Empty space is nothing but. According to the weird rules of quantum mechanics, it’s actually filled with an endless amount of energy, known appropriately enough as vacuum energy.
Quantum mechanics is super weird. One of the lessons of the quantum is that particles, like electrons and photons and neutrinos and whatnot, aren’t what they seem to be. Instead, each of the particles that we see in nature is actually just a piece of a much larger, grander entity. These grander entitles are known as quantum fields, and the fields soak every bit of space and time, all throughout the universe.
There is a quantum field for every kind of particle: one field for the electrons, one for the photons, and so on. These fields are invisible to us, but they make up the fundamental building blocks of existence. They are constantly vibrating and buzzing. When the fields vibrate with enough energy, particles appear. When the fields die down, the particles disappear. (Another way to look at this is to say what we call a “particle” is really a localized vibration of a quantum field). When two particles interact, it’s really just two pieces of quantum fields interacting with each other.
So if you think about all the particles that make up your body, all the electrons and protons and neutrons, those particles are just local vibrations of entities that span the entire cosmos. Neat.
These quantum fields are always vibrating, even when those vibrations aren’t strong enough to produce a particle. If you take a box and empty out all of the stuff – all the electrons, all the photons, all the neutrinos, all the everything – the box is still filled with these quantum fields. Since those fields vibrate even in isolation, that means that the box is filled with invisible vacuum energy, also know as zero-point energy – the energy of these fundamental vibrations.
This means that the vacuum of the universe is really made of something. There’s no such thing as a true vacuum; wherever you go, there are always vibrating quantum fields.
We know that the vacuum energy – this incessant boiling and vibrating of the quantum fields – interacts with the everyday world. For example, electrons inside of atoms occasionally move to more distant orbits away from the nucleus. There’s no reason for the electrons to make their way back down, until they get jostled by the quantum fields, prompting them to fall back into their normal orbital place.
I know this all sounds weird and new-agey, but it’s a real thing. Everywhere you go in the universe, there’s always something.
I asked ChatGPT: “Can vacuum energy be harnessed?”
ChatGPT responded:
Vacuum energy, often associated with the concept of zero-point energy in quantum field theory, refers to the energy that exists in the vacuum of space even when it’s devoid of matter or radiation. This energy is a fundamental aspect of quantum mechanics and is related to the fluctuations of the quantum fields.
In theory, vacuum energy could be vast and could potentially be a source of energy. However, harnessing it presents significant challenges:
Quantum Fluctuations: The energy of vacuum fluctuations is extremely difficult to access or control. These fluctuations are at a very small scale and are not easily tapped into with current technology.
Energy Extraction: To extract useful energy from vacuum fluctuations, we would need a method to convert this energy into a more practical form. The processes required to achieve this are not well understood and remain speculative.
Physical Laws and Conservation: The conservation of energy and other fundamental physical laws, such as the second law of thermodynamics, present constraints. These laws imply that even if vacuum energy is present, efficiently converting it into usable work without violating these laws is a significant challenge.
Experimental Evidence: Currently, there is no experimental evidence or technology capable of directly harnessing vacuum energy. Most research in this area remains theoretical or speculative.
In summary, while vacuum energy is a fascinating concept with potential implications, practical methods for harnessing it remain beyond our current scientific and technological capabilities. Research in this field continues, but there are many hurdles that need to be overcome before it can be considered a viable source of energy.
The vacuum “dark” energy density is uniform and also by definition the lowest energy state of our universe space, so we cannot extract energy from it.
However, specific field vacuum energies such as the Casimir effect can be harnessed in useful applications if work is provided from outside.
“In 2001, Capasso et al. showed how the force can be used to control the mechanical motion of a MEMS device, The researchers suspended a polysilicon plate from a torsional rod – a twisting horizontal bar just a few microns in diameter. When they brought a metallized sphere close up to the plate, the attractive Casimir force between the two objects made the plate rotate. They also studied the dynamical behaviour of the MEMS device by making the plate oscillate. The Casimir force reduced the rate of oscillation and led to nonlinear phenomena, such as hysteresis and bistability in the frequency response of the oscillator. According to the team, the system’s behaviour agreed well with theoretical calculations.” [“Casimir effect”, Wikipedia]