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May 20

Diamond in a rock tumbler

What if you put a big diamond in a rock tumbler? Anna Frodesiak (talk) 00:55, 20 May 2016 (UTC)[reply]

Define "big". ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:43, 20 May 2016 (UTC)[reply]

Like the size of a grape, but maybe the size wouldn't matter. Anna Frodesiak (talk) 01:46, 20 May 2016 (UTC)[reply]

The size might well matter, as more surface area could take longer to polish. The illustration doesn't have a scale, but some of the types of rocks suggest grape size or larger. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:51, 20 May 2016 (UTC)[reply]

But would it polish or just stay the same forever? Anna Frodesiak (talk) 01:59, 20 May 2016 (UTC)[reply]

If you're using standard polishing materials, it wouldn't polish as the prices relies on being able to scratch and smooth the surface. More likely the diamond would shatter or crack as they are brittle and easily chip along cleavages planes. You buffed with other diamonds, you could cut and polish it. EvergreenFir (talk) Please {{re}} 03:09, 20 May 2016 (UTC)[reply]

Rhenium diboride can be made harder than diamond, so you could polish diamonds with that. However, a polished diamond would just look like a glass marble. It's the facets that make them sparkle, and you get those by cleaving diamonds, not polishing them. StuRat (talk) 03:27, 20 May 2016 (UTC)[reply]

Very interesting. Thank you so much you two. Anna Frodesiak (talk) 05:37, 20 May 2016 (UTC)[reply]

It is a misunderstanding of hardness to assume that because diamond is harder than the other minerals involved, it will not be abraded at all. Diamond tipped drill bits do wear out, and have to be replaced - just not as often as other drill bits. When two minerals of differing hardness rub together, both are abraded - but the softer one is abraded much more quickly than the harder one. 86.141.19.154 (talk) 12:14, 20 May 2016 (UTC)[reply]

As an engineer who has done a lot of work with matterials rubbng and weraing, I can tell you that it is a well-known effect that the intuitive "the softer surface is abraded much more quickly than the harder surface" only hold true when both surfaces are harder than silicon dioxide (a major component of dust and dirt). If you have, say, teflon rubbing against stainless steel, the metal wears out. That's because little bits of dust get embedded in the soft plastic and act like a file to wear down the metal. --Guy Macon (talk) 15:59, 20 May 2016 (UTC)[reply]

Hi User:Anna Frodesiak, interesting question as usual! If you'd like some scientific reference for rock tumbling: Here [1] is a whole study that gives empirical results on how size and shape of particles influence roundness, abrasion, and size reduction in the end product. Then they develop a theoretical model based on that that uses exponential functions to predict/relate how the various factors influence the tumbling process. A very nice little paper, IMO. While you could tumble larger diamonds in diamond dust, you could also tumble raisin-sized diamonds together and they would performs abrading action on themselves. Industrial diamonds are also sometimes prepared using a tumbling mill, see here [2] for a study involving that and a new way to impregnate diamonds in cutting tools. SemanticMantis (talk) 13:35, 20 May 2016 (UTC)[reply]

And thank you again. :) Very informative. Anna Frodesiak (talk) 00:46, 22 May 2016 (UTC)[reply]

It would depend a lot on the quality of your diamond. Diamonds are hard, but they're also somewhat brittle, depending on their crystal structure. A monocrystalline diamond (i.e. "flawless", but also pretty much any natural diamond) is strong. Factory-made diamonds from published technologies are mostly polycrystalline: this makes them prone to splitting between the separate crystals. Diamonds aren't strong because they have magic chemistry, it's because they have simple chemistry with high valence and this allows a densely packed, well-interconnected lattice. Anything (like the discontinuity at the surface of a crystal) that disrupts this lattice loses the quality which makes diamonds what they are.

When buying diamond abrasives, a big cost and quality difference is whether they're mono- or poly- crystalline. For abrasive powders (small grains), it's practical to make monocrystalline diamond powders, but it's cheaper to have shorter-lasting polycrystalline. Smaller crystals are quicker to grow, for one thing. A "lab-grown jewellery diamond" isn't yet practical by any published process, as it would have to be both large and monocrystalline (as is already cheap and widespread for sapphires). Many conspiracy theories exist for De Beers et al. having such a process and keeping it secret.

