Numerical Epidemics

[Linguofreak]

Whiskey Tango Foxtrot?

 

[Thorsten]

For the non-German speaking readers - it's a so-called 'hygiene-demonstration' which is used to express a general dissatisfaction with the government, reality, the world, science... (I doubt anyone knows for sure) - it includes people who blame Bill Gates for the pandemic, or the Illuminati, or the underground lizard aliens, those who believe the government is after their bodily fluids etc.

The text reads 'a virus doesn't cause a disease, in a sick immune system the virus thrives'.

The point being - there's a sizable fraction of people in Germany whom I'd call 'unreasonable' as well, and the point of the event on the photograph was that they all meet without distancing or masks to show off their unreasonableness to the rest of the world.

 

[MaxBuzz]

'hygiene-demonstration' which is used to express a general dissatisfaction with the government, reality, the world, science... (I doubt anyone knows for sure) - it includes people who blame Bill Gates for the pandemic, or the Illuminati, or the underground lizard aliens, those who believe the government is after their bodily fluids etc.

I have a similar friend, once I realized that he was afraid of everything
stories about a giant obscure space sounds to him like a horror movie
the idea that the government is not omnipotent causes him panic

 

[Urwumpe]

The text reads 'a virus doesn't cause a disease, in a sick immune system the virus thrives'.

The point being - there's a sizable fraction of people in Germany whom I'd call 'unreasonable' as well, and the point of the event on the photograph was that they all meet without distancing or masks to show off their unreasonableness to the rest of the world.

Yes, and the worst of it all, such thinking also persists in academic circles in Germany. On the positive side though, they are really a small loud minority and can't even agree, which kind of witchcraft is the right one.


These protests also include the usual anti-vaxxer crowd, that would rather kill its own children with full intent than vaccinating them against accidental infections.

 

[Linguofreak]

The text reads 'a virus doesn't cause a disease, in a sick immune system the virus thrives'.

A more literal translation of "wohl fühlen" is probably best here. There's a hint of irony in saying "Viruses feel well in a sick immune system" that's lost if you translate it as "thrive" instead of "feel well".

Of course, the real translation of the text on the sign is: "I'm not crazy, I'm stark raving mad!"

 

[Thorsten]

There's a hint of irony in saying "Viruses feel well in a sick immune system" that's lost if you translate it as "thrive" instead of "feel well".

Actually I think what is meant by the writer is not so much the ironic twist but the theory that a disease isn't primarily caused by the virus but by pre-existing damage in the immune system which enables the virus to not only feel well (which doesn't per se imply any growth or multiplication) but to actually thrive (I've come across that theory a few times discussing with the esoteric healing crowd, so it seems a likely match) - which is why I translated the way I did.

(Disclaimer: Despite not having been there for two decades, I'm actually a native German speaker - but as someone who is very interested in languages, I'm also well aware that it's generally impossible to really capture all nuances in a translation)

 

[Linguofreak]

Actually I think what is meant by the writer is not so much the ironic twist but the theory that a disease isn't primarily caused by the virus but by pre-existing damage in the immune system which enables the virus to not only feel well (which doesn't per se imply any growth or multiplication) but to actually thrive (I've come across that theory a few times discussing with the esoteric healing crowd, so it seems a likely match) - which is why I translated the way I did.

(Disclaimer: Despite not having been there for two decades, I'm actually a native German speaker - but as someone who is very interested in languages, I'm also well aware that it's generally impossible to really capture all nuances in a translation)

But in this case I think the nuance survives well in English: "Feeling well" doesn't logically imply growth or multiplication, but neither do viruses literally have a capacity to feel a sense of wellbeing. But the ironic contrast between human illness and alleged viral wellbeing as a result implies emotionally that the virus is able to multiply (since that's about all that viruses are capable of). If you swear up and down that no such double meaning is possible in German I'll defer to you, but the literal translation comes across in English as emotive, double meaning propaganda that I'm inclined to doubt was accidental.

 

[Thorsten]

I don't doubt the nuance is lost in my translation and I agree that it is there in German - I just doubt it was really ever meant to be there. I may of course be wrong here, but these people rarely have a sense of humour and are usually not into making ironic wordplays - they're convinced they have the one eternal truth and want to show that to everyone. They want to be taken seriously, not appear as witty jokers who are good with words.

