George Cantor is credited as the founder of modern set theory, but other important mathematicians like Dedekind, Zermelo, Fraenkel, Russel, and Godel have made major contributions.
For economics the answer is Alfred Marshall.
Cell theory was developed by the scientist because of it's simplicity complicated value, they found out more about cell. So a cell theory was developed.
The Geocentric Theory was developed by Greek astronomers. The theory was that celestial bodies moved around Earth in circular paths.
Charles Darwin
Albert Einstein
alfred wegener
Alferd Wegner
Albert Einstein
Who: Basically, the set theory was developed by Georg Cantor.
British scientist Charles Darwin (1809-1882) developed the theory of evolution (the theory that living organisms developed slowly over long periods of time).
Alfred Wegener, 1912
There is one version of the caloric theory that was introduced by Antoine Lavoisier. Lavoisier developed the explanation of combustion in terms of oxygen in the 1770s
Isaac Newton who developed the theory of gravity.