Jules Hedges wrote:
Interesting..... I've been wondering whether Petri nets are actually used in real life epidemiology, or if that's a just a lie that keeps circulating. (From what little I've seen of epidemiology it seems to be mostly statisti…
David Tanzer wrote:
The Markov assumption involved in SIR could be a workable approximation as the infection period is small in comparison to the duration of the epidemic. But it does suggest that the application SIR etc. deserves to reviewed …
Sherborne, N., Miller, J.C., Blyuss, K.B. et al. Mean-field models for non-Markovian epidemics on networks, J. Math. Biol. 76, 755–778 (2018).
Quotation from there:
While network models capture contact more accurately, the assumption that the…
A note on the application of Petri nets to compartmental models in epidemiology, such as the commonly cited SIR model:
...these are simplifying models, which are predicated on the assumption that the epidemic process is Markovian. While t…
Well, leaving aside that statistic, the chief point of the clarification remains, which is the tidal approach is modeling some small perturbations that have been observed in the rising historical temperature curve, which have an expected value of ze…
To put the scale of these perturbations into perspective, here is a statistic which shows that global warming due to CO2 is delivering about 1000 times as much power into heating the atmosphere than tidal forces can:
Ocean tides have a power of ab…
The AMO, and hence Paul's tidal model, only describes small perturbations in the rising historical temperature curve - which has been going on since the industrial revolution. Furthermore, these perturbations have a expected value of zero; they ar…
Paul has a model for the AMO, which is a well-known phenomenon:
Atlantic Multidecadal Oscillation
In comment 55, Paul's chart shows both the observed AMO data, and the data predicted by his model.
There's been some confusion on the forum concerning the interpretation of Paul's model of tidal influences in relation to global warming as a whole. In what follows is my attempt at clarification.
Bearing that in mind, I will ask you about the graph in comment #45. What is the Y axis, called Intensity? You have curves for model and data. What is the data?
Since it just shows cyclic behavior, over a course of centuries, has a baseline o…
With a bit more explanation on the background, I believe could understand significantly more of what you write. So I just have a general request, for a somewhat more pedagogical style. Or else every now and then give a "review presentation" for …
Hi Paul, as a point of general feedback, I have trouble understanding a lot of your posts, because you assume a readership that understands more of your assumptions than they actually do. Remember that a lot of us are developers, computer scienti…
Ok.
So how would you refute the following argument from a hypothetical AGW skeptic who says:
ok, so the mean contribution from tidal effects is zero. But there are multiple cycles, and we could just happen to be at a place where all the cycle…
Here is another fallacy: China contributes the most to greenhouse emissions, so we don't have to worry about our contribution. Well, suppose, hypothetically that China contributed 90%, and that the biosphere was at the verge of a tipping point. …
If that were true, then greenhouse gas emissions would be even scarier, as temperatures would be even higher if we were in another phase of a tidal cycle.
One thing you indicated is that tidal effects are not biased either towards warming or cooling, so it is conceivable that lately tidal effects have had a cooling effect on the planet.
Here is one possible response, which I would attribute to innocent confusion: since the moon has an effect on temperature, it's out of our hands, so there's no point in worrying about carbon emissions. The fallacy here is to assume that multiple …
That's an important clarification. I think that it is worth emphasizing when presenting your work, because without being put into full context, it is easy to give an erroneous interpretation of these results -- and some folks with an agenda would …
the dynamics of the moon need to taken into account to fully understand climate change and that this heating is notable when compared with anthropomorphic
How would lunar cycles account for the sharp increase in average global temperatures, ove…
Let's start with the deterministic case. This applies well to chemical reactions involving large numbers of molecules, where the different species involved in the reaction are "well-mixed." (E.g. no clumps of dimers surrounded by zones of monome…
Where do the reaction coefficients show up in these models?
In the deterministic case, the semi-flow will be specified by differential equations, and the reaction coefficients will turn up as coefficients in the equations.
In the stochastic model,…
In the stochastic model, \(t\) is still a continuous parameter, but the state S[t] makes little "jumps" at random times, when one of the reactions randomly "fires." Every time the dimerization reaction fires, the count of monomers goes down by two…
We have a choice on the menu: deterministic or stochastic modeling of S[t].
In a deterministic model, S[t] is a definite function of the continuous parameter \(t\). Once the initial condition is specified, by giving a value for S[0], then the fu…