I was reading a book hoping to work out how to derive E=mc2. My idea was to go from being about 400 years behind science to merely being 100 years behind. This sort of reporting makes me realise those 100 years are not linear.<p>I had to go check that this was real - <a href="https://www.nature.com/articles/s41557-023-01300-3" rel="nofollow noreferrer">https://www.nature.com/articles/s41557-023-01300-3</a>, because it could have as easily been a marketing site for the next Marvel movie for all I could ground it in my understanding of experimentation.
A factor of 1e11, while large, is commonly found in chemistry where most phenomena have a log relationship. The standard pH scale, for example, already spans 14 orders of magnitude.
You've got to love the declaration at the end of the article:<p>> The research was supported by grants from the US Office of Naval Research; the US Army Research Office Laboratory for Physical Sciences; the US Intelligence Advanced Research Projects Activity; Lockheed Martin; the Australian Defence Science and Technology Group, Sydney Quantum; a University of Sydney-University of California San Diego Partnership Collaboration Award; H. and A. Harley; and by computational resources from the Australian Government’s National Computational Infrastructure.<p>This is sponsored by the military.
So they simulated a chemical process, and the simulation ran 100B times slower than the actual chemical process?<p>Kind of like how simulating anything in detail tends to be a lot slower than the actual thing you're simulating?<p>Is the difference here that it's basically an analog rather than a digital simulation?<p>Not following if there was any breakthrough here or not.
> This allowed them to design and map this very complicated problem onto a relatively small quantum device – and then slow the process down by a factor of 100 billion.<p>They say they mapped the problem.... So is this a model of an observation, or an actual observation?<p>> “Until now, we have been unable to directly observe the dynamics of ‘geometric phase’; it happens too fast to probe experimentally.<p>> “Using quantum technologies, we have addressed this problem.”<p>'cos if its a model, they are obviously still not observing whatever-it-is directly, right?<p>PS I'm pretty sure they are talking about their model.
I’m stuck on how it is known that the quantum analog is operating the same as what it is an analog of. I’m completely out of my depth so I fed the paper to Claude 2 and, after some back and forth, got this:<p>“You raise a good point. There is no absolute certainty that the analog quantum system operated in exactly the same way as the original chemical reaction dynamics it was meant to model. Some key caveats and limitations include:<p>- The analog system is still an approximation, so there may be small differences in how the dynamics play out compared to the real system.<p>- Mapping a complex molecular system onto qubits necessarily requires simplifications and abstractions that could influence the outcomes.<p>- Factors like experimental errors, imperfect state preparation or measurement in the trapped ion system may introduce discrepancies.<p>- Important details like multi-particle interactions or higher-order effects may not be fully captured.<p>- Verification that the analog system exhibits the same identifying signatures or phenomena as the natural system would strengthen confidence in the analogy.<p>So while the researchers aim to design the quantum analog to faithfully mimic the essential physics, perfect equivalence cannot be taken for granted due to modeling approximations and technological limitations. The mapping should be validated by testing for characteristic properties before concluding the slow-motion "observations" definitively represent the original phenomenon. With improvements, analog quantum simulation could provide increasingly accurate models of chemistry.”<p>Is this a reasonably well grounded statement? And if so, how can anybody hope to verify the analog is exhibiting “the same identifying signatures or phenomena as the natural system” if the whole point is that we can’t observe the natural system with any precision to start with?
Does anyone have any idea how a person could go about trying to understand the basics of what's going on here, even in just a hand wavey way? This is so far above my head it seems like magic.
I guess some theoretical chemistry basics omitted in the short article wouldn't hurt:<p>In order to describe chemical reactions or atomic arrangements in terms of wave equations one normally treats the motion of the nuclei (slow/heavy) and the motion of the electrons (fast/light) separately simplifying the Schrödinger equation to the Born-Oppenheimer approximation.<p>In introductory chemistry textbooks [0] a diatomic example is mostly used as an illustration, for >2 atoms usually only the ground state is considered. This is because (1) in a diatomic setting the vibrational degree of freedom in the nucleus reduces to 1 and (2) the ground state can be well distinguished from other electronic states.<p>However when studying (advanced theoretical) chemistry or material sciences, polyatomic arrangement with tightly packed electronic states and a lot of nuclear degrees of freedom are the norm and the theory of so-called <i>conical intersection</i> of electronic energies essential in that regard.<p>Early on this was taken into account as the Jahn-Teller distortion[1]: a kind of spontaneous symmetry-breaking which seemed exotic when it was first described in the 1930s; in that same vein Teller later proposed an ultrarare occurrence within a few vibrational periods (sub-femtoseconds) by which a loss of electronic excitation was not followed by a photon being emitted: radiationless decay. Now, in refined orbital models [2] this seems to be a normal state of affairs e.g. in organic chemistry.[3]<p>Because of the tiny time scales involved theoretically predicted phenomena like a Geometrical phase/Berry phase (which itself has the Foucault pendulum in relation to Earth's latitude as its mechanical analogue [4]) have not been observed, yet. So borrowing from a topological analogue (Dirac points) [5] a quantum simulation seemed feasible.<p>To be honest the actual paper [6] linked in the article was hard to follow through so I found a similar paper [7] where the presentation of the general idea is more clear and concise.<p>[0]<a href="https://chem.libretexts.org/Courses/Pacific_Union_College/Quantum_Chemistry/09%3A_Chemical_Bonding_in_Diatomic_Molecules/9.01%3A_The_Born-Oppenheimer_Approximation_Simplifies_the_Schr%C3%B6dinger_Equation_for_Molecules" rel="nofollow noreferrer">https://chem.libretexts.org/Courses/Pacific_Union_College/Qu...</a><p>[1]<a href="https://en.m.wikipedia.org/wiki/Jahn%E2%80%93Teller_effect" rel="nofollow noreferrer">https://en.m.wikipedia.org/wiki/Jahn%E2%80%93Teller_effect</a><p>[2]<a href="https://core.ac.uk/download/pdf/9426023.pdf" rel="nofollow noreferrer">https://core.ac.uk/download/pdf/9426023.pdf</a><p>[3]<a href="https://en.m.wikipedia.org/wiki/Quenching_(fluorescence)" rel="nofollow noreferrer">https://en.m.wikipedia.org/wiki/Quenching_(fluorescence)</a><p>[4]<a href="https://en.m.wikipedia.org/wiki/Geometric_phase#Foucault_pendulum" rel="nofollow noreferrer">https://en.m.wikipedia.org/wiki/Geometric_phase#Foucault_pen...</a><p>[5]<a href="https://condensedconcepts.blogspot.com/2015/08/conical-intersections-vs-dirac-cones.html?m=1" rel="nofollow noreferrer">https://condensedconcepts.blogspot.com/2015/08/conical-inter...</a><p>[6]<a href="https://arxiv.org/pdf/2211.07320.pdf" rel="nofollow noreferrer">https://arxiv.org/pdf/2211.07320.pdf</a><p>[7]<a href="https://arxiv.org/pdf/2211.07319.pdf" rel="nofollow noreferrer">https://arxiv.org/pdf/2211.07319.pdf</a>
You know, I think these sorts is scientific research explainers would be better if they actually just said what they did, what the insight was, what we can do now or what predictions we can now make.<p>I understand the desire to make the discovery accessible but this does not accomplish that. If we measure information by “what predictions can a reader now make that they couldn’t make before” then this press release is information free.<p>Instead we have a lot of words to attempt to create the impression of having read something.