Wikipedia:Reference desk/Archives/Science/2014 July 11

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July 11

Chocolate caramel makes the eye(s) water

Certain foods cause minor irritation in the throat and make the eyes water. Hot, spicy foods are the main culprits, but one that always surprises me is caramel, particularly a chocolate variety. Why does it do this? Caramel tends to affect only the left side of my throat and my left eye, although I have experienced it on both sides. -- Jack of Oz ^{[pleasantries]} 00:14, 11 July 2014 (UTC)

Maybe an allergy? Have you asked your doctor about this? ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:56, 11 July 2014 (UTC)

Some chocolate says "processed with alkali", which sounds rather caustic. Presumably most of it is removed in the final product, but even a hint of it might cause eye irritation. StuRat (talk) 13:25, 11 July 2014 (UTC)

I've had similar experiences with some chocolates, caramels, fudges, etc. My hypothesis is that it's primarily due to the amount of sugar. Sugar is very hygroscopic, so it probably irritates the throat by drying it out - and sugar tends to be present in large amounts in such confections. Many other candies, such as jelly beans, are also high in sugar, but there it is contained or mixed with gelatin or other material. Matt Deres (talk) 14:07, 11 July 2014 (UTC)

Isn't sugar typically contained within the chocolate, too ? I suppose chocolates could be dusted with confectioner's sugar, as donuts often are, but I haven't come across any like that. The closest I've seen is chocolates coated with nonpareils, which still have a shell covering the sugar. StuRat (talk) 19:41, 11 July 2014 (UTC)

Yes, which is why you don't get it all the time. For example, I don't think I've experienced it while munching down on chocolate Easter bunnies - too much milkiness to the chocolate. I'm thinking more like bitter chocolates. In fudges and caramels, the sugar is much more available. Matt Deres (talk) 21:38, 11 July 2014 (UTC)

But bitter chocolates have even less sugar. StuRat (talk) 13:58, 12 July 2014 (UTC)

Jack, you are almost certainly experiencing a mild form of reflux; chocolate is especially efficient at triggering such reactions in that it operates to allow stomach contents into the esophagus through multiple mechanisms -- the seratonin, caffeine, and theobromine in the chocolate all cause the lower esophageal valve to loosen; the fat content common to most chocolates causes increased volume in the top of the stomach and thus increased pressure upward against said sphincter (and ultimately into the esophagus) and; depending on the type of chocolate, it can alter the pH of the stomach contents and/or throat and cause saliva to be lost via phlegm from the esophageal lining where it usually serves as a last mitigating factor against reflux. Snow talk 22:43, 11 July 2014 (UTC)

That sounds like the answer, and explains why maybe only one side of the throat is affected. Does it also explain why typically only one eye waters? -- Jack of Oz ^{[pleasantries]} 22:55, 11 July 2014 (UTC)

Now that I'm at a loss to explain. One eye watering isn't so atypical of course -- that's not such an uncommon stimulus response, but to have the sensation be detectable on only one side of the throat is a bit more peculiar as reflux usually spreads the love around. Have you had previous GERD-like symptoms. Because it is entirely possible for chronic reflux to damage the inner lining of the esophagus, but in the vast majority of cases the person experiencing that process is well aware of it. The esophagus does conjoin with the stomach a little right of center, which is why those with GERD are urged to sleep on their left side so that the stomach contents are more likely to lay lower than point at which the lower esophageal valve separates the stomach from the esophagus, but I've never before heard of the difference in physiology having much significance to symptoms when standing. It's possible that the very minimal angle at which the base of the lower esophagus bends could account for one side getting bathed in more reflux in the case of a very mild reaction, but if this is a case of reflux, my first inclination would be to find a way to explain the difference in terms of perception rather than a significant difference of the fluid mechanics of the bile. A swallow study or some endoscopy might shed some light, but those strike me as excessive responses to having a scratchy throat when eating chocolate. :) Snow talk 03:43, 12 July 2014 (UTC)

The only possible symptom of GERD that rings true with me is a chronic cough, but I'm having that checked out as we speak. This is now getting too close to medical advice, so we'd better call a halt. Thanks. -- Jack of Oz ^{[pleasantries]} 09:52, 13 July 2014 (UTC)

Cl₂O₅

Why isnt Cl₂O₅ reported? Even Cl2O7 exists! Cl2O7 has an extra O(each side), it'll pull the electrons of Cl and make the Cl-O-Cl bond more unstable, doesnt it? --WhitePhosphorus (talk) 13:45, 11 July 2014 (UTC)

