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>
bofh: there's debate because some people call it a spike which there's literature to say doesn't happen, but other literature does say there's a statistically significant long-term increase in insulin levels
<bofh>
100% taste, I don't think I personally find any food objectionable solely or primarily over texture, at least not offhand.
<SnoopJeDi>
Fiora, whoa is there an established link between sugar intake and dehydration by that mechanism?
<egg>
bofh: béarnaise is but hollandaise with some spices
<Fiora>
SnoopJeDi: i mean it's extremely easy to experience yourself, and it's not just sugar
<Fiora>
like, it hardly needs study, it's trivial
<Fiora>
but there's almost certainly literature
<Fiora>
it's the reason you need ~1ml of water per calorie you eat
<SnoopJeDi>
Sure I've experienced vascularity after a meal, just asking
<SnoopJeDi>
Since there's so much bunk about dehydration going around, I just assume anything obvious is wrong
<SnoopJeDi>
Until I track it down somewhere
<Fiora>
highly sugary drinks just have the fun property that they can actually completely fail to hydrate you insomuch as (water required to form glycogen from sugar) ~= (water in drink)
<bofh>
Like there's def. many studies done about this, it's pretty much just a blood osmolarity thing
<bofh>
(that and sugars are quite hygroscopic, and also what Fiora just said)
<egg>
bofh: including chervil, which 1. is called "Kerbel" in german which I find hilarious, 2. the pot of chervil I bought here is from a line of spices where the label says where you can put them (e.g. "fish, meat" or whatever), and the chervil says only "french cooking"
<bofh>
egg: ROFL
<Fiora>
ex: suppose you have a 250ml drink with 40g sugar.
<bofh>
Kerbel Spice Program
<egg>
:D
<SnoopJeDi>
Yea I mean it's not a mind-bender to slot the explanation into the data or anything, it's just in my wheelhouse since I'm collating that bibliography on weight control
<Fiora>
that sugar will require ~120-160ml of water to form glycogen
<egg>
bofh: also "we don't know what this crap is for aside from putting in weirdo french food"
<Fiora>
so the amount of water left over will be near zero
<SnoopJeDi>
(we get a lot of questions about water intake bc society is wildly irresponsible about nutritional education)
<Fiora>
or well, lots less.
<bofh>
UmbralRaptor: are there good wind-tunnel models/data for bovines anyway?
<bofh>
I imagine there have to be.
<egg>
bofh: well there have been numerical simulations of supersonic cows
<UmbralRaptor>
There's a subgenre of testing FEA software on cows, but I don't know the details.
<Fiora>
(this also means that sugar-free drinks are more hydrating than sugary ones)
<SnoopJeDi>
hmm, I'll have to poke at pubmed for a bit to find it
<bofh>
egg: link--thanks
<SnoopJeDi>
LOL
<bofh>
come to think of it I think cows are built decently well for supersonic flight/reentry in that the shockwave should be small and decently far away from the inner layers of the, erm, cow
<SnoopJeDi>
ablative meatshield?
<bofh>
yep
<SnoopJeDi>
I couldn't help myself, the allure of wordplay...
<bofh>
Fiora: that makes a lot of sense, actually, re: sugarfree drinks. also matches my experiences.
<SnoopJeDi>
yea, same, although I avoid sugary drinks like the plague
<SnoopJeDi>
or artificially sugary ones, maybe? I can get down with some orange or apple juice
<Fiora>
juice is even more sugary than a lot of soda
<Fiora>
its like, one of my canonical examples of things that's not a very good thirst quencher
<SnoopJeDi>
Yea, not what I would reach for if I was primarily interested in hydration
<SnoopJeDi>
definitely sweeter, it's criminally irresponsible how fruit is lauded as "healthy" in the US
<SnoopJeDi>
(or any food)
<Fiora>
fruit is different, though :P
technicalfool is now known as TechnicallySleeping
<SnoopJeDi>
yea it occupies a particularly silly role IME
<SnoopJeDi>
Saw one of those video recipes the other day that showed several quinoa "salads", one of which had something like a whole cup of blueberries, a whole medium melon, and some other fruit
<Fiora>
that's really not a bad idea
<Fiora>
fruit is incredibly low calorie and can be quite filling
<SnoopJeDi>
no I'm sure it's delicious
<SnoopJeDi>
and don't begrudge anyone for eating it
<Fiora>
an entire *pound* of raspberries, which would be a legitimate challenge to eat in one sitting, has fewer calories than half a muffin
<SnoopJeDi>
but the fact that "fix your food" gets warped into "reach for nature-candy!" is kinda perverted
<Fiora>
i dunno if you can really define fruit as more "nature-candy" than anything else
* SnoopJeDi
glances at freelee the banana girl
<bofh>
banana girl?
<Fiora>
like if you want something that consists almost entirely of glucose, try potatoes :P
<Fiora>
(i mean, also judging foods in that way makes so little sense given that none of the foods we eat are remotely natural, i.e. they're bred for purpose!)
<SnoopJeDi>
bofh, pretty much what it sounds like. The epitome of white food blogger: "eat a bunch of bananas and you'll be healthy xD"
<bofh>
personally I maintain the best use of potatoes is for watch batteries :P
<egg>
bofh: speaking of potatoes and recipes, I make potato purée with equal parts potato and butter by mass :D
<bofh>
rofl, bananas are a particularly bad example of trying to claim "all-naturalness"
<egg>
(after Robuchon)
<SnoopJeDi>
Fiora, yea, the whole narrative revolves around food instead of people and I find the whole thing very problematic now that I'm on the other side of it
<bofh>
since they're custom-bred to the degree that the entire population is at risk of being wiped out b/c they're all incredibly susceptible to Panama Disease fungus.
<SnoopJeDi>
Maybe it's different for people that didn't fall through the cracks, but I have *some* bile about it
<bofh>
egg: nice
<egg>
bofh: amusingly, 50% butter by mass is also pretty much the composition of my sauces...
<egg>
bofh: oh, by the way continuing on the questions about sauces, I don't suppose you've had any beurre blanc?
