Major quantum computing advance made obsolete by teenager (2018) | Hacker News Reader

Major quantum computing advance made obsolete by teenager (2018)

quantamagazine.org

121 pointskwie49 comments

Her thesis is now available "Quantum Machine Learning without any Quantum"

https://ewintang.com/assets/tang_thesis.pdf

I listened to the "Joy of Y" podcast of an interview with Ewin Tang and thought it was an enlightening view of the current state of quantum computing.

https://www.quantamagazine.org/what-is-the-true-promise-of-q...

Edit: in light of a couple comments here I would like to say the podcast interview with Tang was this year. (May 3, 2025)

Tang's recent work on quantum-inspired classical algorithms has sparked a whole subfield focused on identifying which quantum speedups are truly unique versus those that can be replicated classically.

Quantum computing occupies the same space that Nanotechnology used to hold, and AGI is trying to claim; something so profoundly game-changing that it'll rewrite the rules of society itself.

Venture capitalists love this type of story, because its sells the most funding in future rounds.

I wish more people would celebrate Tang's works as a genuine breakthrough, rather than a pin that's bursting the bubble of quantum computing hype.

Venture capitalists love this type of story, because its sells the most funding in future rounds.

I would have thought the venture capitalists would not love this story so much because it, a little bit, points to quantum computing as being less of a do all sort of technology.

Relevant reading: "Replication of Quantum Factorisation Records with an 8-bit Home Computer, an Abacus, and a Dog" by Peter Gutmann and Stephan Neuhaus [0].

Shows in a humorous way how the vast majority of quantum computing "records" are utter nonsense based on simplifying the factorization so far, that it turns into a problem on the difficulty level of "factorize 9" - _before_ running the experiment.

Journalists however tend to lack the knowledge to accurately represent that, resulting in nonsensical record claims.

[0]: https://eprint.iacr.org/2025/1237.pdf

Related. Others?

Major Quantum Computing Advance Made Obsolete by Teenager (2018) - https://news.ycombinator.com/item?id=28413023 - Sept 2021 (44 comments)

Teenager Finds Classical Alternative to Quantum Recommendation Algorithm - https://news.ycombinator.com/item?id=17654220 - July 2018 (216 comments)

Customers who liked this Recommendation Engine may also like its Dequantization - https://news.ycombinator.com/item?id=17519001 - July 2018 (30 comments)

Very hot take but this result made me believe that BQP and P might be equivalent computational classes (in other words, quantum computers might not offer any computational complexity speedups at all). I found out about this result in college and implemented the algorithm described in the paper for a class project, though I don't remember the code working very well haha

[stub for offtopicness]

(Thanks to all who mentioned the year - we've since added to the title above.)

When you read it, keep in mind it's from 2018. Otherwise it looks as if Tang was 7 or so when he started to work on the problem. In reality, he already was 17 (*).

(*) yes, I know that it still very precocious.

She :)

Am I crazy, or does the article seem to go out of its way to avoid using any pronouns for Tang?

IIUC at the time this article was written Tang was mid-gender-transition and consequently kind of cagey about what pronouns should be used for her. She now goes by she/her.

It's a gender superposition, don't collapse the wave.

We shouldn't be using gendered pronouns anyway.

In very few circumstances is gender relevant. And even when it is relevant, we don't need to bake it into every other sentence, like people should be treated differently based on their gender.

If we baked social caste or race into how we referred to people, on the pronoun level, in every other sentence, it would obviously be ridiculous and terrible. So let's stop doing it for gender.

You're connecting something you dislike to a linguistic phenomenon based on a shared link to a concept. You could just as well argue that we shouldn't use names, because all people need to be treated the same.

Removing gender from language doesn't lead to paradise. Chinese and Turkish don't have gendered third person pronouns, but China and Turkey are not shining examples of gender equality.

Your assumption is wrong.

I agree with you but changing the basic grammatical rules of a language is a difficult coordination problem and you can't just do it by posting that it would be good.

There's an interesting series of fantasy novels by the author Graydon Saunders, occasionally recommended on this website, that almost entirely avoids the use of pronouns: https://www.goodreads.com/series/242525-commonweal . The avoidance of pronouns is a stylistic choice, but not a didactic one—you might not even realize it until you're a third of the way through the book and you start questioning whether a character you'd imagined as male or female might actually be a different gender, or not gendered at all. It's interesting to see how the author achieves this in dense but readable prose, without drawing attention to it.

