Ro and the logarithm in music?

First, the good news: music does not depend on logarithm.

R0X is a number representing the reproduction rate of a virus, which means one infected person is able to infect X persons.

For SARS-CoV-2, the currently estimated R0 is 2.5 – 3.2, meaning one infected person may infect 2.5 – 3.2 people on average.

Now, let’s see what an R0 of 2 may mean. This is an R0 slightly less than the one observed for SARS-CoV-2.

The following example of a logarithmic expansion we found in Daniel Kahneman: “Thinking, fast and slow”; and an opinion by Megan McArdle in the Washington Post:

Imagine a pond with a single water lily. This water lily decided to duplicate once a day. Tomorrow there will be 2 water lilies, the day after tomorrow there will be 4, and another day will bring us 8 water lilies, and so forth. The pond will be covered with water lilies after 30 days. Now, here is the question: On which day did the water lilies cover the pond halfway?

Should your answer be day 15, you would be wrong. The correct answer is 29. What a great example of logarithmic growth.

How far would you think the spread of water lilies would have been on day 20? On day 20 the water lilies would have covered 0.098 % of the pond. Who would have thought that 10 days later the pond were covered entirely?

This is the situation we are facing now with SARS-CoV-2.

Now is the time to stop an explosive spread of the virus. This is why we appeal to you to accept some inconveniences and to help to damp the viral spread.

Stay tuned and take care,

Sabine and Joerg