When we want to talk about nothing, our conceptions take us outside of space and before the Universe began, yet does that even make sense? How can you talk about “outside” when you don’t have space? How can you talk about “before” anything if you don’t have time?
And yet, whatever “nothingness” truly is, it contains the entire Universe. (Philosophically, this is a longstanding tenet of Buddhism.)
Many physicists claim that there’s no way to understand anything, fundamentally, until we understand nothing. And although our understanding of it is partial — which is to say, we understand the fundamental, basic laws of nature that govern empty spacetime — we don’t understand from whence those fundamental laws arise, and whether they themselves are a “thing.”Here's the problem. The universe began with the Big Bang, but this term is misleading. The Big Bang was not an explosion of the universe coming into being as we usually think of explosions. Because of the uniformity of cosmic background radiation across all the observed universe, physicists say that everything that exists started off together. But the origin was only a point and this point was not in space (since space didn't exist yet) and not in time (since time time didn't exist yet). Hence, they call it a "singularity," but all that means is "we don't know." They may as well call it a huffelump or farfsnegoplin.
The problem with this theory is the problem of inflation. No, not what we await happening to our currency, but the unimaginably small time that began the universe. Most people know that the universe is expanding, but not many non-astronomers are familiar with the theory of inflation, which reveals that the term "Big Bang" is misleading, Instead, says NASA's "Universe 101" web site, the universe's creation "is better thought of as the simultaneous appearance" of the universe everywhere there is the universe.
Inflation theory holds that the universe went from nothing at all to more than 99 percent of its present size in less than one-billionth of a billionth of a second – which is to say, instantly. So while empirical data, especially the uniformity of cosmic background radiation, support the conclusion that the universe began from a single point, from any reasonable human perspective there was no explosion. The universe simply appeared everywhere at once, instantaneously.
While no illustration can really represent the very technical theories here, the "nothing" problem can be thought of as, "What is outside the cone?" That is, if you go to the farthest point of the universe, what is one meter beyond that?
The Einsteinian answer is that because matter, the universe, curves space, there is no such thing as the "farthest point" of the universe except in a relative way, and that there is no "one meter" beyond that because there is no beyond at all. But this answer does not satisfy present-day physicists.
A few things are certain: we have not always existed; we will not always exist; we exist right now. Whatever nothingness truly is, we are all something right now. And whatever exists right now, it did, at some level, come from nothing, no matter how you define nothing. And as best as we understand the Universe, it will return to a state approaching an infinite, physical nothingness as well. But as to just what the nature of the ultimate “nothingness” truly is? That’s still, perhaps, the secret we’re all fundamentally searching for.