Is 100 percent vacuum possible?

Answered by Willian Lymon

Is it possible to achieve a 100 percent vacuum? This is a question that has puzzled scientists for many years. To answer this, we need to delve into the realm of quantum theory and understand the concept of virtual particles.

In classical physics, a vacuum is defined as a space completely devoid of matter. In such a vacuum, there would be no atoms, no molecules, and no particles of any kind. However, quantum theory tells us that even in what appears to be empty space, there are still energy fluctuations occurring.

These energy fluctuations, known as virtual particles, are constantly popping in and out of existence. They are particles and antiparticles that spontaneously materialize for an incredibly short amount of time before annihilating each other. This phenomenon is a consequence of Heisenberg’s uncertainty principle, which states that the precise values of certain pairs of physical properties, such as position and momentum, cannot both be known with complete accuracy.

So, even in a supposedly empty space, virtual particles are constantly being created and destroyed. These fluctuations may seem insignificant, but they have real consequences. For example, the Casimir effect is a well-known phenomenon that arises due to the presence of these virtual particles.

The Casimir effect occurs when two parallel plates are placed in close proximity to each other in a vacuum. The virtual particles outside the plates can only exist in certain energy states, but those between the plates are restricted to different energy states due to the boundary conditions imposed by the plates. As a result, there is a slight imbalance in the energy density outside and inside the plates, leading to a net attractive force between them.

This effect, along with other experimental evidence, supports the existence of virtual particles and demonstrates that even in apparently empty space, they play a role. Therefore, achieving a 100 percent vacuum, where virtual particles do not exist, seems impossible based on our current understanding of quantum theory.

In practice, scientists have come very close to creating extremely low-pressure environments, often referred to as “high vacuum” or “ultra-high vacuum.” These conditions are achieved by using sophisticated vacuum chambers and pumps to remove as much matter as possible. However, even in these highly controlled environments, virtual particles still exist.

Based on our current understanding of quantum theory and the existence of virtual particles, it appears that a 100 percent vacuum is not possible to achieve. The constant fluctuations of virtual particles prevent absolute emptiness in space. This concept challenges our classical understanding of a vacuum and highlights the intricacies of the quantum world.