MurphyA/hacker-news huggingface dataset:
by clintonc | 2025-06-24 07:01:19+00:00
There are a couple of strategies for understanding the real numbers. One is to write down a definition of real numbers, for example using rational numbers and Dedekind cuts, hoping that what you're describing is really what you mean. The other is to write down the properties of real numbers as you understand them as "axioms", and go from there. An important property of real numbers that always comes up (either as a consequence of Dedekind cuts or as an axiom itself) is the least upper bound property -- every set which has an upper bound has a least upper bound. That's what gives you the "completeness" of the real numbers, from which you can prove facts like the completeness of the real numbers (i.e., Cauchy sequences always converge), the Heine-Borel theorem (closed and bounded subsets of the reals are "compact", and vice-versa), and Cantor's intersection theorem (that the nested intersection of a sequence of non-empty compact sets is also compact).

The diagonalization argument is an intuitive tool, IMHO. It is great if it convinces you, but it's difficult to make rigorous in a way that everyone accepts due to the use of a decimal expansion for every real number. One way to avoid that is to prove a little fact: the union of a finite number of intervals can be written as the finite union of disjoint intervals, and that the total length of those intervals is at most the total length of the original intervals. (Prove it by induction.)

THEOREM: [0, 1] is uncountable. Proof: By way of contradiction, let f be the surjection that shows [0, 1] is countable. Let U_i be the interval of length 1/2*i centered on f(i). The union V_n = U_1 + U_2 + ... + U_n has combined length 1 - 1/2*n < 1, so it can't contain [0, 1]. Another way to state that is that K_n = [0, 1] - V_n is non-empty. K_n also compact, as it's closed (complement of V_n) and bounded (subset of [0, 1]). By Cantor's intersection theorem, there is some x in all K_n, which means it's in [0,1] but none of the U_i; in particular, it can't be f(i) for any i. That contradicts our assumption that f is surjective.

Through the right lens, this is precisely the idea of the diagonalization argument, with our intervals of length 2*-n (centered at points in the sequence) replacing intervals replacing intervals of length 10*-n (not centered at points in the sequence) implicit in the "diagonal" construction.
by DiogenesKynikos | 2025-06-24 07:02:16+00:00
The "wide" mode is called "survey" astronomy, and there have been several large surveys like Rubin/LSST, going all the way back to the Sloan Digital Sky Survey, which started in 2000 (if you count surveys from before the era of digital sensors, there are surveys going back more than 100 years).[0] Rubin/LSST is just the newest and most advanced large, ground-based optical survey.

Both modes of observation - surveys and targeted observations of individual objects - are necessary for astronomical research. Often, large surveys are used to scan the sky, and then targeted observations are used to follow up on the most interesting objects.

0. https://en.wikipedia.org/wiki/Sloan_Digital_Sky_Survey

Note that "seeing" means something very specific in astronomy: https://en.wikipedia.org/wiki/Astronomical_seeing.
by Aromasin | 2025-06-24 07:03:13+00:00
CertusPro-NX has I/O Configuration in about 4 ms and full fabric config within 30 ms (for ~100 K logic cell device). Certus, full‑device configuration within ~ 8 ms.

Lattice make some really cool devices. Not the fastest fmax speeds, but hell if the time to config and tiny power draw don't half make up for it.
by SlowTao | 2025-06-24 07:03:24+00:00
There has been an idea for a very long time of building an OS and software that targets FPGA systems so it can dynamically change its function for each task. The idea being that it would potentially be faster than a general purpose processor.

Still practically theory as I have never seen anything come of it. It is going up against ASIC design which is a great middle ground for those thing even if it means you are not free to do it yourself.
by oleander73 | 2025-06-24 07:05:14+00:00
I thought the same, until I got cancer (stage 4 even, so the chemo wasn't curative). I don't know if I was lucky or it was the type of chemo, but it wasn't nearly as bad as I expected. It's been nearly five years since diagnosis and I'm very happy I got treatment. Considering the fact that I have incurable cancer, my life is spectacularly good!
by Skeime | 2025-06-24 07:08:46+00:00
Even with a keyboard shortcut, I never found it to be truly satisfying. I cannot quite recall what was annoying, though. Maybe you cannot space back into the formula after closing it? (I certainly recall having the experience of typing a formula, closing it, noticing a mistake, hitting backspace, and deleting the entire formula.) Maybe there was just a slight delay for the formula editor to open? Also, $ is still more pleasant to type than Alt+=.

