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We Finally Know Why Oil and Water Don't Mix
CoveredTrax writes "Everyone knows oil and water don't mix. It's a simple concept, sure, but the hydrophobic interactions between fats and water are crucial to the mechanics of microbiology. The weird thing is, the base theories of chemistry suggest that there's no reason oil and water shouldn't mix, even though it's obvious that's not the case. Now there's an explanation: a team of chemical engineers at the University of California, Santa Barbara have defined an equation that measures a compound's hydrophobic character. It's the first such equation of its kind."
I thought it was to make me exercise more when trying to make my Amish bread every two weeks... the oil always takes extra long to mix in
I read TFA, and I still don't know why oil and water don't mix. Frankly, I don't think these researchers do, either. They seems to have come up with some kind of empirical formula that describes the interactions without really understanding why they are happening.
As I teach in my biochemistry class it is entropic cost of not separating them that causes their separation, but I have yet to really wrap my head around this study. Nonetheless, here are some links to the original research:
* Abstract: http://www.ncbi.nlm.nih.gov/pubmed/21896718
* PNAS (paywalled): http://www.pnas.org/content/108/38/15699
And basically it says van der Waals' theory is wrong, and here is a new equation. That's pretty much it.
Anyone who knows about this stuff want to take a look at the equation, and see if it makes any sense? Not my area.
E(D)= -2i(a-a)e^(D-D)
where:
E = energy
D = distance
a = area of molecule
Vote monkeys into Congress. They are cheaper and more trustworthy.
To research the dynamic of Salad Dressing. And im posting this sitting at work not half a mile from there.
And here I thought it was because they are more attracted to each other than they are to other types of compounds, ie water strongly hydrogen bonds to itself, squeezing out any hydrophobic molecules, while long hydrophobic chains stack strongly, squeezing out anything that doesn't stack strongly.
If you carefully put oil on top of water, you realize it "swims" as it is lighter than water.
Now if you shake it, your might expect it could "mix" with water, like alcohol e.g. does.
Now you have to understand that there are different kinds of "mixes".
Alcohol in water is a kind of solution, like salt in water (albeit looking closer at it, there is a significant difference).
However, oil in fact does mix with water pretty fine if you can make the oil into very small droplets.
Milk e.g. is an emulsion of water an oil (amoung other parts), an ordinary skin cream e.g. is a mixture of oil and water.
The main reaon why oil and water don't want to mix without help is simple: surface tension of water, and the chain building of water molecules. Water molecules are di-poles. They have a + charged and and a - charged end. Like magnets they build long chains of water molecules. That means instead of staying arbitrary close to an oil molecule they turn away from the oil and look for another water molecule. Most oils/fats have no poles.
Bottom line molecules that are bi-polar and those that are mono-polar don't mix good (or not at all).
Anyway that is school knowledge, and yes I have read the posted article ...
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
I have no background in this area, but I'm surprised to learn that we didn't know this already. Makes you wonder what other "simple" discoveries are waiting in around the corner.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
> the hydrophobic interactions between fats and water
> are crucial to the mechanics of microbiology
Also, salad dressing.
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I thought the winners of the 2010 Ig Nobel Chemistry prize disproved the old belief that oil and water don't mix. http://improbable.com/ig/winners/#ig2010
... what would the gulf oil spill have been like if oil and water did mix?
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This is what I was taught as well. So I don't really understand what they've done, except create some derived value that may be useful, but doesn't "explain" anything new. And it took them 30+ years.
Old news -- maybe you youngsters can't remember:
yes they do
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
That would be E(D) = -2y[sub i](a-a[sub 0])e^(-D/D[sub 0])
http://www.newscientist.com/article/dn3408-oil-and-water-do-mix-after-all.html
Hey, if you're not part of the solution, you're part of the precipitate.
I got here through a series of tubes
Actually, I was in gifted algebra and physics classes in 7th grade circa 1977. And I'm sure if Mr. Jaloweic(sp?) were able to hear this nonsense his coffin would be drilling to China about now.
