to form an intuition of the higher dimensional semantic spaces we're dealing with.

dullcrisp 11 hours ago | parent

For anyone here who understands this stuff, help me out because the article dropped me at the end when drawing the connection from memory to LLMs.

For an LLM, the keys are the tokens in your context, and the values are … what exactly?

wilkystyle 10 hours ago | parent

In an attention layer, the query, key, and value are all computed at inference time using weight matrices that are determined as a result of the training. If X is the token representations entering the attention layer, then each of Q, K, and V would be determined by multiplying X by the corresponding learned weight matrix for queries, keys, and values:

Q = XW_q

K = XW_k

V = XW_v

From there, you can think of K and V like keys and values in a Python dictionary, and Q as the key you pass (e.g. d[Q] in Python to return some value V). The difference in an attention layer is that the query is matched to each key using a dot product, and rather than getting a single value back you get a weighted sum of values.

asgraham 10 hours ago | parent

To clarify slightly, K and V are used to construct the dictionary, and then Q is the lookup key D[Q] as described (with the lookup being based on similarity rather than exact hash as it would be in an actual dictionary).

argee 7 hours ago | parent

> The difference in an attention layer is that the query is matched to each key using a dot product, and rather than getting a single value back you get a weighted sum of values.

I understand you meant to compare it to dicts, but this is more like (the only?) similarity to outer product memory. Worth calling out since GP is confused about this connection specifically.

hum3hum3 11 hours ago | parent

The animated bird, the kea is absolutely fabulous. I appreciate the effort and detail that went into this.

kator 7 hours ago | parent

I was about to return here to say the same, I wonder how many people noticed it!

sugarkjube 1 hour ago | parent

I didn't, so thanks for pointing out

femto 11 hours ago | parent

"interference-to-signal ratio", "capacity", ... These terms, and their context, are things a communications/electrical engineer would understand. I encourage comms engineers to start learning how AI works under the hood. Chances are, a lot of what you know about maximising channel capacity and throughput is applicable to AI (can be seen as a channel with memory?).

kridsdale1 6 hours ago | parent

EE here. Indeed I asked Gemini Argon to translate this article in to DSP terms and it helped.

ketothekingdom 10 hours ago | parent

Hey author here! I have a short summary here if people find it helpful: https://x.com/heyyalexwang/status/2111158818730397932?s=46

rd11235 8 hours ago | parent

This is one of the most well written blog posts I've seen in a while. Thanks

ketothekingdom 7 hours ago | parent

Thank you! It's been sitting in my head for so long. I'm glad I finally got to share it with people

nico 7 hours ago | parent

Thank you for putting that excellent article together

The concepts of fidelity/recall and the images/animation at the top reminded me of this small playful project that touches upon these topics: https://nicobrenner.github.io/lossy-git/

ketothekingdom 7 hours ago | parent

That's such a neat idea! Now I want to try it out too

_svm 5 hours ago | parent

Really awesome write-up, and the kea is adorable!

plasticeagle 1 hour ago | parent

I find some aspects of your writeup to be... quite annoying if I'm honest. The writing is good, but you fail to define several of your terms early on.

What is d_k - I assume it's the dimension of the k vector. Similarly, I assume d_v is the dimension of the v vector. What is the "i" suffix for here at this early stage? It doesn't need to be there, it's just confusing.

You say the keys are "used for lookup based on similarity". What does this mean? Similarity to what? The existing keys? Something else?

Your first example then introduces the identifier "M", which seems to be the number of memories. Again, this is not defined. It speaks again of similarities, and introduces "weights". But the matrix Mxd_k is a matrix made of all your keys, which aren't "weights" - or at least this term is new. The term "tokens" makes an appearance around this time also - something else that needs defining.

I think you need to go through the text of this article, with an eye to someone who is reading it for the first time. Define every term you use, remove unnecessary notation - and also perhaps explain at the start why one would be interested in a "memory store" of this nature.

There is a place for something that really explains what's going on here. I've yet to find it.

justinnk 40 minutes ago | parent

I found many of the things are clearly defined after the sentence „Here are the terms we’ll use throughout.“ right at the beginning (e.g. M, d_k, d_v).

sixdimensional 7 hours ago | parent

This sparks a thought that I have not seen revisited in the LLM age - memristors [1].

[1] https://en.wikipedia.org/wiki/Memristor

netfortius 2 hours ago | parent

Funny how age shows up in some cases. For me the first thing that came to mind, when starting to read the article, was Ranulph Glanville's 1978: "What is memory that it can remember what it is?" (Progress in cybernetics and systems research - vol 4)