What is quantum tunneling

Extremely small particles are connected with each other even if very long distances separate them. The wave function evolves and spreads. Hence, the probability of a given particle's existence on the opposite side of an intervening barrier is non-zero, and such particles will appear on the 'other' a semantically difficult word in this instance side in proportion to this probability. Cornell University. To enforce continuity, the boundaries of each region are set equal. To understand the phenomenon , particles attempting to travel across a potential barrier can be compared to a ball trying to roll over a hill.