-- L8R, guitardood
Math is the language used to describe the physical interactions of the universe.
They think they've come up with something that will accurately describe the physical phenomena of oil and water interaction. This will examined by people who are doing work in relevant studies.
If you want an explanation of *why* they act like this, go find someone who's job involves working with this phenomena and he/she will probably be happy to talk about it.
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
a team of chemical engineers at the University of California, Santa Barbara have defined an equation that measures a compound's hydrophobic character. It's the first such equation of its kind.
Perhaps there's an escape via language lawyerism via "of its kind" but for decades there has been software to estimate the hydrophobicity of small molecules and (relying on even more approximations) proteins. Underlying that software are scores of "equations" that use tables of atomic and molecular fragment parameters of electronegativity and polarizability to calculate 'not bad' estimates of molecular hydrophobicity.
And while i'll quibble about "the first such equation"; i really think most folks should quibble over "defined an equation that measures", people armed with instruments "measure", equations 'calculate an estimate'. ok, now: hey you kids get off my lawn!
I would argue that no theological position, atheist or otherwise, is tenable. Everyone believes in something but the only conclusive proof we get is when we die, at which point it becomes extremely difficult to say "ha, I told you so!".
They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance. - Terry Pratchett
How would you propose to "understand" a natural phenomenon better than building a model that explains empirical observations? I argue that building a model that can make accurate predictions is the very definition of understanding something.
Just being pedantic, but homogenized milk is an emulsion; milk out of the cow most certainly separates into milk and buttercream (and the buttercream itself is a high-fat emulsion; it still has a lot of moisture in it.)
If you could explain it away with polar bonds (or lack thereof), why do emulsions emulsify? The hydrocarbon and water molecules have the same number of bonds, and the same density, no matter how vigorously you shake them.
If oil and water DID mix, the total volume of oil, which would have dispersed over the massive body of water that is the Gulf of Mexico, would have been a rounding error. There would have been some localized effects, but not catastrophic ones in any way.
I work in the field on the theory/simulation side, and have actually had dinner and discussed research with Dr. Israelachvili a couple of times. I've only had a chance to skim the paper, but I think I can summarize it pretty well... by the time I've really absorbed it you folks will have moved on to the next shiny new story so I'd better do it now!
First of all, the report claims that the paper is all about how oil and water don't mix and makes a big deal about how we don't know how that works. For simple stuff like say water and a basic hydrocarbon like octane, that's really not true... it's all about what has already been said above, polar vs. nonpolar (electrostatics) and entropy.
Things get more complicated when you want to model something like an extended hydrophobic surface, or the interactions and formation of bilayer membranes like we have in a cell. It's been known from experiments since Dr. Israelachvili's work in the 80's that if you take two such surfaces (usually mica functionalized to make it hydrophobic) and bring them together in water, they will repel each other, up until at some point they very quickly strongly attract, expel the water between them and glue themselves together (also called "cavitation"). This is the sort of data shown in Fig. 2 in the paper. The connection with membrane formation is to describe how two membranes behave when they come close together, they have to do something similar to get close enough to fuse (figure 3).
Figuring out how to describe this behaviour from a theoretical standpoint has been very difficult! We know what all the parts have to be (hydrophobic,electrostatic, steric/Van der Waals, entropic) but haven't been able to put them together in the right way to describe all of the experimental data. What Jacob and his team have done here is found a nice way to 1) describe the hydrophobic interaction between extended surfaces mathematically (the equation above), 2) combine it with all the other parts (figure 4), and 3) show that the equation with a combination of fitted and measured parameters can fit the experimental data pretty well (Table 1). It's very nice work, definitely a step forward in our knowledge of hydrophobic surface and membrane interactions, and I'm going to make sure I study it more carefully soon!
Build a good model.
From upthread: There's a characteristic distance [D sub 0] which represents the size of the organic molecule, and an adjustable coefficient [gamma sub i] that can be adjusted for different substances.
