
It's me, Udi. @soundprintapp @podcastnotes npub1cs0yua9qaehsxg2aml4d04kratgca2q436e5dmzzz4n5wkqv2avqalrhvz
Brooklyn, ny
Joined September 2006
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Udi Falkson retweeted
the fact that this was written … last year … breaks my brain
There's a new kind of coding I call "vibe coding", where you fully give in to the vibes, embrace exponentials, and forget that the code even exists. It's possible because the LLMs (e.g. Cursor Composer w Sonnet) are getting too good. Also I just talk to Composer with SuperWhisper so I barely even touch the keyboard. I ask for the dumbest things like "decrease the padding on the sidebar by half" because I'm too lazy to find it. I "Accept All" always, I don't read the diffs anymore. When I get error messages I just copy paste them in with no comment, usually that fixes it. The code grows beyond my usual comprehension, I'd have to really read through it for a while. Sometimes the LLMs can't fix a bug so I just work around it or ask for random changes until it goes away. It's not too bad for throwaway weekend projects, but still quite amusing. I'm building a project or webapp, but it's not really coding - I just see stuff, say stuff, run stuff, and copy paste stuff, and it mostly works.
Udi Falkson retweeted
Перепробовал кучу браузеров на замену Arc и довольно уверенно заземлился на Yab (@yab_browser).
Шустрый, нормально работает, регулярно обновляется. И у людей хороший вкус.
Пространства, вертикальные вкладки, несколько страниц рядом в split view. Данные из Arc перетащил хорошо. AI встроен классно: можно подключить уже оплаченные подписки Claude или ChatGPT, спрашивать про открытую страницу и поручать ему дела в браузере.
И всё это на WebKit (а WebKit лучше хрома!).
Наконец-то позволил себе окончательно снести Arc.
yetanotherbrowser.com/
Udi Falkson retweeted
Compaction is a mistake.
When an agent's context fills up, tools like Codex and Claude Code compact it:
1. The model prefills the entire session again
2. It writes a summary of everything so far
3. A new session starts from that summary
I measured this on a real ~400k-token session with Opus 5.5:
→ 38 s and $1.99 when the prompt cache has expired
→ 29 s and $0.17 when it hasn't
And the summary is lossy. The exact error message, the file path, the one number you needed is often gone.
So I do something new for Mainplane
Context retrieval works the other way around. Mainplane keeps the full record of every session as a file. When the context fills up, a new session starts right away with one instruction: "You are continuing session X. Retrieve key context from it as you go."
The agent searches the old session and copies the exact lines it needs, when it needs them.
Same session, same model: 15 s and $0.10 to get back to work. It does not depend on a cache hit, and nothing is paraphrased.
This is the bitter lesson applied to agent memory. Don't hand-design what the model should remember. Give it the full record and good tools, and let it decide.
Mainplane is open source (MIT). Link in the first comment.
Udi Falkson retweeted
Have you noticed it gets cold in winter when people start putting warm clothes on?
Have you noticed that flu season starts after the vaccines are given out?
Readers added context they thought people might want to know
Flu shots are given before flu season on purpose. The CDC advises getting vaccinated in September or October, ideally by the end of October, because it takes about two weeks after vaccination for protective antibodies to develop. cdc.gov/flu/vaccines/v…
Udi Falkson retweeted
Instead of getting a little sticker after you voted, you should get a QR code that you could somehow enter into your TV and it would no longer display political ads.
Udi Falkson retweeted
Gen Z coworker was telling me about how he wants to get into sports betting and I was like
“Just remember, they don’t pay for all those commercials because people win all the time”
and I think I accidentally blew his mind he looks down and was like
“Woah… yeah… huh…”
Udi Falkson retweeted
A high school girl in Mexico just won a gold medal for putting out fires with a speaker. It plays one deep, low hum and the flames die in about 5 seconds.
DARPA tried the same idea back in 2012 with a rig so big and clunky they never took it any further, and hers runs on a 12-volt battery and a speaker she can carry around.
Sound is just air being pushed back and forth. A low note at 30 hertz means the air around the flame is flipping direction 30 times every second.
Flames only exist in a thin layer where fuel vapor mixes with oxygen. Shake that layer hard enough and it keeps getting stretched thinner, the heat gets pulled away faster than the flame can make more, and eventually the flame rips right off the fuel. Whatever tears off is too cool to keep burning, so it just goes out.
DARPA's report put a number on how little it takes. Once the air at the flame is moving about half a meter per second, which is barely a breeze, the flame goes out, and pretty much any pitch can get there if you crank the power high enough.
