Wikipedia:Reference desk/Archives/Science/2012 July 26

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July 26

Entropy decrease in disorder

An example in nature would be helpful to understanding this concept better: "Statistical mechanics demonstrates that entropy is governed by probability, thus allowing for a decrease in disorder even in a closed system. Although this is possible, such an event has a small probability of occurring, making it unlikely. Even if such an event were to occur, it would result in a transient decrease that would affect only a limited number of particles in the system." Can someone give an example?GeeBIGS (talk) 03:36, 26 July 2012 (UTC)

It is possible, in a glass of water with food coloring in it, for the food coloring to spontaneously congregate into a blob, but it is extremely unlikely. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 03:41, 26 July 2012 (UTC)

This says it would only affect a limited # of particles, but the example you gave seems like alot more than that. How small is the probabilityGeeBIGS (talk) 03:44, 26 July 2012 (UTC)

It is far more likely to affect only a tiny number of particles than to affect the whole shebang. That is what they mean by "only affects limited # of particles", because the probability is even more vastly tinier that all the particles would be affected. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 04:55, 26 July 2012 (UTC)

It's extremely difficult to calculate for even remotely realistic systems. Say you take two ideal gases in a box, say 1000 particles of each. There is a chance of 1 in 5x10⁶⁰¹ that at a given moment, the two gases will evenly divide such that you could cut the box in half and have only one gas in each half. For realistic systems, you have far more particles, but also the particles interact with eachother in meaningful and often density-dependent ways, which complicates the calculations tremendously. Someguy1221 (talk) 03:52, 26 July 2012 (UTC)

Also, how does a transient decrease count if the ultimate disorder eventually wins?GeeBIGS (talk) 03:59, 26 July 2012 (UTC)

The argument that disorder always increases is based on statistical reasoning. As I showed, even for a relatively puny number of particles in a closed and isolated environment, the chance of spontaneously reaching a highly ordered system is astronomically small. Disorder is deemed to always "win" because anything else is just extraordinarily unlikely. And I'm not talking "Cubs winning the World Series" levels of unlikely, but a monkey typing the complete works of Shakespeare without typos unlikely. That box I mentioned, You can spend your entire life staring at it, and it will never appear as ordered as in the example I calculated (most likely). So in summary, there is no rule that disorder must win. It just always does. Just like the Cubs always lose, and the monkeys pretty much hit the "s" key and poop on everything. Someguy1221 (talk) 04:36, 26 July 2012 (UTC)

At equilibrium entropy will fluctuate (by an undetectable amount) presumably half the time up and half the time down. --81.175.236.109 (talk) 13:09, 27 July 2012 (UTC)

Fluctuation theorem. Count Iblis (talk) 15:27, 27 July 2012 (UTC)

Spend some time watching clouds. On a day with an unstable atmosphere, when you expect you should see large billowy cumulous clouds, you will occasionally see massive updrafts, lateral stratus clouds, or other indicators of laminar flow, indicating that local volumes are not convecting turbulently. In those local regions, we could say that the entropy is lower than in the surrounding, mixing air. Convection in general provides a great insight into the delicate balance between pure randomness and structure. If you enjoy analyzing things numerically, you can look at the empirical laws we use to model convective instability - like a Rayleigh-Taylor instability model. Nimur (talk) 14:46, 28 July 2012 (UTC)

Who is the Oldest Living African-American Man Right Now?

Shelby Harris died today, so I'm not sure who the oldest living African-American man is right now. And for the record, I posted this here because gerontology and supercentenarians are a part of scientific research. Futurist110 (talk) 03:53, 26 July 2012 (UTC)

Howard Hall maybe. According to the list of supercentenarians from the United States, his status is unverified. Clarityfiend (talk) 04:43, 26 July 2012 (UTC)

I seriously doubt that Hall's case is true. Futurist110 (talk) 05:30, 26 July 2012 (UTC)

Deja vu in reverse. Check the list of verified oldest people, linked in the section just below. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:42, 26 July 2012 (UTC)

Were Any Verified Male Supercentenarians Jewish?

I don't think any of them were Jewish, but I don't know for sure. Futurist110 (talk) 03:53, 26 July 2012 (UTC)

Depends on what you'll consider a source. I would say that there are a few in the Bible, but your user page lists you as an atheist so that's irrelevant!

