Subatomic particles, such as electrons, protons, and neutrons, are often described as point-like particles or elementary particles. This description suggests that they have no size or spatial extent in the classical sense. However, it's important to note that this concept arises from the limitations of classical physics and our intuitive understanding of "touch" based on macroscopic objects.
In the realm of quantum mechanics, particles are described by wave functions that represent their probability distributions. These wave functions can exhibit overlapping regions, which can be interpreted as particles being "close" or interacting with each other. The wave functions of interacting particles can become entangled, leading to various quantum phenomena.
When particles interact, their wave functions can overlap and influence each other. They can exchange energy, momentum, and information through forces such as electromagnetic forces or the strong and weak nuclear forces. These interactions are described by quantum field theories, which provide a more comprehensive framework for understanding particle interactions than classical physics.
It's important to recognize that the concept of "touch" as we experience it in everyday life does not directly apply to the microscopic world. The behavior and interactions of subatomic particles are governed by quantum mechanics, which introduces fundamentally different principles and phenomena that can be counterintuitive from a classical perspective.