#qi-hardware IRC log for Thursday, 2014-02-20

nicksydney_whitequark: that's cool finding03:29
wpwrakso ftdi broke potential customer's hardware. nice attitude.03:46
wpwrakone more reason to avoid their chips03:46
Action: whitequark likes cp2102. cheaper and sturdier wrt/ ESD.03:47
wpwrakkl26 is cheaper and a LOT more flexible03:51
whitequarkisn't that an entire microcontroller?03:53
wpwrakexactly !03:54
whitequarkI mean, an advantage of cp2102 is that it works out of the box on major OSes with no flashing03:54
whitequarkyou just solder it and voila03:54
wpwrakso,. buy a ton of kl26, preinstall your fw, still win :)03:55
whitequarkmajor OSes include windows...03:56
whitequarkI meant cp2102 is awesome for one-off stuff though03:56
whitequarkfor something serious sure, you should use an actual micro03:56
whitequarkoh, hm, it also comes with VID/PID03:57
whitequarkwhich probably even adds to the cost03:57
wpwrakyeah, what is it, some USD 2k ? divided by millions ;-)04:01
wpwrak10000% margin or such ;-)04:01
whitequarkDocScrutinizer05: suddenly: http://www.electronic-thingks.de/de/elektronikprodukte/loetzubehoer/galden-ls-230.html04:13
whitequarkthough that's more expensive than that other shop04:14
whitequarkseriously considering buying a 7kg bottle04:18
whitequarkooo: http://www.mikrocontroller.net/topic/224245#353431604:29
DocScrutinizer05rather :-O http://www.mikrocontroller.net/topic/224245#297645604:45
DocScrutinizer05Fluorphosgen eeeek04:46
whitequarkmeh. just don't let it heat up too much04:47
whitequarkI'm sure overheated PCB, components, plastics, etc, etc release not less harmful chemicals04:47
whitequark*rereads* though I think I'll make a fume hood for that04:48
DocScrutinizer05I ponder to build modified deep friers (with emergency cut out at 260°C by dedicated thermofuse) with thermostat replaced by special thermo regulation (processor based?) that also uses additional sensors to detect vapor level in tub, then add some Galden in a bottle to the kit and sell it as convenience-package05:17
DocScrutinizer05actually, it's hard to come up with a good story how considerable amounts of a fluid that evaporates at 200 or 230°C can get heated up to a temperature of 290°C so it decomposes into toxic stuff05:20
DocScrutinizer05I mean, it's not like HS-230 would condensate on the 300°C hot floor of the frier to get destroyed05:22
DocScrutinizer05it's just the vapor that gets into contact with the hot surface, and that's probably not that much substance 05:22
DocScrutinizer05I even wonder if the decomposition products (HF etc) will recombine as soon as they cool down sufficiently05:24
DocScrutinizer05maybe not, since it's basically a polymer aiui05:25
whitequarkDocScrutinizer05: (build modified deep friers) something I'd be pretty interesting in :)05:26
whitequark(decomposition products) to my best knowledge, they immediately fly away and go on to destroy everything good in this world05:27
DocScrutinizer05whitequark: any suggestions for product spec welcome. Like "special lid with integrated cooler for condensing Galden vapor before it escapes the tub. Operates on water or a mixture of water and ice. Condensed Galden flows down to bottom of fryer tub from a special tap directing the liquid to the wall of the tub where it runs down without getting into contact with the PCB"06:03
DocScrutinizer05I think the floor (heater element) temperature sensor may autodetect when boiling temperature got reached (delta-temp/t) and the controller doesn't try to increase temperature above that point.  Or, nore specifically: when controller notices floor temperature rising a maybe 3°C above that temperature plateau and the vapor level sensor doesn't detect vapor reaching the sensor and heating it up as expected, then the controller 06:10
DocScrutinizer05thorows "GALDEN VOLUME TOO LOW!" error and shuts down06:10
DocScrutinizer05when floor temperature reaches - say - 250°C without controller sensing any plateau: -> error: "GALDEN MISSING!"06:12
whitequarkDocScrutinizer05: I want to get my hands on the live process first06:16
whitequarkidle speculation isn't really very productive if you aren't even familiar with the thing you're trying to make06:16
whitequarktalking about condensing galden... I *suspect* this is not very important, due to low vapor pressure => meaning it stays near the liquid?06:17
