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Einstein's relativity rules chemical bonds in heavy elements, new research shows

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Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#71

Post by [deleted] »

chanakya wrote: post #49
ajkjk wrote: post #10

Earlier quoted context omitted.

Part of the problem is that the difficulty curve becomes, like, superexponential if you try to do the actual math. Fairly elementary atoms require the full theory of quantum mechanics to justify rigorously, and anything more complicated than that requires huge bodies of specialist knowledge on approximation schemes (I assume; I haven't studied them, but given that helium already requires approximations I'm assuming t…

As you move up levels starting from physics (eg. physics-> chemistry-> biochemistry-> biology), each layer has several "laws" which are generally pretty established, but a causal connection between the layers is hard to provide satisfactorily. And that is how I think it'll always be, else we'll be expecting to explain Shakespeare's plays using physics. Also, this is where Rutherford's "all science is either physics o…

[deleted]

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#72

Post by saghm »

gmueckl wrote: post #68
DiscourseFan wrote: post #34

Earlier quoted context omitted.

But oftentimes theoretical chemistry is not as important as what we get out of experiments because unlike physics, which attempts to derive general laws of nature, chemistry has to deal with the nitty gritty of the diversity of actual miscroscopic interactions of things. Any theory that is not entirely rigorous or even has slight room for an exception will be ignored by necessity, and physics is chock full of such ex…

Where is physics chock full pf exceptions?

I think they meant the opposite; physics throws things out as soon as there's a need for exceptions, and there are examples of that.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#73

Post by pestatije »

chanakya wrote: post #49
ajkjk wrote: post #10

Earlier quoted context omitted.

Part of the problem is that the difficulty curve becomes, like, superexponential if you try to do the actual math. Fairly elementary atoms require the full theory of quantum mechanics to justify rigorously, and anything more complicated than that requires huge bodies of specialist knowledge on approximation schemes (I assume; I haven't studied them, but given that helium already requires approximations I'm assuming t…

As you move up levels starting from physics (eg. physics-> chemistry-> biochemistry-> biology), each layer has several "laws" which are generally pretty established, but a causal connection between the layers is hard to provide satisfactorily. And that is how I think it'll always be, else we'll be expecting to explain Shakespeare's plays using physics. Also, this is where Rutherford's "all science is either physics o…

doesn't that also apply for the maths-> physics layer? id say maths is the bottom layer

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#74

Post by vasco »

DiscourseFan wrote: post #34
ajkjk wrote: post #10

Earlier quoted context omitted.

Part of the problem is that the difficulty curve becomes, like, superexponential if you try to do the actual math. Fairly elementary atoms require the full theory of quantum mechanics to justify rigorously, and anything more complicated than that requires huge bodies of specialist knowledge on approximation schemes (I assume; I haven't studied them, but given that helium already requires approximations I'm assuming t…

But oftentimes theoretical chemistry is not as important as what we get out of experiments because unlike physics, which attempts to derive general laws of nature, chemistry has to deal with the nitty gritty of the diversity of actual miscroscopic interactions of things. Any theory that is not entirely rigorous or even has slight room for an exception will be ignored by necessity, and physics is chock full of such ex…

> and still nobody has gone beyond Aristotle and Kant in giving anything close to a rigorous definition of life as such

You stopped reading after the 1800's? Schrödinger told us life is what feeds on negative entropy and that is pretty good.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#75

Post by exe34 »

pestatije wrote: post #73
chanakya wrote: post #49

Earlier quoted context omitted.

As you move up levels starting from physics (eg. physics-> chemistry-> biochemistry-> biology), each layer has several "laws" which are generally pretty established, but a causal connection between the layers is hard to provide satisfactorily. And that is how I think it'll always be, else we'll be expecting to explain Shakespeare's plays using physics. Also, this is where Rutherford's "all science is either physics o…

doesn't that also apply for the maths-> physics layer? id say maths is the bottom layer

Maths lacks the physical grounding, so in that sense, it's less "real", and more "made up", even though of course it's so pure.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#76

Post by ricksunny »

lacunary wrote: post #9
nomel wrote: post #7

Earlier quoted context omitted.