You may as well ask why unicorns and fairies don't exist. Things which don't exist don't have to have whys. If you think it should exist because of some reason, perhaps it is your own understanding that is faulty rather than the laws of the universe... --Jayron32 13:54, 11 July 2014 (UTC)

Wikipedia has a behavioral guideline called WP:DONTBITE as well as articles about Unicorn and Fairy. 84.209.89.214 (talk) 15:59, 11 July 2014 (UTC)

And also that logic doesn't apply to chemistry, where if something obviously should exist, then, if it doesn't, we need to revise the laws of chemistry to explain why. For example, the periodic table was initially full of missing elements, but they were filled in later as those elements were discovered. If one simply could never be discovered or created, then we would need to explain why. StuRat (talk) 19:49, 11 July 2014 (UTC)

It does in all likelihood exist, but since it hasn't been reported yet, one can surmise that it is not energetically stable, and would thus only exist at cryogenic temperatures. Perhaps it undergoes disproportionation. Plasmic Physics (talk) 14:14, 11 July 2014 (UTC)

Cl₂O₅, having a structure of "O₂Cl–O–ClO₂", analogous to the "O₃Cl–O–ClO₃" structure of Cl₂O₇ identified in its article, is known in the literature (as well as two other structural isomers!), just nobody has written a wikipedia article on them. But none seems particularly notable (only a total of a half-dozen or so journal references, all appear to be theoretical calculations and/or discussions of reactive intermediates, so it's likely that a viable article might not even be possible.

You have a good intuition about one possible stability detail of the molecular structures. However, the parent acids of these anhydrides don't seem to follow your pattern either. Perchlorate used to be popular as a non-reactive anion, even though it and perchloric acid do have lots of known reactions. Compare to chlorate and chloric acid, which are even less stable. Perchlorate#Chemical properties talks about some of these trends and reasons for them. DMacks (talk) 14:17, 11 July 2014 (UTC)

Note that Cl2O5 is in fact the anhydride of chloric acid, and Cl2O7 that of perchloric acid -- so in fact they do follow the stability pattern of their parent acids. 24.5.122.13 (talk) 19:34, 11 July 2014 (UTC)

See Italian wiki [1]. I cannot translate but maybe Google can or an italian speaking English Wikipedian. The model exists on commons. --DHeyward (talk) 07:12, 12 July 2014 (UTC)

Google translation is pretty accurate as far as meaning compared to the literature refs I can find: it's easy to see various details about its structure, it's highly unstable, it probably hasn't actually been made in the lab. Looks like we do have a fairly canonical set of diagram types at commons:Category:Dichlorine pentoxide. DMacks (talk) 18:26, 12 July 2014 (UTC)

What will been a more technically implex?

What will been a more technically implex electrification or telephonisation? In the USSR always been think that electrification always been a more technically implex.--Alex Sazonov (talk) 17:18, 11 July 2014 (UTC)

("implex" is a weird word choice! I had to look it up...it means "intricate, involved, entangled, complicated, complex")

Anyway...one thing we know is that, regardless of complexity/implexity/whatever - in the USA, the telephone initially gained users faster than electricity - but was soon overtaken by it. It took from about 1900 to around 1960(!) for close to 100% of US homes to have electricity - but the telephone took about 70 years and only ever reached around 95% of US homes. (See, for example this useful graphic).

However, that probably speaks more to the desire of the general public to have such technology than to the complexity of installing it.

In the case of plain-old-telephone-service ("POTS"), the biggest issue is in stringing physical copper wires from some central place to the end user's home/business...and it's pretty much the same deal with electricity.

However, for cellular phones, it's much easier. You only have to put up a cell tower every couple of miles - which is vastly cheaper and easier than digging up streets or putting up poles outside every single home...and the adoption rate curve shows that cellular phones went from zero to 95% in ten years...seven times faster than wired phones.

But, again, "complexity" is a hard thing to measure. If your electricity is coming from a mix of renewable sources like wind, tide and solar, with nuclear power providing the "backup"...then it's going to be a horrendously complex process to get it all together. But if you decided to put a small diesel generator outside everyone's houses - then it's easy...just mass-produce generators with easy technology - and you're done!

