Tropical mathematics and the financial catastrophe of the 17th century. Thermoeconomics of Russia in the early 20th century

In the paper, an example is presented concerning relationships (which cannot be neglected) between mathematics and other sciences. In particular, the relationship between the tropical mathematics and the humanitarian-economic catastrophe of 17th century (related to slavery of Africans) is considered. The notion of critical state of economy of the 19th century is introduced by using the refined Fisher equation. A correspondence principle for thermodynamics of fluids and economics of the 19th century is presented.