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DemeaninDemon posted:The tiny ones like micro, nano, pico, and femto are useful in various scientific fields. Micro, nano, and pico are all used on capacitors because the Farad is stupidly huge.
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May 10, 2016 15:26
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Explosionface posted:Micro, nano, and pico are all used on capacitors because the Farad is stupidly huge. How did the Farad end up so massive anyway?
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May 10, 2016 15:42
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xthetenth posted:How did the Farad end up so massive anyway? 1 Coulomb of charge stored over 1 volt of potential difference because metric/SI units must have a simple unit definition. A Coulomb is a pretty large unit of charge (so it's kind of a cascading effect), although it manages to backfeed decently into the definition of an ampere (1A = 1C/s), which is actually reasonable.
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May 10, 2016 15:53
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They make capacitors with thousands of farads. The problem is they use technologies that end up having low working voltages and they have high ESRs so you can't pulse them as hard as you might like. They're not very big though, like soda can size for a few thousand.
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May 10, 2016 15:58
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xthetenth posted:How did the Farad end up so massive anyway? I'm not sure, but when I saw a 1 Farad capacitor in the UK Maplin catalog when I was a teenager, my reaction was "What? No, can't be that big".
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May 10, 2016 16:09
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Keiya posted:Dust is hardcore. If you get it fine enough, say, using sawdust, you can literally run jet engines on wood and air. https://en.wikipedia.org/wiki/Lippisch_P.13a quote:As conventional fuels were in extremely short supply by late 1944, Lippisch proposed that the P.13a be powered by coal. Initially, it was proposed that a wire-mesh basket holding coal be mounted behind a nose air intake, protruding slightly into the airflow and ignited by a gas burner. Following wind-tunnel testing of the ramjet and the coal basket, modifications were incorporated to provide more efficient combustion. Not so good for an engine with moving parts, but okay with a ramjet. But then again, boronated fuels weren't good for engines with moving parts (since the combustion product is basically a ceramic which does awful things to your turbine blades), but that didn't stop the air force from giving it the old college try.
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May 10, 2016 16:23
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Phanatic posted:https://en.wikipedia.org/wiki/Lippisch_P.13a Nobody cares about the Boron if you only have to fire the weapon once. This is as bad as you imagine.
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May 10, 2016 16:27
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Hexyflexy posted:Nobody cares about the Boron if you only have to fire the weapon once. This is as bad as you imagine. I'm guessing "zip past Soviet air defences on a probably-suicidal nuclear bombing mission"? Computer viking has a new favorite as of 17:31 on May 10, 2016 |
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May 10, 2016 17:29
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Deteriorata posted:Bits of encouragement are given in attoboys (and attogirls). This is great because if I really want to encourage someone, I could give them a femtoboy of encouragement, which could get confusing.
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May 10, 2016 17:37
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Computer viking posted:I'm guessing "zip past Soviet air defences on a probably-suicidal nuclear bombing mission"? I'm guessing this would be a V1 buzz bomb alternative. You could certainly fly a pulse jet engine with coal dust, though it would jam up the mechanism pretty quickly.
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May 10, 2016 17:48
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Enourmo posted:i can't wait for the metric kevin bacon game, 0.10472 radians to Kevin Bacon You're talking about building height there, which is usually given in meters. (Except when we're talking about "they're buiding a skyscraper of over a kilometer tall!") Millimeters and centimeters are also commonly used for all kinds of things. And it's decimal, so it's easy to see that 1.25 m = 1m 25cm. Smaller units of length are often used in all kinds of scientific fields. Milliliter, centiliter and deciliter are all common in cooking. MHz and GHz are common frequencies when talking about computer stuff, and also electromagnetic radiation. KHz is used for ancient computers and sound. I could go on and on. Most prefixes are in common use, just not every prefix for every unit, and it's still useful to have them as a standard for scientific purposes, instead of making up non-decimal poo poo as you go.
