It took about 3 weeks to go from 10k deaths to 100k deaths.
At this point, increasing numbers of deaths are going unreported. But at that growth rate, by the end of April, 1 million deaths.
Now, the current known hotspots are all self isolating. And it took a month to go from 100k cases to 1M cases.
I suspect the control measures where it is hot right now will bend the curve down. Then the places where it isn't hot will heat up.
As an exponential curve, the contribution from areas where it is going 1, 2, 4, 8, 16, 32 is currently small. The areas where it goes from 1000 to 1200 to 1440 contribute more numbers, even as they grow slower in percentages. So the global curve will flatten; but that is sort of an illusion, because more and more areas will start heating up.
With the usual 20 day delay, those increasingly hot areas will either need to lockdown just as the rest of the world thinks it is beat, or they will explode.
Sweden is an example of this. They haven't really engaged in serious social distancing, with the theory that their health care system can handle young people getting sick, and asked older people to self isolate.
Their deaths/day are growing at a rate of 20%-25% ... per day. Except it takes weekends off in Sweden (which it isn't; it just means that their tracking system is taking weekends off. Which means they are probably missing a lot of cases if they are that slack.)
Go here: Sweden Coronavirus: 10,483 Cases and 899 Deaths - Worldometer and scroll down to daily deaths. Notice that every 7 days there is a massive dip in deaths for 2 days. Which then ramps up for the week.
If they have a 3.4% mortality rate and infect half the country, they cap out at around 170,000 deaths. Assuming they are missing half of the deaths due to their slackness, this is 100x more deaths than they have right now. At +20% deaths/day this takes 25 days.
Now as you approach saturation, growth slows, because the virus finds more immune people (or already infected people) when it tries to spread.
Also, your growth rate in deaths is locked in for 20 days after you change policy and behavior.
So we get an interesting experiment out of Sweden over the next month. If Covid-19 is far less deadly than everyone else thinks it is, or their elder isolation is successful, we learn something. If not, Sweden becomes awash in corpses.
Note that Sweden's government is being lobbied by doctors to change course, and they have refused to do so, and have refused to release any models saying why they are going this way. They just state that they are aiming for herd immunity.
They could be right in a few ways. (1) Covid-19 might be less lethal than we think, (2) they might be protecting their vulnerable better than we think, (3) Covid-19 might be harder to contain than we think, and our social distancing is mostly useless.
At this point, increasing numbers of deaths are going unreported. But at that growth rate, by the end of April, 1 million deaths.
Now, the current known hotspots are all self isolating. And it took a month to go from 100k cases to 1M cases.
I suspect the control measures where it is hot right now will bend the curve down. Then the places where it isn't hot will heat up.
As an exponential curve, the contribution from areas where it is going 1, 2, 4, 8, 16, 32 is currently small. The areas where it goes from 1000 to 1200 to 1440 contribute more numbers, even as they grow slower in percentages. So the global curve will flatten; but that is sort of an illusion, because more and more areas will start heating up.
With the usual 20 day delay, those increasingly hot areas will either need to lockdown just as the rest of the world thinks it is beat, or they will explode.
Sweden is an example of this. They haven't really engaged in serious social distancing, with the theory that their health care system can handle young people getting sick, and asked older people to self isolate.
Their deaths/day are growing at a rate of 20%-25% ... per day. Except it takes weekends off in Sweden (which it isn't; it just means that their tracking system is taking weekends off. Which means they are probably missing a lot of cases if they are that slack.)
Go here: Sweden Coronavirus: 10,483 Cases and 899 Deaths - Worldometer and scroll down to daily deaths. Notice that every 7 days there is a massive dip in deaths for 2 days. Which then ramps up for the week.
If they have a 3.4% mortality rate and infect half the country, they cap out at around 170,000 deaths. Assuming they are missing half of the deaths due to their slackness, this is 100x more deaths than they have right now. At +20% deaths/day this takes 25 days.
In a sense, the disease spreads like how rocket ships approach the speed of light. As you saturate the population, the "cost" to spread climbs. For a ridiculously simple model, you can set real_infected = population ( 1-1/virtual_infected ). For virtual_infected far less than the popluation, this is real_infected =~ virtual_infected; but it requires an infinitely large virtual_infected to reach population saturation.
Getting to 50% saturation in this model requires 4 more days than in the more naive model above. But real people recover and become immune, which bends the curve down moreso with this model than it does with one without herd immunity.
Getting to 50% saturation in this model requires 4 more days than in the more naive model above. But real people recover and become immune, which bends the curve down moreso with this model than it does with one without herd immunity.
Now as you approach saturation, growth slows, because the virus finds more immune people (or already infected people) when it tries to spread.
Also, your growth rate in deaths is locked in for 20 days after you change policy and behavior.
So we get an interesting experiment out of Sweden over the next month. If Covid-19 is far less deadly than everyone else thinks it is, or their elder isolation is successful, we learn something. If not, Sweden becomes awash in corpses.
Note that Sweden's government is being lobbied by doctors to change course, and they have refused to do so, and have refused to release any models saying why they are going this way. They just state that they are aiming for herd immunity.
They could be right in a few ways. (1) Covid-19 might be less lethal than we think, (2) they might be protecting their vulnerable better than we think, (3) Covid-19 might be harder to contain than we think, and our social distancing is mostly useless.