A BIG BANG THEORY
By Martin Hickes
THE LATE great cosmologist Carl Sagan once sagely opined: ‘If you wished to make an apple pie from scratch, then you must first invent the universe.’
Scientists have been puzzling about the origin of the universe since, well, the origin of the universe, and are still stumped by the question.
One chap I had a chat with, a specialist in black hole theory, once suggested that, despite the many milestones achieved in trying to prove what happened seconds after the Big Bang, we are still some way from knowing the answer; possibly the greatest understatement of all time.
Others of course – not just theologians –think that there might not have been a Big Bang at all. Even Stephen Hawking, in his marvellous book The Grand Design, acknowledges while science provides many answers, the mystery still remains about who or what lit the blue touch paper at the ‘start’ of the universe.
If we accept that the Big Bang did happen, particle physics can get within a few trillionths of a second of the actual event. But physics itself breaks down at the moment of creation itself. Despite all the ingenuity of such, the moment of creation cannot be explained by science and mathematical knowhow. Though we are creeping ever closer.
What is known is that the Big Bang – which many theorize was an expansion of space and time, rather than a big explosion, seeded all the basic particles which built everything.
Many scientists abhor the very idea of God or a Supreme Being being involved; others are more conciliatory and are more curious as to how ‘He’ created the universe. Many others believe that God did everything.
Whatever your point of view, the physical properties cannot be ignored. Where they all came from is the big mystery – and more so perhaps ‘why’.
All of the matter from which we are formed, and which constitutes our physical surrounds – the table and chairs at which you sit, the computer on which you may be reading this article, and your neighbourhood, are made of up building blocks of chemical elements.
These chemical elements are the residue of the Big Bang – the matter which has formed over a LONG time from the initial energy of such.
It might not seem like much, but from a theoretical state in which there was at first absolutely nothing, followed by a hot state of pure energy (without matter), over 13.7bn years, the whole grand event has cooled to produce the chemical elements, which make up all of matter, including us.
But it need not have been this way.
There are 92 elements which naturally occur, starting from the very light –hydrogen and helium, numbers 1 and 2, to the very heavy, Uranium, in the high 90s.
Chemical elements are basic constituents of matter; the purest ‘substance’ of something; gold cannot be broken down into a lesser elements for example; if you chop gold into little pieces, you are still left with gold, not another element.
However, each element in itself is made up of three smaller parts; protons, neutrons and electrons.
Protons and neutrons are effectively like tiny snooker balls which are ‘glued’ together by a ‘magic’ force called the Strong Nuclear Force. Whizzing around them is an electron, or a cloud of such, which is the tiniest marble by comparison.
And it is the number and shape of these snooker balls (protons and neutrons) within an element which dictate the characteristics of a chemical element.
Carbon, for example, is element number 6; this means it has 6 protons and 6 neutrons glued together in its nucleus. (And six electrons whizzing around such).
The subsets of matter all have an electrical charge; protons are positively charged +1; neutrons have zero charge (0) and electrons have a -1 charge.
So if we add up all the energies in a carbon atom, we have 6 positive charges (+6), which are balanced by six zero charges (the neutrons) and six negative charges (the electrons). The whole atom is thus electrically neutral.
What happens if we want to add another ‘snooker ball’ to our carbon atom? Let’s pretend we are ‘God’, and we happen to have a handy triangle frame full of snooker balls at our side with which we can merrily experiment.
If we pick up a red snooker ball (let’s call these the protons), we can add it to the six we already have, making seven protons. However, just to be fair and to keep things in balance, we have to add a white snooker ball (a neutron) to balance the pack within the nucleus. And to complete the atom fully, we must add an extra marble, an electron.
The whole atom is thus balanced electrically once more and thus we have created the next element on: a gas called Nitrogen (Element number 7).
We could follow this pattern onwards, creating more and more heavier elements: Oxygen (8), Fluorine (9), Neon (10) etc etc.
Because of the way Nature works, it tends to prefer to make additions and subtractions in discrete packets of not just one snooker ball at a time, but in pairs.
Certain chemical elements are naturally ‘radioactive’ and give off protons and neutrons not singly but in the shape of an ‘alpha particle’: very simply a clump of two protons and two neutrons. In our analogy two red balls and two while balls glued together in a neat clump.
Uranium, for whatever reason, is randomly emitting alpha particles over a period of time and it is this radioactive ‘decay’ which eventually we see Uranium decay into another element. Take two protons away from Uranium (and two neutrons) and you arrive at the element which is two elements down from such (Thorium).
But what lies within the protons and neutrons?
Electrons are thought to be ‘point’ particles having no internal ‘Russian doll’ like elements.
But protons and neutrons are made up of curiously named ‘quarks’.
Each proton or neutron has three quarks within each; three very tiny marbles as it were within the protons or neutrons.
The quarks have a charge of either +2/3 and – 1/3 and in combination again balance electrically – and ‘form’ the protons and neutrons.
