23 March

The exponential function in action. It took 3 months for the first 100,000 people to be infected with Covid-19. It took 12 days for the second 100,000. It's taken 4 days for the 3rd 100,000. As the WHO says, if you don't act hard and act fast, the virus will beat you. It also works in reverse, if you can get the transmission rate to lower than 1 (1 person infecting one other person), the rate of infections exponentially declines too. That's what shutdowns try to do. If you have even one infected person wandering through society, the exponential function will start its work.