Much ado about 'nothing' (or a universe therefrom) #
|
|
"The deist God is a physicist to end all physics, the alpha and omega of mathematicians, the apotheosis of designers; a hyper-engineer who set up the laws and constants of the universe, fine-tuned them with exquisite precision and foreknowledge, detonated what we would now call the hot big bang theory, retired and was never heard from again”[1]. |
In the beginning, there was nothing but energy – a vacuum teeming with matter and antimatter, that is, virtual particles with small differences in their energy levels. The vacuum is literally alive with these quantum fluctuations, where little packets of energy appear - and disappear - very quickly. Today our best theories tell us that the universe sprang from this vacuum, and that the rules of the quantum appear to have contributed to the large scale of the entire cosmos. When our universe first came into existence it was many, many times smaller than the size of a proton, and its development since then has been governed by the rules of the quantum world. In fact, the universe is just the quantum world inflated many, many times[2].
How can it be said that something can emerge from nothing? It’s all a matter of definition, really. It involves initially a consideration of what we really mean by such terms as a ‘void’, ‘empty space’, ‘nothing’. In the quantum world, those terms mean something radically different from what we understand them to mean in the macroscopic world we live in and are familiar with. In the quantum world there is no such thing as ‘empty’ space and no such thing as ‘nothing’, for when viewed at atomic scales, so-called empty space is still seething with activity: with particles and antiparticles and their quantum fluctuations - energy. In other words ‘empty space’ does not consist of nothing and it is certainly not empty.[3]
“Within nothingness there is a kind of fizzing, a dynamic dance as pairs of particles and anti-particles borrow energy from the vacuum for brief moments, before annihilating and paying it back again”[4]. However, these energy fluctuations in the vacuum are constrained by Heisenberg’s uncertainty principle (HUP)[5] to last only the briefest of moments, and these 'virtual particles' cannot be seen as anything more than the deviation from energy conservation that these fluctuations amount to. In brief, HUP sets a lower limit, based on Planck’s constant, on the accuracy with which certain pairs of physical quantities of a particle, such as its position and momentum, can be measured together[6].
Particles can radiate energy (that is, photons) in apparent violation of the law of energy conservation, so long as that energy is reabsorbed by other particles within a short space of time, and the more the energy account is overdrawn, the sooner it must be repaid. Another way of expressing HUP in this context is to say that the uncertainty in the measured energy in a system is inversely proportional to the length of time over which we are observing it[7]. The consequence is that in truly tiny amounts of time and space, something can come from nothing, and nothingness is thus revealed as a mass of virtual particles appearing and disappearing trillions of times in a blink of an eye[8].
This was the ‘world’ into which our universe was born as nothing more than the minutest of specks, and if you are wondering why it simply did not simply disappear along like so many other particles and antiparticles beforehand, the answer lies in the fact that firstly, after so many matter/antimatter collisions and annihilations, a very tiny proportion of matter was left over: for every billion particles of antimatter and matter, one particle of matter was left behind - and we don’t know the reason why! The second reason lies in the universe’s unbridled, exponential inflation which followed a split second after it came into being, a subject to which we shall return.
Many present day theorists do not even attempt to describe the universe when it first came into being, since the laws of conventional physics break down at that point, and the big bang is not a theory of cosmic origins. It is a theory that delineates cosmic evolution from a split second after whatever happened to bring the universe into existence, that is its aftermath.
As David Christian says in his Introduction to Big History, Maps of Time: “About the beginning, we can say nothing with any certainty except that something appeared. We do not know why or how it appeared. We cannot say whether anything existed before. We cannot even say that there was a ‘before’ or ‘space’ for anything to exist in, for … time and space may have been created at the same time as mass and energy. So, we can say nothing definite about the moment of the big bang or about any earlier period”[9]. In other words, the so-called big bang may be something of a misnomer, since it says nothing at all about time zero itself, and tells us nothing about “what banged, how it banged, or, frankly, whether it ever really banged at all”[10]. As an alternative, many physicists believe the big bang was a natural phenomenon occurring in the context of a much wider reality[11].
But whatever forces brought it about we do know that thereafter there was space, time, energy and matter. Considered in this way, the Big Bang was a transition point or threshold - an event creating something completely new in an increasingly complex universe - and as the universe moves from one threshold to the next, a new stage of complexity is created in the process. Other thresholds dealt with in the course of these pages stemming originally from the Big History Project website, are star formation, the creation of elements, and the formation of the solar system [12] .