 

[jedidia]

I just doubt it was really ever meant to be there

Yeah, I'd consider that very unlikely too.

 

[Linguofreak]

I may of course be wrong here, but these people rarely have a sense of humour and are usually not into making ironic wordplays - they're convinced they have the one eternal truth and want to show that to everyone. They want to be taken seriously, not appear as witty jokers who are good with words.

Not all wordplay is jokes. There are many fine and ancient traditions of serious, but elaborate, oratory, and being convinced that it's your duty to get The Truth out into the world is all the more reason to try to present it powerfully.

 

[Thorsten]

Not all wordplay is jokes. There are many fine and ancient traditions of serious, but elaborate, oratory, and being convinced that it's your duty to get The Truth out into the world is all the more reason to try to present it powerfully.

Okay, at this point I'm starting to get confused - what exactly is this still about?

We're in a thread about numerical simulation of epidemics to which the picture is a side issue. Realizing that the point of the picture may be lost to non-German speaking readers, I provided a translation - which is a side issue to a side issue. You're not only seriously criticizing that translation, but after two posts in which I explained that I see merit in your argument, yet decided to translate otherwise for the reasons mentioned - you continue to argue against my reasoning? So we're dealing with a side issue to a side issue to a side issue now?

Do you honestly think your text is the only possible and valid translation? I do not, I've stated my reason for choosing a different approach, if you don't think that's valid that's fine by me, let's agree to disagree. Otherwise this is becoming pointless rapidly, sorry.

 

[Face]

I think whenever you start applying strict mathematical models to problems including real people, you will eventually end up at this point: side problems to side problems with side problems. A bit sad, but on the other hand: hilarious to watch!

 

[Urwumpe]

I think whenever you start applying strict mathematical models to problems including real people, you will eventually end up at this point: side problems to side problems with side problems. A bit sad, but on the other hand: hilarious to watch!

First rule of MBSE: "The model is not the real thing" :lol:


And really, it is frustrating how often you have to remind people that just because it works in the model, it does not mean the real product will work the same. The model has to change, not the reality...

 

[Thorsten]

I think whenever you start applying strict mathematical models to problems including real people, you will eventually end up at this point: side problems to side problems with side problems.

And the connection of that with the translation is?

Do you really mean to imply that whether we translate one way or the other has any relevance for the accuracy of the mathematical model (which - by the way - I've been rather careful of not quantitatively applying to any problem involving real people except in showing possible qualitative parallels in the dynamics...)

If any of you guys isn't interested in the topic - you can just opt to not read the thread.

And if any of you guys thinks the model misses something important for the purpose it is applied to - let's discuss math please, not philosophy - the latter has usually not been a good criterion to distinguish a good from a bad model. the ether is a philosophiscally sound concept after all.

 

[Face]

And the connection of that with the translation is?

Do you really mean to imply that whether we translate one way or the other has any relevance for the accuracy of the mathematical model (which - by the way - I've been rather careful of not quantitatively applying to any problem involving real people except in showing possible qualitative parallels in the dynamics...)

There is no connection and I don't mean to imply what your wrote. That is the whole point of my statement: people are irrational, and you can't model that with mathematics. Not even with some random noise.

If any of you guys isn't interested in the topic - you can just opt to not read the thread.

And if any of you guys thinks the model misses something important for the purpose it is applied to - let's discuss math please, not philosophy - the latter has usually not been a good criterion to distinguish a good from a bad model. the ether is a philosophiscally sound concept after all.

Last I've checked, this was an open forum, right? Anybody posting here is interested in the topic by the mere fact that he posted here.
The thing about philosophy is just highlighting my point about people being involved. Heck, even the course of this thread highlights that.

 

[Urwumpe]

And if any of you guys thinks the model misses something important for the purpose it is applied to - let's discuss math please, not philosophy - the latter has usually not been a good criterion to distinguish a good from a bad model. the ether is a philosophiscally sound concept after all.

