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German philosopher Martin Heidegger鈥檚 angst-ridden non-answer to what he called 鈥渢he fundamental question鈥� was that a fear of nothing was the defining feature of the human condition. We certainly seem scared that nothing is some kind of universal default. But why should we presume that nothing is more likely than something? After all, if we accept that we exist to ask the question, then we鈥檝e proved something exists. It鈥檚 a whole lot harder to prove that nothing can exist.

It鈥檚 tempting to think that modern physics has made this line of reasoning easier. According to quantum field theory, even the vacuum of space is a lively soup of particles and fields popping up out of nowhere. This kind of random fluctuation is thought to have ultimately created our cosmos of stars, planets and existential worriers out of the quantum vacuum 鈥� admittedly abetted by some as-yet-unexplained happenstance, such as a period of faster-than-light inflation in the early universe, and matter somehow winning out against its evil twin, antimatter.

But there鈥檚 a huge flaw in this logic: the quantum vacuum is not nothing.

And even if there were no quantum vacuum filling it, empty space would be anything but nothing. According to Einstein鈥檚 relativity, space moves, bends, snaps and has holes in it just like a tangible, material thing. Even old-school physics admits it has a property: size. 鈥淲hen we say there is an absolute vacuum between Earth and the moon, that doesn鈥檛 mean there is nothing,鈥� says physicist David Deutsch of the University of Oxford. 鈥淣o distance between us and the moon 鈥� that would be disastrous.鈥�

Within this context, the idea that something can come from the 鈥渘othing鈥� of free space is not a problem, says physicist Paul Davies of Arizona State University, Tempe. 鈥淭he ballyhoo about a universe popping out of the vacuum is a complete red herring,鈥� he says. 鈥淚t just dodges the real issue, which is the prior existence of the laws of physics.鈥�

More specifically, the question becomes why these laws of physics exist instead of any other set, including no set at all.

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鈥淓ven if the answer to why there is something rather than nothing were because of how quantum field theory works, the question would become why are the laws of quantum field theory as they are,鈥� says Deutsch.

One answer might be because a universe built on this basis is particularly prone to producing conscious observers who ask what they think are probing questions. A popular idea is that all the other possible laws of physics 鈥� including no laws 鈥� exist elsewhere in a 鈥渕ultiverse鈥� of all possible worlds.

In that case, why a multiverse? In the end, says Deutsch, physicists are going to have to accept they can only ever shift the goalposts on this one. 鈥淚t鈥檚 a philosophical question and that鈥檚 that.鈥� He thinks this is actually a good thing. Even if science could reveal an ultimate answer to why stuff is, we shouldn鈥檛 want it. 鈥淲e can鈥檛 have a magic formula that resolves all problems,鈥� he says. 鈥淭hat would be a disaster, thinking would become pointless.鈥�

For him, the question is best explained by an old gag. 鈥淲hy is there something? Because if there were nothing we鈥檇 still be complaining.鈥�

This article appeared in print under the headline 鈥淲hy is there something rather than nothing?鈥