Can equivalent theoretical predictions be calculated in a Bohmian framework for the quantum aspects, or is this (potentially) an interesting case where there’s divergence and falsifiability?
Einstein's relativity rules chemical bonds in heavy elements, new research shows
51–60 of 207 posts
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#52Very farsighted, after working as a patent clerk, to lay claim on such a foundational technology. Back in the day, they must've been like, oh, so Mercury blocks the sun at the wrong time, but where's the commercial value - and now every chemical company throughout the universe is about to get a bill every time they make something more complex than hydrogen gas. Meanwhile, Galilean relativity has long gone out of pate…
They’re already taxed to fund pure research, it would be unfair to charge royalties for non-rivalrous products they can’t monetise.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#53Earlier quoted context omitted.
Sigma and Pi bonds are typically covered in AP Chemistry, even if the “why/how” is hand waved pretty heavily. The valence cloud shapes get wild for heavier atoms and bonds between two or more atoms add even more to the mix.
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?
We have answers. It’s called physical chemistry. The problem is that it takes a shit ton of math
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#54Earlier quoted context omitted.
Are "magic coefficients" not just a result of the units you are using? Like how h-bar is 1 if you are using natural units
It's a different kind. Say, some reaction should run 1.23x faster theoretically. But the theory is approximate (in order to be tractable at all), and so are its predictions. This particular element is special in its own way, diverging from the theory a bit, even though its neighbors fit well. That particular bond requires a bit less energy to break than the theory predicts, due to a complex interplay of bonds nearby,…
Oh alright fair enough, measured vs. expected basically?
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#55In 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.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#56In 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.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#57Earlier 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…
how does biology depend on "dogma and mysticism"? I am really curious - a Google search yielded nothing much relevant.
I would think just because everything is so cumulatively complicated and interconnected that if you tried to trace a line through a complex biological processes and explain it all you will end up with 1,000 PhD thesis topics to figure out and thousands more you just hadn't noticed yet. And at the end of the day none of that might be all that useful for describing the larger process at work. So at some point when someone ask "Why does X do Y" you gotta just settle on "because that's the way it is" and move on.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#58Earlier 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…
how does biology depend on "dogma and mysticism"? I am really curious - a Google search yielded nothing much relevant.
I think he's being a little facetious - what he probably means is that if you attempt to get any true scientific rigor of that is going on in biological or chemical systems you end up facing the limits of physics in being able to explain what is going on. So rather and try to have scientific rigor, you just accept things the way they are and memorize the outputs and if anyone asks "why is it like that", your answers are either:
* Because God said so
* Find out yourself and get a nobel prize
Either way, even if you don't know what the answers are, you can still do serious work at a higher level of abstraction.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#59Can equivalent theoretical predictions be calculated in a Bohmian framework for the quantum aspects, or is this (potentially) an interesting case where there’s divergence and falsifiability?
Bohmian mechanics is nonrelativistic, so it has been "falsified" since its inception. It generally makes identical predictions to nonrelativistic quantum mechanics (i.e. the Schrödinger equation), but finding a relativistic version, equivalent to the Dirac equation in QM, has been difficult due to the nonlocality of the pilot wave.
Re: Einstein's relativity rules chemical bonds in heavy elements, new research shows
#60Earlier quoted context omitted.
It's a different kind. Say, some reaction should run 1.23x faster theoretically. But the theory is approximate (in order to be tractable at all), and so are its predictions. This particular element is special in its own way, diverging from the theory a bit, even though its neighbors fit well. That particular bond requires a bit less energy to break than the theory predicts, due to a complex interplay of bonds nearby,…
Oh alright fair enough, measured vs. expected basically?
More like, “the unmeasurable” or “unmodelable”. Examples could be the “A” in the Arrhenius equation or the “k” in Fourier’s law of conduction.
“A” is described as being derived from the collision frequency of molecules in that specific reaction but really it’s just an arbitrary magic number you look up in a book for the specific reaction that you’re working with. It’s often relatively temperature invariant across some range of temperatures but go outside that range and it becomes a function of temperature too.
Pulling up the wikipedia for “Collision theory” will show you that there has been some work to derive values of A rather than just find them all experimentally for every reaction. But it’s still very unsatisfying to the curious mind.
“k” is the thermal conductivity of a particular material. Curious minds might wonder what’s hidden behind this constant. How would someone predict “k” for a novel theoretical material? Like, say, tetrahedrane?
It’s been awhile, otherwise I’d walk you through a graph containing a couple hierarchical nodes where one constant leads to another equation. But it’s a bit too late to pour through Perry’s Handbook right now to jog my memory.