It's not easy to answer your question clearly. SteveBaker (talk) 18:17, 11 July 2014 (UTC)

the problem with POTS isn't copper wires, per se. (italics mine): "The old systems required big bureaucracies that were reasonably honest and efficient, which many countries, including some Western European ones, couldn't reliably manage. But you can have working cell phone networks in places as anarchic as 1990s Somalia. My guess would be that technology will continue to evolve toward plug and play solutions that will work even in dysfunctional cultures (...)" (source)

"The introduction of cell phones over the last 30 years has been a godsend for low trust cultures . They simply don't require the organizational coordination of the old landline technology. (...) A typical Somali cell phone company would have 500 regular employees (salesmen, technicians, and managers) plus its own private army of 300 AK-47 wielding warriors. Now, that's a lot of overhead, but it's a price Somalis were willing to pay for cellphone service. So a prediction from the past about the economic future of telephone industry in Somalia would have gone askew because it pays to develop new technological workarounds for regional deficiencies." (source) Asmrulz (talk) 09:19, 12 July 2014 (UTC)

Also note that many homes had gas before electricity, and gas pretty much provides identical capabilities for lighting and heating, which were the early applications of home electricity. So, that would reduce demand, at least until other applications for electricity were found, like air conditioning/refrigeration. Telephones, on the other hand, really had no substitute. Telegraph messages would be the closest thing, but they weren't immediate and two-way, so having a conversation by telegraph would take a very long time, something like an email conversation today. StuRat (talk) 19:58, 11 July 2014 (UTC)

Is a mortar a type of rocket?

Is a mortar a type of rocket, even loosely or colloquially speaking? I thought that rockets were propelled by burning propellant exiting the rear of the projectile, while mortars gained all their velocity from an explosion at the bottom of a closed tube, and just coasted after they exited the muzzle. In Palestinian rocket attacks on Israel and a number of subsidiary articles, "mortar" is listed as a type of rocket in the infobox: "Rocket types: Mortar Qassam Al-Quds Katyusha Grad Fajr-5. " Does anyone use mortar shells which are propelled in part by the exhaust gasses from propellant burning in the mortar shell. like an RPG or bazooka? Otherwise wouldn't a pistol or rifle bullet or artillery shell be equally a "rocket"in that it can fly through the air and cause injury, property damage or fright? Edison (talk) 17:40, 11 July 2014 (UTC)

No, a Mortar is more like a muzzle-loading cannon. The thing about a rocket is that it expels propellant through a large proportion of it's trajectory - where a gun or cannon shell is intended to use up essentially all of the propellant before it exits the muzzle of the weapon. A mortar (whether in the modern sense of a thing that looks like a classic SciFi rocket that you drop down a tube - or in the older sense of a cannon that fires at a higher-than-45-degree-trajectory) is definitely in the latter category.

So, no, it's not a rocket. In a 'loose/colloquial sense" just about anything can be said...so who knows who might incorrectly call it a rocket just because it looks like a V2. SteveBaker (talk) 18:04, 11 July 2014 (UTC)

Is it feasible (or possible) to launch a rocket, mortar-style, which only starts rocketing when it reaches its apogee? Seems like it could travel further, but also like it could be risky for the launchers (riskier, anyway). InedibleHulk (talk) 18:49, 11 July 2014 (UTC)

To use a Rocket-assisted projectile in a mortar? Possible, yes. Sensible, no - the weight and space of the rocket motor will mean a smaller warhead, likely to the point where the explosive force of the warhead is negligible. WegianWarrior (talk) 19:13, 11 July 2014 (UTC)

Makes sense. According to base bleed, however, it seemed sensible enough in the GC-45 howitzer. Thanks for pointing me toward those. InedibleHulk (talk) 19:55, 11 July 2014 (UTC)

In case it isn't apparent, the risk of such a thing is that the rocket propellant would detonate when subjected to the forces which result from launching a mortar round. Rockets normally launch at far lower speeds, and are designed accordingly. StuRat (talk) 19:29, 11 July 2014 (UTC)

Yeah, that's what I meant by risky. Thanks for elaborating. Following up, is the M72 LAW both a mortar and rocket launcher? Seems that way to me, from the article and this video by YouTube's most well-armed "regular guy". But I'm still a bit too confused to be convinced. Seems another rather senseless weapon, anyway, so its ambiguity problem shouldn't likely pop up in news stories. InedibleHulk (talk) 19:47, 11 July 2014 (UTC)