So "big monocrystalline diamond in a rock tumbler" is something of a thought experiment. "Big polycrystalline diamond" in there is more likely, but also (and some synthetic abrasives are quite hard themselves) it's not going to last as long as you might think. Andy Dingley (talk) 12:14, 22 May 2016 (UTC)[reply]

Dinosaur skeletons

Are most dinosaur skeletons found in pieces and not assembled together? 50.68.118.24 (talk) 04:02, 20 May 2016 (UTC)[reply]

Yes, in fact only a few bones may be found. A fully intact and articulated dinosaur skeleton is a rare find. But, since scientists can put them together in the proper order, and make fake bone to fill in for any missing pieces, it's not a problem. StuRat (talk) 04:11, 20 May 2016 (UTC)[reply]

Of course it's been a problem. See here, for example. Or for a less academic source, here. --69.159.60.83 (talk) 06:38, 20 May 2016 (UTC)[reply]

Leave it to Stu to reduce an entire scientific discipline (shaped over centuries, with many famous debates over validity of reconstructions) to "not a problem." :) SemanticMantis (talk) 13:47, 20 May 2016 (UTC)[reply]

Here [3] is a link to piece from the Smithsonian that describes how scientists attempt to correctly reconstruct dinosaur skeletons from partial finds, and here [4] is another discussion of the topic from Ohio University. Sometimes nearly a whole animal is fossilized, this is called a Lagerstätte. SemanticMantis (talk) 13:56, 20 May 2016 (UTC)[reply]

How do you find a skeleton in the first place? Many bones are found in the bends of ancient rivers etc., where they were washed by the current. This tends to disrupt a skeleton even before they're fossilised. A skeleton is also commonly found when it starts to be exposed by the surrounding rock splitting or weathering out. So the finder may only half of it to work with. Andy Dingley (talk) 12:16, 22 May 2016 (UTC)[reply]

Equal distribution

(moved to math desk here [5] SemanticMantis (talk) 17:50, 20 May 2016 (UTC))[reply]

Capacitor information sought

I have found amongst my components what I think are polystyrene capacitors hermetically sealed in metal cans. The wires come out via glass to metal seals. The only printing on the cans is 'KS'at the top, then the value in pF (confirmed with a capacitance meter) and the voltage then a long number and finally at the bottom what appears to be a date code like 8/88 or 1/89. I have searched the web to find who might have made these units without avail. Can anyone tell me where to search to find details on these units?--178.106.99.31 (talk) 16:58, 20 May 2016 (UTC)[reply]

KS stands for Polystyrene Film/Foil capacitor. It doesn't seem to have anything to do with the manufacturer. --Jayron 32 17:38, 20 May 2016 (UTC)[reply]

May I ask why the OP wants to know. If he is a radio-ham or old wireless repairer and thinks he may be able to use them, then all that is required is pF and the voltage rating. Being polystyrene they are not electrolytic nor tantalum or anything else but ones exhibiting polystyrene caricaturistics. I think 8/88 is more likely the batch code. These low value pF capacitors in metal cans with glass to metal seals became obsolete many years before 1988. Cut one open, is it really polystyrene or waxed/varnished paper? A photo may help to identify the manufacture and locate the data sheets. But it would help to know why.--Aspro (talk) 21:03, 20 May 2016 (UTC)[reply]

I dont have a specific application in mind. Just thought if they were stable capacitors I may be able to use them as references or something. But Im curious as to why these should be sealed in cans. Is it something to do with preventing moisture ingress?--178.106.99.31 (talk) 16:14, 21 May 2016 (UTC)[reply]

Staphylea colchica flowers

(I'm posting this here rather than at Talk:Staphylea colchica because I suspect that will not get seen). The article currently says "orange flowers"; but the illustration (like the example I saw this week at Nostell Priory) has white flowers. I notice that the external reference (for which I have just found and added an archived link) also shows white flowers, and has the text "Orange blossom fragrant flowers". This is a strange way of saying "orange flowers", and my hypothesis is that it means "flowers with the fragrance of orange blossom". Anybody got any thoughts (or knowledge!) on this? --ColinFine (talk) 21:18, 20 May 2016 (UTC)[reply]

I think you're right. I think the flowers smell either like orange flowers or maybe have a citrus scent. Dave's garden [6] says "white or near white" while the eminently reliable Missouri Botanical Garden says "greenish white" [7] and also describes the flower as fragrant. I felt WP:BOLD and removed the confusing "orange" bit from the article, as I cannot even find evidence of an orange-blooming variant. SemanticMantis (talk) 21:27, 20 May 2016 (UTC)[reply]

Are both soft and hard brake checks dangerous?

