UmbralRaptor changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> … one of the other grad students just compared me to nomal O_o | <ferram4> I shall beat my problems to death with an engineer.
<Iskierka>
... how is a raw image 22.3 MB then resaved as a 108 MB png?
* egg
wonders whether he should zzz
<Iskierka>
!choose zzz|nomal|principia|catpics
<Qboid>
Iskierka: Your options are: zzz, nomal, principia, catpics. My choice: principia
* egg
is confused by 3d geometry
<egg>
Iskierka: we're working on the rendering code (so that we can finally downsample the history, which is the perf-killer right now :-p), and that involves making sense of geometry
<egg>
which is hard
<egg>
mostly because in 3d it's hard to draw things on paper
<Iskierka>
what are the hard bits?
<egg>
Iskierka: currently trying to figure out a criterion for a segment to intersect a cone; ideally a fast (and possibly loose) criterion too
<egg>
(the cone being the space hidden by a celestial body)
<egg>
(which is considered to be a sphere for our porpoises
<egg>
)
<Iskierka>
dunno about speed, but I'd be going straight for the simple method of for each point; get distance to cone axis, divide through by distance to the point, if less than planet radius / planet distance; is in cone; else not
<Iskierka>
which may be slightly imprecise for using different parts of the triangle for different parts but which length is used can be worked on if method basically works
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<egg|work|egg>
!wpn Iskierka
* Qboid
gives Iskierka a just-in-time compactification
<kmath>
<yonatanzunger> @bridgietherease The important thing about this is that it doesn't fail safe: absent continuous maintenance, it *explodes*.
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<egg|work|egg>
!wpn ferram4
* Qboid
gives ferram4 a prompt-critical field extension
<Iskierka>
why do kitchen appliances have a PWM of like 0.2 Hz
* Ellied
thought SNRIs were supposed to make her LESS tired, not more
<Ellied>
Iskierka: referring to microwave ovens?
Thomas|AWAY is now known as Thomas
<Thomas>
!wpn egg|afk|egg
* Qboid
gives egg|afk|egg a ham ███████
<egg|work|egg>
!wpn Thomas
* Qboid
gives Thomas a berkelium term
<Iskierka>
Ellied, and the induction hob
<Iskierka>
both are around that period
<egg|work|egg>
!wpn Ellied
* Qboid
gives Ellied a summation
<Ellied>
Iskierka: Both might just take that long to spin up/down
<Ellied>
although for the induction hob, it seems like a high PWM frequency would just give you a nice stable lower current
<Ellied>
maybe switching losses/overheating are a problem.
<Iskierka>
... well the point of the hob is to generate heat?
<Iskierka>
and neither should really have much spin up/down time. they're purely electrical
<Ellied>
I mean in the switching element itself. MOSFETs have a very low resistance when fully switched on, but during the transient phase, they can easily generate a lot of heat if the current is high and the switching time isn't extremely fast. It could be that the hob is just giving the transistor time to cool between switching events.
<Iskierka>
well both do have active cooling fans. I feel like they should be able to manage
<Ellied>
and the microwave uses a magnetron, so there's probably all sorts of stuff going on during the power-up/down process
<whitequark>
ideally an induction hob should use zero voltage switching
<Ellied>
Oh, true.
<whitequark>
so that at high Rds there isn't any current actually flowing
<whitequark>
this also makes it easier to drive
<whitequark>
because the gate capacitance depends on Vds
* Ellied
keeps forgetting about that whole AC thing.
<Iskierka>
The whole thing that induction heating depends on?
<Ellied>
oh, whitequark, since you're here - does venlafaxine have any interactions with caffeine? I just started it and it looks like my caffeine tolerance increased by a factor of at least two basically overnight.
<Ellied>
Iskierka: I didn't completely forget about it, I was just not remembering zero-cross switching.
<APlayer>
Just a hopefully quick question on orbital mechanics: So, I have a vector for position and one for velocity. Also, I have any necessary data about the centre body. Is there a shortcut way to determine the periapsis from that?
<APlayer>
I found quite a few routines to convert from the cartesian to the keplerian system, but they all deal with SMA and eccentricity, and there is a lot of complicated vector maths for each of those. That's why I am asking.
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<whitequark>
egg|work|egg: so the small cat is now meowing incessantly
<whitequark>
and i think the large cat is slowly developing a neurosis
<whitequark>
ha! take that, asshole, I had to endure you for an even longer time
<egg|afk|egg>
cats!