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May 10, 2016 19:08
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In the machining world, we use decimalized inches with .001 in (called a 'thou') being our basic unit. So loving dumb, just use metric goddamn. I get that change was and is scary, but just like with human children, human societies eventually need to grow the gently caress up.
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May 10, 2016 19:43
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I'd like to express my extreme displeasure with hydrologists for using 'acre-feet per year' as a measure of flow rate, along with half a dozen other units. In hydrology class I wasted a huge amount of time doing step by step conversions to meters cubed per second because my professor demanded it. Occasionally gallons per minute came up too, the whole thing was a horrible mess of units. To contribute to the thread, when I was a kid, my father let me play with a bunch of old chemicals and stuff he had scavenged from labs when his company downsized or moved labs. One such chemical was Potassium Dichromate which he warned me to be careful not to get on me lest I become poisoned, have an allergic reaction or develop cancer. He did show me that the powder burned very impressively with a bunch of sparks though, so that was fun. (I don't recall now if this was some other reaction or straight up burning) I really liked it because it was bright red and, as any kid knows, brightly colored chemicals are the best. Its a neat salt and can be used for photography and wood staining apparently, but I wouldn't suggest letting a 9 year old play with it. Not too bad a substance compared to most of the things in this thread though.
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May 10, 2016 20:42
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Deteriorata posted:Bits of encouragement are given in attoboys (and attogirls). 
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May 10, 2016 21:08
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 'And then Carter said, "Let's bring metric to the US!" Ahahaha,Ahahaha!' - Ronald Reagan Reagan is the entire reason that all my thoughts are still in miles per hour and fahrenheit, even though I use metric for everything else. MrAptronym posted:I'd like to express my extreme displeasure with hydrologists for using 'acre-feet per year' as a measure of flow rate, along with half a dozen other units. In hydrology class I wasted a huge amount of time doing step by step conversions to meters cubed per second because my professor demanded it. Occasionally gallons per minute came up too, the whole thing was a horrible mess of units.  What up dude, I know that feeling of talking about pathetic little streams in cubic feet per second units, without any idea of how to actually quantify what that means.My only real problem with acre-feet is that its a huge measurement.
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May 10, 2016 21:27
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EoRaptor posted:I'm guessing this would be a V1 buzz bomb alternative. You could certainly fly a pulse jet engine with coal dust, though it would jam up the mechanism pretty quickly. Oh, the coal dust engine? I was thinking of the boronated fuels, IIRC those were mostly studied by the USAF in the 50s and the planned applications were of the causing/preventing the end of the world - type.
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May 10, 2016 22:53
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Phanatic posted:https://en.wikipedia.org/wiki/Lippisch_P.13a Why not gasify the coal? Get a head of superheated steam up, run it through the granulated coal, and get CO and H₂ for burning purposes.
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May 11, 2016 01:30
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Zemyla posted:Why not gasify the coal? Get a head of superheated steam up, run it through the granulated coal, and get CO and H₂ for burning purposes. Now you've got to carry something along on your plane to superheat a bunch of steam and run it through your coal. The pilots I know would tend to balk about flying something with a bunch of superheated steam piping which other people would be trying to punch lots and lots of .5" holes in. But then, see the Me163.
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May 11, 2016 01:40
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Zemyla posted:Why not gasify the coal? Get a head of superheated steam up, run it through the granulated coal, and get CO and H₂ for burning purposes. Sometimes a post makes me forget whether I'm in this thread, or OSHA.jpg.
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May 11, 2016 01:50
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LonsomeSon posted:In the machining world, we use decimalized inches with .001 in (called a 'thou') being our basic unit. So loving dumb, just use metric goddamn. I get that change was and is scary, but just like with human children, human societies eventually need to grow the gently caress up. My favorite part is .0001 being called "a tenth" For you non machinists it usually comes up when talking about tolerances as in "this hole is held plus or minus two tenths" meaning +/- .0002 inches.
