Ummm, it's more like, saying, I had one wife 8 weeks ago, and 4 7 weeks ago, and 16 6 weeks ago, and 64 5 weeks ago, and 256 4 weeks ago, and 1024 4 weeks ago and 4096 3 weeks ago, and 16384 2 weeks ago, and 65536 1 week ago, and I have 262144 today, so in 4 weeks I will have 16777216 wives.

That is, there is more than a single data point supporting the claims of exponential growth. There are lots of them.

Nice try though.

It’s not relevant; yes, it is wrong. Firstly, we have a lot more than the one datapoint. Secondly, we can look at what’s happened in other countries (like China). But, most importantly, the models don’t work like this, they’re more like a simulation. Take a look at the “Methods” section of this report, for example. It’s quite easily readable.

https://www.imperial.ac.uk/media/imperial-college/medicine/s...

This is the report credited in the media for changing the government response in a number of countries

US has three months of data from Europe & Asia. Not to mention any other models of contagion. You're comparing it to a comic about extrapolating based on one data point. So no, the comic isn't relevant

& yes, people have talked about inflection points

The exponential growth curves have a couple dozen data points by now. We know they can't be extrapolated forever, but we also have no reason to expect the curve to top out before it hits nearly the entire population.

> So tell me, is this relevant/wrong?

The xkcd is not really relevant. The xkcd is about naive extrapolation from an assumed growth model and two datapoints (which is insufficient to even validate that the growth model has the right general shape, much less to have much confidence about the parameters.)

The covid-19 projections are epidemiological projections which incorporate many data points to estimate parameters and validY the shape of the curve, and even more general knowledge from the field about the likely shape of the curve of an outbreak.

The actually relevant xkcd for this case is:

https://xkcd.com/2278/

"[ The graph is labeled "Things", with "Time" advancing to the right on the x-axis. The level of "Things" has been rising over time to a point labeled "Now". The current level of "Things" is above a level labeled "Good", and about as far below a level labeled "Bad". ]"

"Here's the situation: This line is here. But it's going up toward here."

Published around March 9th. One day later one president was recorded stating:

"It will go away. Just stay calm. It will go away... [B]e calm. It's really working out. And a lot of good things are going to happen."

https://www.msnbc.com/rachel-maddow-show/it-will-go-away-tru...

The article covering that concludes:

... "he's still acting as if he can bluff his way out of the crisis. He cannot."

as already explained, xkcd is extrapolating from a single data point. covid infections are being extrapolated from many data points.