I did find one Jewish suprecentenarian in this Yahoo article, Helen Reichert. She was 108 in 2010, so if she's still alive she'd be 110.

...but apparently Futurist wants only male Jewish supercentenarians, so I don't think that's what he's looking for. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 05:17, 26 July 2012 (UTC)

Damn it that's a fail on my part!

Helen Reichert died almost a year ago at age 109 years and 10.5 months. And Yes, as Whoop whoop pull up said, I'm only interested in verified male Jewish supercentenarians for the purposes of this question. I know that there already were several verified female Jewish supercentenarians, and there is one alive right now in the form of Evelyn Kozak (born 1899).

I looked at the list of all the verified male supercentenarians throughout history (there are almost 150 of them in total) and I think that Henry Hartmann (1894-2005) might have been the only one who could have been Jewish. Of course, I'm not sure if he was Jewish either and none of the other verified male SCs have Jewish last names, and thus they almost certainly weren't Jewish considering that intermarriage among Jews and non-Jews was very or even extremely rare 110+ years ago. Futurist110 (talk) 05:29, 26 July 2012 (UTC)

Alexander Imich is categorized as a Jew and is still around at 109. Clarityfiend (talk) 05:30, 26 July 2012 (UTC)

Yes, but he's not 110 yet (and unfortunately we don't know if he will reach 110--health can deteriorate very quickly at his age). Were there any verified Jewish men throughout history that have already reached 110? Futurist110 (talk) 05:33, 26 July 2012 (UTC)

Is this claim about the scarcity of intermarriage 110+ years ago accurate, and what source based upon and what definition of Jewishness? I would think it's possibly true, but I don't know and suspect it is not accurate to say 'rare' (with what is normally considered the definition, of having ones mother Jewish). Anywhere that conversion was successfully 'encouraged' during parents' or own lifetimes would argue against the supposition (if reasonably flexible on a definition, allowing a person to both be and not be Jewish for some time period), would it not?173.15.152.77 (talk) 13:24, 26 July 2012 (UTC)

I agree. When Western Europe began the emancipation of Jews, assimilation, and hence intermarriage, did result in these western European countries. --Activism1234 23:43, 26 July 2012 (UTC)

The Jewish population in Western Europe in 1900 and before was much smaller than in Eastern Europe, where there was much less intermarriage and assimilation. Futurist110 (talk) 05:51, 31 July 2012 (UTC)

Look through List of the verified oldest people and see if there appear to be any Jewish males. (For example, I think you can rule out Christian Mortensen.) ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:39, 26 July 2012 (UTC)

There are none. Futurist110 (talk) 08:01, 27 July 2012 (UTC)

Just because there are none on that list doesn't mean that none exist, or have every existed. The absense of evidence is not the evidence of absence. A 110-year old Jewish male just may have not attracted notice. It doesn't mean there are none ever. --Jayron32 04:04, 28 July 2012 (UTC)

There might have been some Jewish man out there who turned 110, but if there was one he wasn't verified due to a lack of documents. I checked the names of all 140+ verified male SCs and none of those names appeared Jewish. As for my definition of Jewishness, I meant by ethnicity, not religion. There was some intermarriage in Western Europe, but most Jews in the world 110+ years ago lived in Eastern Europe, where most of them lived in their own areas and villages. Thus, most Eastern European Jews did not really begin to intermarry on a large scale until the Russian Revolution and beyond. The Russian Revolution was 95 years ago, so obviously no verified SCs so far were born before it. Also, here's a story from personal experience, though I'm sure a lot of Jews in Eastern Europe had the same story. Intermarriage among my Jewish ancestors and relatives was non-existent (to my knowledge) before the 1930s (if my knowledge about my great-grandma's Jewish ancestry is correct) and was very rare until the 1950s, when my Jewish grandpas and other Jewish relatives in Russia began marrying locals due to the Jewish population losses of the Holocaust and due to moving to areas of the USSR with few Jews in them. Futurist110 (talk) 20:57, 29 July 2012 (UTC)

cell

is cell can be the supportive unit of life? — Preceding unsigned comment added by Khanzadi (talk • contribs) 04:08, 26 July 2012 (UTC)

Not only can be, but is.GeeBIGS (talk) 04:16, 26 July 2012 (UTC)

Depending on what you consider "life", virions could be another example, besides cells. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 05:19, 26 July 2012 (UTC)

Please see cell (biology). You can't really say that something is the "supportive unit of life" if you haven't defined what that is. But by all means, if you still have questions after reading the article, come back and ask. Someguy1221 (talk) 04:29, 26 July 2012 (UTC)

Hyperdimensional Three-Jet Events

This is really not "a" question but a string of questions revolving around the same general concept.