whitequarkalso very high density of vapor as well06:17
whitequarkyou want to operate it in a way where galden vapor does not overflow the tub at all06:17
whitequark(heating element) I think you should just use a standard PID controller algorithm. I mean, why not?06:18
whitequark(detecting overtemp and telling user that there's no galden) yes, that's an excellent idea06:18
DocScrutinizer05whitequark: when you purr a litre of Galden into the fryer and then cook it at 2kW, it inevitably will escape the fryer sooner rather than later06:19
whitequarkI wonder the exact degree of that06:20
whitequarkhence see above, want to get my hands on the process. Fortunately how much galden has escaped is very easy to measure.06:21
DocScrutinizer05you can simulate with water06:22
DocScrutinizer05eventually the pipe on nozzle of your kettle will start to whistle06:22
DocScrutinizer05sure, that's not the supposed operation mode of a Galden VPS equipment06:23
DocScrutinizer05so consider it the outer safety containment and cooling of a nuclear reactor. Usually not active but for sure not useless06:24
DocScrutinizer05It just came to mind while pondering another type of cooling: some pipes with water cooling at the bottom of tub, to shut down the process in an instant when you start the water flow through the tubs06:26
whitequarkDocScrutinizer05: sounds like overkill06:26
whitequarkthought about galden escaping: think of the diagrams provided by VPS vendors06:26
DocScrutinizer05probably, particularly since you usually want slow gradients, not steep ones06:26
whitequarkin the working area there is significant temperature gradient, with most of space above PCB being lower than Tb06:27
whitequarkit really has no other way to escape than over the edges of the pot, and edges are cold => it condenses and flows down06:27
DocScrutinizer05I meant  gradients over time, not over dimension axis06:27
DocScrutinizer05aka profile06:28
whitequarknono, I'm talking about escaping now. not the water cooling thing (later about that)06:28
whitequarkso I think it would be sufficient to monitor temperature of the bottom of the pot (aka working area)  *and* of the top of the pot (aka condensation area)06:28
DocScrutinizer05yes, exactly06:28
whitequarkif bottom is too cold? not yet ready. too hot? alert, no galden. top is too hot? shut the thing down06:29
whitequarkit really would be much better than fiddling with ice and so06:29
whitequarkthat'd really be a nuisance06:29
DocScrutinizer05but in case that control runs away, your pot will "overcook"06:29
whitequarklike in my laminator.06:29
whitequarkor better: control *and* thermofuse set 5°C higher06:29
whitequarkmaybe 10°C06:29
DocScrutinizer05nonono, you can't do that since you may ise different Galden06:30
whitequarkah, true.06:30
whitequarkduplicate control circuits?06:30
DocScrutinizer05you could place a hard fuse at maybe 150°C at very top of pot06:30
whitequarkpossibly 2 circuits with 2 thermocouples for each06:30
DocScrutinizer05but it's already too late when that one engages06:30
whitequarkwell, you definitely need a fuse at 280°C at bottom06:31
whitequark(hottest galden is ht-270)06:31
DocScrutinizer05I said 26006:31
whitequarkthough ht is heat transfer, ls is vps06:31
DocScrutinizer05I'm reluctant to go beyonf 260, since with titan around it already decomposes at that temperature06:32
whitequarkalso PCBs delaminate above 260 in mere minutes06:32
whitequarkI've investigated that just today06:32
whitequarkunless you have really high-quality specialized FR4 you have 1-2 minutes before delamination06:32
whitequarkno, not experimentally ;)06:32
whitequarkfound some papers06:32
whitequarkI was searching for a suitable activation agent for copper plating06:33
whitequarkand most organic salts of copper decompose at least at 260, and that's lower bound06:33
whitequarkso it's pretty sad on that front06:33
whitequarkI'll still order oxalate, acetylacetonate, formate and citrate to test whether they're suitable06:33
whitequarkbut they are likely not06:34
DocScrutinizer05so it all fails with unavailability of that hypophosphoric acid?06:34
whitequarkapparently hypophosphites are the ultimate sweet spot for copper plating06:34
whitequarkit's hard to find anything even nearly as good06:34
whitequarkwhoever put that on DEA Schedule I, fuck you06:34
whitequarka guy on RU forums did some experiments06:36