I would be willing to try again, but I'm not buying Word for the privilege.
by jeroenvlek | 2025-06-24 07:09:33+00:00
Apologies, I should have been more specific. "Mature" was a reference to its feature set, not its stability. It runs fine in my setup. I meant things like automatic resolution and scale switching, for example, without having to edit my config file Indeed, I can script that myself, I will. My point is more that if that's the kind of thing I need to do myself, then I'm not paying 60 euro a year.
by EGreg | 2025-06-24 07:09:41+00:00
Yeah dude, seriously…

Linear interpolation on small intervals is like, a model of a model. And that’s exactly what differentiable functions are, anyway. And if you want to be fancier then sample the model and fit some polynomials to interpolate between those samples.

If they were really time constrained they could precompute things sparsely first (for a demo the next day) and then progressively refine the values in between.

Why did this trend on HN?
by dmsnell | 2025-06-24 07:13:11+00:00
Yes, that’s correct. All of these measures, of course, stand as a courtesy and are trivial to bypass, as ema notes.

Finding cryptographic-strength measures to identify LLM-generated content is a few orders of magnitude harder than optimistically marking them. Besides, it also relies on the content producer adding those indicators so that can’t be ignored as a major source of missing metadata.

But sometimes lossy mechanisms are still helpful because people who aren’t out with malicious purposes might copy and paste without being aware that the content is generated, while an auditor (be it anyone who inspects one level deeper) can discover in some (most?) cases the source of the content.
by adev_ | 2025-06-24 07:15:14+00:00
Being enthusiastic about battery technologies is one thing, spreading misinformation to support someone convictions is an other.

What causes the Iberian blackout is excessive reactive power and a lack of compensation at a given time (due to multiple factors).

Compensation of reactive power has strictly nothing to do with localization of generation. It barely even can be assimilated to oscillations

That's complete garbage and it shows mainly you do not seem to know much about Electricity power in general.
by AnonymousPlanet | 2025-06-24 07:15:15+00:00
Maybe your use of Linux is limited to those things that happen to work. As far as I understand, Wayland is deliberately incomplete and a number of problems people have stem from design decisions.

Kicad, e.g., reports problems related to this. To quote https://www.kicad.org/blog/2025/06/KiCad-and-Wayland-Support...

> These problems exist because Wayland’s design omits basic functionality that desktop applications for X11, Windows and macOS have relied on for decades—things like being able to position windows or warp the mouse cursor. This functionality was omitted by design, not oversight.

Wayland might work for your or my personal selection of work cases, and currently my stance is "when it's done it's done, let's wait and see". But it might also end Linux support for entire classes of software and use cases.
by dotancohen | 2025-06-24 07:15:42+00:00
> Not to mention that perhaps the state should pay for all this commercially unnecessary storage?

They do. Not upfront, but they pay very nicely for inconveniencing businesses when demanding the data.

Unfortunately, that often creates incentive for the business to error on the side of sharing too much with the authorities, even when proper procedure (warrants) have not been followed. It's the only way to retroactively get payed for all that storage and for the code to retrieve that data.
by DonHopkins | 2025-06-24 07:16:01+00:00
The DEC GIGI (General Imaging Generator and Interpreter) aka VK100 was a cool color VT100 that had BASIC build in!

https://terminals-wiki.org/wiki/index.php/DEC_VK100

https://randoc.wordpress.com/2018/04/08/digital-equipment-de...

I have a friend who is into retrocomputing and has a daughter named Gigi and I would love to get her one!
by ggm | 2025-06-24 07:19:06+00:00
As a user of many of these prior to 1980 i find the quirk of saying they are "non internet" amusing. They aren't all rfc822 conforming as defined. They absolutely did exist and continue to exist inside things like sendmail.cf and uucp over ip was a thing, as was decnet mail. Very few people who used or communicated with BITNET via Unix cared it "wasn't internet" because the whole point in email was to be transport neutral.