The wikicode for that would be ''a'' question --ColinFine (talk) 19:26, 26 July 2012 (UTC)

I formulated this questions when evaluating the possibility of the presence of extra spacial microdimensions (microscopic dimensions) explaining the relative weakness of gravity when compared to the other fundamental forces. During this train of thought I had to reason out exactly why the gravitational force would be the only one present in the hyperdimensional geometry. Why would the other fundamental forces be absent from the extra space. I then began to eliminate things after evaluating why the graviton would even be permitted to enter that space in the first place. The gravitons would be able to enter microdimensions because they have no volume. This can be taken as having a volume that equals 0, which is, of course, lower than the size of microdimensions, which means that they can fit into these microdimensions. Then I looked at photons. They too have no volume. "Why can't they pass into the microdimensions?" I asked myself. Then I thought of how they have wavelength which effectively limits what they are able to probe. I imagined that photons would need an energy level high enough to create ridiculously small wavelengths, in order to fit into microdimensional space. If microdimensional space is assumed to be about planck length, a photon capable of prying into microdimensional space would have to have 12.3 billion joules. As photons of this energy level are unimaginable and probably never emitted under any ordinary circumstances, the strength of electromagnetism is not hindered. Then I arrived at the W and Z bosons and, of course, eliminated their presence in microdimensional space simply through thinking that their volume is probably too large to interact with such geometry. And then I arrived at the gluon. They have neither volume nor wavelength thus there should be absolutely no parameters limiting the gluons themselves from interacting with the hyperdimensional space. But in order to explain the fact the the strong interaction is not hindered greatly I considered the fact that under ordinary circumstances no gluons are free. They are all bound to the quarks that the glue together. And as no quarks are small enough to fit into the microdimensions, one could reason that under the usual circumstances gluons would never stray into a microdimensional divergence. Then I remembered Three-Jet events. Which apparently detected freed gluons. This got me thinking about a potential way to provide more evidence toward the existence of microdimensions. I realized that during these Three-Jet Events, a free gluon might be able to stray off into microdimensional space and become unobservable to us. Thus I have a string of questions to validate/invalidate the plausibility of this hypothesis.

1. In Three-Jet Events does the gluon jet always bisect the vertical angle of the quark angle?

If so, the gluon jets would never be able to diverge from us in the microdimensions.

2. Have there ever been any circumstances in which the conditions for a Three-Jet Event are met but a gluon jet does not occur?

If so some of the gluons might be straying into the extra dimensions.

3. What is the probability of a Three-Jet Event not occurring when the conditions for one are met?

Also feel free to evaluate my evaluation. Doctor Condensate (talk) 07:33, 26 July 2012 (UTC)

If something has zero volume then even in an expanding universe it maintains the same proportion to the universe as time passes.165.212.189.187 (talk) 14:04, 26 July 2012 (UTC)

I find the entire theory suspicious because not only does everything have a wavelength, there is no obvious way to define a particle's volume in quantum physics, and the common practice is to declare that it is zero, the width of a dirac delta. Someguy1221 (talk) 19:40, 26 July 2012 (UTC)

Darn. So what is it exactly that causes only gravitons to venture into microdimensional divergence? Why don't the other gauge bosons do the same, thus causing all of the fundamental forces to be weakened? Or is it perhaps that most gravitons have wavelengths small enough to enter microdimensional space? Or is this one of the as of yet unresolved questions regarding string/M theory? And I am pretty certain that the gauge bosons other than the W and Z bosons have no volume (just as they have no mass). I do know that photons have no volume. Doctor Condensate (talk) 07:55, 30 July 2012 (UTC)