<SnoopJeDi>
I'd like to make Lyonaisse potatoes if I can gather the courage to use that much butter in a single dish
<kmath>
<niwasox> @bofh453 Assuming a Sears–Haack-body-shaped cow...
<bofh>
egg: nope, but googling for ingredients list I'm not sure I'd like that, unless the emulsion traps the vinegar to the point where I can't smell it.
<bofh>
I weirdly cannot stand the smell of acetate
<egg>
bofh: so it's like hollandaise, except no egg; now think about what holds the emulsion of hollandaise, and now you see why beurre blanc is flippin hard to make
<egg>
bofh: most of the taste of that (also holds for hollandaise to a lesser extent) will be that of the underlying stock, with shit stock you'll get shit sauce
<bofh>
yep, that does not sound fun at all, you basically have no emulsifiers
<egg>
bofh: yup
<egg>
bofh: it's well-known for separating if you look at it wrong (and having to be prepared at the absolute last minute)
<egg>
bofh: unless of course, soy lecithin :-p
<egg>
(I use that when I make it, found that trick in Myhrvold's books)
<bofh>
"There are numerous reasons why you wouldn’t see such a flow field in ‘reality’, not unless you happened to witness a reinforced concrete cow propelled at Mach 8."
<SnoopJeDi>
Well beyond my personal emulsification ambitions, hah
<bofh>
egg: oh fun. yep, well beyond mine too :P
<egg>
bofh: suddenly it withstands simmering and cooling cycles without separation
* SnoopJeDi
is the kind of person who is happy to toss a cube of butter in cornstarch for pan sauce
<bofh>
egg: well yes, if you add lechitin to it then ofc it will be much much more stable
e_14159 has quit [Ping timeout: 186 seconds]
<egg>
bofh: yeah, suddenly you have an emulsifier other than the concentrated french madness of it all
<egg>
bofh: so the backstory behind beurre blanc is some cook who forgot the egg in a hollandaise
<egg>
bofh: apparently a béarnaise, but that's basically a hollandaise with tarragon, so if you forget that,
<bofh>
I love how so many of these classical ~*~ fine dining ~*~ foods started out as "chef forgot or was out of $INGREDIENT and substituted or went entirely without it and people thought it was tasty"
<egg>
bofh: yeah, there's this story in Myhrvold's book about the quest for a chocolate cake that's liquid in the middle
<egg>
people were trying to produce that and had invented mad recipes involving making multiple cakes and whatnot
<egg>
and then some cook undercooked his cake, realized it too late, went to the dining room to apologize and was applauded :-p
<kmath>
<CSGV> ⚠️ Unfortunately we must issue the following warning ⚠️ DO NOT SHOOT YOUR GUNS AT THE HURRICANE!!! ?♂️?♂️?♂️https://t.co/diS56jWInX
<UmbralRaptor>
SnoopJeDi: got a casaba howitzer lying around?
<bofh>
UmbralRaptor: I was thinking more a Gatling Gun, honestly.
<SnoopJeDi>
I assume anyone who would actually do so is one of *those* gun owners
<bofh>
win 14
<UmbralRaptor>
bofh: Eh, haven't you always wanted to scare NOAA?
<SnoopJeDi>
UmbralRaptor, hmm, I'd not heard of this before!
<bofh>
UmbralRaptor: so switching back to serious for a second, I don't think I've ever seen meteorologists as terrified as with Irma
<bofh>
UmbralRaptor: apparently the last time this happened it was due to Katrina, but that was before I picked up an interest in meteorology so I lack that as a point of reference.
<SnoopJeDi>
weather twitter has been distinctly tweety this year. certainly since the Ross shelf breakoff
<bofh>
oh god that happened?!?
<bofh>
fuck.
<bofh>
~*~ climate change ~*~
<UmbralRaptor>
Ross? I thought it was Larsen C?
<SnoopJeDi>
Oh, and so it was.
<Iskierka>
bofh: are they pissing themselves more now anyway because it's not just Irma but all the others too?
<bofh>
ahh, yeah I did recall Larsen C
<SnoopJeDi>
My mistake, my Anarctic geography is...not a thing.
<bofh>
Ross on top of that would be horrifying
<SnoopJeDi>
Antarctic* (or apparently my typing)
<bofh>
Iskierka: true, I mean Irma is what, like a week after Harvey drowned Houston?
<bofh>
and Jose's just chilling right behind Irma as Cat 4
<SnoopJeDi>
I think it was the Ross shelf in the Kim Stanley Robinson novel I read this month bofh
<Iskierka>
if that
<Iskierka>
and Jose on the way and it seems like it might still be able to form more?
<SnoopJeDi>
It's not unthinkable, it's the season after all.
<bofh>
Iskierka: 40% chance of cyclone formation in the next 48hrs in the same part of the planet that spawned Irma & Jose
<bofh>
according to NHC
<SnoopJeDi>
seems like the question on everyone's minds is to what extent would these storms have broken apart/blown out in a Gulf with ~1° cooler waters
<bofh>
SnoopJeDi: it definetly would've resulted in a gentler Irma, I mean that thing basically made landfall multiple times as a Cat 5
<SnoopJeDi>
oh yes for sure I don't think anybody could argue it's not mitigating at all
<UmbralRaptor>
Would they have been cat 1-3 in the event of 280 ppm?
<SnoopJeDi>
Harvey I'm not sure about given its striking similarity to Allison, but 1° is a *lot* of storm forming thermal energy
* UmbralRaptor
gets the impression that some houses in FL are built to withstand being run over by a cat 3.
<SnoopJeDi>
and apparently the west portion of the Gulf (not sure what the name is, but the one into which vortices spin off from the Loop) was a smidge warmer, hence the ability to intensify in 72 hours
<Iskierka>
some
<Iskierka>
hopefully not Trump's
<UmbralRaptor>
Notably nicer ones built post-Andrew.
<SnoopJeDi>
Easier to rebuild when you've got the money to take a punch
* UmbralRaptor
stares at walls of an apartment built in the 60s or 70s.
