The Sun
Monthly Archives: February 2025
From Kepler to Ptolemy 7
The Full Ptolemy
We now start the second part of this series: an in-depth look at the Ptolemaic system.
Set Theory Jottings 3. The Paradoxes
Frege added an appendix to volume II of his 1903 magnum opus Grundgesetze der Arithmetik (Foundations of Arithmetic). It began:
A scientist can hardly meet with anything more undesirable than to have the foundations give way just as the work is finished. I was put in this position by a letter from Mr. Bertrand Russell when the work was nearly through the press.
Filed under History, Set Theory
Diagonal Argument 