As far as I know, the only thing we know of that sets gravitons apart is that A) They are the only fundamental spin-2 particles and B) according to string theory, they are the only sort-of-observed particles that exist as closed strings. You could hypothesize that all open strings in the universe are bound at one end to the hypersurface of a 4brane, and that gravitons are uniquely unbound in this manner. You will be well into the realm of purely theoretical physics, but you could run with that hypothesis. It would take at least 8 years of college and graduate mathematics training to be able to express your theory in a way that other physicists would bother listening to you, though. Someguy1221 (talk) 05:23, 31 July 2012 (UTC)

coul you be more specific with your suspicion?GeeBIGS (talk) 06:17, 27 July 2012 (UTC)

I can't accept his conclusions when I reject his assumptions. Someguy1221 (talk) 06:36, 27 July 2012 (UTC)

Models like this are called large extra dimension models. As far as I know they're all based on string theory and what makes the graviton special is that it's the only closed string (as Someguy1221 already said). The extra dimensions need to be much larger than the Planck scale in order to account for the weakness of gravity.

All of the fundamental standard model particles, whether they have mass or not, are "pointlike" in a certain sense. You shouldn't assume that more massive particles are larger. In fact there's an inverse relationship between mass/energy and size in particle physics: higher energies are associated with smaller distances (and the Planck energy is associated with Planck-scale physics).

The general answer to the question "has the LHC seen any anomalous events that hint at new physics?" is "no", unfortunately. -- BenRG (talk) 14:29, 1 August 2012 (UTC)

First off, thank you for your responses. So particles that have no mass can have volume? And I saw an inquiry to a physicist who explained that photons have no volume. In seeing that photons don't have volume, I assumed that all other massless particles lack volume. It's unfortunate to hear that no new anomalous events have appeared. Well, at least they discovered a particle consistent with the Higg's Boson. At any rate, that's pretty cool. So In order for gravitons to be expended hyperdimensionally the extra dimensions through which it propagates must be much larger than planck length? And what is the smallest possible size for a large extra dimension? Also I have been reading that some results of the LHC have severely constrained theories with large extra dimensions. In exactly what way are they constrained? Doctor Condensate (talk) 04:05, 2 August 2012 (UTC)

Superbig Bang Theory ?

There is a multiverse theory that has cosmic expansion occurring not only within our own universe, but also between our universe and all the others. Running the clock backwards, doesn't this again mean that at one time all those universes must have been contained together within a combined singularity ? StuRat (talk) 07:58, 26 July 2012 (UTC)

It would depend on the details of the theory. I've never heard of an expanding multiverse. The simplest way I can imagine having an expanding multiverse would be with a bubble universe type theory. In other kinds of multiverse theories, it can be difficult to define what it would mean for it to expand. Expansion doesn't necessarily imply there was an initial singularity - you could have a steady state theory type thing going on with new universes being continually created to fill in the gaps. --Tango (talk) 12:10, 26 July 2012 (UTC)

Apparently the expanding multiverse theory is called Eternal inflation. StuRat (talk) 18:26, 27 July 2012 (UTC)

Ekpyrotic cosmology seems to fit the bill of your original question, too, but allows for both steady state and cyclic behaviors, and combinations of both. 207.224.43.139 (talk) 22:12, 28 July 2012 (UTC)

Another question

Do two parallel rays of light gradually diverge due to the expansion of the universe? --163.202.48.125 (talk) 13:25, 26 July 2012 (UTC)

I think that depends on the Shape of the Universe and, in particular, whether it has positive, negative or zero curvature. Positive curvature would mean they converge, negative would mean they diverge and zero would mean they remain at a constant distance. --Tango (talk) 20:54, 26 July 2012 (UTC)

The "shape of the universe" article is talking about spatial curvature at a particular cosmological time, while what matters here is spacetime curvature overall. In a spatially flat universe I think the distance between the rays will just scale with the scale factor—so they will separate in a flat eternally expanding universe (as ours seems to be), though they will always be parallel at any given time. This applies only if the rays are a billion light years apart or more in the present era, and never pass close to any concentrations of matter. Otherwise local effects will dominate. -- BenRG (talk) 22:08, 27 July 2012 (UTC)

Follow-up question

So could that provide a way to test hypotheses about the shape of the universe? 203.27.72.5 (talk) 20:57, 26 July 2012 (UTC)

