New Results Contradict Long-Held Chemistry Dogma 316
An anonymous reader writes "Researchers have found that the long-held belief that only the outer, valence, electrons of an atom interact may be false. Computer simulations have shown that at pressures like those in the center of the Earth the inner, core, electrons of lithium also interact."
arXiv link (Score:5, Informative)
For anyone who wants to read the actual paper: http://arxiv.org/abs/0805.2781 [arxiv.org]
Valence != Outer Core (Score:5, Informative)
Sensationalist Bullshit. (Score:5, Informative)
Now that's a fucking shocker. Most Chemistry today focuses on conditions either similar to STP or than can be created within STP. STP is "Standard Temperature and Pressure" Usually defined for the purpose of convenience of communication as 298K and 760 Torr. They define this as "standard" because everybody in Chemistry knows that chemistry changes as you change conditions, and it's useful to have a standard to compare to, even an arbitrary one (298K, 760 Torr is "average" sea level temperature and air pressure). The standard is also very useful for Chemical Engineering.
The article is poorly written garbage.
Re:Poor choice of words (Score:5, Informative)
If it was dogma the priests of chemistry would be denying the evidence and punishing its discoverers.
Evidence you are not a scientist. The word "dogma" just has a different meaning from what you are used to when talking about science. To wit: "The Central Dogma" [wikipedia.org]. You should call up Francis Crick and tell him he was using that word wrong. Maybe they will posthumously take back his Nobel Prize.
Re:Poor choice of words (Score:5, Informative)
500+ years ago scientists thought the earth was flat.
No, they really didn't. Hell, over 2000 years ago the Greeks already knew the Earth was a sphere. They even knew its diameter! The idea that everyone ever thought the world was flat is entirely false - go ready a history book and stop perpetuating such garbage.
Re:Poor choice of words (Score:5, Informative)
No need. Crick has already acknowledged that he really didn't understand the meaning of the word "dogma" when he used it. However, his ideas were so grond breaking that the word itself has changed/added meaning to accommodate him.
Re:Poor choice of words (Score:4, Informative)
core correlation (Score:5, Informative)
Chemists already know that core electrons do influence bonding and such. It is simply a short cut to ignore them. Hence, when one wants to get the last few digits on your answer you turn on "core correlation" which treats the core and valance regions the same.
Furthermore, the conditions in question here are so extreme as to border on being a plasma or some such. So I am not really surprised to see some effect that are negligible under "normal" conditions to grow and become important.
Re:Poor choice of words (Score:5, Informative)
No, they didn't. It's called the flat earth myth [wikipedia.org].
Uh, yeah? That's the whole point of Science. Scientists try to create theories that best fit the available data. More importantly, they are always looking for new evidence which will either corroborate or contradict their theories.
Re:Poor choice of words (Score:3, Informative)
'Dogma' is common in the sciences, but it implies something different than the formal definition you are thinking of. It is usually used to describe a highly simplified model of how a system works. It's just a useful way to think about something.
The most well known example is the central dogma of molecular biology [wikipedia.org]. By the time you finish freshman molecular biology in college, you know that it is a gross simplification of how a cell works, but that it is a very good first approximation.
Chemistry is no different. The vast majority of chemical interactions involve the valence electrons. So how do you introduce the topic? You say 'all chemistry deals with valence electrons (cough, cough)'. If the students learn that, you're actually doing pretty well.
Once you get past the basics, you admit to the students that you might have fibbed, and that under unusually high energy conditions, the inner shell electrons actually can interact. Upper level chem courses have been teaching this for years - there are no surprises here.
All the article says is that a research group is predicting a previously unknown inner shell electron interaction under high energy conditions. While it is news, it is not shocking, and while it violates the 'dogma' that only valence electrons interact, it changes nothing about how the dogma will be taught.
Progress in science is made at the edges. What happens to this at high energies? How will these atoms behave at extremely low temperatures? The easy cases have been understood for years, if not centuries. This discovery doesn't change any of that. So this is cool, but not a fundamental break-though.
Now, if someone replicates this experimentally, and then figures out how to use it to make dilithium crystals to power their prototype warp drive, that'd be revolutionary.
Re:Goes against chemistry dogma? (Score:5, Informative)
For example, a lot of research is being done now utilizing ultra-high pressure water as a replacement for organic solvents, for greener chemistry.
I think you mean ultra-high pressure carbon dioxide, not water. Supercritical CO2 [wikipedia.org] is indeed an interesting area of research, as it can be used to replace dangerous organic solvents, making industrial chemistry safer and greener.
And I agree that there is likely a rich unexplored landscape of interesting chemistry beyond standard temperatures and pressures.
Interesting results, but (Score:4, Informative)
was any 'dogma' really overturned? My understanding was always that the basic chemical rules were first order approximations, not a comprehensive description of how everything must behave. For example, xenon is an 'inert' element, with the outer shell full, but xenon tetra-fluoride (XeF4) is a stable compound. I learned that in high-school in the 1980's.
Re:Goes against chemistry dogma? (Score:1, Informative)
Does anyone check anything before posting?
http://en.wikipedia.org/wiki/Supercritical_water_oxidation
Lithium... (Score:2, Informative)
Let's not forget that Lithium only has 3 electrons, 2s1 and 1s2. With this is mind it's not all that surprising.