<kmath>
<CrimeADay> 16 USC §703 & 50 CFR §21.61(e) make it a federal crime to engage in population control of Canada geese by shooting them with a machine gun.
<Iskierka>
is this like LMG or vickers gun era?
<Iskierka>
because those are both funny in their own way
<SnoopJeDi>
Looks like it was passed in 2006
<UmbralRaptor>
SnoopJeDi: but a semiautomatic or pump action weapon is fine, right?
<egg>
bofh: those eggs come from a village 18 km away as the Град flies
<SnoopJeDi>
"(4) Participants may take resident Canada geese by any method except those prohibited as follows: (i) With a trap, snare, net, rifle, pistol, swivel gun, shotgun larger than 10 gauge, punt gun, battery gun, machine gun, fish hook, poison, drug, explosive, or stupefying substance."
<bofh>
SnoopJeDi: ahh yes, the gulf Loop. that thing is weird.
<Iskierka>
UmbralRaptor, not in the first, which is somewhat disappointing. it's a general law of taking, killing, or posessing migratory birds
<Iskierka>
which does include by machine guns but does not target
<bofh>
SnoopJeDi: I will point out that "400W Nd:YAG laser" is not in the list of explicitly prohibited means of killing canada geese
<SnoopJeDi>
UmbralRaptor, shotgun hunting is pretty well regulated actually, down to requiring a plug to limit loadable rounds for certain game
<Iskierka>
"With a trap, snare, net, rifle, pistol, swivel gun, shotgun larger than 10 gauge, punt gun, battery gun, machine gun, fish hook, poison, drug, explosive, or stupefying substance."
<Iskierka>
okay, it's kind of a funny enough list
<SnoopJeDi>
no chloroform
<Iskierka>
I think that restricts you to only shotguns smaller than 10 gauge?
<SnoopJeDi>
Or bow or some sort of...pike?
<egg>
arbalest?
<Iskierka>
pike might count as a very large fish hook?
<UmbralRaptor>
10 gauge is huge, though, IIRC
<SnoopJeDi>
perhaps a nice mace or cat-o-nine-tails then
<UmbralRaptor>
…laser?
<UmbralRaptor>
laser!
<Iskierka>
"From or by means, aid, or use of any motor vehicle, motor-driven land conveyance, or aircraft of any kind, except that paraplegic persons and persons missing one or both legs may take from any stationary motor vehicle or stationary motor-driven land conveyance."
<egg>
tungsten rod?
<Iskierka>
apparently only disabled people can take them as roadkill?
<UmbralRaptor>
egg: from orbit?
<SnoopJeDi>
it's the only way to be sure
<egg>
UmbralRaptor: yes
<bofh>
so like, 400W Nd:YAG laser will nicely take out a goose if collimated properly
<bofh>
like, it'll cut 10cm thick steel like butter
<SnoopJeDi>
for sure, 400W is a lot of go-go juice
<SnoopJeDi>
you might have high extinction losses in air? I don't really laser.
<bofh>
Nd:YAG is 1064nm so mid-IR, not sure how bad the extinction losses are
<bofh>
it doesn't Rayleigh scatter much, at least.
<egg>
Iskierka: wait, is one of those fancy kinetic anti-tank rounds ok by those rules
<Iskierka>
apparently you're basically not allowed to do it from any vehicle with any kind of propulsion, so I think you need to make sure you fire it forwards from a boat?
<Iskierka>
... maybe?
<Iskierka>
does that count as a battery gun?
<egg>
hm, depends what you fire it from? :-p
<SnoopJeDi>
ohh, I hadn't realized they were mid-IR, I mentally associate them with green so I guess I've only ever seen those operation modes
<SnoopJeDi>
Should probably have very good transmittance then!
<bofh>
SnoopJeDi: so green is when you run it thru a KTP crystal for second-harmonic generation
<SnoopJeDi>
...the Active Denial System is also not explicitly forbidden by these rules
<SnoopJeDi>
bofh, yea I suppose I've just always seen it in a frequency-doubled context
<bofh>
yes, this means that technically speaking, DPSS green laser pointers can leak scary amounts of IR
<UmbralRaptor>
bofh: extinction could vary enormously. Very low if you're in an IR window (possibly better than visible!)
<UmbralRaptor>
If not… good luck with water vapor.
<SnoopJeDi>
"hey, cool laser pointer! where'd you ge--*zap*--Hello darkness my old friend..."
<bofh>
SnoopJeDi: Do Not Look Into Laser With Remaining Eye
<SnoopJeDi>
hah!
<bofh>
like, KTP is in the best-case scenario 60% efficient, at low lasing powers as low as 30% efficient
<bofh>
so your "5mW" green laser pointer by necessity has to lase it with usually a 25mW IR laser
<SnoopJeDi>
bofh, are you familiar with LCLS's knockout scheme?
<bofh>
worst-case scenario is actually when the crystals misalign and the laser pointer appears "dead", since the typical reaction is to stare into it with your eye while poking at it
<egg>
D:
<bofh>
all the while sending invisible (so forget about that blink reflex!) IR radiation into your eye
<bofh>
granted, in the era where you can buy a 5W 445nm laser pointer marketed as I Can't Believe It's Not A Lightsaber, No Really LucasArts Made Us Say This, I'm not too worried.
<SnoopJeDi>
hmm, would that be something you could feel to test? I have no concept for this
<SnoopJeDi>
25 mW seems pretty low but the spotsize is pretty small too
<Iskierka>
mainly just cause I want an actual blue laser but no-one else makes one that's not mismarketed violet
<bofh>
SnoopJeDi: tbh, not too familiar with their knockout scheme
<bofh>
Iskierka: really? most of them are 445nm which to me is clearly deep blue
<bofh>
so I have a bunch of Nichia's 1.4W 445nm laser diodes.
<bofh>
THE CAN IS 7.9 MILLIMETERS IN DIAMETER
<bofh>
it's mind-bogglingly tiny
<Iskierka>
bofh: all the affordable ones seem to be 405 nm?
<bofh>
I once ran it at ~450mW non-heatsinked for a literal second, touched it on the side afterwards and got a burn.