What ambiguity problem? The LAW is a pure rocket launcher, NOT a mortar. And for the record, it was NOT a senseless weapon -- it was pretty darn effective against pillboxes and against Russian armored cars like the BTR, the BRDM and the BMP (though not against heavy tanks), and it's still used sometimes in Afghanistan to destroy terrorist tunnel networks. 24.5.122.13 (talk) 22:53, 11 July 2014 (UTC)

Well, that solves the ambiguity problem. Thanks. I didn't mean to suggest it was totally senseless. Just doesn't seem like the weapon of choice for the sorts of mortar attackers the news generally focuses on. But then, if it's not at all a mortar, "senseless" was not at all correct. InedibleHulk (talk) 00:21, 12 July 2014 (UTC)

There are rocket-assisted rounds for mortars [2] and there have been for some time. The Swedish Coastal Rangers when they had 12 cm mortars could use rocket-assisted rounds to reach 6 kms, instead of 4 as with the regular ammunition. It ignited immediately after firing, though. Sjö (talk) 08:19, 13 July 2014 (UTC)

I've thought about a related design for space launch rockets, though. You would hollow out a convenient mountain, and launch the rocket from inside the mountain, at the base. A pneumatic launch mechanism would be used, and every time the rocket moved a few feet upward, more highly pressurized air would be released below the rocket from an adjacent chamber (the Nazis designed such a launch system during WW2). The desired result is to accelerate the rocket past the peak of the mountain, at a safe and controlled velocity, without using any onboard fuel. Once the rocket cleared the mountain, then it's own engines would be ignited.

This method might be too risky for manned flights, but might work well for launching a series of unmanned rockets. The goal is to reduce the size of each rocket, and therefore the amount of material that is abandoned with each launch, to reduce cost. Alternatively, full-sized rockets could be used, which would hopefully then have increased range and/or payload capacity. StuRat (talk) 19:29, 11 July 2014 (UTC)

Jules Verne's From the Earth to the Moon is of interest in that context. Acroterion (talk) 19:36, 11 July 2014 (UTC)

That wouldn't really work. Remember that energy = force x distance (Newton's second law). The length of the launch tube would be a very small percentage of the total distance to orbit, so, in order to provide any significant component of the spacecraft's energy, the force and acceleration in the launcher would have to be enormous. A rocket (as opposed to a projectile) works because the force to accelerate it can be applied over the entire course of its flight, and because that force is acting on a rapidly-decreasing mass, neither of which apply in the Verne method of TLI. See Tsiolkovsky rocket equation for a proper mathematical treatment. Tevildo (talk) 19:50, 11 July 2014 (UTC)

But the air resistance is far more where the atmosphere is thickest, near sea level. Getting past that area of thick atmosphere would be quite a help. A conventional rocket will spend a disproportionate amount of time and energy during the first few miles, to overcome that, and the lack of inertia.

You could also launch from directly on top of a mountain, but that brings up the difficulty of getting the rocket to the top of the mountain for each launch, and the thin air might cause breathing difficulties for the workers. You'd also lose the advantage of the momentum of the rocket as it leaves the peak.

Does anyone have any figures on how much of the fuel is used up during the first, say, 5 miles, of a launch ? I bet it's significant. StuRat (talk) 20:06, 11 July 2014 (UTC)

This page from NASA goes into plenty of detail about the Saturn V launch. See in particular the graphs at 00:11:33. Max Q (the point at which air resistance starts to decrease) and the end of the first stage burn occur at about 8.5 miles (so 5 miles is indeed the sort of distance we're talking about), but I don't think that delivering the same amount of energy over a distance of 10,000 feet rather than 5 miles would prove successful. Tevildo (talk) 21:18, 11 July 2014 (UTC)

We could find a mountain higher than 10,000 feet. For example, Mount McKinley is twice that high. We could also start below sea level, if necessary. My method should also allow for a more even accel, which hopefully would allow them to optimize for equipment protection and still get a nice velocity at the end. The chart in that article shows only a max of 4 g's, (5, including the Earth's pull), and I suggest that a rocket could be designed which can withstand considerably more than that. (What kind of g's do ICBM's experience at launch ?) StuRat (talk) 23:10, 11 July 2014 (UTC)