Yes. See perhaps tests of general relativity. Imagine doing this here on Earth: Drive 8000 miles, turn 90 degrees to your right, drive another 8000 miles, turn 90 degrees to your right, and then drive a final 8000 miles to return to your starting position. You have just formed an equilateral triangle with three 90 degree angles, which is impossible on a flat plane. What you will have shown is that the actual geometry of the Earth's surface is inconsistent with its being flat. So what you just suggested above is very well a test of this. As on Earth, if you had two people start from the equator and head north in what appear to be parallel trajectories, they will meet at the North pole, which is also inconsistent with a flat plane. Astronomers have long hoped to see something like that, some phenomenon out in space that shows the universe isn't flat (or rather, the equivalent of flat but in 3 dimensions). But except in the vicinity of a massive object, space seems pretty darn flat. As for the experiment itself, the result depends on: A) the rate of expansion; B) the shape of the universe; and C) the interaction between the light beams, if any. Someguy1221 (talk) 23:29, 26 July 2012 (UTC)

Note that this experiment can't be done, even in principle, at cosmological scales because of the continuing expansion of the universe. All of our knowledge of the universe at cosmological scales is based on events from our own past light cone, which is nowhere close to flat at scales of billions of (light) years (that is, it's nowhere close to resembling a light cone from special relativity). It's not straightforward to work out the spatial curvature from that evidence. -- BenRG (talk) 22:08, 27 July 2012 (UTC)

Why has Pluto a different orbit?

OsmanRF34 (talk) 13:51, 26 July 2012 (UTC)

Please see Pluto#Orbit_and_rotation. SemanticMantis (talk) 14:35, 26 July 2012 (UTC)

Different from what? As the recent transit of Venus shows, the other planets may have less eccentric orbits than Pluto, but they don't all line up on the same orbital plane either. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:35, 26 July 2012 (UTC)

Is shooting star is faster than a comet?

OsmanRF34 (talk) 13:52, 26 July 2012 (UTC)

It doesn't. A meteorite is just closer. Perhaps you have fallen for the Television version which for some reason is often shown slowly moving across the sky while the characters watch. Real comets move like planets do. Rmhermen (talk) 14:30, 26 July 2012 (UTC)

meteoroid says " speed may reach about 44 miles per second (71 kilometers per second). Meteoroids moving through the earth's orbital space average about 20 km/s."

comet says they have "velocities of the same order as the relative velocities of stars near the Sun (a few tens of kilometres per second)."

I cannot vouch for the accuracy of these figures, but this would lead me to believe that the comparison in question will depend strongly on when the velocity is calculated, for which specific object, and where it is. SemanticMantis (talk) 14:27, 26 July 2012 (UTC)

Any idea what those speeds are relative to? I would imagine that meteors are given relative to Earth, but comets may be given relative to the sun. 203.27.72.5 (talk) 20:56, 26 July 2012 (UTC)

I would imagine comet speeds would be calculated relative to the sun, since that's the body they orbit. Evanh2008 ^{(talk|contribs)} 01:46, 27 July 2012 (UTC)

* Note particularly that meteor showers are predominantly the debris of comets, still traveling in the same orbital paths as the comets that created them. As such, I think it's fair to say that meteors and comets travel at exactly the same speed (with the usual caveats of "well, of course the universe varies"). — Lomn 15:17, 26 July 2012 (UTC)

On average, shooting stars are slower, as their entry into Earth's atmosphere reduces their speed, eventually down to zero. Clarityfiend (talk) 22:40, 26 July 2012 (UTC)

Before hitting atmosphere, it has fallen into Earth's gravity well and thus picked up kinetic energy. —Tamfang (talk) 00:52, 27 July 2012 (UTC)

But if meteoroids were travelling at exactly the same speed as their parent comets, wouldn't they still be attached the parent comets (i.e., part of the tail)? For them to have become separated from the comet in the first place, there had to have been some kind of loss of kinetic energy, though I'm not exactly sure what would have caused it. Drag of some sort, I would think. Possibly caused by water vapor? Evanh2008 ^{(talk|contribs)} 01:46, 27 July 2012 (UTC)