Low notes just get you there way cheaper, because a speaker moves a lot more air on each push when the pitch is low. Two engineering students at George Mason figured this out by trial and error in 2015. They started with super high pitches, 20,000 to 30,000 hertz, and all the flames did was shiver. It only worked once they dropped down to 30 to 60 hertz, which is basically the bass on a hip-hop track.
Ángela Karime's build is a 12-volt battery, a frequency generator, an amplifier and a speaker, tuned to 30 hertz. She named it Vortex Tech and talks about it shooting out little rings of air, and that's real physics. When loud, low sound gets pushed through a narrow opening, the air curls up into rings like a smoke ring, and those rings carry a puff of air way farther than the sound would get on its own. In her tests it put out small flames from about 2 meters away.
She went through five prototypes and over 100 tests in about a year, and she says it's put out burning wood, flammable liquids, electronics and cooking oil.
The cooking oil one is a big deal. Throw water on a grease fire and it flashes into steam and flings burning oil all over your kitchen, which is exactly the kind of fire where you'd want something that doesn't put anything into the pan.
Now, sound can't cool anything down, so a big fire sitting on red-hot fuel can come right back the second the speaker shuts off. The George Mason guys worried about the same thing in 2015, and it's why this is still a prototype for small flames and the red extinguisher under your sink isn't going anywhere yet.
Space might end up being where this matters first. Up there water floats off in blobs, while sound works the same with or without gravity, and acoustics researchers have already published experiments on fighting fires with sound on spacecraft.
She's still in high school, and she's already working on a version that spots a fire and puts it out by itself. The gold in Indonesia also came with a special award that gets her into another international competition.
Udi Falkson retweeted
Many of you don't understand how serious this is, so let me break it down.
In computer science there is a famous kind of puzzle called 3-SAT. You are given a long list of yes-or-no switches and a set of rules about how they must be arranged, and you have to find a combination that satisfies every rule. The obvious way to solve it is to try every combination, but each new switch doubles the number of possibilities, so a puzzle with a few hundred switches would take longer than the age of the universe to brute force.
For decades, the smartest people in the field found clever tricks that made this a little faster, but every trick still hit the same wall: the time required kept exploding as the puzzle grew.
About 25 years ago, two computer scientists, Russell Impagliazzo and Ramamohan Paturi, working with Francis Zane, turned that wall into a formal idea.
They proposed the Exponential Time Hypothesis, which says this explosion is not a failure of human cleverness but a law of nature. No algorithm, however brilliant, will ever solve 3-SAT without the time blowing up exponentially. Nobody could prove it, but almost everyone believed it, and it became one of the foundations of modern computer science.
Researchers used it as a measuring stick. If you could show that solving some other problem quickly would also crack 3-SAT quickly, you had shown that problem was hopelessly hard too. Hundreds of papers, across scheduling, graphs, logic and much more, rest on this one assumption.
Now an internal AI model at OpenAI claims to have broken it. It says it found an algorithm that solves these puzzles meaningfully faster than the hypothesis allows, and it has checked the proof in a computer verification system called Lean.
And here is the remarkable part: the very people who proposed the hypothesis, Impagliazzo and Paturi, along with MIT's Ryan Williams, are now leading the public review of whether a machine has disproved their own idea.
So what happens next? If the disproof holds, a large part of theoretical computer science has to be revisited.
Every result that said "this problem cannot be solved faster, assuming ETH" loses its foundation, and researchers will have to work out which of those walls were real and which were simply where we stopped looking. It does not mean everything becomes easy. The new algorithm is still slow in absolute terms and this is not the famous P versus NP problem being solved.
But it means our map of what is possible was wrong in a place we were very confident about, and it was an AI that redrew it. If the disproof fails, the hypothesis survives and the field breathes out, but we will still have watched an AI produce serious, checkable work on one of the deepest questions in the discipline, closely enough that the founders of the idea had to take it seriously. Either way, something has shifted.
Udi Falkson retweeted
The lore surrounding hydroxyapatite is rife with rumors, myths and falsehoods (from both sides!)
It's gotten so bad, that I don't blame people for opting out completely because of how confusing it is. My hope is that I can simplify it for you here, with some history of the politics.
Disclaimer: I am biased towards hydroxyapatite as I am an owner of a brand that uses it, @nobsroutines
Myth 1: It's dangerous
Hydroxyapatite is the mineral your teeth are made of. Enamel is about 96% minerals and nearly all of it is hydroxyapatite. Your bones are built on it too.
