This book provides the readers with a broad introduction to the field of particle physics through fictional discussions between three prominent physicists — Albert Einstein, Issac Newton, and Murray Gell-Mann — together with a modern physicist.Matter is composed of quarks and electrons. The forces between quarks are generated by exchanges of gluons and are so strong that they result in the confinement of quarks in atomic nuclei, whereas the forces between electrons and atomic nuclei are generated by exchanges of photons, and the forces between quarks and electrons (or any other leptons) are generated by exchanges of weak bosons.The book is suitable for non-experts in physics.