<SnoopJeDi>
I *think* that paper is the best place to read about it bofh, but the tl;dr is to snag the early SASE x-rays by running the beam through a chicane (whence the x-ray goes straight on), then separate, band-pass, and recombine with the beam.
<Iskierka>
I thiiiiink it might be more sensible to get something pre-assembled with appropriate power limiting systems :p
<SnoopJeDi>
the x-ray pulse is perfectly matched to the stochastic nature of the beam and the spatial knockout corresponds to seeding a pretty specific frequency for ringing in the time domain
<Iskierka>
rather than try build it myself
<bofh>
it's possible to run them at low powers, I current-limit mine to 25mW - 50mW
<bofh>
Iskierka: true, but was just pointing out how cheap they get
<bofh>
Iskierka: honestly I found heatsinking much more difficult than current-limiting. a single LM317T and resistor works perfectly for power limiting.
<SnoopJeDi>
I remember when the speaker came to show us that and I spent the rest of the colloquium scooping my jaw off the floor
<Ellied>
oh god, pls don't burn your retinas out
<Ellied>
blue lasers are so bad
<bofh>
SnoopJeDi: oh god holy fuck
<Iskierka>
They're pretty though
<Iskierka>
(but do note *I* haven't bought one)
<bofh>
Ellied: I have goggles rated for OD4 for ~365nm - 500nm that I wear at all times when working with these
<bofh>
Ellied: I may be careless but I'm not stupid
<SnoopJeDi>
bofh, as if SASE wasn't already super-duper sexy they gave it really strong control on coherence properties ;_;
* SnoopJeDi
just notices that paper was published out of Menlo park
<Ellied>
bofh: good
<bofh>
SnoopJeDi: jesus fuck this paper is amazing
<SnoopJeDi>
Right?!
<bofh>
like I keep just going "what the fuck, that's possible?!?" over and over
<SnoopJeDi>
Scuttlebutt in the FEL circles at NAPAC last year said that Intel bought up some EUV FELs through a subsidiary, I haven't really dug in to see if that's the hotness in past-optical lithography
<egg|phone|egg>
!wpn
* Qboid
gives egg|phone|egg a Lévy–Прохоров falconet
<UmbralRaptor>
Unrelated, is @sigmaeldritch one of this channel's alts/private accounts?
<bofh>
UmbralRaptor: mine
<UmbralRaptor>
Ah, thanks.
<bofh>
EUV lasing is fucking hard due to absurd absorption by pretty much literally everything
<bofh>
like I actually am fairly certain it's easier to find an X-ray window than one that's acceptably transparent to short-wavelength EUV
<SnoopJeDi>
yea, it seems very much more matched to FEL technology than to laser tech
<bofh>
actually of course that's true, thin layers of Be are a pretty good X-ray window
<SnoopJeDi>
no idea if people have tried to do SASE in the not-xray yet
<bofh>
That sounds like the natural next step, honestly.
<SnoopJeDi>
it does
<egg|phone|egg>
!Wpn -add:adj stinging
<Qboid>
egg|phone|egg: Adjective added!
<SnoopJeDi>
bofh, beryllium is pretty good as a proton window too IIRC
* egg|phone|egg
ibuprofen
<SnoopJeDi>
I believe our window separating vacuum from molten salt in our ADS concept was pure Beryllium (although the thickness was half a joke: you can't put O(1 m/s) flow on mm thicknesses)
<bofh>
!wpn -add:wpn Ibuprofen
<Qboid>
bofh: Weapon added!
<SnoopJeDi>
!wpn -add:adj nonsteroidal
<Qboid>
SnoopJeDi: Adjective added!
<bofh>
SnoopJeDi: um.
<bofh>
yeah, that won't work
<bofh>
at all
<bofh>
especially if it's separation from vacuum.
<SnoopJeDi>
as I recall it wasn't *completely* crazy when we looked at some thermal/mechanical simulation, but intuition is enough to tell you that you can't slam coolant flow of...liquid sandpaper...into a window and expect it to hold up
<SnoopJeDi>
(particularly when you're irradiating it with ~10 mA of beam from the other side o.O)
<SnoopJeDi>
I guess you'd say our lab's projects don't always feel compelled to constraint by the plausibility of building something :(
<SnoopJeDi>
(on top of DOE's downright hostility to the notion of progress in nuke)
<SnoopJeDi>
which right upfront involves invoking the tooth fairy of a superconducting energy recovery linac
<bofh>
SnoopJeDi: yeah the DoE is honestly kind of frustrating when it comes to progressing in nuclear power which always struck me as odd since that's, like, their core mandate
<bofh>
ROFL
<bofh>
do any of those exist yet in use?
<SnoopJeDi>
not a one to my knowledge
<bofh>
Yeah, 's what I thought.
<SnoopJeDi>
JLab is betting *hard* on one
<SnoopJeDi>
their EIC concept basically depends on it
<SnoopJeDi>
and, uh...it's actually not crazier than Brookhaven's
<SnoopJeDi>
Brookhaven wants to do coherent electron cooling...
<bofh>
so I actually fully think Brookhaven is nuts. I still wish them success and think it might work and it's super-neat
<SnoopJeDi>
which is basically electron cooling + SASE
<bofh>
but they're nuts.
<bofh>
yep
<SnoopJeDi>
with coherent cooling?
<SnoopJeDi>
yea
<SnoopJeDi>
It's super neat to listen to folks in those communities talk about it (I attended COOL15 which was a real treat) but *jeez* some stuff is just certifiable
* SnoopJeDi
glances meaningfully at muon cooling community
<bofh>
...that's still a thing?
<SnoopJeDi>
ish? it's a thing inasmuch as there are still a bunch of old farts doodling theories in that vein and drawing a paycheck at some of the national labs
<SnoopJeDi>
the concepts I saw were pretty solid, mind, it's just that the level of engagement doesn't really match up to...any interest in doing it, I guess?
<SnoopJeDi>
Higgs factory is the most compelling argument I'm aware of for it
<bofh>
Like I actually think Muon Cooling is less implausible than Coherent Electron Cooling in practise, at least at our level of tech.
