[HN Gopher] Scientists begin building highly accurate digital tw...
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Scientists begin building highly accurate digital twin of our
planet
Author : giuliomagnifico
Score : 82 points
Date : 2021-02-25 15:41 UTC (7 hours ago)
(HTM) web link (ethz.ch)
(TXT) w3m dump (ethz.ch)
| jetrink wrote:
| Is 'digital twin' anything other than a buzzword? Is there
| anything that distinguishes one from a model or a simulation? I
| had the misfortune of being introduced to the term by an
| executive who repeated it until is lost all meaning so I still
| bristle whenever I hear it. I've read the Wikipedia article, but
| it only increased my skepticism with blustery paragraphs like:
|
| > Healthcare is recognized as an industry being disrupted by the
| digital twin technology.[45][34] The concept of digital twin in
| the healthcare industry was originally proposed and first used in
| product or equipment prognostics.[34] With a digital twin, lives
| can be improved in terms of medical health, sports and education
| by taking a more data-driven approach to healthcare.
| scrooched_moose wrote:
| The one distinguishing feature (in theory) of digital twins is
| it is supposed to be such a hyper accurate model that it can be
| used to predict absolutely anything about the system in
| question. No changing of model setup, it's a "perfect"
| representation.
|
| The down side is everything explodes exponentially - setup
| time, mesh count, solve time; and we usually get worse results
| than more focused simulations because we can't squeeze enough
| detail in across the board.
|
| It generally starts because some manager hears that we've
| created 8 different specialized models of something due to
| different areas of interest, and has the bright idea of "lets
| just create a single super-accurate model we can use for
| everything". I've been fighting against them my entire career,
| although 10 years ago it was "virtual mockups"
|
| The next buzzword in the pipeline seems to be "virtual lab"
| which I can't figure out either. I've been simulating
| laboratory tests for over a decade and no one can explain to me
| why that isn't exactly what we're already doing.
|
| None of this is to say that this team isn't doing great work,
| but somewhere along the way it got wrapped up in some marketing
| nonsense.
|
| Edit: Restructured my reply to better address OPs question.
| unishark wrote:
| Yes it's fine if people want to create a new buzzword for
| some special case. But people act like it's a revolutionary
| idea that will allow them to finally address unsolved
| problems (and ergo deserve funding for).
|
| "Light fields" is one that always annoyed me. People who are
| apparently unaware of centuries of knowledge and methods in
| electromagnetism, developing "new" ways to solve problems
| crudely. That's great if they can make some cool new imaging
| system, but is it research deserving of long-term high-risk
| funding? It's just something that anyone skilled in optics
| can work out if they thought to build it.
| roter wrote:
| And building science[0]. But building science has always been
| full of buzzwords.
|
| [0] https://www.iesve.com/digital-twins
| niftich wrote:
| Though it's a buzzword now, the idea behind 'digital twins' was
| that you not only have a detailed and faithful model (of an
| item, or process, or system, or network, etc.) whose
| granularity is congruent with the level of granularity that
| interests you about the real thing, but you also have bi-
| directional movement of data between the 'real' thing and its
| model.
|
| So you can have sensor and measurement data from the real thing
| be streamed to the model in (ideally) real-time, you can make
| decisions off of the state of the model, and have those
| decisions be sent back out into the real world to make a change
| happen.
|
| The specific wording of digital twins originated from a report
| discussing innovations in manufacturing, but I find that
| railway systems and operations make for some of the best
| examples to explain the concept, because they manage a diverse
| set of physical assets over which they have partial direct
| control, and apply conceptual processes on top of them.
|
| Here's three assorted writings [1][2][3] that explain how
| railways would benefit from this.
|
| [1] https://www.anylogic.com/digital-twin-of-rail-network-for-
| tr...
|
| [2] https://www.railwayage.com/analytics/how-digital-twins-
| suppo...
|
| [3] https://www.railwayage.com/analytics/realizing-the-
| potential...
| 7952 wrote:
| In my experience complex sites like railways, airports etc.