I think this is a fish/bicycle comparison uplifted into wiki. John Quartermain would have said this was a misunderstanding, even back then doing "the matrix"

X400 names exist in active directory, ldap and x509 certificates. Every time you connect to a tls protected Web page, the other fields of the certificate encode an x400 distinguished name, which is ignored, using the SNI info
Show HN: Promptive – A native macOS utility for system-wide AI actions
by helro | 2025-06-24 07:19:08+00:00
Hey HN,

I built a tool to solve my biggest LLM workflow frustration: context switching.

The idea came from trying to meta-prompt in Cursor, I found myself constantly jumping to a browser or dedicated AI app just to improve a prompt. This copy/paste/tweak cycle was a huge productivity killer. I wanted AI to integrate seamlessly into my workflow, not disrupt it.

That's why I built Promptive. It's a native macOS app that lets you select any text, in any application, and run a custom LLM prompt on it with a global keyboard shortcut or right-click and select the action in the context-menu.

How it works:

Select Text: Highlight anything on your Mac (code, a foreign language comment, a dense paragraph).

Trigger Action: Hit a global hotkey or right-click to bring up the context menu.

Apply Prompt: Choose from your library of built-in or custom prompts.

Get Results: The output can either replace the selected text directly, copy the result to clipboard or or appear in an overlay.

The goal is to make using LLMs as fast as copy-and-paste. I can now store specialized prompts for things like "Improve This Cursor Prompt", "Explain this," "Make this more concise," or "Convert this to a formal email" and apply them instantly, from anywhere.

I designed Promptive around two privacy-focused models:

Privacy & Bring Your Own Key (BYOK): This is the default. You use your own API keys from OpenAI, Google, or Anthropic. Keys are stored securely in the macOS Keychain, and all API calls are made directly from your Mac to the provider. My servers never see your prompts or data.

Simplicity & Credits: If you prefer not to manage keys, there's a credit system that uses OpenRouter on the backend. In this mode, requests are proxied for billing, but we do not log or store user inputs & prompts.

The site is: https://www.promptiveai.app

Thanks for reading - would love to hear any feedback!
by Avalaxy | 2025-06-24 07:19:13+00:00
Interesting read! My personal experience with Cursor aligns with this. The initial result of my prompt was stunningly good, but adjusting the code afterwards was not a great time. It also aligns with the software 3.0 concept pitched by Andrej Karpathy, making the english language (or other natural language) the new 'code'.
by octo888 | 2025-06-24 07:19:13+00:00
"How do you know it works?"

"It's got tests"

"Who wrote the tests?"

"It did. So?"

They're "tactical tornados"[0] with a jetpack

[0] A term from the book A Philosophy of Software Design - people who constantly chuck out "working" code with no design. Tactical programming vs Strategic programming
by labster | 2025-06-24 07:19:42+00:00
The story is from The Guardian, they have a certain point of view. I like it most of the time, but in this story it’s simpler to assume that spending money on slavery reparations and DEI activity suddenly became a political liability this January, rather than any very theoretical monetary liability in reparations.

Unfortunately, appeasement didn’t work this time, either.
by aleph_minus_one | 2025-06-24 07:19:59+00:00
> As a professor, I believe virtually all profs should have industry experience and occasionally go back for a year or two. (I’ve bounced back and forth!)

For quite some professors I imagine that going back to industry would make them a lot more arrogant. In academia, being surrounded by very smart people dampens the arrogance a lot because you realize that you may be smart, but not that smart. On the other hand, in industry you have much less people around you that can intellectually stand up against you, which easily makes you smug.
by Joker_vD | 2025-06-24 07:20:20+00:00
The main problem is not even if the terminal itself can track the grapheme width "correctly". It's a) the fonts suck; b) does the terminal user tracks the width correctly?