<bofh>
It's just, there doesn't seem to be much interest in it?
<SnoopJeDi>
Yea I'd agree with that assessment
<SnoopJeDi>
at the very least, JLab's ERL effort is developing novel stuff
<SnoopJeDi>
namely a fast RF kicker that uses something like 5 (?) frequencies to make up a square-wave-alike so that they can knock out individual bunches (did I mention they want to do ERL/electron cooling with *bunches*?!)
<bofh>
True.
<bofh>
...wat.
<bofh>
*boggle*
<bofh>
like I mean Fourier series and all that, but still.
<SnoopJeDi>
yea, this is for cooling in the final ring (up to 100 GeV/u) so they have to have bunched beam
<SnoopJeDi>
they did a test at CSRe in China so at least bunched cooling is a thing that can happen, but it's kinda murky what it'd be like at high energy
<SnoopJeDi>
(the CSRe was with carbon at maybe 15 MeV)
<bofh>
yeah that's peanuts
<bofh>
...wait, *carbon*? not a simple proton beam?
<SnoopJeDi>
γ^3 will eat you alive
<SnoopJeDi>
bofh, yea JLEIC is designed to support multiple ion species
<SnoopJeDi>
the EIC white paper makes a sufficiently strong case for polarized electron-ion in addition to "hey can we study nuclear matter with polarized beams?"
<SnoopJeDi>
if the US builds anything it seems like deuterium and lithium are kind of the *minimum* you could get away with, but several up to gold is probably a gimme too
<SnoopJeDi>
RHIC certainly already knows how to do polarized (ish?) gold
<bofh>
polarized electron-ion is cool but tricky
<bofh>
oh man you get to turn gold into lead!
<bofh>
...wait
<SnoopJeDi>
I should probably see if my advisor can find a small pot of money to drag Abhay Deshpande here to give an EIC talk, now that he's the dept head
<bofh>
amusingly turning *Mercury* into Gold is relatively easy
<bofh>
the hard part is enriching Hg-196
<SnoopJeDi>
alchemy will hopefully get a small shout-out in my eventual thesis
<SnoopJeDi>
medical isotopes count, I'm counting it!
<bofh>
but after that you just have it undergo slow neutron capture to Hg-197 followed by inverse beta decay to Au-197
<bofh>
yep they do!
<SnoopJeDi>
oh! bofh since we're on accelerators
<SnoopJeDi>
have you seen crystalline beams?!
<bofh>
nope!
<bofh>
link?!?
<SnoopJeDi>
APPARENTLY YOU CAN CRYSTALLIZE BEAMS
<SnoopJeDi>
sec I don't have a ref off the top of my head but I can find one
<SnoopJeDi>
plot should be free to look at at least
<bofh>
...this is *nuts*
<bofh>
sci-hub, friend, sci-hub :P
<SnoopJeDi>
I'm spoiled by having good library access so I usually play by the rules, but hey whatever you do with a pointer to a paper is none of my business ;)
<SnoopJeDi>
but yes it's crazy!
<bofh>
I have good library access too but this is honestly *easier* :P But yeah, what the actual hell.
<bofh>
...do they actually have a tunable WIGNER-SEITZ RADIUS?!?
<SnoopJeDi>
they don't think beams be like they is, but they do
<bofh>
I mean it's a function of ion density and particle number, so I suppose they do.
<bofh>
*boggle*
<SnoopJeDi>
bofh, "if we build our systems so that literally every thing intended or not has an effect, we have infinite tunability! \o/"
<SnoopJeDi>
if I have to explain what I do to someone, I usually describe how there's this beautiful theory laid out in the early 20th century that perfectly describes the dynamics etc. etc. and we spend 20 years building machines using it and then turn them on and...welp, nothing. "Kay see you in 6 months for first light."
<bofh>
Why 6 months again?
<SnoopJeDi>
Oh I just chose an arbitrary number off the top of my head to represent beamline commissioning
<whitequark>
crystallizing beams?!
<whitequark>
what
<bofh>
Doesn't beamline commissioning time vary wildly based on accelerator type, materials and politics?
<SnoopJeDi>
in practice it's usually much faster than that I believe because Ops is...good at what it does
<bofh>
exactly as insane as you think it is, perhaps moreso
<bofh>
"Here we demonstrate the crystallization of laser-cooled Mg+ beams circulating in the radiofrequency quadrupole storage ring PALLAS11, 12 at a velocity of 2,800 m s-1, which corresponds to a beam energy of 1 eV. A sudden collapse of the transverse beam size and the low longitudinal velocity spread clearly indicate the phase transition. The continuous ring-shaped crystalline beam shows exceptional
<bofh>
stability, surviving for more than 3,000 revolutions ...
<bofh>
... without cooling."
<bofh>
I actually had to read that a few times to make sure I wasn't hallucinating.
<UmbralRaptor>
o_O
<SnoopJeDi>
don't call it an ideal gas, it's been here for femtoyears
<bofh>
Especially the stability of the crystallized beam. Like maybe I'm just too used to superconductors but I'm used to things phase transitioning out of nice states basically the second they no longer are actively cooled.
<bofh>
rofl
<SnoopJeDi>
I guess at 1 eV you don't have to live with...much of any of the icky stuff?
<UmbralRaptor>
!wa 1 eV in kelvin
<Qboid>
UmbralRaptor: convert 1 eV/k_B (electronvolt per Boltzmann constant) to kelvins: 11604.5 K (kelvins)
<SnoopJeDi>
I think 1 eV is the *beam* energy UmbralRaptor o.O
<SnoopJeDi>
"So, you breathed lightly on this beam, if what you're telling me."
<SnoopJeDi>
but they give T_perp ~ 30 K for the gaseous beam and ~ 0.4 K for the crystalline form
<UmbralRaptor>
ah
<UmbralRaptor>
Very o_O
<bofh>
like there definetly would be a dramatic drop in temperature at the crystallization transition
<SnoopJeDi>
I'm glad it occurred to me, I'd been meaning to send it to a friend working in our cyclotron pseudo-department
<kmath>
<ID_AA_Carmack> Was distressed about chromatic aberration only showing up on sides and not top of a screen. Turns out my glasses were fixing it on top.