whitequarkapparently: acetate has too high temp, turns into carbon06:36
whitequarkabout 250-300°C decomposition, also emits vinegar vapors (not good)06:36
whitequarkoxalate: insoluble in water but readily forms suspensions. decomposition is above 350-400°C06:37
whitequarklikely 500°C06:37
DocScrutinizer05there's probably a reason why this got patented06:37
whitequarkso I'm still going to order that. I know a good inorganic chemist, maybe he'll help me to find something workable06:37
whitequarka catalyst sounds about right for this case06:37
whitequarkI'm sure there must be *some* research06:38
whitequark(patented) patented was not just hypophosphite method itself but a variation of it06:38
whitequarknamely he oversaturated the solution with calcium hypophosphite so that there's always a maximal amount of hypophosphite anions in the solution06:38
whitequarkthis gives far superior plating quality06:39
whitequarklike, before this modification it didn't pass GOST standard check06:39
whitequarkand I can frankly tell that USSR-era GOST standards on PCBs is not the strictest in the world06:39
DocScrutinizer05never heard of GOST06:41
whitequarkreally? there's a GOST crypto algorithm in openssl even06:43
DocScrutinizer05anyway, to ideas came to mind, dunno how much of a value in any of them: a) use some other metal, you don't need copper as conductive basis for any galvanic copper plating to a PCB, any conductive very thing coating might do. 06:43
whitequarkbut, several papers I've read mention that copper salts decompose at a *lower* temperature than other metal salts06:43
whitequarkrather significantly so06:43
whitequark(and the mechanism is not currently fully known :)06:43
whitequarkthere's a well-known another process, it uses PdCl206:44
whitequarkthat costs about as much as you may imagine06:44
DocScrutinizer05b) use some kind of "glue" coating that evaporates or decomposes, and dunk all that into an emulsion of nanocopper in water or whatever liquid. should make particles stick to PCB, later you evaporate the glue and particles stay06:44
DocScrutinizer053rd of my 2 ideas: use other forms of energy than mere slow heating to 242.42°C. Like flashlight, laser, microwave, hot air flush at 3000°C, etc06:48
DocScrutinizer05UV light06:48
DocScrutinizer05dunno, there are more than just one way to skin the cat06:50
whitequarkhaha, I love this proverb06:51
DocScrutinizer05think of good ole photography: silver iodine?06:52
whitequarkthat may actually be a good idea06:52
DocScrutinizer05how did they build mirrors in the old days?06:53
whitequarkI think silver nitrate is actually one of possible replacements in pdcl2 in that process I've read about06:53
whitequarkhang on06:53
whitequarkyep, possible06:54
whitequarksoo... SnCl2, AgNO3, CuSO4, C4H4O6KNa, NaOH, CH2O06:55
whitequark:/ formaldehyde06:55
DocScrutinizer05seems you got your very own special way to have some sort of darknet over there in Russia06:55
whitequarkit's not a darknet, I think russians just have insatiable thirst for diy and no money at all06:56
whitequarkit's all over the russian internet, I mean when I type in "hypophosphite" the first page is not linked to ways of cooking meth06:56
DocScrutinizer05I'm talking about this cryptography you are using06:56
whitequarkrather it's filled with ways of making PCBs06:56
DocScrutinizer05those weird characters06:56
whitequarkDocScrutinizer05: it's very sad06:57
DocScrutinizer05almost like the French06:57
whitequarkthis method requires manual deposit of SnCl2 solution in every single hole06:57
whitequarkI say fuck this method06:58
DocScrutinizer05why 2manual"?06:58
DocScrutinizer05why "manual"?06:58
whitequarkI don't know, that's what the instruction says06:58
whitequarklemme think06:58
DocScrutinizer05what the heck means "manual"06:59
whitequarkwith a syringe and a needle06:59
whitequarkand your hands06:59
DocScrutinizer05that sounds silly06:59
whitequarkbtw, look for yourself: http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=ru&ie=UTF-8&u=http%3A%2F%2Fwww.cqham.ru%2Fpcb6.htm06:59
whitequarkit's translated really well06:59
whitequark-Palladium chloride (can be successfully replaced by platinum chloride or, in extreme cases, silver nitrate) 07:00
whitequark>in extreme cases07:00
whitequarkhere "extreme" means "extreme poverty" I guess07:00
whitequark(it's not what it said initially :D)07:00