StuRat, I can neither confirm nor deny that a similar launch system to that which you describe (though no mountains might or might not be involved) has or has not been tested and/or in use in or not in the USA for several years in order to launch small military satellites. If I had ever attended a talk on such a subject which might or might not have been given by a then RAF Wing Commander of my acquaintance, it would have been while I was on the UK's 'Atomic List' and thus cleared to hear such confidential material. Sorry to have to be so . . . unspecific. 212.95.237.92 (talk) 11:07, 12 July 2014 (UTC)

Sorry, StuRat, even going from below sea level to 20,000 feet won't work here -- in order to launch your spacecraft from a cannon with a terminal velocity of 8 km/s (the minimum required to reach orbit) and an acceleration of 10 G (the maximum G-load a human can endure without risk of long-term physical harm), you'd need a cannon 200 miles long! 24.5.122.13 (talk) 23:48, 12 July 2014 (UTC)

You missed two critical points: 1) It's not the only source of launch energy, a conventional rocket ignites once it leaves the top of the mountain. 2) This is not for human launches, only robotic probes, so the 10 g limit does not apply. StuRat (talk) 05:15, 13 July 2014 (UTC)

See Non-rocket spacelaunch#Projectile launchers for some relevant concepts. AndyTheGrump (talk) 03:40, 13 July 2014 (UTC)

Yup, these ideas that Andy points to show that some responses here make implicit assumptions that are not necessarily valid. For example, there is no obstacle to a launch tube 200 miles long, if you allow it to be nearly horizontal, following the curve of the earth in an evacuated tube even thousands of kilometres long. The launch angle does not affect the velocity required to reach escape velocity or any specific orbit (ignoring the atmosphere), and would be better for achieving an orbit than a more vertical trajectory. The somewhat longer path through the dense atmosphere obviously is undesirable, but the very extended launch tube should more than compensate, and one could use aerodynamic forces to optimize the curve of the path. Oh, and the escape velocity of 8 km/s is far too high for achieving orbit: an orbit is precisely when escape velocity is not achieved. And, though I do not have figures for StuRat, the fuel required to lift the fuel means that a normal rocket launch is pretty much exponentially costly in the final velocity required, a problem that does not exist for the launcher-based launch. —Quondum 04:10, 13 July 2014 (UTC)

I'm pretty sure you can't ignore the atmosphere when planning a rocket launch. StuRat (talk) 05:19, 13 July 2014 (UTC)

Given that Quondum doesn't even seem to know the difference between orbital velocity and escape velocity, I'm not sure your argument registered with him. Plus, there's the question of economics: a launch tube hundreds of miles long would be prohibitively expensive, much more so than launching a rocket. 24.5.122.13 (talk) 05:53, 13 July 2014 (UTC)

Initially, yes, but the launch tube could hopefully be used thousands of times, thus paying for itself and then some. StuRat (talk) 15:46, 13 July 2014 (UTC)

Terminology, the escape velocity is ~11km/s. The orbital velocity is around 8km/s.

If we can make a "cannon" 2 miles in length, this would give the projectile a muzzle v of 0.8km/s, which isn't insignificant when it comes to the rocket equation. It shaves some delta v off the "ugly" end of the graph, saving much more than 10% of the fuel.

However, there is another problem; one wants to launch near the equator (Florida is good, but Kourou is better), to exploit the tangential v Earth gives everything on its surface. This alone is 0.4 to 0.5km/s (40,000km over 86,200 seconds) near the equator, and my own experiments with Orbiter show that it's significant, esp. with the more realistic spacecraft like Atlantis (shuttle). Launching from equatorial sites has similar benefits as reasonably-sized "launch mortars"; however, launch mortars would be the superior bulk haulers in the long run. A 2-mile installation can double its delta v by quadrupling the acceleration. - ¡Ouch! (^{hurt me} / _{more pain}) 06:15, 15 July 2014 (UTC)

Also, there's another problem with a system like that: it would only be capable of launching a spacecraft into one particular orbit with one particular inclination, because turning such an enormous launch tube to change the inclination would be out of the question. 24.5.122.13 (talk) 07:18, 15 July 2014 (UTC)

No, that applies if the tube is intended to launch the thing directly into space. Stu's proposal was that the cannon would only be powerful enough to give it a start and get it through the densest part of the atmosphere. Steering to aim for the correct orbit could be done when the first rocket stage is firing, although the amount you could steer while still using less fuel than for a ground-based launch would be limited. --50.100.189.160 (talk) 10:15, 15 July 2014 (UTC)