<UmbralRaptor>
Hah!
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<SnoopJeDi>
UmbralRaptor, hmm, why is a pusher plate necessary at all if the tungsten becomes a vapor? Isn't it just a plain ol' reaction drive then?
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<bofh>
SnoopJeDi: good questiobln
<bofh>
question*
<bofh>
yaey laflg
<bofh>
lag*
<bofh>
you get the poin
<bofh>
point*
<bofh>
ffs
<UmbralRaptor>
SnoopJeDi: wait, for Orion?
<SnoopJeDi>
yea, from that article which I confess I have been tabbing to/from for a bit
<kmath>
<krishansonRCF> Both the European (ECMWF) and the North American (GFS) models are in shockingly close agreement with #Jose. I didn'… https://t.co/Otpp4W6POC
<UmbralRaptor>
I'm still short on context.
<SnoopJeDi>
oh so, they set up the argument for "hey a bomb is a bad choice because you can't use all the impulse, then sets up the conic charge, but is still talking about absorbing the plasma with a pusher plate
<kmath>
YouTube - Deus Ex: Bad choice for close range combat
<SnoopJeDi>
Relatedly, I started the third Three Body novel and it has a tiny passive craft propelled by nuclear boom-booms laid out ahead of time. Very promising read so far, not that I have any other expectations for Liu Cixin by now
<SnoopJeDi>
Never read any Chinese sci-fi before, but I've been loving this series and found a great survey of Chinese authors that is fertile with suggestions for more
<bofh>
Yep, if that's the list you shared with me a bit ago, I read a number of entries on it (some years ago even) and they're consistently great.
<SnoopJeDi>
ah yea, I suppose I did drop that here
* UmbralRaptor
wonders of this retweet counts as trolling.
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<SnoopJeDi>
oh man that whole thread
<egg|phone|egg>
!m
<egg|phone|egg>
!wpn
* Qboid
gives egg|phone|egg a crow
<Fiora>
!meow
<egg|phone|egg>
!Wpn Fiora
* Qboid
gives Fiora a Pauli planet
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<bofh>
(and yet I very vaguely remember watching it myself, tho damn if I remember any of the actual content of it.
<bofh>
also damn, I feel old, I was 7 at the launch time. :P
<bofh>
+)*
<egg>
bofh: I think I remember seeing the tower angle video
<bofh>
I think I saw tower angle and launch of spacecraft ones, or bits of them, but I honestly can't tell if that's actually the case or I'm projecting assumptions onto past memories.
<egg>
same here of course :-p
<bofh>
(especially since they usually start off launch videos with the tower angle shot and Titan/IVB Centaurs aren't exactly unpopular)
<egg>
!wpn atlas
* Qboid
gives atlas a gamma bicyclops
<bofh>
isn't, like, a bicyclops just a person with normal eye placement? :P
<egg>
bofh: all his cyclops friends think he's monstrous
<Fiora>
just make sure you're the one in the dominator
<Fiora>
not in the pizza truck
<egg>
bofh: that somehow reminds me of a swiss math student at ethz who told me about his military service in the meteorological service; one of the thing he had to do was park the meteo truck in a field (because of course you need somewhere clear to be able to measure things), and then *camouflage the thing*
<egg>
a truck
<egg>
in an open field :-p
<Iskierka>
just get a decomissioned MBT
<Iskierka>
plenty heavy enough
<Fiora>
i dunno. would it be heavy enough?
<Fiora>
i think even the Dominator 3 is risky against the strongest tornadoes and that thing has *hydraulic anchoring spikes* that can deploy
<bofh>
egg: LOL
<bofh>
egg: why even bother, it's declassified ops. nevermind the impossibility of the task.
<bofh>
Fiora: spikes?! well I guess when you're dealing with 400km/h+ winds...
<egg>
bofh: well it's an exercise, what if someone invades and decides to take out the meteo trucks :-p
<bofh>
so that's assuming two things: A) someone successfully invading CH, B) them deciding to go for the meteo trucks of all things
<Iskierka>
fiora: no number that I can see for the 3 but the dominator 1 is under 4 tonnes. The first classified I see for a second hand "tank" (actually an APC so much lighter) is 14 tonnes
<Iskierka>
MBTs go into more the 40-60 tonne range IIRC
<egg>
bofh: yeah, the whole thing sounds a bit silly; but then switzerland :-p
<Fiora>
what would matter is density or at least weight to surface area ratio
<Iskierka>
and built to low profile
<Fiora>
also the geometry is incredibly important
<Fiora>
ex: concrete domes have taken F5 tornadoes, concrete walls have been sheared off straight through
<egg>
bofh: but imagine, if someone takes out the meteo trucks, you can't tell if the cows need watering by helicopter :-p
<bofh>
that makes sense actually, based on how they handle strong wind shear.
<bofh>
also man these vehicles are badass
<Fiora>
also keep in mind tornadoes at this strength have literally *pulled conrete foundations out of the ground*
<Fiora>
and *removed steel anchor bolts from cast conrete*
<Fiora>
*concrete
<Iskierka>
There's an advert for one of the two privately owned Challenger tanks. 60 tonnes, for only 50% taller than the base truck the dominator 3 is based on (so less after modification)
<Iskierka>
with the same lateral ground contact increase also
<Fiora>
"A 25-foot section of pavement was scoured from a road in town, with chunks of asphalt scattered up to 1/3 of a mile away"
<Iskierka>
road surfaces often aren't actually that well secured against vertical lifting. They work because they rarely face such forces
<Fiora>
by vertical lifting do you mean solely the low pressure environment?
