What is nothing? This is a question that has bothered philosophers as far back as the ancient Greeks, where they debated the nature of the void. They had long discussions trying to determine whether nothing is something.
While the philosophical facets of this question pose some interest, the question is also one that the scientific community has addressed. (Big Think’s Dr. Ethan Siegel has an article describing the four definitions of “nothing.”)
It’s nothing, really
What would happen if scientists took a container and removed all the air out of it, creating an ideal vacuum that was entirely devoid of matter? The removal of matter would mean that energy would remain. Much in the same way that the energy from the Sun can cross to the Earth through empty space, heat from outside the container would radiate into the container. Thus, the container wouldn’t be truly empty.
However, what if scientists also cooled the container to the lowest possible temperature (absolute zero), so it radiated no energy at all? Furthermore, suppose that scientists shielded the container so no outside energy or radiation could penetrate it. Then there would be absolutely nothing inside the container, right?
That’s where things become counterintuitive. It turns out that nothing isn’t nothing.
The nature of “nothing”
The laws of quantum mechanics are confusing, predicting that particles are also waves and that cats are simultaneously alive and dead. However, one of the most confusing of all quantum principles is called the Heisenberg Uncertainty Principle, which is commonly explained as saying that you cannot simultaneously perfectly measure the location and movement of a subatomic particle. While that is a good representation of the principle, it also says that you cannot measure the energy of anything perfectly and that the shorter the time you measure, the worse your measurement is. Taken to the extreme, if you try to make a measurement in near-zero time, your measurement will be infinitely imprecise.
These quantum principles have mind-bending consequences for anyone trying to understand the nature of nothing. For example, if you try to measure the amount of energy at a location — even if that energy is supposed to be nothing — you still cannot measure zero precisely. Sometimes, when you make the measurement, the expected zero turns out to be non-zero. And this isn’t just a measurement problem; it’s a feature of reality. For short periods of time, zero is not always zero.
When you combine this bizarre fact (that zero expected energy can be non-zero, if you examine a short enough time period) with Einstein’s famous equation E = mc2, there is an even more bizarre consequence. Einstein’s equation says that energy is matter and vice versa. Combined with quantum theory, this means that in a location that is supposedly entirely empty and devoid of energy, space can briefly fluctuate to non-zero energy — and that temporary energy can make matter (and antimatter) particles.
Hellbound and Down 