beecee

Breaking the rules: Heavy chemical elements alter theory of quantum mechanics

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beecee    95

https://phys.org/news/2017-10-heavy-chemical-elements-theory-quantum.html

A series of complicated experiments involving one of the least understood elements of the Periodic Table has turned some long-held tenets of the scientific world upside down.

Florida State University researchers found that the theory of quantum mechanics does not adequately explain how the heaviest and rarest elements found at the end of the table function. Instead, another well-known scientific theory—Albert Einstein's famous Theory of Relativity—helps govern the behavior of the last 21 elements of the Periodic Table.

This new research is published in the Journal of the American Chemical Society.

Quantum mechanics are essentially the rules that govern how atoms behave and fully explain the chemical behavior of most of the elements on the table. But, Thomas Albrecht-Schmitt, the Gregory R. Choppin Professor of Chemistry at FSU, found that these rules are somewhat overridden by Einstein's Theory of Relativity when it comes to the heavier, lesser known elements of the Periodic Table.



Read more at: https://phys.org/news/2017-10-heavy-chemical-elements-theory-quantum.html#jCp
Read more at: https://phys.org/news/2017-10-heavy-chemical-elements-theory-quantum.html#jCp

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http://pubs.acs.org/doi/abs/10.1021/jacs.7b05569

 

Abstract

Abstract Image

The reaction of 249Bk(OH)4 with iodate under hydrothermal conditions results in the formation of Bk(IO3)3 as the major product with trace amounts of Bk(IO3)4 also crystallizing from the reaction mixture. The structure of Bk(IO3)3 consists of nine-coordinate BkIII cations that are bridged by iodate anions to yield layers that are isomorphous with those found for AmIII, CfIII, and with lanthanides that possess similar ionic radii. Bk(IO3)4 was expected to adopt the same structure as M(IO3)4 (M = Ce, Np, Pu), but instead parallels the structural chemistry of the smaller ZrIV cation. BkIII–O and BkIV–O bond lengths are shorter than anticipated and provide further support for a postcurium break in the actinide series. Photoluminescence and absorption spectra collected from single crystals of Bk(IO3)4 show evidence for doping with BkIII in these crystals. In addition to luminescence from BkIII in the Bk(IO3)4 crystals, a broad-band absorption feature is initially present that is similar to features observed in systems with intervalence charge transfer. However, the high-specific activity of 249Bk (t1/2 = 320 d) causes oxidation of BkIII and only BkIV is present after a few days with concomitant loss of both the BkIII luminescence and the broadband feature. The electronic structure of Bk(IO3)3 and Bk(IO3)4 were examined using a range of computational methods that include density functional theory both on clusters and on periodic structures, relativistic ab initio wave function calculations that incorporate spin–orbit coupling (CASSCF), and by a full-model Hamiltonian with spin–orbit coupling and Slater–Condon parameters (CONDON). Some of these methods provide evidence for an asymmetric ground state present in BkIV that does not strictly adhere to Russel–Saunders coupling and Hund’s Rule even though it possesses a half-filled 5f 7 shell. Multiple factors contribute to the asymmetry that include 5f electrons being present in microstates that are not solely spin up, spin–orbit coupling induced mixing of low-lying excited states with the ground state, and covalency in the BkIV–O bonds that distributes the 5felectrons onto the ligands. These factors are absent or diminished in other f7 ions such as GdIII or CmIII.

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John Cuthber    3199

Interesting, but hardly news.

Gold's colour  and mercury's liquidity result from relativistic effects

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druS    1
On 10/4/2017 at 5:22 PM, John Cuthber said:

Interesting, but hardly news.

Gold's colour  and mercury's liquidity result from relativistic effects

 

John, I am hardly an expert, just an interested observer, but that's a touch harsh. As far as I can work out, the journal is more specific than "relativistic effects", it's about specific and unexpected behaviour. We have seen something of a cross over with larger and larger chunks of matter showing quantum effects (think it was  US PhD who used silicon chip manufacturing to create an object that was visible to the eye, and demonstrated quantum effects). Then we have this cross over  happening where very heavy molecules are not following the expected quantum behaviours.

I would think this very news worthy.

BTW, if you'd like to expand on gold and mercury relativistic effects in a thread, I would at least be one interested party.

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John Cuthber    3199
19 hours ago, druS said:

 

John, I am hardly an expert, just an interested observer, but that's a touch harsh. As far as I can work out, the journal is more specific than "relativistic effects", it's about specific and unexpected behaviour. We have seen something of a cross over with larger and larger chunks of matter showing quantum effects (think it was  US PhD who used silicon chip manufacturing to create an object that was visible to the eye, and demonstrated quantum effects). Then we have this cross over  happening where very heavy molecules are not following the expected quantum behaviours.

I would think this very news worthy.

BTW, if you'd like to expand on gold and mercury relativistic effects in a thread, I would at least be one interested party.

OK, it  may be "harsh" but when it comes down to it, this "Heavy chemical elements alter theory of quantum mechanics" just isn't true.

These issues of relativity, as it applies to QM were already known.