DocScrutinizer05platinium chloride, wtf?07:03
whitequarkno idea why is it needed07:04
DocScrutinizer05I can't spot why it's *needed* to apply solution to holes with a syringe07:04
whitequarkwell, I have one guess07:04
DocScrutinizer05seems it just felt natural to the original author07:04
whitequarkwhat would you use instead of syringe?07:04
DocScrutinizer05anyway, sounds like a job for your CNC solderpaste spreader extension07:05
whitequarkoh, that... hm. that's an option07:05
DocScrutinizer05err, I would try to dunk the PCB into a bath of the solution, maybe move it vigorously to make solution enter all holes07:06
whitequarkyes, exactly07:06
whitequarknow think, you have 1-2ml of your precious metal salt in a syringe07:06
whitequarknow you need a *bath* of that07:06
whitequarksounds a bit expensive doesn't it?07:06
DocScrutinizer05maybe the stuff is just too expensive to prepare and use large amounts of solution to allow that process?07:06
DocScrutinizer05;-D ^^^07:06
DocScrutinizer05you might be able to come up with drastically improved variations, regarding amount of solution needed07:08
DocScrutinizer05think of a bag with 5ml of solution and the PCB, sealed without air inside, then place that to vacuum07:09
whitequarkI suspect the Pd is not catalyst though07:10
whitequarkbut is the actual thing which is deposited initially07:10
whitequarkooh look07:11
whitequarkDocScrutinizer05: another one of your guesses was right07:11
whitequark"Excimer lamp-induced decomposition of platinum acetylacetonate films for electroless copper plating"07:11
whitequark>Photo-induced decomposition of platinum acetylacetonate films using an excimer VUV source of 172 nm radiation is reported. VUV irradiation of a substrate coated with platinum acetylacetonate film results in the formation of platinum, which acts as an activator for copper plating by means of a subsequent electroless bath process.07:12
whitequarknot suggesting to use that though, 172nm UV is highly carcinogenic and causes cataracts07:12
DocScrutinizer05yeah, hard UV is a tad nasty to deal with, but not unfeasible07:14
whitequarktrue words of the guy who suggested "exploding wire method" ;D07:15
DocScrutinizer05dunno if 172nm already gets into the range that really becomes impossible to handle since plain air and other gasses absorb it07:15
whitequarkDocScrutinizer05: a quick search reveals that gasses don't absorb UV at that freq, rather water vapor does07:16
whitequarkand no, seems still within usable range07:17
whitequark~1-2 orders of magnitude worse than visible spectrum07:17
whitequarkthough no, don't take my word for it. needs further investigation07:19
DocScrutinizer05chip waver exposure by hard UV is done in vacuum, but I guess that's another class of UV07:19
whitequarkwell... no, I was wrong07:19
whitequarkUVC (100-200nm) is blocked by O207:20
whitequarkso that needs vacuum even07:20
DocScrutinizer05eventually they had to switch from lenses made of bizarre expensive material to concave mirrors since the lens material wasn't able to cope with the UV wavelength07:20
whitequarkplus what exactly will you make UVC with? arc lamp?07:20
DocScrutinizer05yeah, light sources for hard UV are another problem07:20
DocScrutinizer05so that clearly classifies as "not feasible on a DIY level"07:21
DocScrutinizer05they  use similarly biszarre light sources in chip manuf07:21
whitequarkdon't they use xray already?07:21
DocScrutinizer05meanwhile they do07:22
DocScrutinizer05UV was too long wavelength07:22
whitequarkwow, they used it in 1987: https://www.engr.wisc.edu/alumni/perspective/13.3/chips.html07:22
whitequark>Masks themselves (due to the nature of x-rays) are made up of light, thermally stable, extremely flat, optically transparent low-atomic-weight materials, such as beryllium (which is absolutely the best, but costs like the GDP of Argentina)07:23
whitequarkGDP of Argentina hahaha07:23
DocScrutinizer05sure, it takes a while from emerging new technology to industrial level mass usage07:23
whitequarkanyway beryllium masks are evil apart from being expensive07:23
whitequarkBe is really toxic07:24
DocScrutinizer05check "UV lithography"07:24
whitequarkSo, elements such as platinum, gold (nice 'cuz they don't oxidize, lousy 'cuz they're as soft as butter), or tungsten, or especially uranium (which has its own problems with oxidation) are the masking 'stuff'.07:25
