According to Werner Heisenberg's uncertainty principle, in quantum physics, the position (coordinates) and momentum (mass x velocity) of a particle cannot be measured simultaneously with absolute accuracy. With this principle, the "probabilistic" character of quantum mechanics is revealed. In the wave/particle duality, if we emphasize one aspect of the event (for example, the particle), it makes the other aspect uncertain, and the exact relationship between these two is determined by the uncertainty principle.

Niels Bohr put forward the idea of complementarity to better understand the wave/particle connection and considered both the particle description and the wave description as two complementary descriptions of the same reality. Bohr argued that this could be a useful concept outside the field of physics. Because the opposites yin and yang relate to each other in a polar or complementary manner, the modern concept of complementarity is the result of ancient Chinese thought that had a profound influence on Niels Bohr Perhaps Bohr's greatest contribution to modern physics was his development of the atomic model. The Bohr model of the atom shows the atom with a positively charged nucleus and electrons circulating around it. Bohr was the first scientist to discover that electrons revolve in different orbits around the nucleus and that the number of electrons in these orbits determines the properties of the atom.

Bohrium atom, whose atomic number is 107 in the periodic table, is named after Niels Bohr. liquid droplet model Niels Bohr's theoretical work made significant contributions to the understanding of nuclear fusion. The droplet in his liquid droplet model represented the atom. If a sufficient amount of energy was supplied to this atom, the atom would split into two almost equal parts and a huge amount of energy would be released. This theory was used in the 1930s in attempts to split the uranium atom, which would later be used to make an atomic bomb.

His Debate with Einstein and Quantum Theory The concept of complementarity, about which Bohr published several papers between 1933 and 1962, predicts that an electron moves either as a wave or as a particle. But he cannot act as both at the same time. Anyone who is not shocked by quantum theory has not yet understood it. Niels Bohr Einstein always criticized quantum theory and therefore Bohr's work. This discussion between Bohr and Einstein contributed to the understanding of the hundred-year-old quantum theory. Regarding quantum theory, Einstein said: 'God does not play dice.' he said. In response to this, Niels Bohr said, 'Einstein, stop telling God what to do.' He is said to have said. This debate has also brought new gains to the scientific world. Einstein presented the EPR Paradox to refute the uncertainty principle of quantum theory. The epr paradox actually led to the further development of quantum theory.