| tend to have a lot of nominally digital data already. Things
| like topographic surveys, engineering drawings, surveys etc.
| But usually they are more "drawing" than useful data
| products. Massive directory structures full of random cad
| files with obtuse layering for small limited contracts, often
| using a local coordinate system. For a long time there have
| been efforts to improve data quality under the bim banner,
| and now perhaps digital twins.
| [deleted]
| Munam wrote:
| It's not all a buzzword fest.
|
| I work as a Computational Researcher at Stanford Med. My work
| is quite literally translating 3D scans of the eyes (read MRI)
| into "digital twins" (read FEA Models).
|
| I think that there is a subtlety in differentiating a digital
| twin from a model/simulation in intent. Our intent is to quite
| literally figure out how to use the digital twin specifically,
| NOT the scan that it is based on, as a way to replace more
| invasive diagnostics.
|
| Of course, in the process, we figure out more about diagnosing
| medical problems as a function of just the scans themselves
| too.
| tobmlt wrote:
| I sympathize. I was buzz-worded half way to brain death by this
| at a prior job.
|
| Maybe we were in the business of building better business
| builders, I am still not sure.
| MikeDelta wrote:
| As soon as I saw Gartner mention digital twins as one of the
| next big things in innovation in one of their reports, I
| concluded it was a buzzword.
| a_zaydak wrote:
| Usually Digital Twin = Model = Simulation. Different industries
| have different words for it. Some call a difference between a
| Digital Twin / Model and a Simulation where the simulation is
| the result of some external input being applied to a Digital
| Twin.
|
| Either way I wouldn't think too much about it. Tech is full of
| these things. I have been working with AI and neural networks
| for years before it was called Machine Learning. Now I'm forced
| to use the term ML to sound relevant even though it is the same
| thing.
| jarenmf wrote:
| It is a shame they are using these buzzwords, It's basically an
| earth system model, one that we had for many many years. They
| probably will improve the code base, I don't know if they want
| to build everything from the ground up or use some physics
| aware hybrid machine learning approach for sub-grid
| parameterization but really nothing seem novel except trying to
| improve the resolution of the current models we have.
| martingoodson wrote:
| Does anyone know any evidence for or against the feasibility of
| this concept? Policy makers in the uk are talking about investing
| in digital twins for the purpose of AI research and it just seems
| to be buzzword salad. Can someone point me to a reference?
| [deleted]
| jedberg wrote:
| You know the fjords in Norway? I got a prize for creating those,
| you know.
| FigmentEngine wrote:
| here's a towel
| olivermarks wrote:
| Reminds me of the biosphere projects whose failures have been the
| subject of multiple debates over reasons why.
|
| https://www.euronews.com/living/2020/07/09/living-in-a-bubbl...
|
| Highly sceptical the digital version of this will be playing with
| a full deck of data resulting in skewed results. still think it's
| a good idea but definitely not the accursed 'settled science',
| more an experiment.
| ravi-delia wrote:
| I'd imagine that like weather predicting, the best way to
| simulate a complex system is to slightly vary the starting
| conditions and sample the results. Obviously it's not going to
| be perfect, but it gives a clear idea about what things to
| worry about.
|
| Reading the article, it seems that the purpose of the twin
| isn't simulation, it's mapping. That data can then be used as
| the input to simulation of your choice.
| jiofih wrote:
| Just expand the map in GTA V to cover all countries, should be
| accurate enough.
| Barrin92 wrote:
| > _" Observational data will be continuously incorporated into
| the digital twin in order to make the digital Earth model more
| accurate for monitoring the evolution and predict possible future
| trajectories. But in addition to the observation data
| conventionally used for weather and climate simulations, the
| researchers also want to integrate new data on relevant human
| activities into the model. The new "Earth system model" will
| represent virtually all processes on the Earth's surface as
| realistically as possible, including the influence of humans on
| water, food and energy management, and the processes in the
| physical Earth system."_
|
| I think I've seen something like it on the latest season of
| Westworld. Jokes aside this reminds me a little bit of the brain
| project. I'm really not sure if attempting to build full fidelity
| models of hugely complex systems is the way forward to understand
| this systems. It seems increasingly that scientists are trying to
| replace theoretical models of the say, the mind or the city with
| purely data driven approaches that don't necessarily produce any
| insight, or even accurate forecasts. Sometimes it feels like with
| increasing computing power we've gone back to the problems of
| empiricism of the mid 20th century.