Could safety be improved by a soft brake check? After all, this could get a tailgating car off your tail. --Llaanngg (talk) 23:28, 20 May 2016 (UTC)[reply]

Maybe?^{[citation needed]} It might also start a positive feedback loop of braking that suddenly slows traffic (traffic congestion#Causes) or causes a 13-car crash. The butterfly effect-like mechanics is very complicated. Sagittarian Milky Way (talk) 00:16, 21 May 2016 (UTC)[reply]

This article seems relevant to your question. --Jayron 32 00:17, 21 May 2016 (UTC)[reply]

As a safer alternative to actually touching your brake pedal (which might slow you enough to cause the tailgater to hit you), you might consider just switching your rear fog lights on and off. This might momentarily cause the tailgater to think you're braking, and if the tailgating is not deliberate, this might alert them to the fact that they're too close.

However, if it is deliberate, you might just provoke them, and someone who is deliberately tailgating is not the clearest thinker to start with. The advice in Jayron's link is good.

For interest, I personally know of instances of the tailgater being a local police car apparently hoping to provoke the victim (a local publican) into exceeding the speed limit or "driving in an unsafe manner" (which brake-testing would be), presumably so that they could stop and charge or at least inconvenience him. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:37, 23 May 2016 (UTC)[reply]

May 21

What form can "HCO" can have?

49.135.2.215 (talk) 01:01, 21 May 2016 (UTC)Like sushi[reply]

What context? What do you mean by HCO? --Jayron 32 01:03, 21 May 2016 (UTC)[reply]

Assuming it's a chemical formula, HCO doesn't exist. H₂CO is formaldehyde. See HCO (disambiguation) for other possible meanings. Tevildo (talk) 12:22, 21 May 2016 (UTC)[reply]

There is no stable molecular or ionic configuration of one hydrogen, one carbon and one oxygen atom. Roger (Dodger67) (talk) 15:17, 21 May 2016 (UTC)[reply]

HCO (the formyl radical) and HCO⁺ have both been detected in the interstellar medium. --Wrongfilter (talk) 19:02, 21 May 2016 (UTC)[reply]

Do you have a reference for this? It would be a useful addition to our Aldehyde article. Tevildo (talk) 23:14, 21 May 2016 (UTC)[reply]

Not at all my field of expertise, but here is a random one (HCO mapping of the horsehead nebula). A long list with "HCO" in the title can be obtained like this. --Wrongfilter (talk) 17:32, 22 May 2016 (UTC)[reply]

The formyl radical and isoformyl are noted in list of interstellar and circumstellar molecules. Formyl redirects to aldehyde. Sagittarian Milky Way (talk) 19:49, 22 May 2016 (UTC)[reply]

Hydrogen inbetween Lithium films? Helium inbetween carbon films? Spherical spaces in carbon, silicon, or "sulfer glass"?

(I would not surely be back)

49.135.2.215 (talk) 01:31, 21 May 2016 (UTC)Like sushi[reply]

You've been back several times despite promises to never return. Since you keep coming back, can you elaborate on your questions. Your questions are hard to understand because you rarely explain exactly what you are looking for. --Jayron 32 03:29, 21 May 2016 (UTC)[reply]

I'd say these questions are difficult to understand because they have no verbs? He could well mean: "<injecting> Hydrogen inbetween <to make> Lithium <thin> films".--Llaanngg (talk) 20:49, 21 May 2016 (UTC)[reply]

500 tons of TNT

In this YouTube video (which is likely from the Discovery Channel or the History Channel), the narrator says that 500 tons of TNT is capable of leveling a "small city". I'm having trouble imagining a non-nuclear weapon that could destroy a city. Is that accurate? — Melab±1 ☎ 02:44, 21 May 2016 (UTC)[reply]

The Wikipedia article titled TNT equivalent may help you in you research. It is worth noting that energy is energy; nuclear bombs are not magic destruction spells. The Hiroshima bomb was only about 30x as powerful as that (15000 tons of TNT), and it was leveled; Hiroshima is a fairly large city. It would of course depend on how you define a "small city". The Halifax explosion was 6x the size of that, was amazingly destructive, it destroyed everything in a 2.6 km radius. --Jayron 32 03:27, 21 May 2016 (UTC)[reply]

See also Largest artificial non-nuclear explosions, which has a list of large explosions, and gives the destruction caused by some. Note that air bursts tend to be more destructive that ground-level blasts. LongHairedFop (talk) 09:32, 21 May 2016 (UTC)[reply]