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May 11, 2016 02:00
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In college I worked with a laser with femtosecond long pulses. We'd talk about the pulse using microns as that was the length of the chunk of light. Did some weird things with power as that's J/s.
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May 11, 2016 02:49
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TheRagamuffin posted:Sometimes a post makes me forget whether I'm in this thread, or OSHA.jpg.
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May 11, 2016 03:03
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Keiya posted:One homestuck ago. Wolfram Alpha says that the speed of growth of human hair is about .7 smoots per Homestuck.
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May 11, 2016 04:40
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That's a useful unit, because now we know how far down his body smoot's beard would get if he stopped shaving for homestuck
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May 11, 2016 04:54
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honda whisperer posted:My favorite part is .0001 being called "a tenth" Which is completely against what people are taught in school. gently caress getting looked at like a moron when you say your tolerance is .01 so you say a tenth and people think .0001. rear end backwards stupid but it's a result of hands on learning in a machine shop and no real schooling so much of everything is passed down. Side note do we have a machine or factory thread on the forums? I work on edms which are pretty cool and not many people know. I use electricity to cut metal into cool shapes and cut carbide 
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May 11, 2016 08:13
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UCS Hellmaker posted:Side note do we have a machine or factory thread on the forums? I work on edms which are pretty cool and not many people know. I use electricity to cut metal into cool shapes and cut carbide There is a metalworking thread: https://forums.somethingawful.com/showthread.php?threadid=2905844 There's even another edm goon who posts, so it comes up from time to time.
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May 11, 2016 13:39
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UCS Hellmaker posted:gently caress getting looked at like a moron when you say your tolerance is .01 so you say a tenth and people think .0001. Isn't that a hundredth?
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May 11, 2016 13:49
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Syd Midnight posted:Isn't that a hundredth? No, you see, “tenth” = ten thou.
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May 11, 2016 13:52
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UCS Hellmaker posted:Which is completely against what people are taught in school. gently caress getting looked at like a moron when you say your tolerance is .01 so you say a tenth and people think .0001. rear end backwards stupid but it's a result of hands on learning in a machine shop and no real schooling so much of everything is passed down. The base unit is a thou, you're talking about a tenth of a thou, not a tenth of an inch. Right? Keiya has a new favorite as of 13:59 on May 11, 2016 |
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May 11, 2016 13:57
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Gann Jerrod posted:Some asshats are posting this around the internet: Pardon my ignorance, but what exactly is that mixture going to do? Explode horribly and maim the person?
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May 11, 2016 14:16
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axeil posted:Pardon my ignorance, but what exactly is that mixture going to do? Explode horribly and maim the person? Produce chlorine gas. e: But yes it will also produce enough pressure to pope the bottle. I’d still be more concerned about the chlorine than the shrapnel. Platystemon has a new favorite as of 14:24 on May 11, 2016 |
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May 11, 2016 14:20
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axeil posted:Pardon my ignorance, but what exactly is that mixture going to do? Explode horribly and maim the person?
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May 11, 2016 14:21
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Yep. It forms chlorine gas. Like any gas generator in a sealed container, it will increase in pressure until it bursts into a shrapnel-filled cloud of nastiness.
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May 11, 2016 14:22
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Keiya posted:The base unit is a thou, you're talking about a tenth of a thou, not a tenth of an inch. Right? I think the confusion is tenth of a thou vs ten thou. I've heard both used, even more fun with mixed units: Little brother had the crank reground on his old triumph, measured in decimal inches, ground in thousandths of a mm.
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May 11, 2016 14:25
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Platystemon posted:Produce chlorine gas. I don't understand how TCCA and isopropyl alcohol generate chlorine gas. It should oxidize the IPA to acetone, generating HCl and heat.
