The Mysteries of Quantum Mechanics

The fundamental physical laws of nature newly discovered and established in the 20th century are the theory of relativity and quantum mechanics. When the velocity of a particle is so great that it is comparable to high speeds, the theory of relativity must be used. On the other hand, quantum mechanics applies to phenomena in the microscopic realm, such as atoms and molecules. Past theoretical calculations and experimental facts guarantee that both theories have, to this day, described nature with perfect accuracy.

However, quantum mechanics has aspects that are incompatible with common sense. It states that all particles, such as electrons, are "both particles and waves at the same time." Indeed, it has been confirmed that they behave like particles at times and like waves at other times. Large objects, like a baseball, move as a whole along a trajectory determined by Newton's equations of motion, as if they were particles. However, the atoms and molecules that make up the ball exist because electrons are waves. Your actions can probably be explained by Newtonian mechanics, but the microscopic atoms and molecules that make up your body obey quantum mechanics. It appears that Newton's equations suddenly apply when the object under consideration becomes large enough, but no one has yet been able to explain these contradictory aspects in a convincing way. Many researchers are in the stage of proposing various ideas.

Quantum mechanics is a truly mysterious theory from its very origins, and it could be said that the fact it perfectly describes nature is itself a mystery. I think it is worthwhile to ponder the mysteries of the natural laws of this world. Challenging difficult problems should lead to the discovery of even greater fundamental laws beyond them.