Re:Poor choice of words (Score:1, Informative)
Sometimes a bit harder for evidence that would support their theories...
Electron-Nucleus Interactions (Score:5, Informative)
IAAC (I am a chemist)
Honestly this result is not unexpected. The interactions of electrons and nuclei depend on several factors: distance, energy, and charge. There is also the factor of election-electron interaction, which is where the idea of valence electrons comes about.
Normally the outermost electrons of an atom are far enough from the nucleus that the distance from the nucleus and the repulsion from the other electrons on the atom allows them to more easily interact with other atoms. This is how bonding works, an electron gets "shared" between two atoms or the electron completely jumps off the atom and turns the atom into an ion which is attracted to other, oppositely charged, ions. Yes, I'm oversimplifying quite a bit for the layman.
Every electron in an atom can interact with another atom, it's just MUCH less likely to happen for the inner electrons of an atom and the interactions of the inner electrons to other atoms are much weaker than those of the outer electrons. Increasing the pressure allows the inner electrons to interact more strongly with other atoms.
Under higher pressures and energies two things happen. First of all atoms are pressed closer to each other. This means that all of the electrons are closer to other atoms. This increases the likelihood that an electron will interact with another atom, forming a bond. The second effect is that the increased energy tends to cause the electrons in atoms to jump to higher energy states which are further out from that atom's nucleus. This means less crowding which means less repulsion from other electrons which means that each atom's nucleus is more exposed to interaction with other atom's electrons. Again, I'm oversimplifying for the layman.
The extreme of this is when the pressure is great enough that each nucleus gets close enough for the nuclear force to overcome the electrostatic repelling force between the two positively charged nuclei. When this happens you get neutronium, the core of a neutron star. Obviously you don't normally see these levels of pressure on Earth!
What is really in question is the exact numbers of the interactions. At what pressure does a certain phase of atom to atom interaction appear? How does the increased pressure affect rates of reactions between atoms? Scientists are trying to measure hard numbers of the effects of pressure on chemistry. There already is a good deal of theoretical work but the experimental work is a bit tough to do given the conditions needed.
Re:Poor choice of words (Score:2, Informative)
Great, another electrical universe nut.
1. Find some part of cosmology that is not yet fully explained (there are a lot of these, so this part is easy!)
2. Claim the explanation is ELECTRICITY!
3. Never provide any proof ever, only claim that the prevailing, incomplete theory is wrong.
Dogma... in like high school. (Score:2, Informative)
"Researchers have found that the long-held belief that only the outer, valence, electrons of an atom interact may be false.
Take Chemistry 101 and 102 in a college today. They no longer believe this. Though I guess it is unusual for lithium. However the center of the Earth is as hot as surface of the sun, and is essentially a ball of plasma, which is so hot nucleons congregate together and all the electrons dance around it.
Re:Poor choice of words (Score:3, Informative)
The catholics use the bible as some sort of starting point for their dogma but the exact rules are set by the leadership, not the book (and are often mutable). The protestants are the ones who follow only the book (of course different groups follow it in different ways...). That's where the big division came from.
Re:Poor choice of words (Score:2, Informative)
Re:Proof that Proof isn't Always Right (Score:4, Informative)
No, you cannot. Its impossible to show scientifically that anything doesn't exit. You can just show that something actually does exist. Thats why we were able to prove that, under condition XYZ, only valance electrons react. As long as we didn't test it in every possible scenario (and even then, we cannot prove that there aren't any other possibility), we cannot say that there aren't some ways where that theory doesn't hold. And as this showed, there was a scenario we hadn't tested.
Scientists (real ones) will never say that its impossible for God to exist. They'll just say that all of the currently provided evidence are bogus, and that there isn't any valid theory that shows its existance beyond wishful thinking by a few zealots. Doesn't change that God may exist. We just have nothing to lead us to think it does.
If some scientist claims to be able to prove that it doesn't exist (or that ANYTHING ELSE doesn't exist), they're doing faux-science.
Re:Poor choice of words (Score:5, Informative)
Oh dear... as someone said already, I expect this is probably an electric universe rant, and that responding to it will do almost nothing. I could moderate it down, but other mods probably wouldn't understand my reasons for doing so, as the parent avoided mentioning the crackpot theory itself.
It should be said, however, that the odd thing about the dark matter predictions are that they work very well, as do the dark energy predictions. We did many have other models that were put forward, some containing significant changes to various theories. None of them worked nearly as well as our current model with dark matter. There are many people in the community that don't like our lack of knowledge about dark matter, but it works so well that, as with many things in high energy physics, we can only assume that it is actually there until we come up with a better theory.
As for black holes, I would suggest that you actually learn modern GR before suggesting that you understand the theory better than everyone else in the community does. In fact, try learning real cosmology, and looking at results like measurements of CMB anisotropy, and Big Bang nucleosynthesis.
Re:Poor choice of words (Score:3, Informative)
They weren't dark because they completely lost the Greek knowledge rather they simply never built on any previous discoveries and doing so pissed off the church. In fact, the church was pretty good at locking that stuff away.