One of the cases where the atmosphere can help, if we use a rocket with aero control surfaces. Depending on the location, we'd have a near-perfect config for one inclination (the mortar must be aligned west-east, and the latitude must match the inclination we want). The result would never be a stable orbit, but either a ballistic course back to Earth (if we don't achieve escape v) or a direct escape course (if we do). Since we want a "small" mortar, it's gonna be a ballistic course if the projectile stays inert, and the crash site will be known in advance and fixed. - ¡Ouch! (^{hurt me} / _{more pain}) 12:46, 15 July 2014 (UTC)

So is it inappropriate or "unencyclopedic" to include "mortar attacks" in an article listing "rocket attacks? Is there a policy-based justification for changing either the title or the content of these articles? Edison (talk) 03:32, 13 July 2014 (UTC)

Perhaps "projectile" or "missile" would be better words. They are definitely both projectiles and missiles; though the latter term has in the last century become a synonym for "rocket", it used to be a synonym for projectile. Projectile would cover both self-powered projectiles (rockets) and non-self-powered projectiles (mortars). --Jayron32 04:29, 13 July 2014 (UTC)

Apparently "improvised rocket-assisted mortar" is the name for a type of rocket, but only because it has a high trajectory like a mortar. See Lob bomb. So, technically lob bombs are rockets, but they are sometimes called mortars. If you want to be strict, a mortar is a mortar and a rocket is a rocket, and they are two different things. Sjö (talk) 08:19, 13 July 2014 (UTC)

Public polls on naming recently discovered stuff

I just looked at NameExoWorlds. The International Astronomical Union will allow the public to vote on the names of 20-30 exoplanets. Have there been other scientific things named by the public in a poll? New species for example? (I do mean occasions where the elected name will also be recognized and used by the scientific community, not campaigns like Uwingu's inviting us to name Martian craters for a fee). Thanks in advance! ---Sluzzelin talk 17:47, 11 July 2014 (UTC)

An insect has been see:[3]. Richerman (talk) 17:58, 11 July 2014 (UTC)

Years ago the Astronomy magazine conducted a poll to name nebulae. It was on the web and open to the public. In the end I realized it was a marketing gimmick. I doubt anybody's contribution was accepted. I am still a subscriber. --AboutFace 22 (talk) 20:57, 12 July 2014 (UTC)

Thanks! ---Sluzzelin talk 16:00, 14 July 2014 (UTC)

Soap and infection risk

Is there any correlation between how frequently someone showers and risks to infections, whether airborne transmissions, contact transmissions or sexually transmitted transmissions? 176.254.44.153 (talk) 19:42, 11 July 2014 (UTC)

Hand washing certainly reduces the spread of infections, in places like hospitals, where it's a problem, otherwise. Showering would be less effective, as the areas you only wash in the shower are less likely to be exposed to infectious agents and less likely to come into contact with common sites of infection, like the eyes. Of course, if you know you've been exposed, like if you fell into a pile of manure, then showering would make sense (for more than just the obvious reason).

Also, there could be some negative effects from excessive washing. Irritated skin from excessive washing could be more vulnerable to infection, and overuse of antibiotics in soap could lead to antibiotic-resistant bacteria. There's also the argument that you want to maintain a "healthy flora" of your own skin bacteria, as they can prevent infections, such as a fungal infection.

Also, it might be good to bathe babies more often, as they have a unique talent for exposing themselves to bacteria, whether by drooling on themselves, getting food stuck in nooks and crevices, crawling in the dust under a table, or diaper related causes. StuRat (talk) 20:19, 11 July 2014 (UTC)

But the Hygiene hypothesis says that minimizing a baby's exposure to germs causes allergies and other ailments later. Contra that notion, even a tiny but of some microorganisms like E Coli, Cholera, or Typhoid can be deadly. See also the circa 1919 poem "Strictly -germ-proof" by Arthur Guiterman,(1871-1943), which begins:

"THE Antiseptic Baby and the Prophylactic Pup

Were playing in the garden when the Bunny gamboled up; They looked upon the Creature with a loathing undisguised;—

It wasn't Disinfected and it wasn't Sterilized...." Edison (talk) 21:56, 11 July 2014 (UTC)

Certainly keeping a baby in a completely sterile environment has that risk, but for most babies, this isn't a problem. StuRat (talk) 22:41, 11 July 2014 (UTC)

