log☇︎
227300+ entries in 0.13s
asciilifeform: and there are no provisions for safely ~removing a tx~ from mempool, ever, at all
asciilifeform: and not only of std::map in the abstract, but of the same set of maps everywhere in trb, simultaneously, and at the same time with the pestilential global locks
a111: Logged on 2017-01-03 22:06 asciilifeform: asciilifeform's (and later again jurov's) utter failure to unravel the heap, at least, suggests this.
jurov: http://btcbase.org/log/2017-01-03#1595849 iirc the issue is pervasive use of std::map, which fucks with the heap like horny pig ☝︎
asciilifeform: (recall one of the nails in the ethertardium coffin)
asciilifeform: esp. if the actual computation is unbounded
asciilifeform: ben_vulpes: a non-algebraic ('programmatic') hash algo opens the possibility of crafted cpu-ddos
asciilifeform: (and tends to be small)
ben_vulpes: wyrdmantis: again with the laptop messages
ben_vulpes: why is 'fixed number of cpu cycles' a great thing?
asciilifeform: they are arithmetical, because the designers insisted that the hash be computable in fixed number of cpu cycles.
asciilifeform: all well-known hash algos, afaik, lack this property.
asciilifeform: essentially, anything where you cannot, in any practical computer, express the hash's reversal as an n-sat problem
asciilifeform: but i could think of one definitive improvement over traditional hashes: non-algebraic (see recent 'rsa padding' thread) tranform
asciilifeform: i know of 0 uses for a 'hash' where the same ~input~ is not guaranteed to produce ~same output~
asciilifeform: to go back to hashes, and if you for some reason eschew 'when hiring fortune-teller, hire the cheapest', ☟︎
asciilifeform: all by itself it'd be a worthwhile thing, if only for this.
asciilifeform: and if you can achieve it in a ~discrete~ system, you can get wolfram to drink himself to death, by properly demonstrating 'cellular physics' (tm) (r) where he failed. ☟︎
asciilifeform: ben_vulpes: if you know how to get effect entirely analogous to gas turbulence in a purely electric machine, there are many folks who will clap, do say.
asciilifeform: most schemes naively stemming from such confusion end up equivalent to electric version of invisible ink.
ben_vulpes: b-but turbulence!
asciilifeform: there is ~0 actual relationship between 'confusing to the naked eye' and 'crypto-hard' ☟︎
asciilifeform: because 'life' automaton tends to settle into quiescent states (bunch of small oscillating 'critters', no real turmoil) ☟︎
asciilifeform: but if you actually try this, you will learn that it is not.
asciilifeform: ben_vulpes: to take toy example: 'game of life' playing field state, with initial state S and move count M, naively might seem like good crypto
asciilifeform: (tldr -- a digital approximation of a complex process is 1) not ~the process itself~, noshit.jpg 2) not necessarily all that complex, in the chaos/avalanche sense, or in any way cryptologically hard)
asciilifeform: and if you want reading material, reread the thread where mircea_popescu suggested crypto using transcendental constants etc
asciilifeform: then list things you do ~not~ want
asciilifeform: just take a piece of paper, and list'em
asciilifeform: ben_vulpes: consider the things you actually want from a cryptographic hash
ben_vulpes: or point me at something to read?
asciilifeform: in a hash for just about any application you want to always live in the former and never, ever in the latter.
asciilifeform: because the transition between 'irreducibly complex' and 'braindamagedly simple' phase space is unknown.
asciilifeform: almost the very definition of terrible hashing function
ben_vulpes: asciilifeform: it would be utterly nutso to consider an ode/fluids sim as a hashing function, right?
asciilifeform: ben_vulpes: lulzy contrast of the solid 'hp oscilloscope' goodness of the console buttons, with the crapple turd
davout: asciilifeform: point is piloting a small plane there's just a few things to pay attention to constantly ☟︎
asciilifeform: davout: different thing from what? from piloting on grid paper and with pen? i'd imagine so!
davout: basically "watch your airspeed, watch the fucking airspeed"
ben_vulpes: asciilifeform: i suspect that if i start to explore this risk manifold i will have trouble not ratcheting the risk back
davout: ben_vulpes: piloting when you're actually in the plane is an entirely different thing
davout: below which the rudder loses sufficient authority to compensate for the asymmetric thrust
ben_vulpes: trained response to risky dynamics problems
davout: which is also why there's yet another minimum speed for a multi engine running on a single engine
asciilifeform: ben_vulpes: wai's that
ben_vulpes: yeah see when they start talking like this my flugenboner starts to droop
davout: also trinque is right, when losing an engine on a multi-engine you need to apply rudder to compensate for the thrust differential
davout: gyroscopic precession of the propeller when changing directions is yet another thing
davout: asciilifeform: propeller torque is one thing
trinque: easiest example that comes to mind would be losing an engine on a multi-engine plane
asciilifeform: (gyroscopic moment of the motor, but also differently-impacting stream from propeller on one wing vs other)
asciilifeform: davout: i thought motor effect could only affect roll
davout: lemme check out how that's referred to in engrish
asciilifeform: (and in fact, do those entirely ~demand~ yaw-without-roll?)
