Showing posts with label quantum fluctuations. Show all posts
Showing posts with label quantum fluctuations. Show all posts

Monday, 24 September 2018

Why Is There Something Rather Than Nothing?

For scientists, space is not empty but full of quantum energy
Posted by Keith Tidman

Gottfried Wilhelm Leibniz introduced this inquiry more than three hundred years ago, saying, ‘The first question that should rightly be asked is, “Why is there something rather than nothing?”’ Since then, many philosophers and scientists have likewise pondered this question. Perhaps the most famous restatement of it came in 1929 when the German philosopher, Martin Heidegger, placed it at the heart of his book What Is Metaphysics?: ‘Why are there beings at all, and why not rather nothing?’

Of course, many people around the world turn to a god as a sufficient reason (explanation) for the universe’s existence. Aristotle believed, as did his forerunner Heraclitus, that the world was mutable — everything undergoing perpetual change — which he characterised as movement. He argued that there was a sequence of predecessor causes that led back deep into the past, until reaching an unmoved mover, or Prime Mover (God). An eternal, immaterial, unchanging god exists necessarily, Aristotle believed, itself independent of cause and change.

In the 13th century Saint Thomas Aquinas, a Christian friar, advanced this so-called cosmological view of universal beginnings, likewise perceiving God as the First Cause. Leibniz, in fact, was only proposing something similar, with his Contingency Argument, in the 17th century:

‘The sufficient reason [for the existence of the universe] which needs not further reason must be outside of this series of contingent things and is found in a substance which . . . is a necessary being bearing the reason for its existence within itself. . . .  This final reason for things is called God’ — Leibniz, The Principles of Nature and Grace

However, evoking God as the prime mover or first cause or noncontingent being — arbitrarily, on a priori rather than empirical grounds — does not inescapably make it so. Far from it. The common counterargument maintains that a god correspondingly raises the question that, if a god exists — has a presence — what was its cause? Assuming, that is, that any thing — ‘nothing’ being the sole exception — must have a cause. So we are still left with the question, famously posed by the theoretical physicist Stephen Hawking, ‘What is it that breathes fire into the equations and makes a universe for them to describe?’ To posit the existence of a god does not, as such, get around the ‘hard problem’: why there is a universe at all, not just why our universe is the way it is.



Some go so far as to say that nothingness is unstable, hence again impossible.


 
Science has not fared much better in this challenge. The British mathematician and philosopher Bertrand Russell ended up merely declaring in 1948, ‘I should say that the universe is just there, and that’s all’. A ‘brute fact’, as some have called it. Many scientists have embraced similar sentiments: concluding that ‘something’ was inevitable, and that ‘nothingness’ would be impossible. Some go so far as to say that nothingness is unstable, hence again impossible. But these are difficult positions to support unquestionally, given that, as with many scientific and philosophical predecessors and contemporaries, they do not adequately explain why and how. This was, for example, the outlook of Baruch Spinoza, the 17th-century Dutch philosopher who maintained that the universe (with its innumerable initial conditions and subsequent properties) had to exist. Leaping forward to the 20th century, Albert Einstein, himself an admirer of Spinoza’s philosophy, seemed to concur.

Quantum mechanics poses an interesting illustration of the science debate, informing us that empty space is not really empty — not in any absolute sense, anyway. Even what we might consider the most perfect vacuum is actually filled by churning virtual particles — quantum fluctuations — that almost instantaneously flit in and out of existence. Some theoretical physicists have suggested that this so-called ‘quantum vacuum’ is as close to nothingness as we might get. But quantum fluctuations do not equate to nothingness; they are not some modern-day-science equivalent of the non-contingent Prime Mover discussed above. Rather, no matter however flitting and insubstantial, virtual quantum particles are still something.

It is therefore reasonable to inquire into the necessary origins of these quantum fluctuations — an inquiry that requires us to return to an Aristotelian-like chain of causes upon causes, traceable back in time. The notion of a supposed quantum vacuum still doesn’t get us to what might have garnered something from nothing. Hence, the hypothesis that there has always been something — that the quantum vacuum was the universe’s nursery — peels away as an unsupportable claim. Meanwhile, other scientific hypotheses, such as string theory, bid to take the place of Prime Mover. At the heart of the theory is the hypothesis that the fundamental particles of physics are not really ‘points’ as such but rather differently vibrating energy ‘strings’ existing in many more than the familiar dimensions of space-time. Yet these strings, too, do not get us over the hump of something in place of nothing; strings are still ‘something’, whose origins (causes) would beg to be explained.

In addressing these questions, we are not talking about something emerging from nothing, as nothingness by definition would preclude the initial conditions required for the emergence of a universe. Also, ‘nothingness’ is not the mere absence (or opposite) of something; rather, it is possible to regard ‘nothingness’ as theoretically having been just as possible as ‘something’. In light of such modern-day challenges in both science and philosophy, Lugdwig Wittgenstein was at least partially right in saying, early in the 20th century (Tractatus Logico-Philosophicus, section 6.4 on what he calls ‘the mystical’), that the real mystery was, ‘Not how the world is . . . but that it is’.