Sounds more like a fit then a model. It even has 'finaglers constant' (gamma sub i).
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
science |sns| noun the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment : the world of science and technology. a particular area of this : veterinary science | the agricultural sciences. a systematically organized body of knowledge on a particular subject : the science of criminology. archaic knowledge of any kind. ORIGIN Middle English (denoting knowledge): from Old French, from Latin scientia, from scire ‘know.’
I understand what math is used for. My problem is with proclaiming that we KNOW FOR A FACT when in fact all we have is a theory that has yet to be scrutinized (ie observed and experimented) by anyone but the people coming up with the equation. Science would be impossible without theories. But those theories need to be proven, usually by exhaustively trying to disprove the theory. That is what I was taught was the correct scientific method. Theories based on theories based on other theories have no place in real science other than to stimulate debate and the 'observe and experiment' phase. There is more proof of the existence of God (again a theory) than some of the theories put forth over the last century.
I have problems with stating something is a fact when in fact it is just a theory, occasionally accompanied with some circumstantial evidence.
For example, we are told that the sun IS a Hydrogen fusion reaction. Has anybody actually visited the sun, scooped up some of it's core, performed molecular analysis of said core and shown that it is in fact hydrogen atoms? NO! So the correct statement should be: Current theories suggest that the sun is a hydrogen-fusion reaction. However, it is possible that the sun may be some other as yet undiscovered atomic process on some as yet undiscovered non-existent-on-Earth element that we know nothing about. The fact that it burns similar in a vacuum as hydrogen is just circumstantial evidence among others on which the theory is based, but it still is just theory.
Again, I have no problem with theories, just the teaching/preaching of theories as fact. In theology, this is possible because faith comes into the equation, however, in science the only things that are truly relevant are facts.
Think of all the wasted brain energy and the wasted decades of time coming up with theories which expand on Einstein's relativity, which was based on Einstein's 'self-made-up' fact that the speed of light was the maximum velocity that anything could travel which you should know was just DISproved by the folks at CERN.
All of those theories are now in question because of one missed fact: things can travel faster than light. Coming up with theories which can neither be proved or disproved are a great part of science and make for great science fiction but at some point you have to come back to the real physical world with real problems that require lots of brain hours AND experimentation.
A scientist making up facts to support a theory would never be taken seriously by a truly scientific mind
There could be nor more clear example of what I'm talking about than the whole speed-of-light 'fact' which is now NOT-fact.
God is love.
Love is blind.
Therefore, Ray Charles is God
-Richard Jeni, RIP
-- L8R, guitardood
...now figure out why people have the hiccups. *hic*
My blog
i think you rather have a problem with things that are beyond your understanding. just saying "However, it is possible that the sun may be some other as yet undiscovered atomic process on some as yet undiscovered non-existent-on-Earth element that we know nothing about" tells me that to you everything should be "theory" and nothing can ever be proved, unless you your self prove it.
I agree people saying something is fact when it should be theory is wrong, but i didn't see fact anywhere.. and even if their equation is off - for now it gives us a better understanding and therefor helps ups "know" what is going on.
also your "There could be nor more clear example of what I'm talking about than the whole speed-of-light 'fact' which is now NOT-fact." comment. does you more harm than good to be honest.. the speed of light is in fact a fact.. it can and has been measured and confirmed. I can only assume you are referring to a different finding from a few weeks ago.. which is going though one of the toughest reviews ever, in due scientific process.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
Science has mere "practical" or "real world" value. The unmeasurable cosmic power of Spaghetti, on the other hand, is theologically tenable.
Huh? I thought oil and water don't mix because oils have primarily non-polar covalent bonds vs the ionic bonds in water molecules? That's what I was taught, and a quick google finds that this appears to be the generally accepted answer.
Modern copyright is theft of culture from everyone and it retards the progress of the useful arts and sciences.
