robryk @robryk@qoto.org
I enjoy things around information theory (and data compression), complexity theory (and cryptography), read hard scifi, currently work on weird ML (we'll see how it goes), am somewhat literal minded and have approximate knowledge of random things. I like when statements have truth values, and when things can be described simply (which is not exactly the same as shortly) and yet have interesting properties.
I live in the largest city of Switzerland (and yet have cow and sheep pastures and a swimmable lake within a few hundred meters of my place :)). I speak Polish, English, German, and can understand simple Swiss German and French.
If in doubt, please err on the side of being direct with me. I very much appreciate when people tell me that I'm being inaccurate. I think that satisfying people's curiosity is the most important thing I could be doing (and usually enjoy doing it). I am normally terse in my writing and would appreciate requests to verbosify.
I appreciate it if my grammar or style is corrected (in any of the languages I use here).
Joined Nov 2020
robryk
boosted
When electronics importer Cara Leon goes missing, private investigator Sam Mujrif is hired by her sister to investigate. Cara is 8 times taller than Sam, but evidence soon points to players much smaller than either of them.
As Sam and his cross-scale colleagues pursue the case, it becomes apparent that Cara’s disappearance is linked to technology with the potential to reshape their whole society, and radically alter the balance of power between the scales.
A friend was driving me back from new year's boardgames and on the way we've encountered a swan strolling on the roadway of a bridge. (The swan was alone, appeared completely fine, and was AFAICT fully adult: its body was ~1m tall, its head was at ~1.5m and its plumage was fully white.)
I was surprised in many ways:
- did the swan walk there or land there?
- is there some obvious reason why a swan would want to be on a bridge (my friend's hypothesis was that that swan might have been doing that semi-regularly and just been surprised by ~nonzero traffic at that time of night there)?
- do swans stroll? I don't recall seeing a swan more than a few meters away from water (other than a flying one).
robryk
boosted
@ai@cawfee.club
Coherer - The first kind of radio wave detector ever invented in history. It's basically a loose metal contact, similar to a "cold" solder joint. After applying a voltage, even under 1 volt, the contact resistance drops from near-infinity to a hundred ohms or so. Later versions used a tube of loose metal particles. Now 100 years have passed and its exact physical mechanisms remained unexplained.
Coherence of particles by radio waves is an obscure phenomenon that is not well understood even today. Recent experiments with particle coherers seem to have confirmed the [micro-welding] hypothesis [...] so-called "imperfect contact" coherers is also not well understood, but may involve a kind of tunneling of charge carriers across an imperfect junction between conductors.
Exploding bridge-wire detonator - A safe detonator for high explosives and nuclear weapons. You basically discharge a capacitor bank to a tiny wire in microseconds, the high energy causes the wire to explode, achieving detonation. The exact step-by-step physical mechanism that causes the wire explosion is still not fully explained.It is remarkable that 75 years later and after literally millions of EBW detonators have been fired, there is still uncertainty about how they actually work.
Look at the construction (and the proof in appendix) of public key encryption scheme out of witness encryption in https://eprint.iacr.org/2013/258.pdf
It uses witness encryption, where the only confidentiality guarantee is that "if you encrypt the plaintext in a way that does not admit decryption at all, there will be no way to recover the plaintext from ciphertext", to construct something that actually has standardish confidentiality guarantees by exploiting that this property must extend to cases that are computationally indistinguishable from ones where the assumption really holds.
robryk
boosted
Things you can do with zero-knowledge: prove that you performed some algorithmic process correctly.
Things you can’t do: prove that you kept a secret.
This is an important point that really limits what we can do with the technology.
robryk
boosted
Our electronics educational segment for today: U.S. Army Restricted Training Film: "Vacuum Tubes (The Triode)": 1943. - https://www.youtube.com/watch?v=acGXBJv6AT4
Rereading a novel I got amused by:
> Wanaka’s rather grim smile could just be made out behind her mask. “Until we get a better idea,” she
gestured. “All hands, start thinking.”
robryk
boosted
#NixOS on the @PINE64 #PinePhonePro .