(Fixed your link.) --69.159.60.83 (talk) 09:43, 21 May 2016 (UTC)[reply]

(Fixed your link.) too. --Llaanngg (talk) 14:52, 21 May 2016 (UTC)[reply]

Not only do you have to define "small city", you have to define "destroy". Would it turn a small city into a crater? No, not unless your city is like, one building. Could it render every building uninhabitable? Maybe. From playing with various blast-radius calculators on the internet, it seems like a 500 ton air burst could theoretically damage every structure in a half a kilometer radius. There are "cities" smaller than that, though they may be cities in name only. Someguy1221 (talk) 10:52, 21 May 2016 (UTC)[reply]

Also, it depends very much on how you distribute the TNT. A lot of small explosions will be a lot more destructive than one big explosion. I've tried to google how much explosives are used to demolish a skyscraper, but most hits lead to 9/11 truther sites. But the original WW2 blockbuster bombs weighed 4000lbs, about 3000lbs or 1.35 tons of which where explosives. These were supposed to be enough to to level one city block. --Stephan Schulz (talk) 17:35, 21 May 2016 (UTC)[reply]

Agreed. You also want to avoid explosions in open air, where the force mostly dissipates into compressing and heating the air. Yes, with enough force, like a nuclear weapon, it can still be massively destructive when this is taken into effect. Of note is that destroying some types of bridges from aerial bombing is extraordinarily difficult because of how the force of the explosions mostly dissipates in air. On the other hand, a demolition team can easily bring the bridge down with far fewer explosives, say by drilling holes in the supports and placing charges there. StuRat (talk) 18:30, 21 May 2016 (UTC)[reply]

Our Building implosion article is pretty thin on cites and has no information on how much explosive is used for modern techniques. DMacks (talk) 19:16, 21 May 2016 (UTC)[reply]

People who do explosive demolition for a living pride themselves on how little explosive they can use. They find the key structural members, sever those with carefully shaped and placed charges, and then let gravity do the rest. Inexperienced demolitionists who use lots of explosives to just "blow it up" are derisively referred to by their more-sophisticated peers as having "launched the building".

My point is that if you want to figure out how much damage a single randomly-placed bomb is going to do, you're not going to learn much of anything by comparing to multiple carefully-placed demolition charges. —Steve Summit (talk) 11:23, 22 May 2016 (UTC)[reply]

Sometimes a little too little [8]. P.S. To be clear this is a joke, I have no idea of the actually reason. Nil Einne (talk) 20:18, 22 May 2016 (UTC)[reply]

Wow! Leveling cities! That's heavy stuff. It can be pretty hard to imagine, if you've never seen it. I happened to have been reading about clearing terrain this week, so I have a few thoughts and can share some of my reading material.

In actual fact, it's much easier and cheaper to level a city with thousands of tiny deployments of explosive than to use one giant blast. Quoting this reference that I regrettably drag out of my archive once again... if your enemy wanted to obliterate and level your city, "...the first thing that's going to hit you is the Soviet artillery, and that artillery is going to come into your area at about 1,200 rounds per square kilometer in the first forty-five minutes." (U.S. Army General Sunell, on his Experience and Visions...)

Here's what a tiny barrage - little itty-bitty- man-portable mortars - did to a formerly very-nice building in Golan Heights. They save the big guns for further targets. Have you ever seen a whole city after an artillery shelling? Here's the August 1982 cover of Time Magazine. Post-artillery-barrage cities look remarkably unlike civilization. Decades later, you could find leveled buildings on every street in the city. But for a real taste of the terrifying power of artillery, read about the Battle of Berlin. Two weeks of Soviet shelling - with conventional munitions - are estimated to have killed more people than the atomic bombing at Hiroshima - even if we count deaths due to adverse health effects of nuclear radiation. Nuclear war is bad and its destruction can be devastating, but conventional weapons of war make devastation and destruction cheap and easy. That might actually be a worse problem.

Last week, while reading about parachute drop zones, I came across Field Manual 5-164 Tactical Land Clearing (an obsoleted manual available from Archive.org). It contains, in chapter 4, both qualitative and quantitative discussions of land clearing operations for engineers employing large munitions (e.g. an M121 T56E4 10,000 pound munition). That munition - about 5 tons of high explosive - seems to level all vegetation within a five meter radius, and clears some vegetation within a 25 meter radius. While nearly instantaneous, this method of land clearing is difficult, dangerous, and expensive; and it usually requires follow-up operations by a bunch of combat engineers armed with chainsaws.