<Iskierka>
That plus the shear that can get at sections that are tending to lift and catch them when they would have been able to fall back in place
<Iskierka>
Jet exhaust, which does not generally point down at the surface and so must diffuse, is regularly known to lift even high-quality runway surfaces if run for a time in place
<Iskierka>
(at sufficient power)
<Fiora>
oh gods
<Fiora>
"A freight car, weighing 36,000 lb (16,000 kg) was thrown 0.75 mi (1.21 km). The car bounced as it traveled, remaining airborne for 50 to 100 yd (46 to 91 m) at a time. "
<Fiora>
so that's probably the closest thing (not equivalent, but still) to a tank that's been picked up
<Iskierka>
that would be quite scary but *is* a lot bigger and lighter than a MBT
<Iskierka>
perhaps tank would want modifications for the strongest tornadoes, but it could laugh at anything else
<bofh>
wow.
<Fiora>
i suppose at least the tnak wuold *probably *be mostly immune to flying debris, though i'm not actually sure
<Fiora>
because tank armor isn't actually designed for (relatively) low velocity, extremely heavy objects
<Fiora>
ex: a 1 ton piece of metal impacting at 200km/h is very different from a 1 pound bullet at 2000km/h
<Iskierka>
I wouldn't be concerned about most things that are doing damage in a tornado. the rail car would be a worry
<egg>
!wa 1 tonne * 200 km/h in kg m / s
<Qboid>
egg: convert 1 t (metric ton)×200 km/h (kilometers per hour) to kilogram meters per second: 55556 kg m/s (kilogram meters per second)
<egg>
!wa 1 lbm * 2000 km/h in kg m / s
<Qboid>
egg: convert 1 lb (pound)×2000 km/h (kilometers per hour) to kilogram meters per second: 252 kg m/s (kilogram meters per second)
<Fiora>
actually let's see. if the freight car was airborne for 100m at a time, how fast was it moving?
<Iskierka>
you would need to estimate how much lifting effect the tornado has
<Iskierka>
(and check the accuracy of such claims)
<Fiora>
it's probably safe to assume much less than gravity
<Fiora>
insomuch as it's *mostly* wind picking it up, then the car falling down, bouncing, etc
<Iskierka>
if it were just wind pushing it sideways it would never lift in the first place
<Fiora>
so.... formulas....
<Iskierka>
which means there is a lifting effect
<Fiora>
yeah, but once it's moving fast you can probably approximate speed from the time it takes to fall back to the ground? oh i guess we don't know how high it bounced
<Fiora>
well let's guess 100km/h.
<Fiora>
@wa (100 km/h)^2 * 0.5 * 16000kg
<Fiora>
!wa (100 km/h)^2 * 0.5 * 16000kg
<Qboid>
Fiora: (100 km/h (kilometers per hour))^2×0.5×16000 kg (kilograms): 6.173×10^6 kg m^2/s^2 (kilogram meters squared per second squared)
<Fiora>
what
<Fiora>
!wa (100 km/h)^2 * 0.5 * 16000kg in joules
<Qboid>
Fiora: convert (100 km/h (kilometers per hour))^2×0.5×16000 kg (kilograms) to joules: 6.173×10^6 J (joules)
<Iskierka>
just guesstimating 3m width/height, 15m length, it only takes 3.5 kPa or 0.5 psi difference across the top and bottom to fully lift it
<Iskierka>
that seems an eminently achievable pressure differential
<Fiora>
that little?
<bofh>
that seems oddly low, yeah
<Iskierka>
!wa 16 tonnes * 9.81 m/s^2 /(3m*15m)
<Qboid>
Iskierka: 16 t (metric tons)×(9.81 m/s^2 (meters per second squared))/(3 meters×15 meters): 3488 kg/(m s^2) (kilograms per meter per second squared)
<Iskierka>
!wa 16 tonnes * 9.81 m/s^2 /(3m*15m) in Pa
<Qboid>
Iskierka: convert 16 t (metric tons)×(9.81 m/s^2 (meters per second squared))/(3 meters×15 meters) to pascals: 3488 Pa (pascals)
<Iskierka>
just to verify
<Iskierka>
big and when empty, quite light for its size
<Fiora>
then again, that's a hell of a pressure *differential*
<bofh>
but wpuld explain why a tornado suffices, you're all-but-guaranteed 35hPa differential in one
<Fiora>
over such a short area
<Iskierka>
Wings do that quite easily
<Fiora>
a lot easier when you're travelling at 800km/h!
<Iskierka>
Except they do it at below tornado speeds
<Fiora>
plus, the wing is creating a localized pressure differential not a global gradient
<Fiora>
(global relative to the object, at least_
<Fiora>
or do you mean the idea that the object itself could act as a wing and help create the differential?
<Iskierka>
Very vaguely and as an inefficient wing, yes
<Fiora>
ahhhh. makes sense
<Fiora>
basically though my thought was that given the train bounced, it clearly has *way* more force pushing it sideways than up
APlayer has quit [Ping timeout: 383 seconds]
<Iskierka>
A380 in level flight MTOW is 6.9 kPa over the wing, with approach speeds in the F3 range. Entirely believable that half that could be achieved with an impromptu and temporary aerofoil in an F5
<Fiora>
"A tornado in Minnesota, USA, in 1931 lifted an 83-tonne train 25
<Fiora>
metres (80 ft) into the air and dropped it in a ditch. Many of its 117
<Fiora>
passengers died."
<Fiora>
"*May 27, 1931 -
<Fiora>
coaches weighing 70 tons each were lifted off the track. One was
<Fiora>
carried 80 feet. 57 of the 117 passengers were injured and one was
<Fiora>
A tornado struck the "Empire Builder" near Moorhead, Minnesota. Five
<Fiora>
blown through a window and killed"
<Fiora>
geez
<egg>
Ꙩ_ꙩ
<Iskierka>
the comparison there is why witness quotes are silly as the second clarifies no, it did not lift 80 ft straight up
<Iskierka>
still moved quite a lot quite far though
<Fiora>
... that was apparently an F3
<Fiora>
Iskierka: nothose are two different ones
<Iskierka>
both 1931, minnesota, 80 foot, with 117 pax?