| whatshisface wrote:
| You couldn't call it full-fidelity.
| etiam wrote:
| Last I saw anything of it, the EU brain Flagship project had
| lots of actual brain scientist unhappy about having almost no
| scientific or professional benefit from the huge public
| spending, and one happy Henry Markram for having the final say
| that huge chunks of the money should go into his guys building
| a really, really big computer.
|
| I foresee a Big Science project with little to no benefit for
| meteorology, climatology, geology, etc and a lot of public
| money going into building a really, REALLY big computer.
|
| Which isn't necessarily a bad thing to buy per se, but if the
| intent really was to understand Earth, they'd be better off
| putting the money into fundamental research in the Earth
| sciences.
| plumsempy wrote:
| dibs on biyomon
| TimTheTinker wrote:
| "Digital twin" is such a misleading term, as it implies the
| ability to perfectly model a non-digital system, which is
| inescapably impossible.
|
| The best we will ever be able to create is approximate models
| that have varying tradeoffs. The term "digital twin" obscures the
| fact that there _are_ tradeoffs involved in the first place. It
| also causes harm to decision-makers, who ought to be able to
| choose which tradeoffs to make.
| mceoin wrote:
| To think, there was a time before we had a permanent, high-res
| historical record of the entire planet that we could wind
| forwards and backwards and observe history through.
| jrochkind1 wrote:
| Eh... I'm skeptical this will work out very usefully. The proof
| is in the pudding though. But sure, I can see why someone would
| fund the research project. But this is mostly just a press
| release with buzzwords, right?
| tejtm wrote:
| Wonder if there is a way to wrap it in Dwarf Fortress or
| something and crowd source the intractable parts.
| thisisbrians wrote:
| This is an extremely ambitious project, and hopefully turns out
| to be worthwhile. For complex/interconnected systems, building
| ~accurate simulations can vastly decrease the cost of decision-
| making, and I'm very bullish on digital twin technology,
| generally. Trying things out in a simulation can be a cheap way
| to guide more detailed engineering analysis and 'rough in' an
| approach.
|
| As an example, my startup, Bractlet (bractlet.com), uses
| detailed, physics-based energy simulation (aka "digital energy
| twin") technology as a tool to optimize HVAC design and controls
| in large commercial buildings. I'm sure efficacy varies widely by
| domain, but it's worked extremely well for us so far; we
| typically help our customers save about 20-30% on their energy
| expenditures annually, and the digital twin is the bedrock of our
| approach.
| nydev wrote:
| Fascinating. Would love to see a "digital energy twin" product
| for residential properties.
| thisisbrians wrote:
| Would love to hear what you're thinking! We've prioritized
| commercial office as it's great bang-for-buck for our
| business, but we'd love to expand to other verticals in the
| future.
| saeranv wrote:
| Interesting, I have a couple of questions:
|
| - How do model random variables with high variance like
| occupancy or equipment use? Are you using sensor/monitoring
| equipment or just trying to model it as best as you can?
|
| - Did you guys use the initial energy model (built by by the
| design/consultant team) or do you guys build your model from
| scratch?
|
| - What energy simulation engine do you guys use? I'm just
| curious if there's any big advantage between the engines for
| digital twin applications.
| datalus wrote:
| I also like the digital twin concept as it applies to sci-fi.
| Sometimes I daydream our universe is a digital twin built by an
| advanced civilization meant to simulate the universe's history
| looking for clues as to what lead to a calamity that they're
| trying to undo. Random thought :)
| eightysixfour wrote:
| Can/does your system simulate the quality of the air as well?
