M1TE5H's recent activity
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Comment on Tropical bedbugs in temperate regions make pest control more difficult in ~health
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Comment on What programming/technical projects have you been working on? in ~comp
M1TE5H LinkComputational Science, Game Development, and Machine Learning Modern C++20/23 research software to model microstructure, simulate defect interactions and the evolution of defect networks, and...Computational Science, Game Development, and Machine Learning
Modern C++20/23 research software to model microstructure, simulate defect interactions and the evolution of defect networks, and explore mesoscale informatics by leveraging data-oriented design. If done well, the same code scaffold could be applied to various problems across materials (metals, semiconductors, ceramics, polymers, composites, etc.), biology and nanotechnology.
For the Computer Scientists and Engineers here, it is a fascinating problem and the basic premise is as follows. Consider a tessellation in which each cell is hosting its own N-body “game loop” — “Barnes-Hut-Voronoi”— it seems deceptively achievable but there are some notable caveats:
- Complexity. The bodies represent individual defects, but defects come in many varieties, each with their own rules: some are mobile and some are stationary; some can create and/or destroy others; some can merge to become different objects; and some remain in their respective cells whereas others can cross between compatible neighbouring cells; etc. Useful analogies can be made to the Entity-Component-System setup so some further investigation is needed.
- Heterogeneity. Each cell can be thought of as a homogeneous “microcosm” (i.e. an isolated subregion that is straightforward to deal with on a standalone basis) but it is the overall aggregate of hundreds/thousands/millions of cells (and the defects therein) which is of great academic and industrial relevance. So opportunities for parallelism and/or concurrency are plenty.
- Anisotropy. Underlying atomic structure can govern directional preferences, which — when coupled with the aforementioned heterogeneity — brings computational geometry into the fold, but in a manner that is unlike the isotropic worlds of the video games.
- Non-Linearity. Actual (classical, relativistic, quantum and statistical) mechanics are needed as opposed to the approximations used in game engines. However, the program does not need to be burdened with slow (linear algebra-based) numerical solvers; some crucial physical insight paired with clever mathematical techniques could make the dynamics comparable to those of games.
- Scales. One aim is to generate visualisations of the simulations as micrographs that convey information pertaining to lengths/distances/sizes in the O([1nm,1mm]) range. In short, there is also a neat graphic design aspect to this project.
- Dimensionality. The discussion so far has centred on a two-dimensional representation but the real world has three spatial dimensions. And there is also the time dimension to contend with, especially when processes occur at rates differing by orders of magnitudes but still influence each other.
- Performance. For a given set of input parameters, each execution with a random initialisation will culminate in one possible realisation (read: final configuration) and the randomness needs to be averaged out over multiple realisations — strangely reminiscent of this ML/AI experiment. For most end-users, parameter space sampling will be conducted on a local workstation (i.e. no HPC) and hence the need for a careful selection of the lowest-lying data structures and perhaps some upfront optimisations.
Over the past decade, the main challenge has been to establish a tractable framework that balances algorithmic complexity and physical complexity. That is, a computational framework that scales reasonably with the microstructural features (e.g. numbers of cells and densities of defects) and events (i.e. interactions) whilst also retaining the essential science and customisation points for generalisation.
After having published some of the groundwork, the next step is to do some serious prototyping, and periodically post updates for suggestions and feedback.
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Comment on Why the empty atom picture misunderstands quantum theory in ~science
M1TE5H (edited )LinkThe classical or semi-classical (solar system-like) picture of the atom is outdated, but so is the quantum mechanical (cloud-like) picture to an extent in that both represent isolated subsystems...- Exemplary
The classical or semi-classical (solar system-like) picture of the atom is outdated, but so is the quantum mechanical (cloud-like) picture to an extent in that both represent isolated subsystems of the fundamental particles that constitute the atom, namely, the electrons and the quarks that compose the nucleons.
Now that Quantum Mechanics (QM) has been somewhat superseded by Quantum Field Theory (QFT), Quantum Chemistry is understood to be the low-energy limit of the (relativistic) QFT of the electromagnetic force — Quantum Electrodynamics (QED) — where the very notion of an electron is completely different. That is, there are no lone electrons in classical, semi-classical or even quantum mechanical senses i.e. no individual electron particles or electron waves or even electron clouds.
Instead, QFT proposes a single electron field that permeates the entire universe, and it is the local excitations of this field that correspond to supposed electron entities in Quantum Chemistry.
So the electron clouds in the QM viewpoint can be reimagined as, say, events in an infinite electron ocean in the QFT viewpoint. This electron ocean is all around us and we are an inseparable part of it; the electrons in the atoms of our material bodies are short-lived crests that move along within this vast electron ocean.
And, much like the electron ocean, the same applies to other fundamental matter fermions (including the quark species that constitute the protons and neutrons of the atomic nucleus) as well as the fundamental force bosons that mediate interactions, the relevant one being the photon for the electromagnetism in Quantum Chemistry. So now there are multiple “overlapping” and “interweaving” oceans for the electron and (each of) the quarks as well as the photon; here, electromagnetic interactions holding an atom together resemble peaks of the electron and quark oceans perpetually firing ripples along the photon ocean to each other.
In comparison to the QM picture of the cloud-like atom, which is already complex to visualise with everyday language, graphics and thinking, there is a whole new challenge with the QFT picture of the multi-ocean happenings that create the “illusion” of an atom in some small region of space/time.
And all this without once mentioning Grand Unification (Strong, Weak and Electromagnetism), Higgs field (mass), gravity, String Theory,…
Chemical pest control seems to be a far too short-term treatment for bedbugs considering their exceptional biological traits when it comes to individual and collective survival in the context of an infestation. For example, a few flat-bodied adults — hiding in some forgotten crevice — can easily avoid a series of pesticide attacks over multiple months and then repopulate the colony.
Of course, it may be that bedbugs (eventually) receive long-term political attention; but such a coordinated response would perhaps not be in the same capacity as, say, mosquitoes which are known disease-vectors that are responsible annually for almost a billion illnesses and almost a million deaths. However, such wishful thinking is of little comfort to those households who are presently dealing with bedbugs, and the myriad challenges that come with repeated infestations.
Instead of the short-term chemical or long-term political strategies, here is then a more mid-term mechanical solution to pragmatically alleviate the problem of bedbugs at home. The “mechanical” descriptor refers to the act of physically impeding bedbugs from obtaining their blood meal, and the “mid-term” qualifier corresponds to the 3–18 month period needed to starve out all individuals and completely eradicate a localised colony. In addition, the pragmatic aspect concerns how the implementation itself is straightforward, immediate and cost-saving. This approach is based on a mixture of lived experience and personal practice as well as established research and common advice, the main disclaimer being that it will require some creativity, discipline, and patience.
The general outline is as follows:
For all of their evolutionary advantages, bedbugs, unlike mosquitoes, cannot (yet) fly and hence must crawl from hiding place to host, and so leveraging this weakness is crucial. The central hypothesis is that starvation can be effective if the blockade is sustained over a sufficient period. Remain open to, and accepting of, the aesthetic sacrifice: duct tape on the bed frame and bedside cabinets is a small price for quality sleep.