Hacker News Reader

vecteron U.S. math scores drop on major international test

Wait, the US overall is ranked 18th out of approximately 50 countries (on the first chart for Math + Science). Obviously some American demographics are doing better, but across all demographics, the US scores are not excellent and not near the top.

vecteron Trump wins presidency for second time

As long as America has a first-past-the-post voting system, then game theory dictates that it will always be a two-party system.

vecteron VC Fund gives money back, says startup market too weak

Weak probably means too much VC competition relative to the number of good investment opportunities, leading to higher valuations, fewer investments in top companies, and lower expected returns.

vecteron Twitter kills its San Francisco headquarters, will relocate to South Bay

The point has nothing to do with Elon. It's just the correct way to analyze revenue graphs due to seasonality. Whether or not X is "collapsing" isn't obvious from the graphs either, and I made no such claim. We'd need to know other things that aren't public, and it's probably too early to tell anyway. But it's incorrect to say that revenue is growing. It's down quarterly YoY, which is the only real meaningful way to look at it.

vecteron Twitter kills its San Francisco headquarters, will relocate to South Bay

That's the wrong way to read revenue graphs. You need to compare quarterly year over year. From that perspective, it's down across the board.

vecteron Twitter kills its San Francisco headquarters, will relocate to South Bay

Isn't revenue declining according to that data?

vecteron I was a 20-something dethroned dotcom ceo that went to work at mcdonald's (2000)

Confirmed: https://www.linkedin.com/in/sheif/

From May 2022 - Jan 2023 · 9 mos

vecteron The Greatest Educational Life Hack: Learning Math Ahead of Time

This is simple but so effective. When I was 5 or 6 years old, my mom would sometimes give me one page of simple math problems. They were all basic arithmetic, things like 12+17 or 99+99 or 8x7, etc. I did them and got on with my life. They probably didn't take more than 15-20 minutes. They didn't feel like much because they really weren't. I think any 5 year-old can do them.

I believe that whatever little "edge" that gave me in learning math in school compounded exponentially over the years. I always felt "ahead" of the standard school curriculum, and that created a virtuous feedback cycle of success, which bred confidence, which bred success, and so forth.

Just a little nudge here or there at home can make a big difference.

vecteron Einstein and his peers were resistant to black holes

The general belief that singularities are “unphysical” and reflect a flaw in our models than actual reality. Hard to prove definitely right now of course.

vecteron P vs. NP and the Computational Complexity Zoo (2014) [video]

Can you explain why?

vecteron Solving the minimum cut problem for undirected graphs

I doubt it. Finding faster deterministic min-cut algorithms has been an interesting problem for a long time. Programming puzzles have no practical impact on theoretical research.

vecteron Solving the minimum cut problem for undirected graphs

My very rough understanding from reading the article (I could be wrong, I'm not a researcher) is that this is accomplished by the key insight of Kawayabarashi and Thorup (2015), which is that min-cuts must have low conductance. So it seems that you can partition the graph into well-connected components (perhaps by measuring the conductance of edges?) and preserve the min-cut of the original graph in the new reduced graph where you contract each the partitioned components into a single node.

Unless you're asking about the randomized graph sparsification of Benzur and Karger, in which case the output is correct with high probability [0], but like with many randomized algorithms, is not guaranteed to be correct.

[0] https://en.wikipedia.org/wiki/With_high_probability

vecteron 2023 ACM Turing Prize awarded to Avi Wigderson

Theoretical CS is basically a branch of applied math

vecteron Compressing chess moves for fun and profit

"Software", like "science", is a broad term. Just like there are many kinds of scientists and you could be, say, a biologist or a physicist, there are many entirely disparate fields of software engineering. At the end of the day, software itself is just a means to an ends: solving a problem. Solving some of these problems like the one that GP discussed have more to do with math than programming. The programming is mostly the implementation of the math. So if you're not versed in that math, of course you wouldn't understand the code that's being written to implement it.

Building machine learning systems is vastly different from building operating systems which is vastly different from embedded systems which is vastly different from networking which is vastly different what most of us do (myself included), which is building CRUD apps. We're just solving different problems. Of course there are common themes to writing good code, just like there are common themes to performing science, but the code and solutions will look almost nothing alike.

vecteron Swirling Forces, Crushing Pressures Measured in the Proton

Why does the proton not meet this criteria?

vecteron Venture backed or bootstrapped? There's a third way: just raise one round

In a very narrow strict sense, yes. But I would argue it's not really venture-backed. For me, venture-backed means that over time, the founders collectively own a minority of the shares, and the board structure is such that venture capitalists collectively hold a majority of the board seats. This means that technically the investors could do anything they wanted to with the company.

This is qualitatively different from the founders collectively having a majority of the shares (even factoring in granting tons of equity to thousands of employees), or, if not, they at least control a majority of the board seats for a long time, if not forever.

vecteron What is the point of a public key fingerprint?

