Astronomical causes of climate change. Milanković–Bacsák cycle and the last ice age

György Bacsák, a Hungarian polyhistor, was born 150 years ago and died 50 years ago. He played an important role in refining and further developing the Milanković cycle. Milanković's theory describes the effect of changes in Earth's movements on the climate. The theory came from its creator, Milutin Milanković, a Serbian geophysicist and astronomer. The Serbian scientist was imprisoned in the Austro-Hungarian Monarchy during World War I as a citizen of a hostile state. He developed his theory in the library of the Hungarian Academy of Sciences. Understanding the essence of the theory, György Bacsák enjoyed the theoretical support of Milanković in the form of regular correspondence between 1938 and 1955. In total, György Bacsák wrote 56 letters to Milutin Milanković, while the Serbian scholar wrote 10 letters, all of which can be found in the Library of the Hungarian Academy of Sciences. The language of the letters was German, since both Bacsák and Milanković spoke German fluently. Three articles from György Bacsák, from the year 1940, were published in the Magazine “Weather” and a part of his book “Earth’s history of the last 600,000 years” was published in 1944 both of them were based on this letter exchange.