I just have to step in. If you do a bit of study of systems theory, particularly Rossby's constructability analysis and complexity theory, you will learn a particular fact about systems, which is that the complexity of the controller of a system must always be greater than the complexity of the system - else it can not control it. Without going into the details, one of the outcomes of this point is that no entity within a system can know (or deduce?) everything about the controller.
And from that one can see that no matter what argument you come up with either for or against a God ('controller') that controls the Universe ('system'), there is an equally valid argument against it. The question of whether there is a God is indeterminable, it's a matter of choice. Or, put in scientific terms, both existence and non-existence are not falsifiable.
Which is just my way of saying (to all sides), "Let's all just quit arguing about this, and let it be!!". Folks who disbelieve in God are not inherently crazy or stupid, and folks who believe in God are not inherently crazy or stupid. And some members of each group are crazy, stupid or both - but not for that reason.
This does make Pascal's Wager more interesting.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
First of all the OP title: "We Finally Know Why Oil and Water Don't Mix" please read.
Second, I didn't say that "I" had to prove anything for myself, just that before spouting off things as fact, they should be facts and not theories. It should be the job of the theoretical scientist to prove his own theory to him/her self through scientific method prior to submitting for peer review.
Third, in regards to:
I can only assume you are referring to a different finding from a few weeks ago.. which is going though one of the toughest reviews ever, in due scientific process.
That is exactly what I'm referring to. Not the speed-of-light but the made-up fact that the speed-of-light is the fastest that anything can travel.
Lastly, the only thing that I'm having trouble understanding is how someone can argue against my basic premise which is don't teach a theory as fact.
-- L8R, guitardood
It's NOT a "theological position" by any definition of the word "science".
because your examples are so horridly flawed.. your saying that "you" don't have to prove it but that's the jobs of scientists. yet you seem to think the only way of proving the fusion reaction on the sun is to "scoop".. it up and check it.
and the fact that you are saying "Einstein's 'self-made-up' fact that the speed of light was the maximum velocity that anything could travel which you should know was just DISproved by the folks at CERN" and trying to say people shouldn't preach theories as fact is just ironic. In that case nothing has been "disproved" they have witness something they don't understand and there is peer review going on now (more than just about any other claim this decade) and we will have results in time, clamming that they "disproved" something shows that you are trying to spew theory as fact.
You are the type of person who questions anything they don't understand and grasps at threads to make things you think are wrong look quite not right. you are the type of person who tries to appear as if they understand a topic and then convince people who have no clue that you know what your saying and make them question the people who actually do understand what is going on.
In my "theory" you are a troll, and i submit your own comments as evidence.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
The link below is a transcript from an Australian ABC network science show in 2005, Catalyst.
Professor Ric Pashley found he could make oil and water mix, and keep the result for more than a year in a sealed container without them separating, simply by getting rid of dissolved gases in the water.
He demonstrated this in his kitchen!
http://www.abc.net.au/catalyst/stories/s1314925.htm
And you are a moron!
-- L8R, guitardood
I unfortunately have better things to do sometimes than go back and read posts from several days back. Sometimes I will continue the conversation, but once a post comes days later, usually Im not going to continue eagerly awaiting your burst of brilliance. Im sure if I were to ever go on vacation we could rely on you to burst into the abandoned conversation to declare victory; your contributions in that regard are appreciated.
Im glad that you were able to come up with a clever name for me, while remaining AC all the while, however; the irony of it all is delicious and nourishing.
By the way, regarding your posts on that topic, the fact that you post AC on slashdot and are vigorously trying to defend yourself in such an arena to someone you dont know and who has no standing in the dev community kind of kills your credibility. If you had like published articles on this, or even your own blog, you would gain some shreds of credbility, but posting in un-monitored comments on someone ELSES blog and arguing on slashdot dont really do much for your rep.
Its kind of why I really had no interest in seeing your response-- as wikipedia might have noted, "[citation needed]", and unfortunately you seem to HAVE no citations or credentials-- other than your unsubstantiated claim to have "known Mark from years ago". OOOh, that really tells me whether you know what youre talking about or are simply some wanna-be hack on slashdot.