Classical physics is built upon the concept of classical information. The classical bits of information can be read, copied, multiplied, processed, stored or erased. Determinism is the main characteristic feature of classical physics. Determinism implies that the knowledge of the mathematical structure of the physical laws and the current state of a physical system is sufficient for calculating, at least in principle, the state of the system at any other future time. Maxwell's equations axiomatize neatly classical electrodynamics. Matter is made of massive elementary particles such as the proton, neutron and electron. Einstein's axioms imply that space and time are no longer independent but are interwoven into a single continuum known as spacetime. All irrational numbers are represented by infinite aperiodic decimal expansions. The collection of all rational and all irrational numbers forms the set of real numbers. A convenient way to geometrically represent the real numbers is to use points on the real line.