The point is, there are lots of ways to level terrain, using conventional methods.

The manual also contains some photographs - mostly of combat engineering operations in Army test facilities - but if you go searching around, you can find other spectacular, awe-inspiring, and terrifying photographs of wartime combat engineering operations. When it comes to levelling terrain, there are none better at it than the construction battalions - the combat engineers whose irregular unit evolved in to what we now call Navy SEALs.

At one point in history, the United States evaluated using nuclear explosions for such construction purposes, too. Notably, we created the Sedan crater in Nevada; and there was a serious investigation into creating an artificial harbor for Alaska's North Slope oilfields. You can take a look at photos and diagrams of those experiments to see how they would have worked.

Generally, at this time, most informed people concur that we ought not use nuclear detonation at all.

At least one very well-informed individual who knew a little about the topic also seemed to think we all ought to use less conventional detonation, too.

Nimur (talk) 19:40, 21 May 2016 (UTC)[reply]

Does a pin get blunter without being used?

Imagine a perfectly sharp steel pin, never having been used, put inside a vacuum sealed container, and that container being surrounded by a metre of lead and then a 3 metres of bronze, and the whole kept at a low temperature. If a million years were to pass, would that needle be as sharp as the day it was put away? How about a billion years? I am thinking about the possibility of random quantum effects gradually making the point less sharp. Would a higher temperature make the process of blunting the needle faster? Given enough time, say quadrillions of years, would the needle become a shapeless mass, even though no force other than quantum effects came into play. Myles325a (talk) 07:06, 21 May 2016 (UTC)[reply]

Theoretically in 10⁶⁵ years, all solid matter will have been rearranged into spheres through quantum effects. See Timeline of the far future for some more bizarre but plausible predictions about what might happen. Someguy1221 (talk) 11:00, 21 May 2016 (UTC)[reply]

I'm just wondering who's going to pay the electric bill to run the refrigerator during those quadrillion years. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:08, 21 May 2016 (UTC)[reply]

Interplanetary space is quite cold. No bills ones placed in the correct position. Bytesock (talk) 20:12, 22 May 2016 (UTC)[reply]

Yes, "solid" molecules move around all on their own, but rather slowly. Cold welding#Nanoscale may be of interest. So, if two pins were in contact, they would weld together (just on the nano scale, at first, then on the macro scale, as time goes by). And yes, I do expect heat to speed up the process. Even at absolute zero, though, there's still radioactivity within the pin itself (such as from carbon-14), to provide the energy, and your precautions won't keep neutrinos out. StuRat (talk) 18:11, 21 May 2016 (UTC)[reply]

A "pin" will be unchanged by anything less than rusting or other bulk chemical processes. They're just not that sharp, to this sort of scale.

Back in the '70s (maybe 1955 from the WP article, but that's news to me) the first imaging at the atomic level was done by a field ion microscope. This uses an incredibly sharp point (neat piles of individual atoms). Now for that, a per-atom change could be said to blunt the tip. Even then though, what's causing it? Metal atoms are bound into the lattice by fairly strong forces. Quantum effects bend these bonds (and we now make use of such effects every day) and change their energy, but they don't break the bonds or free atoms. It's the difference between twanging a spring and snapping it.

It's all probabilistic, of course, so these effects can shift an atom, but rarely. Yet you're asking two things here: to have a rare event happen, and to have it happen to one of a small number of specific atoms (there are only a few atoms on your pinpoint). The ratio between those chances involves Avogadro's number: 6×10^23. The chances are so vanishingly small that this is thus unlikely: also a million or a billion years isn't that long. It is more likely (at these scales) for such an event to happen to "an atom on the surface of a macroscopic pin" (there are more than billions of these) than it is to happen to one of a small number of atoms on the pinpoint in the billion years. Andy Dingley (talk) 09:49, 22 May 2016 (UTC)[reply]

If this is accurate at room temperature (a big if), then the equilibrium vapor pressure of iron at room temperature (300 K) is about 1 atom per cubic meter. At that level, we expect about ~3 atoms to evaporate off of your pin per square meter per hour. If you continue to pull a vacuum, such atoms will be removed. If not, then they will tend to be deposited somewhere randomly within the chamber. If we assume your pin is 1 mm wide and 3 cm long, then it would have a surface area of about 1×10⁻⁴m² and a mass of about 0.2 grams (~2×10²¹ atoms). So, we would expect the whole pin to evaporate at room temperature after roughly 8×10²⁰ years. That's a fantastically long time (800,000 quadrillion years), but over time such things ought to happen if you can keep the experiment running and nothing else interferes. Dragons flight (talk) 11:16, 22 May 2016 (UTC)[reply]

