Title: Can True Vacuum Ever Exist? Exploring the Deepest, Emptiest Places in the Universe
Imagine going out to the deepest, emptiest place in the universe, achieving a perfect, total vacuum. Would you be surrounded by emptiness?
The modern journey into the vacuum began in the 17th century, with a flashy experiment designed by Otto von Guericke, mayor of the town of Magdeburg in the Holy Roman Empire. As part of a political stunt to show that his city had rebounded after the ravages of the 30 Years’ War, von Guericke put on a demonstration for the emperor and other notables to show off his newly invented vacuum pump. By placing two hemispheres together and pumping out all of the air, Otto showed that not even a team of horses could pull the hemispheres apart.
Contrary to millennia of thought in Europe following Aristotle’s argument that “nature abhors a vacuum,” von Guericke showed that the vacuum was possible.
However, even far from Earth, there’s plenty of stuff floating around: charged particles zipping here and there, wandering hydrogen atoms, bits of fluff and dust minding their own business. Even though the density of interstellar space is billions of times lower than even our emptiest human-made vacuum chambers, it’s not 100% percent empty.
To reach the emptiest places in the universe, you have to travel to the cosmic voids, the vast regions of nothingness that dominate the volume of the cosmos. In the depths of the largest voids, you can stand hundreds of millions of light-years from the nearest galaxy. The cores of the voids are so empty that not even dark matter — the mysterious, invisible form of matter that makes up the bulk of every galaxy — doesn’t even have a presence.
But still, space wouldn’t really be empty. Suffusing the entire cosmos are lightweight, neutral particles called neutrinos as well as the radiation left over from the early days of the universe. This radiation, known as the cosmic microwave background (CMB), is responsible for over 99.99% of all the radiation in the universe, and it’s impossible to escape.
Quantum physics provides a surprising answer to the question of whether true nothingness can exist. Physicists have discovered that quantum fields soak all of space and time, and these quantum fields give rise to the particles of everyday life. But when left to their lonesome, the quantum fields have an intrinsic energy, known as vacuum energy. This energy is omnipresent throughout the universe. Even though you wouldn’t have any particles around you, you’d still have this energy to be your sole companion.
So is space just a mathematical abstraction, a tool we use to describe the relationship between physical objects, or is it something more? There is no firm answer to the question of whether true nothingness can exist. It could be that the concept of space is just a mathematical trick and does not exist in its own right. Or it could be that no matter where you go, you’re always somewhere in space, so you’ll always be surrounded by something. The search for true vacuum continues as we explore the deepest, emptiest places in the universe.