<egg|afk|egg>
!wpn whitequark
* Qboid
gives whitequark a principal proof
egg|afk|egg is now known as egg
<Ellied>
whitequark: did you find anything about venlafaxine && caffeine?
<egg>
!wpn Ellied
* Qboid
gives Ellied a molten capacitive 2N3906
<Ellied>
huh, the ceiling appears to be disintegrating.
<egg>
uh
<Ellied>
there are big chunks of peeled paint all over the floor
<egg>
Ellied: on what timescale is it disintegrating
<Ellied>
days, I think. wasn't like this when I left for the weekend.
<whitequark>
Ellied: was running to the post, had to leave
<Ellied>
'sfine
<whitequark>
lemme send the tracking # to someone and I'll reply
<APlayer>
Uh, can I take the cross product of two 2D vectors in 2D space? Or do I need a third dimension for that?
* egg
makes up terrible acronyms
<egg>
APlayer: um, so there are two ways to look at that; either the result is a pseudoscalar on a 2d space, or you do it all in 3d
<egg>
the latter is probably easier on the algebra
<egg>
otherwise I'm going to have to define alternating multilinear forms and I'm tired
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<egg>
[today's episode of "there is no such thing as a simple answer" was brought to you by egg]
<APlayer>
(That is, if there is a cheap and dirty way to find a periapsis from cartesian vectors, I would be glad to skip the heavy vector maths, still)
<APlayer>
*silence*
<APlayer>
Well, I guess there are no simple answers
<kmath>
<softfennec> Egg on Outside, But Not on the Inside
<egg>
Sarbian: cats!
<Sarbian>
Yes !
<egg>
Sarbian: also my Saturn 5 is still backordered :-/
<Sarbian>
:(
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<Iskierka>
Sarbian, helpfully it also means that even bred cats like munchkins are reasonably healthy, as there's only been so long to develop bad features. So with cats we have an opportunity to avoid over-breeding before it's a problem
<Sarbian>
I don't really see cats breeding reaching dogs level. Hopefully.
<Iskierka>
hopefully
<Sarbian>
"ultra-fluffy purse cats who look like kittens forever" <= might lead to the end of humanity
<Sarbian>
But it could be a nice way to pass time while the machine take over
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<Sarbian>
And on that note I ll go back to slowly roasting in my bedroom
<Sarbian>
(30°C at 11PM FFS)
<Iskierka>
managed to keep it down to 27C here
<Iskierka>
and tomorrow amazon will deliver a smallish desk fan
<kmath>
<SoVeryBritish> Giving serious thought to sleeping in the shower
<egg>
bofh: from doing things in coordinates it is obvious that "multiplying" a pseudoscalar with a pseudovector (a trivector with a bivector) yields a vector; but a trivector is an alternating trilinear form, a bivector is an alternating bilinear form; how do you combine those to get a vector (given an inner product)?
<kmath>
YouTube - CSB Safety Video: Half an Hour to Tragedy
<whitequark>
everyone in there qualifies as too dumb to live
<egg>
whitequark: I see you are also watching CSB videos back to back
<whitequark>
a propane tech not realizing that liquid propane jet escaping from a plug he's unscrewing means he should stop
<whitequark>
four store employees not realizing that intense smell of gas means they should leave
<whitequark>
after being TOLD TO SHUT DOWN THE STORE DUE TO GAS LEAK THEY REMAINED INSIDE
<whitequark>
not one but TWO firefighters just kinda hanging around a tank leaking a jet of liquid propane
<whitequark>
and an EMT
<egg>
Ꙩ_ꙩ
<whitequark>
and two of the techs, including one that WAS trained in safe operation of propane tanks
<egg>
!wpn -add:adj propane
<Qboid>
egg: Adjective added!
<whitequark>
like
<whitequark>
just
<whitequark>
do these fuckers have any shred of common sense at all?!
<bofh>
whitequark: HOLY MY GOD WHAT THE FUCK IS THIS IDIOT
<egg>
whitequark: bofh: Ꙩ_ꙩ Ꙩ_ꙩ WTF
<bofh>
I literally started yelling incoherently at my monitor
<bofh>
Got asked why I was doing that, showed them the video, now we're both just staring blankly at it
<bofh>
Like this is "poured plutonium salts down floor drain, causing them to go critical in the process and fatally irradiating self" levels of idiocy
<bofh>
egg: hm. good question. hm.
