Flights from China
Wuhan city and Hubei province are likely dysfunctional, with a severe shortage of test kits and with a health system so overwhelmed that it no longer has the ability to diagnose and process new cases. Although Hubei reports 9,074 confirmed cases, total cases have been estimated to be 75,000.
Hence there is no point reviewing the data from Hubei. No one likely knows what is happening there anymore.
Likewise, there is little point looking at the total data as the vast majority of cases are still in Hubei (i.e. the total data is compromised by the uncertainty regarding Hubei).
Instead, it makes sense to look at the data from other mainland provinces. The epidemic is sufficiently established that there will be person-to-person spread, but the provinces should still have the ability to collect accurate data. We all accept Eclan's point that the data is subject to political interference. However we only have the data we have.
Anyway I looked at 7 different provinces, and looked at the number of cases reported at 0002 UTC 1st Feb, and compared it to the number of cases reported at 1021 UTC 2nd Feb (i.e. 34 hours later). On average over these 7 provinces, cases increased by 136% (from 2014 to 2731).
Put another way, 1/4 of cases now were not cases 34 hours ago.
Given this outbreak has been going on for several weeks, this dramatic increase over 34 hours can surely only be described as exponential.
Hence there is no point reviewing the data from Hubei. No one likely knows what is happening there anymore.
Likewise, there is little point looking at the total data as the vast majority of cases are still in Hubei (i.e. the total data is compromised by the uncertainty regarding Hubei).
Instead, it makes sense to look at the data from other mainland provinces. The epidemic is sufficiently established that there will be person-to-person spread, but the provinces should still have the ability to collect accurate data. We all accept Eclan's point that the data is subject to political interference. However we only have the data we have.
Anyway I looked at 7 different provinces, and looked at the number of cases reported at 0002 UTC 1st Feb, and compared it to the number of cases reported at 1021 UTC 2nd Feb (i.e. 34 hours later). On average over these 7 provinces, cases increased by 136% (from 2014 to 2731).
Put another way, 1/4 of cases now were not cases 34 hours ago.
Given this outbreak has been going on for several weeks, this dramatic increase over 34 hours can surely only be described as exponential.
The instantaneous rate of growth is 18% per day. If that persists, then:
Exponential growth is a phenomenon that occurs when the growth rate of the value of a mathematical function is proportional to the function's current value, resulting in its growth with time being an exponential function. And just opposite when the value of rate decrease called Exponential Decay.
Exponential growth is a phenomenon that occurs when the growth rate of the value of a mathematical function is proportional to the function's current value, resulting in its growth with time being an exponential function. And just opposite when the value of rate decrease called Exponential Decay.
Thread Starter
So we can see that in the early stages the number of cases increased at about 50% per day, or more than doubled every two days. From about 28 Jan the rate decreased to about 25%. Recently the rate of increase has dropped even further. Conclusion: the rate of increase is no longer exponential but is moving towards a null rate of increase.
Any quantity that grows by a fixed percentage at regular time intervals exhibits EXPONENTIAL growth - in the form y = a(1 + r)^x
E.g. Cumulative Number of Cases = Starting Number of Cases x (1 + Growth Rate) ^ Number of Days Since Start of Time Period
This doesn't map on to public understanding of the term "exponential" when the growth rate is low - but nevertheless it is.
So for 25% daily growth you've got...
Cumulative Number of Cases = Starting Number of Cases x (1 + 0.25) ^ Number of Days Since Start of Time Period
Join Date: Oct 2003
Location: Australia
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
I never claimed that it was. What is your point? My exact words were:
Just so we're clear... a contagious disease exhibits exponential growth only in the absence of any quarantine of vaccination efforts. As soon as humans start to mitigate the propagation of the disease, it is no longer exponential. We can still use exponential functions to help describe it (lines on a graph), but the theory says that the increase in the number of cases is described by more complicated formula.
