ABSTRACT
In chapter 1 probabilities were classified into three kinds: chances, epistemic probabilities and credences, satisfying the same mathematical rules. But this is not all that these kinds of probability have in common, as we can see by comparing them with three different kinds of waves: water, sound and light waves. These too share some mathematics, since they all have speeds V, frequencies F and wavelengths W, which in consistent units (such as metres per second, cycles per second and metres) satisfy the equation https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203504864/0ffbc490-13ed-49d7-80b5-96b4f4ec0bc9/content/ch2_page22-01_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