<bofh>
let me finish having my brain BSOD at that CSB video first
<egg>
bofh: "poured plutonium salts down floor drain, causing them to go critical in the process and fatally irradiating self" << this seems oddly specific, I gather that idiocy was a thing too?
<Iskierka>
... store closed due to gas leak, remain in store
<whitequark>
egg: look up "Mayak plant"
<whitequark>
it had multiple incidents on that level
<whitequark>
In 1957 the cooling system in one of the tanks containing about 70–80 tons of liquid radioactive waste failed and was not repaired. The temperature in it started to rise, resulting in evaporation and a chemical explosion of the dried waste, consisting mainly of ammonium nitrate and acetates (see ammonium nitrate/fuel oil bomb). The explosion estimated to have a force of about 70–100 tons of TNT
<whitequark>
, threw the 160-ton concrete lid into the air.
<whitequark>
one of those, IIRC the floor drain one, actually, had a *shift supervisor* enter the room and start *making things worse*
<Iskierka>
... okay windscale looks like nothing now
<whitequark>
oh no, different one
<whitequark>
Solutions of plutonium were being transferred from a large tank into a stainless steel vessel using a glass bottle. While a worker was pouring a second load from the glass bottle into the vessel, a criticality excursion occurred, producing a flash of light and a pulse of heat. The worker dropped the bottle, which shattered and spilled its remaining contents on the floor, and left the room. A smalle
<whitequark>
r excursion occurred while the room was empty. Two supervisors approached the room, but were halted by high radiation readings; the radiation control supervisor prohibited further approach but was misled into leaving, after which the shift supervisor entered the room and attempted to move or drain the vessel. The largest criticality excursion occurred then, exposing the supervisor to 2,450 rem and
<whitequark>
covering him with plutonium solution. The supervisor died one month later. The worker received a dose of 700 rem, leading to acute radiation sickness and amputation of both legs and one hand; he was still alive in 1999.
<kmath>
YouTube - CSB Safety Video: Half an Hour to Tragedy
<Iskierka>
@ icefire
<whitequark>
whereas the firefighters, EMT and techs who stood by the leaking propane tank didn't
<egg>
well tbh they *stood by the propane tank*
<whitequark>
they were killed by the shrapnel from the store
<whitequark>
apparently the store was rapidly expanding outwards, so everyone outside of it was obliterated but the ones inside were merely burned and hit with a shockwave
<bofh>
"
<Iskierka>
merely
<bofh>
"Only 14 states in the country have ANY formal training or testing requirements for PROPANE TECHNICIANS"
<bofh>
grate. wonderful. extremely wonderful. grate. very grate.
<icefire>
I'm guessing the remaining states have informal training
<bofh>
"The state of West Virginia currently does not require propane technicans be trained in how to perform their task"
<icefire>
"if you smell something. run"
<Iskierka>
the remaining have no requirements whatsoever
<egg>
icefire: well evidently they don't actually know that
<whitequark>
^
<bofh>
^
<egg>
(more seriously, it's what Iskierka said)
<whitequark>
the *lead* technician, who *did* have training, do you know what he did when ontified of the leak?
<bofh>
call the fire department to ask what to do, apparently.
<whitequark>
he called the tech support of his company. instead of, say, replying with "evacuate the entire station"
<whitequark>
no, FIRST he called the tech support, THEN he told the junior tech to call 911
<egg>
*boggling intensifies*
<whitequark>
and 911 dind't tell everyone to evacuate EITHER
<whitequark>
they just passed it to the fire department...
<whitequark>
who drove RIGHT TO THE STATION on their own trucks
<bofh>
oh right, I think my brain broke so hard it's trying to institute sanity where none exists
<Iskierka>
I'd suggest maybe he thought the kid would be smart enough to have told the people inside to evac already, but I presume not since he stood right by it
<whitequark>
the lead tech then arrived himself.
<whitequark>
he did not start evacuating people either. instead, he stood with the junior tech right by the propane tank.
<Iskierka>
"in loving memory of" sticker needs correcting to "a fucking idiot"
<bofh>
^
<whitequark>
seriously, *everyone involved* is a moron except the EMT who was directing traffic away from the station
<whitequark>
just... how
<Iskierka>
he was still standing rather too close rather than going down the road, and getting another person on the other side
<whitequark>
that is true but that's not his fault, apparently the evacuation ranges weren't in the training
<Iskierka>
true, he didn't know distance, just that it should be non-zero
<egg>
whitequark: two evacuation ranges for propane were in the DOT guide referenced by the hazmat training for emergency responders though
<bofh>
"Guidance for emergency responders recommends evacuation as the first task in a hazardous materials emergency..."