The "alterations" had already been made.

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jimmydasaint    154

John, I don't understand the abstract and your comments on gold and mercury.  Can you please simplify for non-experts just a little bit. Cheers mate.

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jimmydasaint    154
Posted (edited)

Found the explanation for gold. Electrons around the nucleus are in probabilistic shells. https://chem.libretexts.org/Under_Construction/Textmaps_and_Wikitexts/MVC%3A_Chem_1406/Chapters/02._Atomic_Structure/2.5%3A_Arrangement_of_Electron_(Shell_Model)

Electrons can absorb energy from light and "jump" from one shell to a higher energy shell.  They absorb at different frequencies for silver and gold.  Silver s-shell electrons absorb light in the ultraviolet end of the light spectrum and reflect all the other colours evenly giving silver  that silvery metal colour. 

Gold has s-shell electrons attracted with by an intense, 79 + charges from the nucleus.  As a consequence, the electrons  in gold following Einstein's relativistic principles, because, IIRC, the electrons gain speed/ angular momentum to avoid the attractive forces from the nucleus and also gain mass. The angular momentum orbit radius decreases.  The light absorbed by the electrons is in the blue part of visible light, as opposed to the ultraviolet end of the light spectrum so that the remaining colours combine to give a yellow gold glitter. 

https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry

Please correct as appropriate. 

Edited by jimmydasaint

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Dubbelosix    6

Yes, this is now among the many discrepancies of the standard model. There have been quite a few in the last seven years that I cannot recall them all. We have deviated some way from the standard model, this just hasn't been realised publically while yet, scientists in the background are aware of this.

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Strange    2478
2 minutes ago, Dubbelosix said:

Yes, this is now among the many discrepancies of the standard model. There have been quite a few in the last seven years that I cannot recall them all. We have deviated some way from the standard model, this just hasn't been realised publically while yet, scientists in the background are aware of this.

Can you provide some examples or some sort of supporting reference for this?

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Dubbelosix    6

Sure... I'll provide one, and we'll keep going...

 

 

You will need to give me time, a big long story, but the links I once had are no longer accessible. But... I know of a few. One relatively recent one was the discovery of the Pentaquark, which was one deviation from the standard model, but was predicted in beyond standard models. 

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Strange    2478
6 minutes ago, Dubbelosix said:

One relatively recent one was the discovery of the Pentaquark, which was one deviation from the standard model, but was predicted in beyond standard models. 

"the possibility of five-quark particles was identified as early as 1964 when Murray Gell-Mann first postulated the existence of quarks.[3] Although predicted for decades, pentaquarks have proved surprisingly difficult to discover and some physicists were beginning to suspect that an unknown law of nature prevented their production.[4]"

https://en.wikipedia.org/wiki/Pentaquark

Seems to be pretty much part of the standard model.

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Dubbelosix    6

It isn't. At least, was never considered to be. It was never needed. You see, the standard model is a sketch, if you think we get it right all the time from the word go, this would be remarkable, to me.

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swansont    6208
1 hour ago, Dubbelosix said:

It isn't. At least, was never considered to be.

What about pentaquarks is inconsistent with the standard model?

Quote

It was never needed. 

That's a separate issue, I think.  

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Dubbelosix    6

You won't find anything inconsistent with the standard model. That isn't what this is about, you won't find anything violating the laws of physics. The standard model isn't about that, it was a very early model, or sketch if you like which we have continued to find divergences from.

Edited by Dubbelosix

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Strange    2478
1 hour ago, Dubbelosix said:

Yes, this is now among the many discrepancies of the standard model. 

 

Just now, Dubbelosix said:

You won't find anything inconsistent with the standard model.

So, which is it?

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Dubbelosix    6

good question though as i WASN'T clear

Just now, Strange said:

 

So, which is it?

I don't understand. 

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Strange    2478
4 minutes ago, Dubbelosix said:

I don't understand. 

You started off saying there were discrepancies in the standard model and claimed the pentaquark was not part of the model (when it obviously is).

Then you said there is nothing inconsistent.

Maybe "discrepancy" and "inconsistent" mean very different things to you. Perhaps you need to explain what you mean.

And provide some actual examples of these "discrepancies". Or are they all, like the pentaquark, due to your lack of knowledge?

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Dubbelosix    6

You can take when I say discrepancies, as a statement against saying the standard model is all there is. No offence, but the nature of your posts supporting defence against my accusations there have been many divergences since the original standard model, is testament to that fact - you seem to think there hasn't been changes since it was first proposed... do you know how many years ago that was?

Edited by Dubbelosix

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Strange    2478
1 minute ago, Dubbelosix said:

You can take when I say discrepancies, as a statement against saying the standard model is all there is. 

I don't think anyone thinks the standard model is all there is. Because of dark matter, if nothing else.

But so far, there is no evidence as to what might be beyond the standard model.

Quote

No offence, but the nature of your posts supporting defence against my accusations there have been many divergences since the original standard model, is testament to that fact - you seem to think there haven't been changes since it was first proposed... do you know how many years ago that was?