DocScrutinizer05the predecessor of x-ray lithography07:25
whitequarknow I knew depleted uranium can be used highly successfully if you need a really heavy brick07:25
whitequarkbut don't they have to keep work area *really* clear of any radiation? and while depleted U is not very radioactive it will still crap all over occasionally07:25
DocScrutinizer05x-ray lithography is probably also out meanwhile (I don't follow closely anymore). Maybe now electron beam is the thing they use07:27
DocScrutinizer05all of that not really an alternative for anything PCB related07:28
whitequarkright, electron beam07:28
whitequarkdefinitely not for PCBs :)07:28
DocScrutinizer05just a funny read when you got the rant of "we want open source hw manufacturing, down to the roots of the creation chain" zealots in mind07:29
whitequarkwell that would certainly be nice07:29
whitequarkbut people tend to severely underestimate the real complexity and cost of all the tasks07:29
whitequarkby 5-10 orders of magnitude, I think :D07:30
DocScrutinizer05yes, by a factor of 10^6 to 10^1207:30
Action: whitequark is watching live stream from UA07:52
whitequarkDocScrutinizer05: that guy from µC.net responded with a quote... 110 eur for 0.5L07:57
whitequarkI say this is a really good price07:57
DocScrutinizer05yes, definitely08:05
whitequarkso... will still phone a local distributor, but they likely don't want to work with me08:07
whitequark4/5 list MOQ=100kg08:07
whitequarkwhat ever are you even going to do with 100kg of galden08:07
whitequarkthat's probably enough for a small country for a year08:08
DocScrutinizer05operate a *real* vapor phase?08:09
DocScrutinizer05sinze of two fridges, or 408:09
whitequarkmm, perhaps08:09
whitequarkanyway I'm going to sleep08:12
wpwrakAAH. finally a timer signal. what was missing is to un-suspend timers in debug mode. gnargh.09:58
DocScrutinizer51\o/ EDF deadline process scheduler in kernel 3.1411:40
DocScrutinizer51earliest deadline first11:42
DocScrutinizer51real realtime11:43
DocScrutinizer51also: kGraft yay! finally ksplice for the masses11:43
pcercueithat's great11:44
whitequarkDocScrutinizer05: >"of course is it ok for me to ship to Moscow, why not?"13:21
whitequarkI see he never actually tried it :D13:21
DocScrutinizer05him shipping is no trouble at all. You *receiving* it might well be though13:22
DocScrutinizer05customs might have a hard time verifying the content of this bottle is actually what's written on the outside, and not any listed substance13:24
whitequarkwell, the right thing to write in declaration is "solvent fluid", that is even technically true13:25
DocScrutinizer05non-toxic, non-corrosive13:26
DocScrutinizer05note that this soup is also used for lubricant and for vacuum pumps13:27
DocScrutinizer05and even to drown mice and scare them to death err not ;-P13:30
DocScrutinizer05I need to start a test - see how long it takes til a drop of that stuff vanishes on glass, at room temperature13:32
whitequarkdrown mice, hmm13:33
whitequark(drop vanishes on glass) yep, an important test13:34
DocScrutinizer05are you thinking of shipping a drowned living mouse in the bottle? X-P13:34
DocScrutinizer05will shock the shit out of customs13:35
wpwrakafaik they don't survive the ordeal for very long13:35
DocScrutinizer05prolly not, they are dieing from dehydration I guess13:36
Action: DocScrutinizer05 picks a straw and a drinking glass13:37
wpwrakit seems that they day a short while after you take them out of the liquid. not sure of what. maybe they simply succeed in convincing themselves that this experience can't have been survivable.13:37
DocScrutinizer05while mice actually can do this (die from shock), I suspect here the problem is lungs clogged with liquid, thus blocking gas flow to alvioles13:39
DocScrutinizer05basically a very severe lung emphysema13:40
DocScrutinizer05err, nope. dang, emphysema isn't the right term13:41
DocScrutinizer05almost but not really13:41
DocScrutinizer05lung oedema13:43
DocScrutinizer05to not suffer this, I'll stop smoking this cig before I proceed with the Galden13:43
DocScrutinizer05and I'll place the glass with the drop to evaporate outside13:44
DocScrutinizer05test started13:59
DocScrutinizer05and already failed. the drop isn't visible though still some liquid is there14:00
DocScrutinizer05I seen something moving when tilting the glass14:01