<whitequark>
right, he failed as an emergency responder, but at least he had common sense to not go directly to ground zero
<egg>
not sure if the emt had that training
<whitequark>
the former is an institutional failure, the second is personal
<egg>
the fire cpt did (nonrefreshed)
<egg>
(and was a dolt)
<whitequark>
egg: it might've predated the DOT guideline
<whitequark>
since they mentioned the 2008 edition and he last had training in '98
<egg>
hm
<egg>
good point
<Iskierka>
... that is actually strange because I recall it mentioning this occurred in 2007
<whitequark>
well we can probably find the complete report of CSB for this
<Iskierka>
so unless it's published like sports games and this was like december ...
<whitequark>
and not the abridged video version
<whitequark>
Iskierka: I think sometimes these documents have a titular date later than publication date
<whitequark>
as in "regulations that start working in 2008"
<egg>
whitequark: they don't say 2008 I think? only the video shows the thing that says 2008
Pap is now known as Pap|AFK
<Iskierka>
not necessarily the case that they would be looking at those in 2007, though I don't know why the regulations would have changed in this regard
<Iskierka>
(beyond as advised in report)
<Ellied>
"Huh, flammable gas is hissing out of this valve when I try to open it, I'd better open it all the way" --no one who should be left unsupervised.
<egg>
whitequark: so possibly just the video editor picking the last edition to put on there
<egg>
(video from 2008)
<whitequark>
perhaps. but their videos usually don't have these kinds of mistakes.
<kmath>
<stavvers> Hi, international followers. I know you're giggling at the UK as we all die at just 30C heat, so here's a little thread about *why* that is
<Iskierka>
humidity was okay earlier at 50% but it's now gone back up to 70%, probably climbing
<Iskierka>
yep going up to 85%
<whitequark>
"There are currently no federal requirements addressing the siting of chemical facilities near residential areas, schools or hospitals" in another video about the largest explosion CSB has ever investigated
<whitequark>
that's from 2016
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<bofh>
you are shitting me
<whitequark>
oh and OSHA and EPA do not regulate storage of ammonium nitrate *at all*
<whitequark>
... when it's used as fertilizer.
<whitequark>
when it is used as a blasting agent though they do.
<whitequark>
WHAT
<bofh>
wait seriously?!?
<whitequark>
yes.
<bofh>
*headdesks repeatedly until LCD dies*
<whitequark>
the city just casually built right up to the ammonium nitrate storage building
<whitequark>
and emergency responders had no idea that it'll blow
<egg>
bofh: wouldn't that be headscreen?
<bofh>
egg: shush you :P but yes
<whitequark>
it's been what, almost 100 years since Oppau explosion?
<Iskierka>
No, he's hitting his desk so hard it jumps and falls off the desk
<kmath>
<Woodborg_Ninja> @LaurakBuzz When I was at uni I was hearing tons of international students from hot countries complaining about not… https://t.co/fSoqvmWy3S
<whitequark>
Iskierka: find a wall to drill. drill it. run the freon lines as convenient.
<bofh>
just not on what I linked which was the past 3 weeks data as well, since this week is honestly kinda okay, but the first week here was utterly awful.
<bofh>
(oh, for fun, toggle "Feels Like" on via the settings icon, which I think is a lowball estimate of what it's actually like but yeah)
<Iskierka>
your humidity's mostly similar, just a little higher
<Iskierka>
at the moment
<bofh>
yeah, hovering around 100% or thereabouts.
<Iskierka>
thunderstorm and it's only gonna be 3 mm rain?
<bofh>
like I said, this is the most livable it's been in about 2 weeks.
<bofh>
I see chance of rain :p
<bofh>
don't worry, it's rained on and off the past few days
<egg>
bofh: oh you're still in china?
<bofh>
egg: yea
<Iskierka>
london's 30 C but weirdly low humidity, only peaks at 87%, 40% at 2 pm
<bofh>
like on the bright side we don't get much in the way of typhoons here
<bofh>
that's more a Taiwan/Guangdong thing mercifully
<whitequark>
oh that reminds me the video where they poured methyl mercaptan down the sewer in the same building the manual valve was located
<Iskierka>
is there a section of american maintenance people who just want to try cause explosions?