The fear comes from the word “nano.” The EU’s SCCS first reviewed nano-hydroxyapatite (nHA) about a decade ago, their answer was basically “we don’t have enough data yet.” Somewhere that became labeled "it's not safe"
The follow-up reviews got a lot less attention. The committee drew the line at particle shape. Rod-shaped particles cleared, needle-shaped particles were out. In 2025 they concluded rod-shaped (this one is important, we'll come back to it), uncoated nHA is safe in toothpaste at up to 29.5%.
You’ll also hear “the EU banned nano ingredients.” The 2024 regulation people point to did ban 12 nanomaterials. Hydroxyapatite wasn’t one of them. It was approved with conditions. That's the main takeaway; Nano is a size, not a specific thing. There are good nano particles, and bad ones.
And if you swallow meets stomach acid, which breaks it down into calcium and phosphate. The same minerals already in your food. Basically a harmless and under-dosed supplement.
Myth 2: It heals cavities
This one mostly comes from overzealous influencers trying to get engagement, equally as harmful to the mission as the people who lie against it.
A cavity starts as a weak, chalky spot where acid has pulled minerals out of the enamel. At that stage the surface is still intact and the tooth can take minerals back in. That’s the type of remineralization where nHA does its best work at reversing.
Once decay breaks through the enamel and becomes an actual diagnosable cavity, no toothpaste/gum/mouthwash/powder is fixing it.
nHA can help an early weak spot get stronger, a true cavity still needs a dentist.
Myth 3: It doesn't work
Japan has been putting hydroxyapatite in toothpaste since for almost 50 years and officially approved it as an anti-cavity ingredient in 1993. That’s over 30 years on shelves.
Since then, over 13,000 randomized controlled trials and systematic reviews have shown it remineralizes early enamel lesions and reduces tooth sensitivity.
Sensitivity is usually what people notice first. The particles plug the tiny open channels in exposed dentin, the ones that carry cold and sweet straight to the nerve. This is my magic trick for patients in the dental chair, it works almost immediately.
When someone says “it doesn’t work,” they’re usually reacting to one of two things. The wild claims from Myth 2, or the fact that it isn’t FDA approved for cavities. That second one is a regulatory story, and I’ll get to it more later.
Finally, if I may brag a little bit, we've been at this for 4 years, with millions of people that have used it and if it didn't work, we'd probably know by now.
Myth 4: More is better (arguably the most important one)
Spend a few minutes googling hydroxyapatite and you'll see two wildly different opinions, either:
ITS DANGEROUS or YOU NEED TWICE AS MUCH
The percentage number tells you how much is in the tube. It doesn’t tell you:
- how small the particles are
- what shape they are
- what else in the formula is working with or against it
- whether the finished product was ever tested on actual teeth
Those are the things that decide what ends up on your enamel. A formula with published data behind it tells you more than the biggest number on the shelf.
Same goes for how you use it. A pea-sized amount (or one tablet) is plenty, brushing harder doesn’t push more mineral in, and you want to spit, not rinse, so it has time to sit on your teeth.
10% gets thrown around as the "minimum for efficacy" This is a lie peddled by a few brands that picked concentration as their marketing angle. The myth has become immortalized and will live on long beyond those lying brand owners.
It's simply not true, while NOBS uses 5%... 2-3% is shown to be sufficient at preventing cavities in certain studies. Not only that, some studies even show that LESS concentration has more protection (this is explained by the fact that shape/size etc are equally important).
Most times brands that use 10% are buying second rate raw materials, so it's basically bunk.
Myth 5: Everyone is lying
It's a seven front war out here, and candidly, I'm one of the fighters.
Fluoride people scream that it doesn't work.
Certain brands scream that you need more.
Other people yell that it's dangerous
At this point, no one can stop talking about nano hydroxyapatite for better or for worse. This may come as a shock, but I'm tired of the ingredient even though I love it and will always use it... leading me to my next point....
Myth 6: Nothing Else Matters
Somewhere along the way people get so emotional about hydroxyapatite that there is no mention of other ingredients. Kind of like how everyone forgot about other viruses during covid. Remineralizing agents are super important, but they aren't the only thing that matters.
In fact, the peer-reviewed study we conducted on NOBS ended with the following conclusion: cavities are a bacterial disease, and while mineral loss is part of that disease... there are many ingredients that control the pathogenicity and colonization of the cavity causing bacteria.
I hope this cleared some things up, and that you take my opinion with a grain of biased salt.
Udi Falkson retweeted
That the Communist hammer and sickle isn’t commonly regarded as evil and offensive as the Nazi swastika is a failure of education.
“Dear Italian students, who today take to the streets carrying flags with the hammer and sickle and wearing T-shirts emblazoned with ‘CCCP’,” began an open letter in Italian by Lithuanian expat Neringa Budryt.