Or a gain of kinetic energy. Or no change in net kinetic energy, just a change of direction. I think comets are usually broken up by tidal forces. 203.27.72.5 (talk) 01:54, 27 July 2012 (UTC)

Actually, Meteor_shower#The_origin_of_meteoroid_streams gives a good description of how the meteroids get separated from the comet's body. Drag from water vapor does come in to it too. There is usually quite a time delay from when they first separate and when they finally impact Earth though, so the speed may vary substantially. 203.27.72.5 (talk) 02:02, 27 July 2012 (UTC)

It seems like tidal forces should play a significant role, though. Evidently there are also some meteor showers which arise from asteroids, not comets. Given the low water content of most asteroids, I would have to assume that tidal forces (most likely from the sun) would be the key factor there. Evanh2008 ^{(talk|contribs)} 02:04, 27 July 2012 (UTC)

A meteorite looks faster because it streaks across the sky, whereas a comet just kind of hangs there, moving extremely slowly from our perspective. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:34, 26 July 2012 (UTC)

Bodies in the same orbit have the same speed at the same distance from the sun. If a meteoroid is in substantially the same orbit as its parent body it will be moving at substantially the same speed as the parent body when crossing Earth's orbit. μηδείς (talk) 02:12, 27 July 2012 (UTC)

I don't think many meteoroids actually are in the same orbit as their parent bodies, though. It seems likely that they would have drifted over time from their original location, which would be the reason none of the comets which left their debris behind are projected to collide with Earth (which they most likely would, if they were in the same orbit as their meteoroid ejecta). And the correlation between orbit radius and velocity only holds true for stable orbits, does it not? In other words, if a loss in kinetic energy caused the orbit of a sun-orbiting meteoroid to become unstable (degrading), it would necessarily change orbital vector relative to its parent object, and vice-versa. Given the fact that they have in fact become separated from their parent bodies, it seems highly unlikely to me that any meteoroid streams are still in the same orbit as said bodies. Evanh2008 ^{(talk|contribs)} 03:16, 27 July 2012 (UTC)

The meteoroid streams are most definitely still in pretty much the same orbit as the parent comets. It's called the meteoroid trail and it's mentioned in the article that I linked to above. Though once they actually get into the Earth's atmosphere, they may have been perturbed by graviational interaction with other bodies that can change their speeds. 203.27.72.5 (talk) 03:43, 27 July 2012 (UTC)

That's also why many showers are regular, periodic occurrences. 203.27.72.5 (talk) 03:44, 27 July 2012 (UTC)

Relative to what? 207.224.43.139 (talk) 21:19, 28 July 2012 (UTC)

using dialysis in cooking

I'm trying to locate how-to guides on using selective semi-permeable membranes to remove excess sweetness or saltiness from foods. Sometimes, I want to add more of a flavor or ingredient, but the existing saltiness or sugar in that ingredient (fish sauce, beef bouillon, etc.) precludes me from adding more (and dilution isn't practical). Unfortunately, Google is being retarded and returns me recipes for kidney dialysis patients instead. 76.104.28.221 (talk) 14:06, 26 July 2012 (UTC)

To remove overspicing or over salting from food, drop a peeled potato in. The potato will absorb the excess and can be removed when tender. Is that what you're after? --TammyMoet (talk) 15:37, 26 July 2012 (UTC)

I don't think dialysis will do what you're after. The difficulty is the sugar and salt molecules you wish to remove are about the same size as the flavor molecules you want to add more of. The trick with dialysis is to have a membrane which is permeable to the item you wish to cross, but not permeable to those that you don't wish. The easiest way to do this is by having microholes in the membrane. Things that are smaller than the holes (e.g. waste products in the blood) can cross, and big stuff (e.g blood cells and plasma proteins) stays put. But typical membranes aren't all that specific in the *type* of molecule that can cross - anything below the size cutoff goes through. (Note that while there are membranes that are specific for certain molecular properties, it's highly unlikely you'll find one that's sugar/salt permeable but flavor impermeable.) That's why they don't use plain water for kidney dialysis - you need special solutions with the right balance of salts, etc. on the other side, otherwise you'd mess up the electrolyte balance. Likewise for your use case. Small flavoring molecules would pass through the membrane just like the sugar and salt you're trying to remove. You would need to have a solution with the same concentration of flavor molecules (but not the sugar or salt) on the other side to avoid diluting out the flavor. -- 205.175.124.30 (talk) 17:37, 26 July 2012 (UTC)

