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.
I had to go check that this was real - https://www.nature.com/articles/s41557-023-01300-3, 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.
I'm not sure I really "get" the 400 year old physics. Things like the Lagrangian, Lagrangian transform, and the principle of least action and the Hamiltonian. I understand them on a superficial level and I know very well how to use them, but I just don't really get it. Why can we even write equations for this stuff. I have a degree in physics which makes it all the more depressing.
That's "just" special relativity. I would suggest to see it exposed in current textbooks.
Spoiler: E=m_rest c2 + E_kinetic unless you redefine the mass as a function of velocity. Something that people used to do a century ago but is unusual to it nowadays
This is really a bad idea to study anything. Actually this is what sets aside naïve hobbyist interested in Physics vs someone studying Physics systematically and efficiently as part of PhD program. I did this mistake repeatedly. I started with annotated version of Newton's Principia, spent about a year just pulling my hair and gave up to realize how much time I had lost in all kind of minutia, noise and random things that were completely useless to develop good understanding of core principles. I repeated this mistake yet again by buying Maxwell's original publications and wasting yet another year. And then again with Einstein's original papers and wasting yet another year.
I thought I would do differently and everyone else was doing wrong. I was the one doing wrong. I didn't learned much from all these original manuscript. I also lost precious years which I could have obtained real Masters degree. It is super important to understand that original manuscripts have tons of noise and baggage that only make sense in historical context. They also have unbacked goods which are super hard to digest, if you can digest at all. A ton of experts have already spent their lives distilling these original writings that fits with everything else, easy to digest and doesn't have all that noise. So, get a good textbook and follow that. Stop chasing original manuscripts.
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.
I think there is a key difference in magnitudes of ion concentration vs time. At this scale, a faster detector seems to be comparatively less trivial than a more sensitive one.
You've got to love the declaration at the end of the article:
> 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.
Sure, but you're using the internet, courtesy of military-funded research, using electricity that's been routed through distribution and substations that exist thanks to military-funded research, travel places based on GPS, courtesy of direct military research, your modern life is only possible because just like everyone else, the military has a budget allocated for researching computing and electronics advances that they can use, which invariably translates to things the private sector can use.
> “Our experiment wasn’t a digital approximation of the process – this was a direct analogue observation of the quantum dynamics unfolding at a speed we could observe,” he said.
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.
I'm no expert but my understanding is that the word 'simulation' is a misnomer in this context. A better way to describe what they're trying to do is a proxy system. Effects observed in this proxy system would be used to predict interactions in reality. Whereas simulations are better at describing how real world interactions diverge from our models.
> Kind of like how simulating anything in detail tends to be a lot slower than the actual thing you're simulating?
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.
> 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.
They say they mapped the problem.... So is this a model of an observation, or an actual observation?
> “Until now, we have been unable to directly observe the dynamics of ‘geometric phase’; it happens too fast to probe experimentally.
> “Using quantum technologies, we have addressed this problem.”
'cos if its a model, they are obviously still not observing whatever-it-is directly, right?
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:
“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:
- The analog system is still an approximation, so there may be small differences in how the dynamics play out compared to the real system.
- Mapping a complex molecular system onto qubits necessarily requires simplifications and abstractions that could influence the outcomes.
- Factors like experimental errors, imperfect state preparation or measurement in the trapped ion system may introduce discrepancies.
- Important details like multi-particle interactions or higher-order effects may not be fully captured.
- Verification that the analog system exhibits the same identifying signatures or phenomena as the natural system would strengthen confidence in the analogy.
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.”
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.
There are chemical processes, most notably photochemical processes like photosynthesis, that funnel molecular states into new configurations so rapidly, that observation of the details of the reaction is impossible. This research simulated one class of such reactions (conical intersection reactions) by modeling the wave function that governs the time evolution of the reaction using a quantum computer, allowing them to run the reaction 100B times slower than occurs in nature, and to measure the quantum state evolution. They are thus able to get a clear picture of how the reaction proceeds, as measured by several different observables, from the simulation.
It's a direct demonstration of the utility of quantum computation in molecular modeling. The meta-relevance, to me at least, is that it demonstrates real progress in one of the areas where quantum computation is most likely to have an important impact.
I guess some theoretical chemistry basics omitted in the short article wouldn't hurt:
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.
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.
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 conical intersection of electronic energies essential in that regard.
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]
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.
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.
They're using an analogous system. The speed of the process in the analog does not have to be the same as in the original system, in terms of wall-clock time.
Unfortunately they didn't change the speed of a process. They mapped the process and them change the replay speed to watch it, like changing the play speed on a video.
>According to the discoverers, a minute amount of administratium causes one reaction to take over four days to complete when it would have normally occurred in less than a second.
There are 86k seconds in a day. 345 600 seconds in 4 days.