davout: if the wind comes from the right you'll end up landing with right wheel first, then left wheel, then nose wheel
asciilifeform: davout: are there any situations other than crosswind landings/takeoffs where you need yaw-without-roll ?
trinque: yeah I thought that was called yaw
davout: you apply roll to counter the drift
davout: but that causes the plane to drift
davout: and when you are about to touchdown, you apply rudder to align the nose with the runway
trinque: isn't that yaw?
ben_vulpes: note! this does not mean the wings are not horizontal
davout: when landing in a crosswind you basically apply rudder during the approach so that your airplane flies towards the runway, but the nose pointing to the side
asciilifeform: davout: the place that made'em is not far from where i live, it was slowly demolished over decades
asciilifeform: davout: it was a (long-extinct) machine from the age of 'everybody will have an airplane'
davout: trinque: actually you *are* supposed to
davout: asciilifeform: i'll research this ercoupe thing, seems interdasting
trinque: right, not as if you can roll the aircraft when you're about to touch ground (intentionally!)
trinque: anecdotally I seem to recall my dad talking about using rudder in crosswinds on large aircraft
asciilifeform: davout: e.g., 'ercoupe', had rudder, but linked to ailerons
davout: well, you need rudder, how else are you going to, you know, pilot?
asciilifeform: ben_vulpes: my current (wholly nonexpert) understanding is that airplane DELIBERATELY omits 'hard interlocks' wherever possible, on the principle that not-being-able-to-X-when-you-must is worse than can-X-when-you-mustn't ☟︎
davout: small thread is small
davout: maybe i'll understand the answer to this mystery when i become retractable gear certified!
a111: Logged on 2016-11-30 21:04 asciilifeform: i have here a b00k on piloting circa 1940, and already then author insists that rudder pedals are obsolete and have killed a thousand men
asciilifeform: davout: http://btcbase.org/log/2016-11-30#1574899 << thread ☝︎
ben_vulpes: fuck levers, pressure on the wheels should engage hard interlock
davout: asciilifeform: they *are* very different
asciilifeform: davout: didja ever weigh in on the rudder thread ?
davout: i have nfi why some airplanes allow this
asciilifeform: i'd naively think that this would've been resolved in 1930s, if not earlier, just make the levers vastly different (shapes, or lengths, and feel, etc) ☟︎
davout: in these case it appears the cause is often confusion with the flaps lever
davout: yeah, i've heard some things like that too
asciilifeform: gear button is right next to starter button, or wat.
asciilifeform: davout: similar book i recently read -- claimed that 'gear retract on parking lot' accidents are still a regular thing
davout: pilot handbook 101: "if after landing you need to apply full throttle to get back to your parking spot, you probably forgot to lower the gear"
asciilifeform: (this is a certainty if the various components do not AT ALL TIMES agree)
asciilifeform: davout, ben_vulpes , et al : it is also tricky to properly rule out the situation where split-trb node behaves like a 'split-brain patient', and external observer gets contradictory answers from it to some possible question
davout: either way, imma head to bed, interdasted in comments re mah wallet cut piece
asciilifeform: for the components to speak to one another.
asciilifeform: let's take the cuts as specified by mircea_popescu earlier.
davout: the miner does require the transactions being mined to be valid, so there's that
asciilifeform: davout: could, theoretically, hurt, if it requires adding 100,000 lines of i/o glue logic
davout: asciilifeform: i think it would be hard to make the argument that a separate binary sitting aside the node could hurt in any way
asciilifeform: no transformation of mud-todays into jam-tomorrows plox.
ben_vulpes: (fwiw i'm down to the last ghostly suggestion, which was to read in the hash as a bignum)
davout: make the miner a separate bin ☟︎
davout: asciilifeform: i don't thing the argument that the block validation logic can be found in the block validation logic is tenuous
ben_vulpes: unless i misunderstand, the project is truly blocked on making checkpoints configurable.
asciilifeform: incidentally, ben_vulpes -- what height are your 'solipsist nodes' up to nao?