(Citation needed. Why should anyone care about your speculation and opinion on how the hygiene hypothesis relates to child rearing?! ) SemanticMantis (talk) 23:17, 11 July 2014 (UTC)

Since you failed to say what part you want a citation to support, I'm going to assume it's the part about a completely sterile home being rare. See the second paragraph here, and follow those links for references: Hygiene_hypothesis#Cleanliness. StuRat (talk) 23:33, 11 July 2014 (UTC)

I think that article needs a look at. The main references in that section are to a site about home hygiene that has now gone out of business and what is said in the section you pointed at contradicts what is said in the rest of the hygiene hypothesis article. Dmcq (talk) 08:13, 12 July 2014 (UTC)

I've fixed the references, the .com's should have been .org. The section does seem to overstate what is said in the references though as if the hygiene hypothesis was discredited which they most definitely did not say. Dmcq (talk) 08:41, 12 July 2014 (UTC)

I think we can safely say that the OP's question has not been answered at all. The question was not about transmitting diseases and was specifically about the frequency of showering. It is difficult to imagine how showering frequency and general hygiene of the individual concerned would have an effect on contracting an airborne or contact-transmitted infection, including sexually transmitted diseases, unless the health (skin integrity and general immunity) was compromised as a result. Use of antimicrobial soaps etc. when showering may complicate matters, but not necessarily beneficially. I failed to find any studies examining the correlation in a simple search. —Quondum 14:28, 12 July 2014 (UTC)

I would somewhat disagree on the airborne/contact part. AFAIK, it's generally accepted that regular handwashing (also avoiding touching your face)reduces risk of various airborne diseases (which are frequently spread at least partially by contact) and contact diseases, particularly influenza and the common cold as well as various bacterial infections. (See e.g. our articles or [4].)

I don't see any reason to assume regular showering is not going to be at least partially as effective since in ordinary circumstances you would at least wash your hands (and probably your face) a bit. Of course regular showering is probably not going to have much benefit if you're already regularly hand washing but this wasn't established in the question. And of course it's true showering every hour or so, or at least before every meal and perhaps every time after you go to the toilet is dumb instead of regular handwashing and may have other negative effects. But intriscly, I don't see how we can rule out frequency of showering having an effect on the risk of diseases based on a simple check of sources and taking the question as worded where the issue of handwashing and what is meant by 'frequency' wasn't established.

BTW I see any reason to think antimicrobial soaps may be beneficial under you assumptions. AFAIK they have little lingering benefit (meaning even if the antimicrobial effect does anything, it doesn't do anything 5 minutes after you showered), so if they did benefit so would showering with ordinary soap (let's ignore it's quite questionable if they do have any benefit).

P.S. I suggested in my response regular showering may be less effective than regular handwashing assuming we're talking about the same frequencies. One possibility, as I also mentioned, is such an extreme frequency of showering may have additional negative effects.

But the other more important thing is that I'm not sure how effective it as a form of handwashing. One the one hand, I think most people probably don't directly wash their hands that well when showering. On the other hand, I believe most people don't wash their hands very well in general and if you use your hands to help while showering, the added motion could improve over such poor handwashing even taking into account that the hands are rubbing against not so clean areas (including perhaps the anal area).

P.P.S. It's also worth remembering showering twice or even three times a day is probably not unresonable in some circumstances. Some people may wash their hands less than once a day, I suspect even some who shower two or three times a day. For such a person, showering two or three times a day would probably reduce their risk of various airborne and contact infections compare to those who showering every two days. So we're not even just talking about hypothetical cases.

Nil Einne (talk) 15:56, 13 July 2014 (UTC)

I had a quick search and found [5] and [6] which suggest in certain extreme cases showering frequency may have an effect on infection rates although the first one seems highly theoretical. I also found [7] which talks about hand hygeine, They don't think showering generally has much effect on infection rates for the general population, but it doesn't seem they're considering the issue of hand hygeine as part of showering. Probably because as I said, it is dumb to shower so much when you'd be better off just hand washing and they've consider hand hygeine seperately. Both that and [8] do mention something interesting, it seems showering actually increases the airborne microbial load. So whatever it does for you, it may not necessarily be beneficial to others in your environmental, particularly if they are immunocomporomised (and perhaps it's also be worse for you if you are immunocompromised). Nil Einne (talk) 16:28, 13 July 2014 (UTC)