How do you know the rate of evaporation? ie 3 atoms/m²/hour. Bytesock (talk) 20:13, 22 May 2016 (UTC)[reply]

The rate of evaporation in a vacuum is

\approx {P_{eq} \over {\sqrt {2\pi \,m\,k\,T)}}}

, where P_eq is the equilibrium partial pressure, m is the atomic mass, k is Boltzmann's constant, and T is the temperature. Dragons flight (talk) 20:20, 22 May 2016 (UTC)[reply]

Unit? N/(m^2.5*J^0.5) ? Bytesock (talk) 20:47, 22 May 2016 (UTC)[reply]

[Pa] / sqrt( [kg] [J] ) = ([kg] / [m] / [s]^2) / sqrt( [kg]^2 [m]^2 [s]^2] ) = 1 / [m]^2 / [s], which is implicitly atoms evaporated per m^2 per second. Dragons flight (talk) 21:17, 22 May 2016 (UTC)[reply]

'Hybrid' cells

What are these rechargeable 'hybrid' cell batteries they are selling noe in Maplin? Are they NiMH or alkaline or what? Searching the web does not find refs to 'hybrid' cells.--178.106.99.31 (talk) 17:27, 21 May 2016 (UTC)[reply]

You can read here. Ruslik_Zero 18:03, 21 May 2016 (UTC)[reply]

Residual radioactivity after detonating a nuclear bomb

Couldn't a "no waste" nuclear bomb exist, which consumes all the fuel being used? --Llaanngg (talk) 21:28, 21 May 2016 (UTC)[reply]

It's too complicated to answer here, but some pointers:

This has been a goal since the 1950s. The key factor is to make the physics package work by nuclear fusion of hydrogen, rather than fission of plutonium. As is well-known, the H bomb is a couple of orders of magnitude more powerful than an A bomb, but it's also cleaner and (once designed) easier to make. In particular, it reduces the need to enrich uranium or to operate reactors to make plutonium. Fusion requires tritium, which also requires a reactor, but the bulk of it can be the rather simpler to produce lithium deuteride.

A second factor is to detonate a weapon as an air burst, rather than a ground burst. Much of the fallout produced by the blast is due to the irradiation of material from the ground and spreading this as a dust cloud. Andy Dingley (talk) 22:53, 21 May 2016 (UTC)[reply]

I'm slightly puzzled by the wording of your question. Are you asking "residual radioactivity" or "all fuel consumed"? "Fallout", as a general environmental problem, is created by the irradiation of ground material during the explosion, not by left-overs from a bomb's already radioactive fuel. They're a tiny fraction of what's produced.

For some exceptional designs, the cobalt bomb, or the "dirty bomb" form of the B41 Y1, the irradiation of a final fission stage would also produce considerable fallout (from the products of irradiation, not from the original fuel itself). These are unlikely to have ever been considered for use though, even by the Dr Strangeloves of RAND. Andy Dingley (talk) 09:52, 22 May 2016 (UTC)[reply]

In a word no (the gadget blows itself apart well before all the fuel is consumed) and the radiation will create other stuff like Cobalt-60 in ferrous metals. Also, the workings of high efficiency nuclear devices are still classified. So you will not get an answer here in case Kim Jong-un's scientists are reading this Ref Desk.--Aspro (talk) 23:00, 21 May 2016 (UTC)[reply]

Also, a hydrogen bomb using a regular old dirty atomic bomb to set it off will have that as a source or radioactivity. But, if you could manage to set one off without that, and did so out in space so there was nothing around to transmute into radioactive elements, it should be pretty clean then, yes. StuRat (talk) 00:21, 22 May 2016 (UTC)[reply]

left over radiation from an air burst is almost a completely non-issue/non-existent..68.48.241.158 (talk) 01:15, 22 May 2016 (UTC)[reply]

I don't think anyone has linked to neutron bomb. μηδείς (talk) 03:16, 24 May 2016 (UTC)[reply]

I don't see why it's that relevant; a neutron bomb is intended to produce more ionizing radiation than a "conventional" nuclear weapon. --71.110.8.102 (talk) 09:22, 24 May 2016 (UTC)[reply]

