The Four Scientific Meanings Of ‘Nothing’
“How does spacetime emerge at a particular location, when there’s no such thing as space? How can you create the beginning of time if there’s no concept of something like “before” without time already existing? And where, then, would the rules governing particles and their interactions arise from? Does this final definition of “nothing” even mean anything at all, or is it just a logical construct with no physical meaning of its own?”
We talk about nothing all the time, most often as the polar opposite of something or anything. But when it comes to the idea of physical nothingness, even scientists can’t agree on a single definition. There are four ways of speaking about the concept of nothing that scientists use all the time, and they’re extremely different from one another. Some use it colloquially, simply referring to a time at which their thing of interest didn’t exist. Others mean the Universe, as it is, removed of all matter, radiation, particles, and even spatial curvature. Some would go a step further, and ensure that the empty space of nothingness is in its ground, or lowest-energy, state. And finally, some would do away with space, time, and the laws of physics altogether. But which one of these can lay claim to truly being nothing, and how far can you go before what you have has nothing to do with reality any longer?
These are not easy questions to answer, and so I’d rather present the four scientific meanings, the context in which scientists use them, and how to identify what’s being said. After all, isn’t the point to increase our understanding?