What's it good for?

Hacks of System Engineering to Understand Exponential Growth and Vaccine Panic. Okay! Today I get to play armchair epidemiologist! But first, let's all learn the Rule of 72! The Rule of 72 is a way to understand exponential growth. Exponential growth is something we see all the time in information technologies. Moore's law [1] is an example. It says that every two years the number of transistors you can fit into a fixed area doubles.  This picture is updated from one of Kurzweill's books: [2]  The Singularity is Near. It shows several things that will become very useful to be able to predict exponential growth rates. There's a linear X-axis that goes in terms of years (it could be any standard increment of time, days, hours, weeks, months, etc. Then there is a Y-axis that is given in powers of 10. Each tick represents 10 times the tick below it. Thus a straight line in this graph is actually an exponential growth curve. For every increment of time you get a multiplicati...