May 22

Standard for CR123A batteries

Is there a standard, from any of ISO/DIN/ANSI/JIS, for CR123A batteries? I googled "CR123A battery datasheet" but only manufacturer's own specification turned out, and annoyingly enough they're all slightly different from one another. Is there standard, international or otherwise, that governs the physical dimensions of CR123A batteries? Johnson&Johnson&Son (talk) 13:02, 22 May 2016 (UTC)[reply]

The IEC standard is CR17345, and the ANSI standard is 5018LC. See, for example, this datasheet and this forum thread. Tevildo (talk) 14:51, 22 May 2016 (UTC)[reply]

And, indeed, our article, linked to in the original post. Tevildo (talk) 14:52, 22 May 2016 (UTC)[reply]

Where are they (* *) linked in the List of battery sizes article? Bytesock (talk) 20:59, 22 May 2016 (UTC)[reply]

Most tables on that page include the IEC and ANSI designations, and the "External Links" section contains links to the various datasheets. Feel free to add an explicit link to the CR123A entry if you think it would improve the article. Tevildo (talk) 21:57, 22 May 2016 (UTC)[reply]

Thanks a lot, Tevildo!

Does anyone know where I can find either IEC CR17345 or ANSI 5018LC on the internet? Johnson&Johnson&Son (talk) 03:26, 23 May 2016 (UTC)[reply]

Not legally, I'm afraid. You can buy the IEC standard from their site, here, and the ANSI standard from their site, here, but the prices are positively extortionate. Tevildo (talk) 07:30, 23 May 2016 (UTC)[reply]

You could try looking for the 'final draft' of either standard. They normally the same as the published standard (although possibly a few minor wording differences), kept available even after the final standard is published, and most importantly, they are free. However, if you need to meet the exact standard, buy it. If it's only for your own elucidation, then feel free to find it. LongHairedFop (talk) 19:00, 23 May 2016 (UTC)[reply]

Non-question FYI for archaic medical terms

Just wanted to share with the reference desk that I stumbled onto the fact that the website known as Rudy's List of Archaic Medical Terms which is located at www.antiquusmorbus.com has changed its URL to www.archaicmedicalterms.com. The old URL apparently still works (for now?) but the webmaster states that no new information will be added to that version of the list. Koala Tea Of Mercy (KTOM's Articulations & Invigilations) 15:34, 22 May 2016 (UTC)[reply]

Apparently by sheer chance you're managed to hit the exact person that would find that information useful. Well done and thank you. I will update the page. Matt Deres (talk) 21:09, 22 May 2016 (UTC)[reply]

I have added to the article "Medical terminology" a link to that new website.

—Wavelength (talk) 21:16, 22 May 2016 (UTC)[reply]

It's a sad thing when someone who calls himself a "webmaster" doesn't know how to create A 301 redirect... :( --Guy Macon (talk) 22:13, 22 May 2016 (UTC)[reply]

Would not consider it a particularly reliable source based on my perusal. Interesting list but largely unreferenced, not a MEDRS. — soupvector (talk) 02:12, 23 May 2016 (UTC)[reply]

Indeed, which is why I only used it as an external link for further reading; it's an excellent starting point. Matt Deres (talk) 03:32, 23 May 2016 (UTC)[reply]

Fully agree - and I do find it interesting. I did not mean to sound argumentative. — soupvector (talk) 13:04, 23 May 2016 (UTC)[reply]

For those wanting to help clean up, list of all WP pages linking to *.antiquusmorbus.com. DMacks (talk) 03:43, 23 May 2016 (UTC)[reply]

Etymology of sphygmomanometer

Duplicate question deleted (and existing answer moved). Please post questions to only one desk. --69.159.60.83 (talk) 22:18, 22 May 2016 (UTC)[reply]

Whats the limit?

If it was possible (as has recently been reported) to induce multiple successive orgasms in a man, how many orgasms could he take before losing conciousness or dying in the act(s)? --178.106.99.31 (talk) 22:26, 22 May 2016 (UTC)[reply]

This sounds like a variation on an old traveling salesman joke concerning a milk machine. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:35, 22 May 2016 (UTC)[reply]

No. You are thinking of the man who broke into a milking parlour and decided to try out one of the machines. After a while, hearing screams of agony, the farmer appeared and reassured the man that the machine would switch off automatically when the container was full. Anyway, thats not the Q.--178.106.99.31 (talk) 23:00, 22 May 2016 (UTC)[reply]