You can see that on the graph. An assumption of exponential increase (say, the red 50% or yellow 25% line) clearly fails to match the data beyond approx 28 Jan (50% line), or approx 2 Feb (25% line) for mainland China cases. For ROW (rest of the world) the inflection points are earlier. In other words, the actual data fails to fit an exponential model.
As I said, this is good news.
We no longer have 25% growth. Based on the actual data the daily rate of increase has been less than 25% since29 Jan 2 Feb (mainland China data) or 27 Jan 1 Feb (rest of the world), approx a week a few days ago.
Conclusion: the rate of increase is no longer exponential but is moving towards a null rate of increase...
Conclusion: the rate of increase in number of cases is going down
Conclusion: the rate of increase in number of cases is going down
You can see that on the graph. An assumption of exponential increase (say, the red 50% or yellow 25% line) clearly fails to match the data beyond approx 28 Jan (50% line), or approx 2 Feb (25% line) for mainland China cases. For ROW (rest of the world) the inflection points are earlier. In other words, the actual data fails to fit an exponential model.
As I said, this is good news.
We no longer have 25% growth. Based on the actual data the daily rate of increase has been less than 25% since
Last edited by FlareArmed2; 4th Feb 2020 at 12:34. Reason: I should read the actual data before posting...
Even if the total number of cases only increases 1% each day - that's still technically exponential - although it doesn't fit with public understanding of the term.
Join Date: Oct 2003
Location: Australia
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
My point is that where you have a % daily increase in total cases - it is incorrect to claim that it's "no longer exponential". Any daily % increase in total cases can be represented with an exponential function as I've shown above.
Even if the total number of cases only increases 1% each day - that's still technically exponential - although it doesn't fit with public understanding of the term.
Even if the total number of cases only increases 1% each day - that's still technically exponential - although it doesn't fit with public understanding of the term.
So what's happened to the confirmed cases in Australia? Are they still strapped to a hospital bed at death's door, or did they recover and go home (but that doesn't suit the narrative)?
I would be sitting back and waiting to see the 'peak' of infections before deducing any conclusions from what is known as flawed data........
The Bill and Melinda Gates Foundation is the WHO's second biggest donor. China comes in at 14, behind countries like Australia and Norway and organisations like Rotary International.
Since aviation has been the vector for spreading the virus internationally, understanding what the disease is and how virulent it might be is the first step in understanding its spread and the consequences of that spread. Yes, there is a lot of chaff in some of the comments, but there is also useful information that can help us understand whether there is an over-reaction with the stoppage of flights into and out of China. There might also be information about the risks crew take in flying to infected areas. The spread is exponential (but not by a square factor) and may be slowed to an exponent less than 1 by breaking chains of infection, including not flying. Aviation is a key factor in this.
Join Date: Jan 2020
Location: Bucharest
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
For example, a constant 3% daily increase rate can be described as exponential. In that scenario, over 365 days, if you start with only one person infected at day 0, you will end up with around 50k people infected. While this is exponential growth, it probably wouldn't cause worldwide panic, because researchers will have a lot of time to find a way to fight it.
Let's say instead you have a 40% daily increase rate, that is itself decreasing by 0.2%, each day. After about 3 months the entire Earth population would end up infected. While this wouldn't be textbook exponential growth, compared to the previous example, it is clearly a much worse situation.
Join Date: Jul 2011
Location: Sydney
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
With lots of expat guys in China being put on leave without pay at short notice and others told don’t bother coming back from leave it has a lot more to do with aviation than some of the other threads on here . It threatens the industry as a whole . Just the fear , wether justified or not will see a significant drop in passenger loads .
More info the better in my opinion . Exponential or not !!
More info the better in my opinion . Exponential or not !!
Join Date: Jul 2011
Location: Sydney
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
To Kjvmw,
I agree totally and am not concerned personally about contracting it . I was just stating it is already having an effect on our fellow pilots / aviation. The hysteria created will also hit forward bookings until an end as described in the above article is in sight .