About a): some fonts have the glyphs for e.g. the playing cards block that are 1.5 columns wide even though the code points themselves are defined to be Narrow. How do you render that properly? Then there are variation selectors: despite what some may think, they don't affect the East Asian Width of the preceding code point, so whether you print "\N{ALEMBIC}\N{VARIATION SELECTOR-15}" or "\N{ALEMBIC}\N{VARIATION SELECTOR-16}", it still, according to wcwidth(), takes 1 column; but fonts have glyphs that are, again, 1.5 and 2 cells wide.

And then there is the elephant in the room problem b) which is management of cursor position. But the terminal, and the app that uses the terminal need to have exactly the same idea of where the cursor is, or e.g. readline can't reliably function, or colorful grep output. You need to know how many lines of text you've output (to be able to erase them properly), and whether the cursor is at the leftmost column (because of \b semantics) or at the rightmost column (because xenl is a thing) or neither. And no, requesting the cursor position report from the terminal doesn't really work, it's way too slow and it's interspersed with the user input.

The TUI paradigm really breaks down completely the moment the client is unsure how its output affects the cursor movement in the terminal. And terminals don't help much either! Turning off autowrap is mostly useless (the excess output is not discared, it overwrites the rightmost column instead), the autobackwrap (to make \b go to the previous line from the leftmost column) is almost unsupported and has its own issues, there is no simple command/escape sequence to go to the rightmost column... Oh, and there is xenl behaviour, which has many different subtle variations, and which original VT100 didn't even properly have despite what terminfo manual page may tell you — you can try it with the terminal emulator mentioned in TFA for yourself: go to setup, press 4, 5, move with right arrow to the block 3 and turn the second bit in it on by pressing 6 so it looks like "3 0100", exit setup (what you did is put the temrinal into the local mode so you can input text to it from your keyboard and turned the autowrap on), then do ESC, print "[1;79Hab", do LINE-FEED, print "cd" — you'll see that there is an empty line which shouldn't really be there, and it is not there if you do e.g. printf "\033[1;1Hxx\033[1;79Hab\ncd" on xterm (ironic, given how xterm's maintainer prides themself on being very faithful to original VT100 behaviour) or any other modern terminal.
by madaxe_again | 2025-06-24 07:20:52+00:00
That is absolutely not what school is for. It would be really nice if it were, but it is not.

School is for creating the next generation of obedient workers - the entire modern model of schooling emerged from the Industrial Revolution in order to produce better factory workers.

Claims are handed to you at school as truth. Questioning them will get you detention.

Ironically, I am homeschooling my daughter because I want her to be a critical thinker who demands hard evidence for anything presented to her - not someone who doesn’t know which century the Second World War happened in, and that it was maybe the Chinese or the Australians who started it, not sure, but they were 100% bad and we were 100% good. Sounds ridiculous, I know, but these are the educational outcomes where we live, where most kids finish school at 13. I could barely pick my jaw up from the floor when witnessing this debate.

I had a handful of teachers who encouraged independent thought - the majority however couldn’t explain or justify what they taught except with a meter ruler or a dunce’s cap.
by tripletao | 2025-06-24 07:21:42+00:00
> You don't intend to immediately nuke your geopolitical rivals

I don't see why intent requires immediacy? Perhaps this becomes uselessly philosophical, but I would say MAD requires the defending state to intend to nuke its adversary, conditioned on some future event (a nuclear attack on themselves, an existential conventional attack, etc.). They hope that condition is never satisfied, but intend to strike if it is.

> I still don't believe there's "no question" that Iran was going to build a nuclear weapon if nobody else intervened.

For clarity, I don't believe that either. By "working actively towards", I mean only that Iran was taking costly steps that bring them closer to a working bomb, and no other rational purpose could justify those costs. I think the distinction of what such steps we count as "lowering latency" vs. "building a bomb" is arbitrary and mostly meaningless, since as the latency approaches zero the latter goal is effectively achieved.