I don't know about humans (have you tried this experiment yourself?) but I recall a story from ca. 2000 about a male guinea pig that got into a pen with 24 females, got it on with all of them, and then slept for two days.[9] ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:50, 22 May 2016 (UTC)[reply]

We do have an article on the Venus 2000, incidentally, and doubtless other products with the same functionality are available. Tevildo (talk) 07:32, 23 May 2016 (UTC)[reply]

Refractory period (sex) is the relevant article. Why would you expect loss of consciousness or death? I don't think there's some fixed number of orgasms per period of time that one can have. Obviously you could eventually experience exhaustion, but there's no significant difference to exhaustion from other physical activity, and with the wide variation in individuals' physical fitness, genetics, etc. you can't really put a fixed number on it. As the article says, there's debate over whether women have something that can be considered a refractory period, but women don't seem to be keeling over from too many orgasms at once. --71.110.8.102 (talk) 03:39, 23 May 2016 (UTC)[reply]

According to the nun teaching health at Paul VI HS in the 1980's, men can only orgasm once a day. I hope I have not been misinformed. μηδείς (talk) 02:57, 24 May 2016 (UTC)[reply]
I'm pretty sure that's the recommended minimum, not maximum. these statements have not been verified by a medical professional. I'm not a doctor, but I play one on TV. --Jayron 32 02:59, 24 May 2016 (UTC)[reply]

Cygnus CRS OA-6 return

What is the status of the Cygnus CRS OA-6 resupply mission to the International Space Station? Our article gives a planned unberthing date of May 20 (a couple of days ago), but I haven't heard news either of it happening or of it being delayed. Orbital ATK's mission page for that mission was last updated back on March 26 when the Cygnus was grappled and berthed. -- ToE 23:27, 22 May 2016 (UTC)[reply]

With a name like that, it may have fallen into a black hole. :-) StuRat (talk) 23:45, 22 May 2016 (UTC) [reply]

This shows a scheduled mid-June departure for a Cygnus. I think they only dock one at a time. Rmhermen (talk) 00:23, 23 May 2016 (UTC)[reply]

Thanks. That was exactly the sort of reference I was looking for. I'd started looking in the very informative NSF forums, which includes lots of info from industry insiders and watchers, but I was looking at the Atlas OA-6 launch thread, not the RNDZ, Berthing and ISS mission thread I should have been looking at. Now that I found it, I see they are saying 14 June, but it's not referenced sufficiently for our purposes. -- ToE 03:47, 23 May 2016 (UTC)[reply]

And here is the NASA source for that spaceref article. -- ToE 09:22, 23 May 2016 (UTC)[reply]

May 24

Cellulite in other species

Is cellulite present in species other than humans? Munci (talk) 02:48, 24 May 2016 (UTC)[reply]

[10] is all I can find. --Jayron 32 02:53, 24 May 2016 (UTC)[reply]

Humans have rather thin skin, little or no fur, often live past the fertility age, and don't always exercise to stay fit (don't rely on running away from predators and/or chasing prey). All these factors combined make cellulite more apparent. --Dr Dima (talk) 16:47, 24 May 2016 (UTC)[reply]

Elephant skulls

Imagine an expert who had never seen or heard of an elephant before. To what extent could this expert deduce the presence of the elephant's trunk just by looking at the skull? Presumably, there would be some evidence in terms of attachment points for muscles that wouldn't make sense without a trunk. But could an expert tell much about what type of non-bone-containing appendage had been present in the living animal? And are there any fossils of large extinct animals (megafauna, dinosaurs, etc.) for which experts can predict large appendages that have no remaining fossilized parts like an elephant's trunk? Edgeweyes (talk) 17:54, 24 May 2016 (UTC)[reply]

An interesting question. Perhaps research on the history of the discovery and description of mammoths might help. I believe some have been found in very good condition (not fossilised) in ice (confirming the trunk), but were fossilised forms found before that, and if so, what did the scientists at the time think? DrChrissy ^(talk) 18:02, 24 May 2016 (UTC)[reply]

Their similarity to modern elephants would suggest that they also had a trunk. StuRat (talk) 18:05, 24 May 2016 (UTC)[reply]

Concorde's yellowish exhaust

On this and other videos Concorde's exhaust jets are yellowish or of mud color. I haven't seen such tinted exhaust gases on other modern aircraft like Airbus or Boeing. Why is that?--93.174.25.12 (talk) 18:17, 24 May 2016 (UTC)[reply]