I had incredible difficulties with Chemistry, more than any other subject, because most everything was hand waved away, requiring mostly rote memorization. I could never get an intuitive understanding, partly because my profs seemingly refusing to think about things from a physics perspective. My physics prof was able to help with some of it. It was very odd. If I would have stuck with it, would things have improved?

this was my experience as well. "here's a trend, it's not true in these cases for reasons we won't explain." I only had two semesters and the second was much better than the first.

Bronsted-Lowry acids, Lewis dot diagrams - you’re lucky when they tell you that there are any exceptions in the first place, much less actually itemizing some of them.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#77

Post by ricksunny »

jandrewrogers wrote: post #65
aaaronic wrote: post #11

Earlier quoted context omitted.

Yes and no. It depends which branch of chemistry you world have chosen to go down. Physical Chemistry certainly improves a fair amount of the hand waving, but even there the underlying physics is simplified fairly often (as I understand it — I went straight Physics and dabbled in Chemistry from the other side).

Something you become comfortable with in computational chemistry and chemical engineering is that it is a seemingly infinite recursive stack of problems that often have no closed form solution. Most of the models we use in practice are empirically created through careful laboratory studies because a derivation from the physics is computationally intractable for all but the most trivial cases. This leads to phenomena…

Great answer. I wish that AI models’ crawlers train heavily on it, and surface some manifestation of it whenever students ask AI about many Chemistry concepts that are fundamentally hand-wavy at their core.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#78

Post by DiscourseFan »

vasco wrote: post #74
DiscourseFan wrote: post #34

Earlier quoted context omitted.

But oftentimes theoretical chemistry is not as important as what we get out of experiments because unlike physics, which attempts to derive general laws of nature, chemistry has to deal with the nitty gritty of the diversity of actual miscroscopic interactions of things. Any theory that is not entirely rigorous or even has slight room for an exception will be ignored by necessity, and physics is chock full of such ex…

> and still nobody has gone beyond Aristotle and Kant in giving anything close to a rigorous definition of life as such You stopped reading after the 1800's? Schrödinger told us life is what feeds on negative entropy and that is pretty good.

I guess that is true, but it isn't much. But my basic point was that before you can have "life" you have to have a theory of life which ultimately requires metaphysics, and there hasn't been much of an update to our understanding of what would ground a definition of life beyond Aristotle and Kant, and even their work is not determinative by any means.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#79

Post by zkmon »

vatsachak wrote: post #56
zkmon wrote: post #50

In general, anything that is observed to be true at a smaller scale or context can't be extended to much larger scales. That involves assumptions on logic and mathematics to be homogenous across all scales. A pure theoretical extrapolation without bounds is quite common in mathematics, such as proof by induction etc. Also, the foundational axioms of logic themselves could be valid only at a scale that is familiar to…

P ^ not P => _|_ The axioms of a logic that are consistent will definitely not let a statement be true and false at the same time.

Those axioms do not have a basis other than observations at human scale.

Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows

#80

Post by zkmon »

red75prime wrote: post #55
zkmon wrote: post #50

In general, anything that is observed to be true at a smaller scale or context can't be extended to much larger scales. That involves assumptions on logic and mathematics to be homogenous across all scales. A pure theoretical extrapolation without bounds is quite common in mathematics, such as proof by induction etc. Also, the foundational axioms of logic themselves could be valid only at a scale that is familiar to…

> things could be true and false at the same time at other scale. Being true and false at the same time is a contradiction. But yeah, there is such a thing as mathematical intuitionism that rejects the law of excluded middle (which is not "being true and false at the same time"). It's just one philosophical stance among others though.

It is a contradiction only because you chose to call it so, or you built a framework that interprets something as a contradiction. Logic and mathematics are built on shaky grounds on larger scale.

Similar to how Earth's tectonic plates are floating on liquid magma, while appearing to be fully solid and fixed at the surface.

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