I agree that Iran might just have been saber-rattling; or even if they currently intended to build and test a complete bomb, they might have discontinued the program before succeeding. I just don't think intent is a useful focus (vs. practical capabilities), since it's fundamentally unknowable and could change at any time.
by looofooo0 | 2025-06-24 07:21:44+00:00
Colleagues worked in some project for cancer research where they connected terminally ill patient with certain studies. Most of these studies did the same thing, sequencing DNA of the cancer and then finding the right combination of medicines. It turned out that sometimes the treatment was too successful with the right combination, and it killed all cancer cells in a very short time. This was also bad outcome as it was very toxic. Anyway a bunch of people with very late stages did survive all of this and are now cancer free. So now the researchers try to match the DNA with the right amount of treatment to strike a balance.
by eviks | 2025-06-24 07:22:17+00:00
> this isn't the same as what the headline implies.

Correct, you need to read the actual article to find justification for the headline, not limit yourself to a generic "everything ends"

For example, re funding running out

> Even though Cellini was eventually given a budget for 2025, albeit a fraction of what he had asked for, the university would soon halt his work entirely.
by dismalaf | 2025-06-24 07:23:04+00:00
Full of licenses and regulations doesn't mean that the licensing requirements for bars in particular are onerous.

An example is where I'm from, in Canada. Licensing for cars is easy. Business licenses are easy enough, if they're non-physical.

But opening a bar means at least $50k of licenses/compliance costs. To have a bar, you need to serve food. To serve food, there's minimum requirements for all sorts of things from electrical to ventilation to plumbing. So you need to apply to the city to do a study and plebiscite in the neighborhood to determine no one objects to your bar. You need to have an engineer sign off on your design and the fire department to sign off on that. Liquor license is $$$.

And that's before even bringing up the cost of the lease (1 year rent as deposit) or the actual construction costs (last I checked, over $400 per square foot).
by BrenBarn | 2025-06-24 07:23:28+00:00
Way back in the day I downloaded this game called "The CRISIS Strategic Wargaming System". It was mostly a tactical thing, but it included a much more prominent role for supply lines and logistics than any other game I can recall. Unfortunately it was a "beta" version and apparently was never completed. I had looked for it a few times but seeing this spurred me to look again and I was able to find the old site on Internet Archive: https://web.archive.org/web/20060923152338/http://museum.sys... . I can still download the EXE so maybe I'll give it a try and see if it's similar to what I remember.
by ggm | 2025-06-24 07:23:59+00:00
Such a misnomer. Europe has cables to the far east which don't transit the USA, and cloud service providers exist which are not dependant on Google and Amazon.

The US has always been capable of enormously disruptive influence on the internet. Make wise choices of dependency.

I hesitate to bring this to the table. But is what Russia did to test internal systems resiliency under isolation not at the very least wise, for any economy?

The root trust of the dns, that's embedded in HSM solely in the USA, one east coast. One west. That's a structural weakness, but the people to ask about it are ICANN who have offices in Geneva and Singapore. Additional HSM could be run. Verisign would have problems here as would almost all the icann staff unfortunately. Systems resiliency demands many extra costs like non us staffing.

Rpki is somewhat devolved already, however all the rir have risks having to observe mandated excluded economies under interdiction.
by npodbielski | 2025-06-24 07:24:17+00:00
Do you often connect a monitor with keyboard via serial? Obviously I meant seeing boot errors of some linux machine, which is what usually monitor is for, but you have to be there, on site, with the monitor and keyboard to hook it up and see what the problem is. This is sometimes not possible and NanoKVM or JetKVM would be very helpful. I do not see relevance of you comment here. I hope you at least had a nice time writing it because it was otherwise a waste of time.
by brunooliv | 2025-06-24 07:26:07+00:00
I can totally relate to that feeling but after a few rejections, and having to work 9-5 during the day and prepare in the evenings with a drained battery, it just totally kills the motivation. Maybe it's the type of circumstance when if I'd really need I could do it, but to try to "suffer" through the process just to be rejected is quite hard.
by hansvm | 2025-06-24 07:28:05+00:00
In terms of modifying the house it depends on your local market. The general observation is that something making the house "special" tends to drive the price up rather than down. E.g., radiant heating via floor circulation can be seen as risky and novel, but enough people care that it tends to be profitable. Similarly with "risky" amenities like a backyard walking path. The location determines what a normal house is, so specifics vary wildly, but targeting a large enough sub-market is almost always better than "targeting" a wider market.