DocScrutinizer05though I already had to look *very* closely14:01
DocScrutinizer05seems optical density of galden is just too close to that of normal glass14:03
DocScrutinizer05when I could find a glass with roughened (etched) surface, I bet this would be easier to see14:04
whitequarkDocScrutinizer05: wait, you got yourself some galden?!14:11
Action: whitequark is envious14:11
DocScrutinizer05sure, since weeks, I mentioned it here14:11
Action: DocScrutinizer05 just starts to wonder how much HF might be solved in Galden, to begin with14:14
DocScrutinizer05when I let's say drop a 5mm glowing hot steel ball into the bottle, will HF and other shit escape the bottle immediately or will it much rather solve in Galden?14:16
DocScrutinizer05how much of that effect might have happened in factory already, during production? How much due to aging, by cosmic particles or dunno what?14:17
whitequarkDocScrutinizer05: (hot steel ball) I would fully expect it to escape immediately. you'd get hot HF vapours with very low density14:19
whitequark(during factory) I'd imagine they clean it carefully from HF, because HF is highly corrosive and you can't really sell your liquid as "chemically inert"14:19
DocScrutinizer05sure, but wouldn't they solve in the galden around them?14:20
whitequarkHF is a gas14:20
DocScrutinizer05oxigen too14:20
DocScrutinizer05Galden is known to solve gasses very good14:20
whitequarkwell. solubility of gasses in liquids is an unsolved problem in general as I have already found out14:21
whitequarkso without experiment it is really hard to say for sure14:21
DocScrutinizer05it seems even H2O is solving easily in Galden, so you might call it hygroscopic14:21
whitequarkI would really think that at the decomposition temperature *and* low pressure HF would not be soluble well in galden14:21
whitequarkbut that's my idle speculation14:22
whitequarklet's find out?14:22
whitequarkactually, no, shouldn't be needed14:23
whitequarksuch data should be contained in MSDS or related documents14:23
DocScrutinizer05I already heated a dropplet of that stuff on a spoon, with my lughter :-o14:23
DocScrutinizer05lighter even14:23
whitequarkbut how would you detect HF?14:23
whitequarkalso, that's a bit suicidal14:23
DocScrutinizer05exactly, that's why I won't repeat that14:23
whitequarkI mean, if you were a bird, you'd drop dead already; birds are extremely sensitive to ppm concentrations of fluorocarbon decomposition products14:24
DocScrutinizer05I wonder why14:24
DocScrutinizer05birds are strange14:24
whitequarkhighly relevant14:25
whitequarkthough after reading that I want to live in a forest or something :S14:26
whitequarkDocScrutinizer05: btw, what happened after heating it in a lighter?14:28
DocScrutinizer05it vanished14:28
whitequarkso, likely just evaporated14:29
whitequarkbut whatever miniscule quantities went to the flame decomposed to that toxic shit14:29
DocScrutinizer05maybe 5% got decomposed by flame14:29
DocScrutinizer05initial qty esimated a 0.01g14:29
whitequarkI wonder, if you heated it over a container, something like a frying pan14:30
whitequarkwould it condensate back on it?14:30
whitequarksuppose no side wind14:30
DocScrutinizer05I seen it partially condensing at spoon further away from flame14:30
DocScrutinizer05it kinda creeps away from the flame14:31
DocScrutinizer05well, I guess for this experiment to get really dangerous the stuff had to be VX, not Galden14:32
DocScrutinizer05or tritium-water14:34
whitequarktritium-water isn't really dangerous as it does not bioaccumulate14:35
whitequarkand ²¯-decays14:36
DocScrutinizer05well, the tritium light on my keyring is forbidden in Germany 14:38
DocScrutinizer05despite the immesurable amount of tritium gas inside14:39
DocScrutinizer05it has a radiation above a certain Becquerel14:40
whitequarkbecause people are stupidly paranoid about radiation14:40
DocScrutinizer05that doesn't even escape the glas tube14:40
DocScrutinizer05but it *could*14:40
DocScrutinizer05when you destroy it14:40
DocScrutinizer05and gamma radiators are really evil when ingested14:40
whitequarkand the whole milligram of T2 will go to air and in about three seconds go below natural background levels14:41
whitequarkit's not gamma14:41
whitequarkit's ²¯14:41
DocScrutinizer05err beta14:41
