Is the existence of a complete void possible?

*This text was written by a TecMundo columnist; finally learn more.

Before considering the title question, let’s think about “nothingness” and define what emptiness is. Vacuum is characterized by the complete absence of matter. In other words, we cannot have atoms or even subatomic particles in order to say that there is a vacuum in any medium.

This concept of complete vacuum is more complex than it seems, especially when we assume that we spend our lives in a very small and extremely dense region of the universe.

It’s almost common sense to think that there is a vacuum in space, but in reality we only have what we call “partial void”. For comparison purposes, we have an average of 5 atoms per cubic centimeter in our Solar System, and that number drops to just a single atom in interstellar space. In the space between galaxies this number is 100 times smaller. This means we have a single atom for every 100 cubic centimeters. All these “partial voids” are much better (less dense) than any artificially produced voids on Earth.

Also, the existence of a perfect vacuum is physically impossible. The existence of a space in which there is absolutely nothing violates an already validated and very well documented idea of ​​Quantum Mechanics: so-called “virtual particles”. The name can be deceiving and the concept is pretty intense, but these are real particles that interact with our world, and one of their most interesting features is that they can “suddenly” appear.

To understand this, we can imagine a ladder where each rung represents the energy levels of our universe. The further we go up this ladder, the higher we find ourselves in a state of energy. As discussed in a previous text, we know that mass and energy are equivalent, so the higher we are on this energy ladder, the more matter we have. Therefore, it would be correct to think that the first rung of this ladder represents an energy equal to zero, and therefore zero particles, right?

Wrong! The wonderful thing is that on this imaginary staircase, the steps float from one floor to the next. Nothing in nature is static. That is, even if we don’t have any particles in a particular region of space, there are enough fluctuations in energy levels to bring virtual particles into existence. These fluctuations are of short duration, but that’s enough for virtual particles to affect the space around them in a way that has been measured and proven since 1996 (we suggest researching it for those who are more curious). called “effect Casimir”).

But precisely because of these energy fluctuations that have occurred and are happening since the “Big Bang,” we have an uneven distribution of matter in our universe. That is, if there were no virtual particles, the matter of our universe would probably be evenly distributed in space. And as we know (and have witnessed) these fluctuations caused the mass of matter that formed and continues to form planets, stars, galaxies, and us.

All this is extremely intriguing, as we may think that nature does not allow the existence of “nothing”. So the existence of something is an intrinsic part of our universe, and we are here as proof of that. Therefore, when we stop thinking about “nothing”, we realize that there is still much to think about.

Rodolfo Lima Barros SouzaProfessor of Physics and columnist Technology World. He holds a master’s degree in Physics and Science and Mathematics Teaching in Public Perception of Science from Unicamp. Available on social networks as @rodolfo.sou.