Negative probability is defined mathematically as non-negative, making its existence impossible. In contrast, the concept of negative energy photons is a physics issue that remains open to interpretation. Paul Dirac's 1942 paper introduced negative energies and probabilities as mathematically valid concepts, likening them to negative amounts of money. The discussion highlights the distinction between mathematical definitions and physical interpretations, particularly in quantum mechanics. The potential for negative energies and probabilities in photons continues to be a topic of interest in theoretical physics.