Ancillary Justice is told from the point of view of a character of a culture that doesn't draw the distinction in language. It is occasionally remarked on, but generally from the point of view of the main character being always a bit paranoid that they'll cause offense by not referring to characters of other cultures and languages correctly.

Which grammatical rule is that? Singular they has been used in English for over four centuries. Using they instead of he or she does not break any rules.

The proposal was to get rid of "he" and "she", which is a very different proposition.

If men and women are the same, then why transition from one to the other? Men and women are different and there are many examples of when they should be treated differently.

Relative social status is built-in to some languages, such as Japanese. I suspect it fuels a lot of their social constructs, like the whole senpai/kohai thing.

maybe they don't know the gender and playing it like at parties when you don't remember someone's boyfriend name.

No because several times they directly quote people talking about Tang and editorialize the quote to use [Tang] where a pronoun would have been.

I used to know a chap called Colin who's dog was called John, or was it the other way around? I could never remember so never used their name.

Would have been easier if the dog was called Fido.

(2018)

2018?

A recommendation is in the domain of subjectivity, meaning that there is no consensus on the correctness... so, even if the algorithm is faster, its usefulness shouldn't be superior to a random pick based on some matching criteria... which is already as fast as it can be

You're mixing up two things here. It doesn't really matter if the recommendation algorithm is good or not.

The advancement isn't that we now have a better recommendation algorithm, it's that we thought that there was a problem that was impossible to solve with current computers and was being used as example of a problem that only quantum computing could solve and we've now learned that that isn't the case.

It's a theoretical result. There was a problem believed to take exponential time on a classical computer but polynomial time on a quantum computer. It turns out to be solvable in polynomial time on both types of computer, removing the quantum exponential speedup. Whether one polynomial was bigger or smaller than the other wasn't of much interest, as I understand it. The surprise was just that both are polynomials.

>superior to a random pick based on some matching criteria...

this is a recommendation right? hard to understand your point here

my point is, the quantum part isn't (/wasn't) necessary in the first place...

The actual problem that is being solved here is well defined mathematically and is matrix completion via low rank matrix factorization. And using a sampling approach for it. (I have not read the paper in its entirety, just skimmed the intro a bit). It is called "recommendation system" largely due to some history around some of its common appplications (Netflix challenge). But this is not addressing the subjective recommendation problem, but a very particular instantiation of it.

Yes, I get that..., my issue was with its application (a movie recommendation)... the idea itself isn't qualified for the quantum realm...

I don't see how this follows.

Besides, "subjectivity" concerns the subject, "objectivity" the object. The former is a matter of how an object is received by the observer, and so all perception is subjective in that sense; it can't be otherwise. But the subject can become an object of another subject. We can infer with varying certainty what someone is more or less likely to enjoy based on our knowledge of what they like.

As long as you accept subjectivity, you must also accept that logical inference isn't really useful... because the observer can add rules at any given time - without any logical constraint - thus preferences aren't deterministic... so a random option is as good as it can be.

The application, method and algorithm needs to be separated. The application is movie recommendation. One of the methods which works pretty well for this is low rank matrix completion. There are several algorithms for this method, one of which is quantum.

"Tang skipped the fourth, fifth, and sixth grades in order to enroll at the University of Texas at Austin at the age of 14."

Oh wow, that is either insanely cool, or a huge loss. At my university, there were so many great parties that I feel like you'd be seriously left out of everything social going on if you're underage when joining.

People don't necessarily need a school environment to find friends to party with.

If anything this would open up more opportunities for them when they're at that age. What's stopping them from being invited to parties where they don't go to school anyway?

Regarding opening up more opportunities, are you suggesting that they might go to parties while others would be at school? With who(m)?

I don’t mean to say that school is necessary for this, but I don’t think it is irrelevant either.

Well, they're 18 now and have university out of the way, I'm sure they can party as much as they want

Hey Ms. Tang, here's a little weekend project for you. There's this thing called Transformers and GenAI. The problem is, it doesn't scale. Propose a better architecture and call it AGI.

(Fingers crossed)

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