<egg>
Iskierka: they don't try, they do
<bofh>
whitequark: WHAT
<Iskierka>
you have to start by trying to manage it on this level
<bofh>
egg: "HOWEVER THEY DID NOT PURGE AIR FROM THE PIPE ATTACHED BEFORE STARTING THE HEATER ON THE PIPE BEING PURGED WITH NATURAL GAS"
<bofh>
WHY WHY WHY
<egg>
I like how the backlog is an endless stream of intensifying contagious boggling
<whitequark>
bofh: well first they accidentally put 2000 gallons of water into a tank with methylmercaptan
<whitequark>
since it was on a cold day, their mixture in the piping formed a hydrate, which congeale
<whitequark>
*congealed
<bofh>
THEY VENTED THE PIPE INTO A CLOSED, UNVENTED ROOM WITHOUT *ANY* GAS DETECTORS?!?
<whitequark>
they started to remove the plug by heating the pipes and letting any methyl mercaptan escape into a vent system
<egg>
bofh: for hours
<whitequark>
at some point the plug cleaned but someone forgot the methyl mercaptan storage tank pump on
<bofh>
*headdesk*
<whitequark>
so it started pumping liquid methyl mercaptan into the vent system
<bofh>
what is the LD50 of methyl mercaptan anyhow?
<whitequark>
the vent system has had condensation problems in its low areas so often that draining that became a routine occurrence
<whitequark>
so the shift supervisor ordered two distinct workers to drain the stuff
<bofh>
oh 150ppm... that low? huh.
<whitequark>
and yeah, it released several tons of stuff until a proper hazmat response team arrived
<Iskierka>
how does nuclear reactor on fire for 3 days without noticing rank in these events?
<whitequark>
bofh: how about the phosgene accident
<bofh>
Iskierka: is the nuclear chain reaction clearly contained?
Snoozee is now known as Majiir
<whitequark>
dupont had a plant where dozens of cylinders with liquid phosgene were stored in an open shed
<whitequark>
and they had a worker transfer phosgene from cylinders into the plant reactor WITHOUT ANY PPE AT ALL
<bofh>
OH MY GOD
<whitequark>
they used PTFE-lined steel pipes. PTFE is permeable for phosgene and stainless steel corrodes
<whitequark>
so they had a procedure to replace the transfer hoses every 30 days, which the plant operators bypassed for some reason
<Iskierka>
bofh, numerous fuel rods were removable after the fire was controlled, so any meltdown was very incomplete
<whitequark>
not mentioned in the video
<bofh>
that's, like, even worse than the 500k TONS of white phosphorus stored in an open-top tank with 3m of water as the only thing preventing it from autoigniting, THREE KILOMETERS FROM AN ELEMENTARY SCHOOL.
<whitequark>
as luck would go, the hose failed and sprayed a worker right onto chest and face with liquid phosgene
<Iskierka>
wiki implies that the ones not removed were due to fire damage, not because of being blobbed corium
<whitequark>
because he was walking right past
<bofh>
that sounds pretty lethal
<whitequark>
he didn't die quickly
<bofh>
...oh god
<whitequark>
in fact his condition only started to worsen four hours later
<bofh>
well doesn't phosgene kill you by fucking up gas exchange in lung alveoli?
<whitequark>
it does
<whitequark>
but like, in 24 hours or later
<whitequark>
for... some reason i never understood
<kmath>
YouTube - Runaway: Explosion at T2 Laboratories
<whitequark>
yes, "scale-ups made by morons" is a recurring topic
<whitequark>
like how on earth are these supposed chemical engineers graduated without understanding square-cube law?!
<bofh>
I still love how the industrial prep for that is "oh just react this hydrocarbon with MOLTEN SODIUM by the way did we mention it's an exothermic reaction?"
<whitequark>
see also: multiple explosions where management desired a switch from a process where multiple batches were added to one where you just mix all ingredients for an exothermic reaction once
<whitequark>
and optionally also increase the total amount
<bofh>
*boggle*
<whitequark>
honestly how on earth was the guy handling phosgene not wearing a respirator
<kmath>
<whitequark> reason #342 you should have a respirator: if a sick kitten brought by your roommate gets diarrhea all over the bathroom you can still use it