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May 11, 2016 14:37
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EoRaptor posted:I'm guessing this would be a V1 buzz bomb alternative. Nah. It was gonna be used as a fuel additive type of thing in supersonic jet aircraft. They'd use regular fuel for takeoff/landing/cruising, then switch over to special boron-enhanced fuel for extra performance in combat. It didn't work because when the boronated fuel was actually burned it created byproducts with a hellishly high melting point that immediately and irreversibly hosed up the engine. After the armed forces gave up on trying to make boron into an aircraft fuel they let the rocketmen have a go at it. The results were slightly better but still discouraging, and John Clark wrote a whole chapter about them in Ignition. The long and short of it is that boron just does not work as a propellant outside of one or two very niche places (there's a variety of Diborane that could probably be used in deep space). Vincent Van Goatse has a new favorite as of 15:08 on May 11, 2016 |
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May 11, 2016 15:00
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Cakefool posted:I think the confusion is tenth of a thou vs ten thou. Yeah, the entire exchange about this illustrates exactly why and how the thou/tenth poo poo is confusing. Another favorite of mine is the micrometer, a precision measuring tool not to be confused with the American-spelled micrometer, a unit of measurement which would be in use in the American machining world if we ever broke down and cooperated with everyone else. For sort-of content, Wolfram Alpha advises me that one thou(sandth of an inch) is 2,540 beard-seconds.
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May 11, 2016 20:58
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EoRaptor posted:I'm guessing this would be a V1 buzz bomb alternative. You could certainly fly a pulse jet engine with coal dust, though it would jam up the mechanism pretty quickly. If you want insane ramjet/cruise missile propulsion, it's hard to beat Pluto/SLAM.
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May 11, 2016 23:12
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DemeaninDemon posted:The tiny ones like micro, nano, pico, and femto are useful in various scientific fields. In metabolomics & lipidomics Mass Spec we're nearing measures of pg/ml depending on the molecule's ionization efficiency and the ability of equipment. For instance I'm having to develop a quantitative method covering 5 vitamin D2 & D3 compounds from human serum. While 4 of the analytes are in relatively easy to measure ng/ml amounts the active, and most important, analyte is at 5 - 60 pg/ml making the analysis quite difficult. There tons of other biologically relevant metabolites that have extremely short half-lives due to their importance within biological systems and often they're tightly regulated as in the case of 1,25-dihydorxy Vitamin D3. The newer generation of QToF mass specs like the 6600 QToF, SYNAPT G2-Si, and the microTOF focus II all are pushing the limits of lower detection limit and high sensitivity these days. A co-worker of mine does a lot of lipid profiling and qualitative protein work on an instrument similar to the 6600 and it is stupid mass accurate with low amounts of background. The newer triple quad instruments(QqQs), such as the 6500 Qtrap +, paired with a good LC system can technically get to the fg/ml levels of measure. Since I've bored you guys with mass spec talk a bit let me regale you with a story my 70 year old boss relayed to me. Back in the day he was a GC/MS researcher before he became an LC/MS guy. Always looking for new tech he took up an invitation to the CDC to observe their new Fast Atom Bombardment ionization system for their mass spec. They chummed around drinking coffee for a bit while checking out the machine in operation. To give you an idea the oldest instrument that resembles what he describes is a system that would likely look something like this. Well the boss decides to take a stroll around the instrument to give it a look down. While circling the instrument he stopped at the rear of the instrument to comment on a particular difference between it and another he'd seen when he was interrupted by the host investigator proclaiming, 'I wouldn't stand there if I were you!' To which he quickly shuffled, coffee in hand, out of the way and made an about face to see a wall that had a perfect indention of the back of the instrument. At one point in time they had been using hydrogen, not sure if by choice, necessity, or negligence, as a collision gas and it had ignited one day to send the instrument flying back against the wall. He claimed to be impressed with the instrumentation ability but not so much by the complicated nature of it's problem areas. onemanlan has a new favorite as of 01:49 on May 12, 2016 |
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May 12, 2016 01:43
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Gobbeldygook posted:I don't understand how TCCA and isopropyl alcohol generate chlorine gas. It should oxidize the IPA to acetone, generating HCl and heat. HCls great if you're all congested up.
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May 12, 2016 01:55
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