Kind of like how simulating anything in detail tends to be a lot slower than the actual thing you're simulating?
Is the difference here that it's basically an analog rather than a digital simulation?
Not following if there was any breakthrough here or not.
No, they didn’t simulate it in the way we typically simulate. They created a physical process that was an analogue of the actual process but 100b times slower so they could directly observe it.
With a regular simulation, whether analogue or digital, you create a mathematical model, and evaluate that model in some way to get a result, which hopefully matches the actual phenomena in whatever it is you were trying to simulate.
Here, it's more like instead of measuring the phenomena, they instead measured something that is physically related to that phenomena. There seems to be no modelling involved.
An analogue is a physical entity with the same physics as some other thing.
A straightforward engineering example would be scale model of an airplane in a wind-tunnel.
> The MONIAC (Monetary National Income Analogue Computer), also known as the Phillips Hydraulic Computer and the Financephalograph, was created in 1949 by the New Zealand economist Bill Phillips to model the national economic processes of the United Kingdom, while Phillips was a student at the London School of Economics (LSE). The MONIAC was an analogue computer which used fluidic logic to model the workings of an economy. The MONIAC name may have been suggested by an association of money and ENIAC, an early electronic digital computer.
Analogue: something that is similar or comparable to something else either in general or in some specific detail : something that is [analogous] to something else
Analog: of, relating to, or being a mechanism or device in which information is represented by continuously variable physical quantities
GP's comment has nothing to do with whether the simulation is "analog" (as opposed to digital), their point is that instead of being a "model" of a way a physical system might behave, the mechanism in this case has the exact same physical properties represented in a different form. An example might be doing a calculation in decimal vs doing it in binary—the exact steps you take will look different, and the answer might look strange, but there's absolutely no doubt about the fact that you'll get the same answer however you happen to compute it. Another synonym for the word "analogue" in the sense that the GP is using it might be "isomorphism"—you can prove that some transformation holds, and then you can do whatever you want to the transformed version and know that the results you get can be "transformed back" to the original form and reinterpreted.
Ahh, "analogue - (mostly Commonwealth) Alternative form of analog" https://en.wiktionary.org/wiki/analogue#Adjective .
https://dictionary.cambridge.org/us/example/english/analogue... gives examples like "The new digital technology—which we welcome—merely replaces the present analogue system" and others.
English is a nuisance.
From the article[1]:
Our approach avoids the limitations of direct experiments on molecular systems, where only few observables such as spectra and scattering cross sections can be measured. [...] A further advantage comes from the ratio (r) of the ion’s natural timescale (ms) and the measurement speed (ns), leading to an increase in the observable timing resolution of r ∼ 10^6. This improves the achievable resolution of chemical dynamics measurements relative to ultrafast observations.
So seems this would be more like running a computer simulation with a super-short timestep, allowing you to extract more details of a process. It's only related to the wall-clock in that they're using a physical analog system, rather than a computer.
> Not following if there was any breakthrough here or not.
Again from the paper:
Our approach to quantum simulation using an MQB trapped-ion system makes chemical dynamics that are otherwise unmeasurable directly accessible in the laboratory. This is a key demonstration of the utility of small-scale quantum computational devices to offer practical insights into chemical dynamics and resolve intractable problems in chemical physics.
Seems the measurement itself was a showcase for the techniques developed.