whitequarkand in this case it's not evil, you know why? because nothing in your body uses or accumulates H2 from air14:41
DocScrutinizer05can't pass a sheet of paper, but can shoot your DNA from an angstrom distance14:42
whitequarkit'll just dissipate14:42
DocScrutinizer05yeah, unless you burn it to water, that is14:42
whitequarkwhen you sit on a granite pavement you subject yourself to a higher risk14:42
whitequarkI don't think it's even possible to burn that amount of T2, simply because it *doesn't burn* at that concentration14:42
whitequarkat all14:42
whitequarkyou have min and max amounts of H2 and O2 for reaction to proceed14:43
DocScrutinizer053H2 is for sure not dangerous, 3H2O though...14:43
DocScrutinizer05and it inevitably would react with oxygen from air to form 3H2O in a flame of a lighter14:44
Action: whitequark sighs14:45
DocScrutinizer05I still dunno if it would be more dangerous than widespread natural occurrence of Radon in cellars14:45
whitequarkshall I take absurdly low yearly exposure limits and prove that even by current paranoid official standards it is not dangerous at all?14:45
whitequarkit'll probably start to become bad if you burn a pallet of those things14:46
whitequarkeven so doubtful14:46
DocScrutinizer05the effect is very similar to that of polonium and plutonium aiui14:47
whitequarkpolonium decays as ± too, though14:48
DocScrutinizer05and I still wonder if that glolite keyring thing does emit xray. The energy of beta is some 25keV iirc14:48
DocScrutinizer05for sure less than any crt tube, particularly color14:49
whitequark>In the early twentieth century, radiographers would commonly calibrate their machines by irradiating their own hand and measuring the time to onset of erythema.14:50
DocScrutinizer05I still seen and *used* the shoe checker xray box in shoe shops14:51
DocScrutinizer05my mother got panic14:51
DocScrutinizer05must've been 1964, 6514:51
whitequarkshoe checker?14:52
DocScrutinizer05they should've been outloawed by then, but in some cheesy little province town they had one still14:52
whitequark> that it made it more fun for kids to go to the shoe store14:54
whitequarkfun for the whole family indeed14:54
DocScrutinizer05yea, I was damn mesmerized by that thing14:55
whitequarkwait, how old are you exactly?14:55
DocScrutinizer05when my mother didn't watch for a minute, I managed to sneek to it and start it14:55
whitequarkI see there's something time doesn't change :D14:56
DocScrutinizer053 years later I wouln't have approached that thing, by no means. But in that age my education wasn't sufficient, regarding stuff like xray. Only sufficient to design an electromotor without ever having seen one from inside14:58
DocScrutinizer05and I don't even know what's been written on the sign they placed on that pedoskop - prolly "Achtung! Roentgenstrahlung! Gefahr!". I didn't know to read by then15:02
DocScrutinizer05except digits and "LOTTO" ;-P15:04
whitequarkso you designed your first electric motor before even learning to read? :D15:05
DocScrutinizer05age of 415:05
DocScrutinizer05or 515:05
DocScrutinizer05it worked with only one statically mounted electromagnet and a rotor with three steel poles15:06
DocScrutinizer05and for sure you had to give it a kick to make it start spinning, but it would have worked15:07
DocScrutinizer05I drawn it to a sheet of paper and shown it to my dad. Damn been I proud when he said "yes, that's basically how motors work"15:09
DocScrutinizer05that's why I still remember it, I guess15:13
DocScrutinizer05while other experiments like building a Marconi-alike "transmitter" from a buzzer and 2 m of antenna wire are more or less forgotten15:15
DocScrutinizer05and better stay forgotten, I guess I annoyed roundabout 100 neighbours with that jammer15:15
DocScrutinizer51wpwrak: hey, I just compared your food to new zealand ox. Not bad either!18:34
nicksydney_looks like soon Bitcoin is going to be game over sooner than later http://www.zerohedge.com/news/2014-02-20/bitcoin-exchange-mt-gox-finished21:20
larscnow seems to be the perfect time to buy bitcoins ;)21:27
larscsure, price is low21:30
nicksydney_FREE eBooks from NASA http://www.nasa.gov/connect/ebooks/ebooks_archive_1.html#.UwWhO_mSwsw21:53
nicksydney_uhhh everything need to be smart nowadays http://www.businessinsider.com.au/iphone-of-guns-now-selling-in-california-2014-222:24

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