This quantum-slowing effect reduces the speed by 100 000 000 000.
Administratium is about as close to the actual speed of the reaction as it is to the slowed-speed reaction.
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.
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.
Instead we have a lot of words to attempt to create the impression of having read something.
lifeisstillgood|2 years ago
I had to go check that this was real - https://www.nature.com/articles/s41557-023-01300-3, 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.
Panoramix|2 years ago
sharikous|2 years ago
Spoiler: E=m_rest c2 + E_kinetic unless you redefine the mass as a function of velocity. Something that people used to do a century ago but is unusual to it nowadays
unknown|2 years ago
[deleted]
voidmain0001|2 years ago
sytelus|2 years ago
I thought I would do differently and everyone else was doing wrong. I was the one doing wrong. I didn't learned much from all these original manuscript. I also lost precious years which I could have obtained real Masters degree. It is super important to understand that original manuscripts have tons of noise and baggage that only make sense in historical context. They also have unbacked goods which are super hard to digest, if you can digest at all. A ton of experts have already spent their lives distilling these original writings that fits with everything else, easy to digest and doesn't have all that noise. So, get a good textbook and follow that. Stop chasing original manuscripts.
Horffupolde|2 years ago
datameta|2 years ago
verisimi|2 years ago
> 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.
This is sponsored by the military.
TheRealPomax|2 years ago
So what's your point?
shepherdjerred|2 years ago
raylad|2 years ago
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.
fnordpiglet|2 years ago
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.
Out_of_Characte|2 years ago
magicalhippo|2 years ago
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.
[1]: https://arxiv.org/abs/2211.07320
marginalia_nu|2 years ago
[1] https://en.wikipedia.org/wiki/Quantum_Zeno_effect
unknown|2 years ago
[deleted]
unknown|2 years ago
[deleted]
verisimi|2 years ago
They say they mapped the problem.... So is this a model of an observation, or an actual observation?
> “Until now, we have been unable to directly observe the dynamics of ‘geometric phase’; it happens too fast to probe experimentally.
> “Using quantum technologies, we have addressed this problem.”
'cos if its a model, they are obviously still not observing whatever-it-is directly, right?
PS I'm pretty sure they are talking about their model.
dazzaji|2 years ago
“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:
- The analog system is still an approximation, so there may be small differences in how the dynamics play out compared to the real system.
- Mapping a complex molecular system onto qubits necessarily requires simplifications and abstractions that could influence the outcomes.
- Factors like experimental errors, imperfect state preparation or measurement in the trapped ion system may introduce discrepancies.
- Important details like multi-particle interactions or higher-order effects may not be fully captured.
- Verification that the analog system exhibits the same identifying signatures or phenomena as the natural system would strengthen confidence in the analogy.
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.”
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?
astrashe2|2 years ago
walnutclosefarm|2 years ago
It's a direct demonstration of the utility of quantum computation in molecular modeling. The meta-relevance, to me at least, is that it demonstrates real progress in one of the areas where quantum computation is most likely to have an important impact.
unknown|2 years ago
[deleted]
dav_Oz|2 years ago
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.
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.
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 conical intersection of electronic energies essential in that regard.
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]
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.
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.
[0]https://chem.libretexts.org/Courses/Pacific_Union_College/Qu...
[1]https://en.m.wikipedia.org/wiki/Jahn%E2%80%93Teller_effect
[2]https://core.ac.uk/download/pdf/9426023.pdf
[3]https://en.m.wikipedia.org/wiki/Quenching_(fluorescence)
[4]https://en.m.wikipedia.org/wiki/Geometric_phase#Foucault_pen...
[5]https://condensedconcepts.blogspot.com/2015/08/conical-inter...
[6]https://arxiv.org/pdf/2211.07320.pdf
[7]https://arxiv.org/pdf/2211.07319.pdf
sytelus|2 years ago
magicalhippo|2 years ago
unknown|2 years ago
[deleted]
unknown|2 years ago
[deleted]
mycall|2 years ago
10g1k|2 years ago
unknown|2 years ago
[deleted]
ChrisMarshallNY|2 years ago
https://www.mit.edu/people/dmredish/wwwMLRF/links/Humor/Admi...
Qwertious|2 years ago
There are 86k seconds in a day. 345 600 seconds in 4 days.
This quantum-slowing effect reduces the speed by 100 000 000 000.
Administratium is about as close to the actual speed of the reaction as it is to the slowed-speed reaction.
amelius|2 years ago
MichaelZuo|2 years ago
unknown|2 years ago
[deleted]
AbrahamParangi|2 years ago
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.
Instead we have a lot of words to attempt to create the impression of having read something.
unknown|2 years ago
[deleted]
10g1k|2 years ago
syspec|2 years ago