I agree totally and am not concerned personally about contracting it . I was just stating it is already having an effect on our fellow pilots / aviation. The hysteria created will also hit forward bookings until an end as described in the above article is in sight .
Thread Starter
To Kjvmw,
I agree totally and am not concerned personally about contracting it . I was just stating it is already having an effect on our fellow pilots / aviation. The hysteria created will also hit forward bookings until an end as described in the above article is in sight .
I agree totally and am not concerned personally about contracting it . I was just stating it is already having an effect on our fellow pilots / aviation. The hysteria created will also hit forward bookings until an end as described in the above article is in sight .
Join Date: Jan 2004
Location: Joobs
Posts: 0
Likes: 0
Received 0 Likes
on
0 Posts
Yes indeed, that’s the kind of humanistic attitude we all admire.Be careful what you wish for, you could find someone else burning up your former carbon quota. I am personally right in the target audience for an early funeral, and my viking longboat isn’t finished yet so I am hoping for an improvement. For everyone.
It is a fact that a billion or so less people would ease the burden on this planet. China is responsible for nearly half the world's use of coal, nearly a million megawatts of coal fired power, the obsession with dams like Three Gorges which is an environmental catastrophe, air pollution, water pollution, expansionism, totalitarianism, the list goes on...… ask the Tibetans what they think of the crisis.
Animal cruelty, bear bile farms, torture (and consumption) of cats and dogs, shark fin soup, rhino horn to put more lead in their tiny pencils, tigers' genitals for Christ knows what (both re-legalised a year ago), they even eat koala! Have you been to China? I have and I have absolutely no issue with seeing it thinned out by Mother Nature striking back with a disease allowed to develop in a filthy, putrid food market where **** like this and like this and like this is perpetrated by Chinese against animal life. [If you don't have a strong stomach for abuse of "food" don't click those links.]
This isn't "racism" as some whining do-gooding lefty ignoramus pathetically tried to claim. This is acknowledging that Mother Nature has tried to find a solution for the impact of plague proportions of certain cultures on the Earth. Nature tried with SARS and MERS, now it's trying again with a new version which the Chinese facilitate with their own lifestyle. If this fails, it will happen again with another new version.
I don't have a problem with it (as long as they keep it to themselves) and I couldn't give a toss if you think that's bad.
By the way Sunfish you illustrated Godwin's Law in record time. Great work.
One last "food" video for you guys...…. She's trying to eat a live octopus for christs sake.
Thread Starter
But the biggest hit to the narrative and China's officially reported epidemic numbers came overnight, when a slip up in China's TenCent may have revealed the true extent of the coronavirus epidemic on the mainland. And it is nothing short than terrifying.
As the Taiwan Times reports in a report first spotted by user @IN_174, over the weekend, Tencent "seems to have inadvertently released what is potentially the actual number of infections and deaths, which were astronomically higher than official figures", and were far closer to the catastrophic epidemic projections made by Jonathan Read.
According to the report, late on Saturday evening, Tencent, on its webpage titled "Epidemic Situation Tracker", showed confirmed cases of novel coronavirus (2019nCoV) in China as standing at 154,023, 10 times the official figure at the time. It listed the number of suspected cases as 79,808, four times the official figure.
And while the number of cured cases was only 269, well below the official number that day of 300, most ominously, the death toll listed was 24,589, vastly higher than the 300 officially listed that day
As the Taiwan Times reports in a report first spotted by user @IN_174, over the weekend, Tencent "seems to have inadvertently released what is potentially the actual number of infections and deaths, which were astronomically higher than official figures", and were far closer to the catastrophic epidemic projections made by Jonathan Read.
According to the report, late on Saturday evening, Tencent, on its webpage titled "Epidemic Situation Tracker", showed confirmed cases of novel coronavirus (2019nCoV) in China as standing at 154,023, 10 times the official figure at the time. It listed the number of suspected cases as 79,808, four times the official figure.
And while the number of cured cases was only 269, well below the official number that day of 300, most ominously, the death toll listed was 24,589, vastly higher than the 300 officially listed that day