<Fiora>
oh right nvm misread
<Fiora>
apparently the 136 ton locomotive managed to avoid being picked up
<Iskierka>
You'd hope so
<Fiora>
apparently people have done some of this math
<Fiora>
"
<Fiora>
A very strong F5 tornado at 318 mph would apply about 56,700 lbs
<Fiora>
(28.35 tons) to the side of a M1A2 Abrams tank, that might could be
<Fiora>
enough to get it tilted on its side."
<Fiora>
"If the wind tilted it on its side and caught the bottom it would apply
<Fiora>
155,520 lbs (77.76 tons) of force over the bottom of the tank."
<Iskierka>
if it lifted then it would be a problem but I'm dubious that it would in the first place given the weight distribution and wide tracks. That's a lot less lateral force than its weight
<Fiora>
so it might be able to roll the tank.
<Fiora>
but probably not lift it into the air
<Iskierka>
wear a padded suit and make sure you bought one with an escape hatch
<Fiora>
lol
<Fiora>
actually yeah that's a major issue: hatches
<Fiora>
like, in tornado shelters, there are two things that can cause problems
<Fiora>
1) debris covering your escape hatch
<Fiora>
2) water filling your shetler
<Fiora>
1) is why they recommend you register your shelter with local authorities with an exact GPS coordinate
<bofh>
...I just realized that Infected Mushroom may not be a very good song to test a flanging effect algorithm on.
<bofh>
(Heavyweight off Vicious Delicious in particular, which is like "here let's just twiddle all the sliders in FL Studio at random while this is playing")
<bofh>
kmath: ...is that an orbiting Kerbin cubesat?
<egg>
!wpn whitequark
* Qboid
gives whitequark a tin panzer/elephant hybrid
<egg>
UmbralRaptor: bofh: I somehow never touched a Lagrangian, because never took classical mechanics (only trubowitz's methods of mathematical physics), but holds for Hamiltonians too :-p
* egg
pets a Hamiltonian
<egg>
bofh: no, that's a Kerbal orbiting a smol cubic Kerbin
<bofh>
egg: is the orbital center of mass that localized? I mean that would imply smol cubic Kerbin is much more dense than a Kerbal.
<egg>
bofh: so this is KSP
<bofh>
Hamiltonian and Lagrangian mechanics are in many ways equivalent
<bofh>
but one is more useful in places and the other in others.
<egg>
bofh: the Kerbal follows a conic centred around the main body
<bofh>
(I'll admit to being more familiar with the former in some contexts thanks to QM, but my classical mechanics knowledge is all the latter)
<bofh>
egg: ahh. right.
<bofh>
stock KSP.
<egg>
everything follows a conic focused on the parent unless someone summons the egg
<egg>
even then, with Principia vessels are massless
<egg>
and Kerbals are vessels
<egg>
(you could give Kerbin a J2, but a cube is badly approximated by that I'd say)
<bofh>
(LOL)
<bofh>
Kerbals are vessels? I'dve expected them to be planetary satellites, Phobos-style.
<egg>
um
<egg>
bofh: also reminder to poke atlas with a rootn ccing Fiora and me
<egg>
!wpn atlas
* Qboid
gives atlas a corrosive life
<bofh>
they're in tech/software, all they need to do for that is open The Orange Website :P
<UmbralRaptor>
A cube would suffer from ringing, I guess?
<bofh>
well yeah, just standard Gibbs
<egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a Yukawa egg|egg|egg
<bofh>
...that would be a really weird gravitational field model
<bofh>
oh perfect, egg has a nice S-matrix representation then
<UmbralRaptor>
egg: please do not make me deal with the weak and/or strong forces.
<bofh>
UmbralRaptor: but the electroweak unified Lagrangian is so much fun!
<kmath>
<BiologistDan> I've had a Captain's license for 20 years and I've never seen twin waterspouts. But yes, #sharks can get sucked int… https://t.co/ZHemdrL0wy
<bofh>
also yes those are twin waterspouts, courtesy Irma.
<egg>
(and also some boggling from an actual mathematician :-p)
<bofh>
I'm mostly inquiring about the log in fraktur, I have none of: the patience, the attention span or the mathematical background to actually read the thing & extract anything useful out of it :P
<egg>
bofh: me neither; it's worth staring at just for the boggliness of it all
<egg>
11.2. Hodge-Arakelov Theoretic Evaluation and Gaussian Monoids in Bad Places.
<egg>
11.3. Hodge-Arakelov Theoretic Evaluation and Gaussian Monoids in Good Places.
<egg>
11.4. Hodge-Arakelov Theoretic Evaluation and Gaussian Monoids in Global Case.
<bofh>
ROFL
<bofh>
I have to check that out just to see if those are actual chapter headings
<egg>
7.5. Some Objects for Good Places.
<bofh>
they are, what.
* soundnfury
gives egg some Good Kings and Bad Things
<bofh>
!wpn -add:adj Hodge-Arakelov
<Qboid>
bofh: Adjective added!
<egg>
!wpn -add:adj good
<Qboid>
egg: Adjective added!
<egg>
!wpn -add:adj bad
<Qboid>
egg: Adjective added!
<egg>
!wpn -add:adj global
<Qboid>
egg: Adjective added!
<egg>
bofh: it's amusing to look at the table of contents, the headings start out reasonable, and then they seem indistinguishable from snarxiv (but then again after 300 pages of concentrated definitions anything would)
<bofh>
erm, that's what "Теорема сравнения" *means* >_>
<bofh>
whitequark can prolly explain this better than I can
<egg>
bofh: the theorem part means theorem right?
<egg>
the CAT inequality often gets expanded to Cartan- instead of Comparison, because immediately after that there's the Riemann-Cartan-Александров-Топногов theorem to confuse things
<kmath>
<FioraAeterna> *we reach a lightsaber over the fence to open the apt. complex door because the digital lock is out* @mirihawke: oh, so it's a keyblade now
<kmath>
<FioraAeterna> *we reach a lightsaber over the fence to open the apt. complex door because the digital lock is out* @mirihawke: oh, so it's a keyblade now
* UmbralRaptor
? fingers
<bofh>
rofl
<egg>
I guess if your autocorrect writes flora at least you're not switching your phone to italian