The Bohr–Einstein debates were conversations between the physicists Niels Bohr and Albert Einstein. They talked about the Atom, which is the smallest building block of all matter. They wanted to figure out why atoms behave the way they do, and what makes them work. Bohr believed that atoms were made of particles which had a certain amount of energy, which he called “quantum energy”, and he said that with this energy, atoms interacted with each other in a consistent way. Einstein thought that atoms were more like waves, which could be broken up and changed, and would interact differently with other particles in different ways. They argued about this for a long time, but in the end, neither one could prove their point of view. So the debate ended without a definite answer, and scientists still talk about it today.