If you can tell us which foods you are trying to desalt or desweeten, we may be able to come up with specific suggestions. Personally, I find some way to dilute excess saltiness and sugar works in just about anything. For example, as mentioned above, some bland potatoes often work, although I leave mine in the finished dish. For other foods, like olives, I will drain, soak in fresh water, then drain again. StuRat (talk) 17:54, 26 July 2012 (UTC)

The reason that you can't find what you're looking for is because dialysis refers specifically to removing waste from blood. The terms you ought to be searching under are microfiltration and reverse osmosis, but don't bother, what you're talking about isn't really possible. While you probably could remove salt with a semipermeable membrane in a procedure analagous to dialysis, once you start getting into small organic molecules like sugar, they're going to be too close in size to the rest of the matrix that you actually want to keep. Theoretically, you could remove specific species using an ion-exchange resin, but you would need to know what constituents there are and specifically which ones you want to remove, and even then there will almost certainly be no perfect solution that removes the things you don't want keeps the things you do. The other point is that there are so many chemcial components in something like fish sauce that there would be plenty of things that would likely stick to membranes or otherwise wreck the equipment you're using, and it's also all generally pretty expensive stuff. 203.27.72.5 (talk) 20:49, 26 July 2012 (UTC)

Um, "The reason that you can't find what you're looking for is because dialysis refers specifically to removing waste from blood." that's actually entirely incorrect. There are numerous dialysis membranes made specifically for in vitro use, ie removing low MW or small molecule impurities or contaminants from protein or polymer solutions. Yes, you can do that with filters, but it's certainly not the only way. (+)H₃N-Protein\Chemist-CO₂(-) 21:12, 26 July 2012 (UTC)

True. I was thinking of the medical term as opposed to the word as used by biochemists. Anyway, I already mentioned essentially that technique, but I just refered to it as "a procedure analagous to dialysis" using a semipermeable membrane. The OP's google searches no doubt failed to return the information he was looking for because the medical term is used far more frequently. 203.27.72.5 (talk) 22:27, 26 July 2012 (UTC)

Actually micro- and ultrafiltration are used in the food industry to separate components. Whey protein can be separated form the carbohydrates and salt in whey with microfiltration. Also Kikkoman claims their lower sodium soy sauce is brewed the same way as the original, and the sodium is extracted later, but they don't say how. Your best bet is to search online for specialty products that cater to people on sodium-restricted diets. I doubt you'll find fish sauce, but you should be able to find a bouillon substitute. Jerk182 (talk) 23:02, 26 July 2012 (UTC)

No whey!Edison (talk) 13:43, 27 July 2012 (UTC)

That pun made my blood curdle. StuRat (talk) 17:48, 27 July 2012 (UTC)

hunting in county parks

Where I live, there is an extremely large County Park that is at least 1000 acres. I called the state and they said that according to them it was legal to hunt in any area of public land, including parks, however, there may be local regulations against it. I called the local park and they said hunting was not allowed there, but they didn't seem to know if there were any criminal laws that would be broken by hunting their. So my question is, if one did hunt their would they be breaking any criminal laws and if so, what would likely be the law?--64.38.226.92 (talk) 15:42, 26 July 2012 (UTC)

Assuming you are in Arizona then this site is useful. If you look down a bit you'll see under vandalism that it is illegal to harm any plant or animal. I guess you can hunt them gently but don't hurt them. Caesar's Daddy (talk) 16:06, 26 July 2012 (UTC)

We can't give legal advice, but I think it is safe to point you to http://www.azgfd.gov/regs/mainregs.pdf, an online version of the Arizona hunting and trapping regulations. Looie496 (talk) 18:35, 26 July 2012 (UTC)

Hunting is generally open on state-owned land in Arizona - but you are talking about a county park, Different owner, different rules.[1] Rmhermen (talk) 23:53, 26 July 2012 (UTC)

Foul smell from mouth

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This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis or prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the Reference Desk's talk page. --~~~~

203.27.72.5 (talk) 21:08, 26 July 2012 (UTC)