“I would like to ask you a question: do you truly know what the symbols you carry represent? And do you know what would have happened to many of you had you openly demonstrated in countries living under the oppression of communist regimes?
Let me tell you something. It is easy to display a red flag when, for you, communism is merely an abstract idea of equality, social justice, and rebellion against the system. It is easy to wear a T-shirt with "CCCP" on it when you have never experienced the reality of a communist regime.
We come from that part of Europe where communism was not a T-shirt, a symbol of rebellion, or a romanticized notion of equality. It was the system in which we lived—a system we never chose.
We know the history of Soviet repression, Stalinist purges, the Gulags, and mass deportations. Above all, we know the word "Siberia"—a place to which thousands of innocent people were forcibly deported, simply for thinking differently.
In Siberia—amidst freezing cold, starvation, and forced labor—many lost their lives; those who survived carried the scars of that experience forever. Entire families were torn apart, and generations were denied the chance to live freely in their own homeland.
In the countries of the Soviet bloc, censorship, political police, surveillance, and the suppression of dissent drastically curtailed individual freedoms.
We grew up in a system where state control permeated even our daily lives. At school, we were required to wear the red necktie of the "Pioneers." We were monitored; they tracked where we went and even whether we attended church. Even faith—a choice that should belong to an individual’s own conscience—could become a cause for suspicion.
We used to celebrate Christmas with our windows blacked out, to ensure no one would see us and report us. Because it was forbidden—just like so many other things: jeans, rock music, and all the symbols of a Western lifestyle. My mother returned from a Soviet labor camp. And do you know what happened to her? She was barred from continuing her education because she had been labeled an enemy of communism.
Under a communist regime, you could not protest. You risked arrest, imprisonment, interrogation, persecution—and, in certain historical contexts, even death. In the Soviet Union and other communist regimes, political dissent could cost you your freedom and your life.
Demonstrations independent of the authorities were not a guaranteed right; they were often suppressed by force.
That is why it strikes me to see young Italians proudly displaying the hammer and sickle—symbols associated with regimes that persecuted and imprisoned millions of people.
Today, you are free to take to the streets, shout against the government, criticize institutions, and wave your flags precisely because you live in a democracy that grants you these freedoms. Under an authoritarian regime of that kind, protesting against those in power could have landed you in prison.
This is not about denying the existence of social injustices, inequalities, or the right to fight for a better world. You are free to take to the streets to demand a more just society—but you should not idealize a system that denied so many people the very things you are free to exercise today: the right to choose, to believe, to speak, and to dissent. Before wearing a T-shirt with "CCCP" on it, listen to those who experienced that world. Talk to the deportees and their descendants; read the accounts of those who endured the gulags and forced exile to Siberia. Learn what it meant to be stripped of your freedom, your home, your loved ones—and even any prospect of a normal life—simply because of your background or your beliefs.
Before waving the hammer and sickle, please, study history thoroughly.”
Udi Falkson retweeted
What are your favorite apps and software that closed down back in the day but you loved and remember fondly
Udi Falkson retweeted
The factoid that '50% of marriages end in divorce' was kinda true decades ago.
But the divorce rate peaked in 1980.
Now, less than 40% of all marriages since 2000 end in divorce.
For college graduates, it's under 30%.
For college graduates who get married after age 25, and who don't have any kids before marriage, it's under 20%.
Anybody promoting the outdated, deceptive 50% rate has some kind of anti-marriage or anti-natalist agenda.
It scares young people away from getting married and having kids. That is their goal.
Udi Falkson retweeted
I've been spammed with password reset demand from my Microsoft account. At a rate of 2 per days. Not phishing, just pure brute force.
Password resets needs 6 digits they send by email. So it doesn't seem likely to find anything.
But a malicious actor which try every day, with a dump of millions of leaked account he found somewhere?
Well he will crack a few of those with brute force every day...
Use 2FA.
Udi Falkson retweeted
so for all the people that think their phone has been listening and targeting ads even though it is almost impossible, it just might have been the tv in the room and that is basically verified xitter.gq/0x0SojalSec/status/211…
WTF, $3000 Samsung TV has an always-on mic, automatic content recognition, geo tracking, network mapping, and ships your data to Samsung + 400 partners.
Bro Rooted a brand-new 2025 Samsung TV after noticing absurdly targeted ads.
Firmware was locked down, so zero-days it was.
Got a root shell.
then found: always-on voice service, ACR, geo, full telemetry pipeline, and four separate DRM systems.
This isn’t a bug, It’s the product bro.





