There are still alot of steps to take, but it will get there.
Hm~ thought experiment: how would the world look like if trademarks could only be owned by corporations[1] with a responsibility only towards upholding the trademark's reputation[2]?
[1] question of ownership unresolved (theoretically it should be immaterial)
[2] question of who has standing to argue that they're not fulfilling this duty also open
robryk
boosted
the sad reality of open source software development
In short: folks love the amazing decentralised encrypted comms utopia of Matrix. But organisations also love that they can use it without having to pay anyone to develop or maintain it. This is completely unsustainable, and Element is now literally unable to fund the entirety of the Matrix Foundation on behalf of everyone else - and has had to lay off some of the folks working on the core team as a result.
https://matrix.org/blog/2022/12/25/the-matrix-holiday-update-2022
We define the rank of a matrix as the minimal number of rank-1 (i.e. of the form w^\dagger{}v) matrices that sum to it. I wonder what happens when we decide to optimize for something else: say, norm of type $foo over norms of type $bar over those matrices. Obvious candidates for $foo are L_{something}, for $bar are operator norms or Frobenius norm.
In particular, $foo=L_n and $bar=operator norm inherited from L_n seems potentially interesting (in particular for n=2).
Ok, it seems to have the the old-and-well-known preponderance to just pull numbers and multiply them without regard for what they are: https://you.com/search?q=How+heavy+is+1l+of+air+at+10atm%3F&fromSearchBar=true&tbm=youchat
robryk
boosted
Question: Why has there been nearly 0 media coverage in the US about Enovid and other nasal sprays?
"Most significantly, it showed, specifically for a higher risk population, that a negative PCR was achieved on Day 4 (median) compared to Day 8 for placebo."
That's really good?!
The chatbot-style answers of https://you.com seem impressive.
If asked nonsensical questions, they provide nonsensical answers. However, contrary to chatgpt, when asked very weird but sensible questions or fact lookup questions, it does provide correct answers (also, doesn't refuse to answer questions on fake grounds).
How do client blacklists work with gdpr?
Why do PKP IC (https://www.pkp.pl/) and Blik (https://blik.com/en) put people under time pressure when performing transactions? They teach people to click stuff without reading (and probably also lose some part of ability to claim that customers really know the terms of service, given that they make them impossible to read in the timeframe).
robryk
boosted
I figured out why the #fediverse clicks with so many GenXers. It's "yesterday's tomorrow!"
That is, it's the decentralized networked future we imagined as kids, complete with the billionaire baddies, evil corps, and environmental degradation plot lines all playing at the edge of the screen.
robryk
boosted
Speaking of Zener breakdown, here's a classic #electronics brainteaser. Find a generic small-signal bipolar transistor, e.g. 2N3904, 2N2222. Connect Emitter to +12 V via 1 kΩ, and ground Base. You can then find a negative voltage around -0.4 V relative to ground at Collector. Why can it be negative, when there's no negative voltage anywhere in this circuit?
When the base-emitter junction experiences Zener breakdown, it emits red light, which shines upon the base-collector junction. Photovoltaic effect creates this negative voltage. https://www.youtube.com/watch?v=bKlbO5mOZm4
I enjoy things around information theory (and data compression), complexity theory (and cryptography), read hard scifi, currently work on weird ML (we'll see how it goes), am somewhat literal minded and have approximate knowledge of random things. I like when statements have truth values, and when things can be described simply (which is not exactly the same as shortly) and yet have interesting properties.
I live in the largest city of Switzerland (and yet have cow and sheep pastures and a swimmable lake within a few hundred meters of my place :)). I speak Polish, English, German, and can understand simple Swiss German and French.
If in doubt, please err on the side of being direct with me. I very much appreciate when people tell me that I'm being inaccurate. I think that satisfying people's curiosity is the most important thing I could be doing (and usually enjoy doing it). I am normally terse in my writing and would appreciate requests to verbosify.
I appreciate it if my grammar or style is corrected (in any of the languages I use here).
Joined Nov 2020