So do you just mean the standard model has been extended to include new observations? If so, that is how science proceeds. (Is English not your first language? I would be surprised because it appears perfect but you seem to be using "discrepancy" and "divergence" in a slightly idiosyncratic way.)

But actually, I'm not even sure that is true. The existence of pentaquark was predicted long before they were seen. I am not aware of anything that has been found that was not predicted as part of the standard model.

Many physicists are very frustrated that nothing as been found to "break" or extend the standard model. Many were hoping that the Higgs wouldn't be found. Or that it would turn out to have properties different than expected. People still hope to find something that will support some for of supersymmetry but instead more and more constraints are being placed on any extension to the standard model.

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Dubbelosix    6

Dark matter is only one parameter that physicists used to change the standard model, if you have no complaints, will you tell me exactly what the nature of your posts earlier where about, before I continue?

By the way, anything that predicts something that is not concurrently within the standard model, is beyond it, let's be clear about that also. 

You see, when you have additional features that are not exactly required by the theory, means your theory needs to somehow accommodate and give reason why it is happening - that doesn't mean, though, (and I really understand why you are struggling with me), this does not always include the notion of ''breaking'' any fundamental parameter. Sometimes, we are finding very strange artefacts of our science which has not been postulated to exist within a first principle of the standard model. 

 

These divergences from the usual model though, are beyond the standard model physics, by strict definition. This is not surprising, at least, a few sources I have read, physicists expected this quite a few times. It means, additional parameters over all have to be concluded, but as Swansont noted, these are often called error bars. The errors can be overwhelming though, when you look at the entire model of physics - this is why physicists actually get frustrated and call the standard model, ''the theory of nearly everything.''

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Strange    2478
8 minutes ago, Dubbelosix said:

will you tell me exactly what the nature of your posts earlier where about, before I continue?

Possibly a complete misunderstanding of your use of the word "discrepancy". 

However, there is absolutely nothing observed that is outside of the standard model and nothing that has caused the standard model to be revised since, I think, the addition of quarks (one of the major paradigm shifts Have lived through!). I may be wrong, but your one example of "discrepancy" doesn't seem to require any change to the standard model.

Quote

By the way, anything that predicts something that is not concurrently within the standard model, is beyond it, let's be clear about that also. 

Indeed. But (again, as far as I know) none of the possible extensions have predicted anything that has been found.

Everything discovered to date is within the standard model. Hopefully something will be discovered soon that forces the standard model to be revised or extended. (My time is running out, apart from anything else!)

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Dubbelosix    6

Predicting something outside the standard model that somehow ''shouldn't exist in nature,'' is nonsense, do we agree, or are you promoting this?

'However, there is absolutely nothing observed that is outside of the standard model and nothing that has caused the standard model to be revised since''

 

 

Nonsense, let me just get that out there... I won't reply to everything ... I just won't put that time in. I will get straight to the point though: You just agreed that any additional feature is beyond the standard model, I know quite a few. If you are calling me a liar, then do so, don't beat about the bush. 

Edited by Dubbelosix

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Strange    2478
20 minutes ago, Dubbelosix said:

Predicting something outside the standard model that somehow ''shouldn't exist in nature,'' is nonsense, do we agree, or are you promoting this?

Huh? 

Supersymmetry predicts a number of particles that are not part of the standard model. There are other hypothetical ideas like axons.

So it is quite possible to predict the existence of things outside the standard model. That doesn't mean they "shouldn't exist in nature". What an odd thing to say.

Quote

'However, there is absolutely nothing observed that is outside of the standard model and nothing that has caused the standard model to be revised since''

 

 

Nonsense, let me just get that out there... I won't reply to everything ... I just won't put that time in.  

Could you provide some examples then. As this is so obvious to you, that shouldn't take much time.

(And why would I say you were lying, when you haven't provided any examples yet.)

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Dubbelosix    6

Just reading that first paragraph, we're not even on the same page, don't take offence, but I stay away from people who might be causing me trouble. Not saying you are, but we are not even on the same page.

Edited by Dubbelosix

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Strange    2478
Just now, Dubbelosix said:

Just reading that first paragraph, we're not even on the same page, don't take offence, but I stay away from people who might be causing me trouble. Not saying you are, but we are not even on the same page.

Well, I'm sorry you feel that way. But I can't really understand why you do. If my knowledge of the standard model is lacking, then I am interested in learning more. So if the standard model has changed in ways I am not are of then I would like to learn about it.

We both seem to agree that the standard model cannot be complete. But beyond that, I seem to have misunderstood several of your statements. So I am also trying to understand where I have gone wrong and what you meant.

For example, I initially thought you meant that there were things that had been discovered that were not part of the standard model. I see know that this was just a misunderstanding on my part.

Then I thought you were saying that if you predict something outside of the standard model then you are predicting something that can't exist. But obviously, I was wrong about that as well.

So I am not really sure where we stand. 

I would appreciate some examples of ways the standard model has changed or been extended since the discovery of quarks (even the Higgs mechanism is earlier than that) as it seems I have missed some stuff.

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