| In particular particulate matter and CO2 levels.
| thisisbrians wrote:
| We've given this a lot of attention in the age of Covid, as
| you might imagine. Many modern HVAC control systems include
| CO2 sensors in the return air streams to make sure they're
| bringing in enough outdoor air to meet indoor air quality
| standards, and that's fairly easy to simulate. Particulate
| counts are trickier, and may be better estimated using out-
| of-simulation engineering calculations based on the type of
| filtration in place.
| eightysixfour wrote:
| Interesting, mind if I shoot you an email? My family has a
| business in this space (residential side) and I'd love to
| chat more.
| robertlagrant wrote:
| The carbon generated by running this simulation will be offset by
| planting trees in the simulation.
| ruined wrote:
| they better plant some trees in real life too or we'll diverge
| from canon
| OneGuy123 wrote:
| This will be a failure of epic proportions.
|
| Due to the complexity of the real world we can't even predict
| weather for 2 days in advance and you they think they can predict
| the world...
|
| The sad part is that they will then use this model and its result
| to create policies not knowing that you can never rely on such a
| "copy" because even the smallest difference will create an insane
| amount of divergence even 1 day down the line of future
| simulation let alone years...
| hikerclimber wrote:
| hopefully this fails.
| jandrewrogers wrote:
| I am highly skeptical of this approach. Not only has this been
| attempted before, it appears to be on course to repeat the same
| technical design mistakes that caused prior attempts to fail. You
| can't decompose weather/climate style supercomputing models below
| a certain resolution because the fundamental characteristics of
| the computation are not meaningfully representable that way.
| Scalable models that correctly and efficiently capture the macro
| effects of many types of sparse, high-resolution dynamics require
| much more sophisticated computer science, systems engineering,
| and ways of representing data. You can't brute force it.
|
| In particular, this is a notoriously poor approach to modeling
| complex large-scale interactions between humans and their
| environments. There was a study I was involved in last year to
| determine why one of the epidemiological models for COVID was so
| badly off target. The root cause was modeling human behavior in
| the same way you would model weather, which is quite
| inappropriate but the implementors of the epidemiological model
| did not have the expertise to know better.
|
| The selection of GPUs is also not appropriate for the nominal
| objectives of the program. When modeled correctly, i.e. not as
| weather, these kinds of things aren't the kind of workload GPUs
| are good at. They tend to look more like very high dimensionality
| sparse graphs -- latency-hiding is more important than
| computational throughput. CPUs are actually quite good at this.
|
| This looks more like a program more designed to produce press
| releases than useful results.
| alecst wrote:
| I know it's off topic but I'd love to learn more about how the
| modeling of COVID went wrong. You can pm me if you want to take
| the discussion elsewhere.
| nostromo wrote:
| The models tended to overshoot the number of deaths by huge
| amounts. For example, the Imperial College of London
| estimated 40m deaths in 2020 instead of the 2m that occurred.
|
| https://www.wsws.org/en/articles/2020/03/18/covi-m18.html
|
| https://www.nature.com/articles/d41586-020-01003-6
|
| https://www.imperial.ac.uk/news/196496/coronavirus-
| pandemic-...
|
| The model authors have since argued that the data was
| correct, but people responded to the pandemic by changing the
| way we live. That's OP point: that feedback cycles and
| corrections exist and they make modeling dynamic systems very
| difficult.
| mattmanser wrote:
| But they never learn either, the ICL react studies are
| still getting it spectacularly wrong, 4 weeks ago they
| claimed cases were rising in the UK, that R was above 1.
|
| Even a cursory glance at the actual data, even the data
| available at the time, shows they were completely and
| utterly wrong.
| rajansaini wrote:
| Seconded!
| cossatot wrote:
| Quanta had a decent write-up of challenges faced by some
| researchers about a month ago:
| https://www.quantamagazine.org/the-hard-lessons-of-
| modeling-...
|
| Of course there are many ways that things went wrong, and not
| everyone made the same mistakes.
| neolog wrote:
| I would like to read about that too.
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