Well, for example: How would the model appear, if you have hidden infections? Like for example, the pandemic spreading wildly in a small population, that does not get tested, either because this population is mostly ignored (east-european low-wage workers in Europe) or does not want to be tested (alternative medicine believers).



Or: What about having a graph of population nodes, which have their own SIR parameters, and edges describing how such a node interacts with other nodes, like a reproduction number for one infected from node X infecting a number of persons in node Y?



The hypothesis is: Could we have a pandemic of different speeds, not just different strategies between countries explaining the development? The classic SIR model treats everything as one big average with total knowledge. In reality, both such assumptions don't work. We have no population of uniform clones. And we still know little of the disease, including how it really spreads among the population.



Could for example the Italian observation of virus particles in December water samples be explained by a hidden group of visitors from somewhere, that did not interact much with Italians and did not cause an earlier outbreak - or simply did accounted as infections when they returned home, when a second phase of the disease caused symptoms (A malaria-like behavior)?

 

[Thorsten]

Last I've checked, this was an open forum, right?

I believe it's moderated - I'm not sure how strict the stance on off-topic posts is here. But as for me - I ask people politely using the keyword 'please' to return to the topic of the thread - which is math. That's all - doesn't really seem to warrant invoking something like freedom of expression, does it now? .

How would the model appear, if you have hidden infections? Like for example, the pandemic spreading wildly in a small population, that does not get tested, either because this population is mostly ignored (east-european low-wage workers in Europe) or does not want to be tested (alternative medicine believers).

By definition the model has perfect knowledge of what happens, so we know simulated truth and there are no hidden infections. You'd have to add a testing model to post-process the data to see how it appears under different assumptions how perfect your tests are. When looking at reality, I'd make the assumption that testing catches (with fluctuations) a subsample of what is actually happening, and so allows to statistically infer the actual numbers. So I'd consider e.g. averaged growth rates more reliable than absolute numbers.

What about having a graph of population nodes, which have their own SIR parameters, and edges describing how such a node interacts with other nodes, like a reproduction number for one infected from node X infecting a number of persons in node Y?

I've actually planned to include the concept of 'domains' into the grid to see how that - qualitatively - changes the dynamics. Quantitatively... see below.

Could we have a pandemic of different speeds, not just different strategies between countries explaining the development?

If you're specifically interested in Coronavirus- yes, I believe we see different speeds in different countries - largely driven by the different social connectivity. People who live in a favela don't go on skiing holidays - their social interactions are restricted to their immediate neighbourhood, and that makes a difference in spread - which you can get in the model by setting up different social mobility.

But as in the previous case - the caveat is that (to my surprise) we do not really know much of any of these things in reality. I had expected that someone has assembled a model of different social groups in e.g. Germany - how often they go out, how many people they meet on average, how easy people from different social groups mix - that'd be highly relevant data for an accurate model for how a disease spreads in Germany. But such data does not seem to be there (or if so, it is not mentioned). Augmenting a simple grid model with the capacity to compute such effects in essence introduces a large number of new parameters - but that does nothing for realism if you end up guessing the parameter values.

So there's that.

 

[Face]

I believe it's moderated - I'm not sure how strict the stance on off-topic posts is here. But as for me - I ask people politely using the keyword 'please' to return to the topic of the thread - which is math. That's all - doesn't really seem to warrant invoking something like freedom of expression, does it now? .

I also believe it is moderated, and you are free to call on moderators to check if certain posts are off-topic. Non-mods like us can't really decide that, as the rules don't narrow down the scope of discussions explicitly.
I think in a topic with "epidemic" in its title, math will not be seen as only allowed content, though.

 

[Thorsten]

For anyone still interested, we've now reached the next version. I've added the capability to propagate different virus strains on the same grid so that one can see how they interact with each other.

Here's an example of a standard strain (violet) being contained by a measure, at which point a more agressive strain (green) is introduced to the grid and quickly takes over the dynamics, but is unable to penetrate into pockets which have been left by the standard strain.



The code is GPL V2+ and - including a short tutorial - available from my page.

 

[Urwumpe]

Now, which command do I need to use for ending this pandemic? It gets a little bit repetitive... ?