Infinity in Physics

Following Arthur Eddington’s motto that “the contemplation in natural science of a wider domain than the actual leads to a far better understanding of the actual,” we will investigate various conceptual issues in physics which arise when systems involving infinity are considered. We will see that many common understandings of classical physics (e.g., understandings of determinism, Newton’s laws of motion, and the laws of energy/momentum/symmetry conservation) break down for systems involving infinity. These results will show that classical physics is, contrary to common beliefs, more conceptually problematic than modern (quantum and relativistic) physics in several respects. How modern physics deals with these problems and what new problems it confronts will be briefly discussed.