But perhaps the universe did emerge from something after all: itself
Of recent times a new theory has emerged about how the universe came into being, one built upon the foundation of hypothetical closed time like curves in the early universe. It goes something like this[13]:
Remember that under general relativity matter and energy warp spacetime. In extreme cases, the conditions may be such that spacetime will bend around upon itself to curve or even form a loop. In 1983, Kip Thorne, a physicist at the California Institute of Technology, hypothesised the existence of closed timelike curves called wormholes – a kind of tunnel joining two different locations in spacetime – which opened up the theoretical possibility of time travel into the past. In 1991, J. Richard Gott, an astrophysicist at Princeton University, showed how cosmic strings – infinitely long structures that may have formed in the early universe – would allow closed timelike curves where two strings intersected.
For a wormhole to form in the first place, there would need to be negative energy: particles moving through the wormhole would loop back around an infinite number of times, leading to an infinite amount of energy, and because energy deforms spacetime, the entire thing should collapse into a black hole, but unlike black holes, which are a natural consequence of general relativity, wormholes and closed timelike curves in general are completely artificial constructs affording a way of testing the theory.
The creation of a loop in spacetime would require some very extreme physics, and the most likely place to expect extreme physics is at the very beginning of the universe. In 1998, Gott and Li-Xin-Ji, presently an astrophysicist at Peking University argued that closed timelike curves are not merely possible but essential to explain the origin of the universe, the question posed being whether a time loop at the beginning of the universe would allow it to create itself. In other words, could the universe could be its own mother?
Gott and Li hypothesised that the universe “started” with a bout of inflation – just as in standard big bang cosmology, where an all-pervasive energy field drove the universe’s initial expansion. Many cosmologists now believe that inflation gave rise to countless other universes besides our own. Our universe is but one of these branches, but where did the trunk come from, inquired Gott and Li. Could it be that one of the branches just looped around and grew into the trunk. A simple two-dimensional sketch of Gott and Li’s self-starting universe would look something like the number 6 with the spacetime loop at the bottom and our present-era universe at the top. A burst of inflation, Gott and Li hypothesised, allowed the universe to escape from the time loop and expand into the cosmos we inhabit today.
Although hard to contemplate, the main appeal of this model is that it eliminates the need for creating a universe out of nothing. As noted, Stephen Hawking and others have proposed models in which the universe does indeed arise out of nothing: according to the laws of quantum mechanics, empty space is not really empty, but is filled with “virtual” particles that spontaneously pop into and out of existence. Hawking and his colleagues theorised that the universe burst into being from the same quantum vacuum stew. But in Gott' and Li's view, the universe is not made out of nothing; it is made out of something – itself.
# See also “More ado about (something out of) nothing at /more-ado-about-something-out-of-nothing.html
[1] Richard Dawkins, The God Delusion, Black Swan, 2007.
[2] Jim Al-Khalili, Everything and Nothing, 2 Part series, 2nd part - “Nothing”, BBC documentary, 2011, repeated SBS23 Feb 2014. See partial transcript at http://hassers.blogspot.com.au/2011/03/how-everything-was-formed-from-nothing.html See also Lawrence M. Krauss, Why there is something from nothing - A Universe from nothing, Free Press, New York, 2012; https://www.youtube.com/watch?v=VdUYw59ztyw
[3] Al-Khalili, op cit.
[4] Ibid.
[5] Considered later in the context of Quantum Mechanics.
[6] Richard Gauthier, Ph D, The Dirac Equation and the Superluminal Electron Model, http://www.superluminalquantum.org/diracequation.pdf , 2 Planck’s constant is considered in more detail elsewhere..
[7] Lawrence M. Krauss, A universe from nothing, - Why there is something rather than nothing, Free Press, New York, 2012, 71.
[8] Al-Khalili, op cit.
[9] David Christian, Maps of Time, An Introduction to Big History, University of California Press, Berkeley, 2011, 23.
[10] http://www.edge.org/3rd_culture/guth02/guth02_print.html Greene (2005), 272.
[11] See, for example, Brian Greene, The Hidden Reality – Parallel Universes and the Deep Laws of the Cosmos, Alfred A Knopf, New York, 2011
[12] Big History Project: https://www.bighistoryproject.com/chapters/1#intro and https://www.bighistoryproject.com/chapters/1#the-big-bang
[13] This is an edited summary from Tim Folger's article, "A brief history of time travel", in Scientific American, Special Issue - 100 years of General Relativity, September 2015, 58 at 62-63.