It's just a fingerprint for their chat. It's almost the same as a random four-letter code to verify that you're both seeing the ame thing.

vecteron Super Mario RPG is an endearing, perplexing relic

What was so fun about Super Mario RPG for me was the sheer amount of Easter eggs. From Geno's Whirl's 9999 damage (only to normal enemies, not bosses, EXCEPT for Exor), to fighting Culex, to all the steps you need to do to unlock the lazy shell, and hundreds of others I forgot or never knew about, it felt like a truly endless adventure.

vecteron In two moves, AlphaGo and Lee Sedol redefined the future (2016)

  How would this computer fare against the top 10 best players collaborating(or even top 90-100)? I would bet it would lose big time.

It would destroy them in the same way. The marginal value of each additional human brain quickly approaches zero (or perhaps even negative as the team tries to communicate/collaborate).

The top 10 chess grandmasters in the world working together could not beat the best (or even "mediocre") chess engine. Not even close. They're practically playing different games.

vecteron Unix Time reaches 1.7 billion

Another fun one: pi * 1e7 seconds is approximately one year.

vecteron The 8000th Busy Beaver number eludes ZF set theory (2016)

FTA this is an interesting tidbit about Busy Beavers:

  But the BB function has a second amazing property: namely, it’s a perfectly well-defined integer function, and yet once you fix the axioms of mathematics, only finitely many values of the function can ever be proved, even in principle.  To see why, consider again a Turing machine M that halts if and only if there’s a contradiction in ZF set theory.  Clearly such a machine could be built, with some finite number of states k.  But then ZF set theory can’t possibly determine the value of BB(k) (or BB(k+1), BB(k+2), etc.), unless ZF is inconsistent!  For to do so, ZF would need to prove that M ran forever, and therefore prove its own consistency, and therefore be inconsistent by Gödel’s Theorem.

vecteron Sam Bankman-Fried doesn't recall

Interesting. How would someone prove this?

vecteron Ask HN: PG's 'Do Things That Don't Scale' manual examples?

This is a great list. I could be wrong but I believe that some early version of Dropbox was usable not too long after the demo.

vecteron LK-99 isn’t a superconductor

In their preprint, the Korean authors note one particular temperature at which LK-99’s showed a tenfold drop in resistivity, from about 0.02 ohms per centimetre to 0.002 ohms per cm. “They were very precise about it. 104.8ºC,” says Prashant Jain, a chemist at the University of Illinois Urbana–Champaign. “I was like, wait a minute, I know this temperature.”
The reaction that synthesizes LK-99 uses an unbalanced recipe: for every 1 part copper-doped lead phosphate crystal — pure LK-99 — it makes, it produces 17 parts copper and 5 parts sulfur. These leftovers lead to numerous impurities — especially copper sulfide, which the Korean team reported in its sample.
Jain, a copper-sulfide expert, remembered 104ºC as the temperature at which Cu2S undergoes a phase transition if exposed to air. Below that temperature, Cu2S’s resistivity drops dramatically — a signal almost identical to LK-99’s purported superconducting phase transition. “I was almost in disbelief that they missed it.” Jain published a preprint on the important confounding effect on 7 August.
[...]

“That was the moment where I said, ‘Well, obviously, that’s what made them think this was a superconductor,’” says Fuhrer. “The nail in the coffin was this copper sulfide thing.”

Science is hard. Kudos to everyone involved for trying to replicate it and figuring this puzzle out.

vecteron Transcript of taped conversations among German nuclear physicists (1945)

I didn't downvote you, but in this very article itself that these comments are discussing, the German scientists talked about how it's possible that even if Germany had developed the bomb, perhaps all they would've been able to do is destroy London and a few other cities but still lose the war.

vecteron Computer scientists discover limits of gradient descent (2021)

It must be a compact convex set. The entire reals is not compact.

vecteron I'm Peter Roberts, immigration attorney who does work for YC and startups. AMA

Is submitting multiple applications illegal? I'd have to imagine that you would get caught for doing this once they see the same person in the system, especially if they approve the same person multiple times.

vecteron Private equity is buying everything from vet offices to tech conglomerates

That sounds bad for the customer, but how does that play out for the owners? Does this sort of behavior end up working out better for them financially? If so, despite how bad it sounds, it does seem like they end up with more efficient economics (assuming it's sustainable). If not, then surely the PE firms will suffer too right?

vecteron Hobson’s choice

This is interesting. Can you share some practical examples of Hobson's choices that you gave your children?

vecteron Google employees complain about CEO's pay raise as cost cuts hit company

This would be true if Sundar chose his own compensation, but he does not. It is decided by the board.

I'm not saying it's the right thing for the board to do (if I were on the board, I would've suggested he keep his pay even or take a cut), but it's not right to say that Sundar gets paid more because he has "coercive power" over employees.