Quarks cannot be physically seen but can be detected; the key question then: from where did these quarks come?
That answer is not really known; quarks seem to be fundamental particles of matter formed within the first few moments of the universe.
But what is known is that the quarks seem to the very basic building blocks of the universe given that they form protons and neutrons, which in turn form the atoms which lie at the heart of all the chemical elements we know; which in turn go on to make up all the matter we know.
At the point of creation, physicists surmise that the universe was at one point analogous to a pencil balanced on its tip. As impossible as is seems, it was in perfect balance or equilibrium.
Something then happened which caused it to come into being, and the ‘pencil’ effectively toppled in one direction; in the case of our universe it produced all the right conditions which would lead on to the quarks of matter being created.
It could have toppled in the direction of creating an anti-matter universe; matter and anti-matter naturally annihilate each other. In the case of our universe, matter for whatever reason became favourable – and the rest literally is history.
But to go back to Carl Sagan, perhaps the most remarkable occurrence lies in the fact that from these very seeds of initial creation have sprung quarks, which have formed protons, neutrons and electrons, which produced the initial chemical elements - number 1 and 2 are hydrogen and helium. These in turn have gone on to form ‘us’.
Many years after the Big Bang happened, enough hydrogen clumped together to start fusing together at the atomic level; in doing so creating elements of helium and emitting a vast amount of energy in turn. These basic nuclear reactors are called stars.
Stars as part of their nuclear process synthesize other elements – right up to iron at their solid iron cores.
When they run out of fuel to drive the process, they often explode in spectacular supernovae (depending on their size), scattering their heavier elements into space. These heavier elements themselves clump together under the force of gravity to eventually, after many millions of years, form planets. Some say a mere 10 billion years are needed to cook this form of the universal apple pie.
And a planet which lies at a perfect distance from its parent star – within the so-called Goldilocks Zone – can in theory go on to support life.
That intelligent life can then go on to study itself, invent complex machinery and scientific processes and eventually gaze back at the universe and contemplate where it all came from in the first place.
As Carl Sagan once said, we are the means by which the universe can know itself.
Why this might seem a little pithy, as Stephen Hawking surmises in The Grand Design, even the most hardened sceptic must be impressed by the series of occurrences which have led to humans seemingly only arising on the earth - but also having the ability and intelligence to look back and wonder.
At any stage along the route, over 13.7 billion years since the Big Bang, any number of tweaks or chance other happenstances along the way might have led to our non-existence.
Perhaps it all is just that – a chance series of happenings which fortuitously seems to have ended in the human being ‘being here’.
But some mathematicians reckon if you factor in the odds, the chances of humans arising again - were you to start the whole process from scratch again - would be tremendously large.
Almost so astronomically large as to lend enough evidence to convince some people that it might hint at something approaching a grand design. Catholic theologians at the time before Galileo certainly thought so.
Others argue that if the universe is indeed infinite, then by the laws of probability, the existence of humans elsewhere is not only a chance but a certainly. Strange things happen when you factor in infinities, largely resulting in chance evaporating.
Perhaps the greatest puzzle is the one which relies on a thing called the anthropic principle. There is more than one version of this but one roughly states that we see the universe as we do simply because life has arisen in that part of the universe which is conducive to intelligent life evolving – and thus allowing us to contemplate such.
Those poor souls who might have lived in a different part or type of universe never got the chance to see such (and how different it might be from our part of the universe) simply because the conditions were never right in the first place.
Even more confusingly, philosophers have suggested that human beings are the sole purpose of the universe, along the perhaps spurious lines that if humans had not evolved, there would be no-one to evolve and ponder at such, or a way for the cosmos to ‘know itself’, a loose argument towards some sort of cosmic consciousness.
It you think about it too much, your brain starts to spin in one of those never ending loops.
Some are even now beginning to question the nature of the electron, surmising that it might not be just a simple point particle, but might actually be curled in on itself at the very small scale in multi-dimensions.
String theory and M-theory suggest that aside from our familiar large four dimensions of space and time, at the very, very small level, single length one dimensions might exist (which might equally be curled up in rubber band like dimensions).
Some suggest as these strings ‘vibrate’ under some force of energy, (perhaps dark energy) in turn they generate the very small particles (perhaps those lesser than at the quark level) which go on to build up all the matter in the universe. Such strings might also be powering the expansion of the universe.
Some have even surmised that there may be an analogy between a vibrating guitar string and the very small dimensions of the universe. How elegant, perhaps, if there was an underlying ‘musicality’ to the universe, twinned with hard science at the fundamental level.
Will science or religion ever meet or solve the problem or is the universe actually ‘knowable’? Perhaps God only knows.
Professor Vlatko Vedral, in his brilliant Decoding Reality, suggests that the universe might be effectively dealing us the greatest-ever card trick. He argues that quite aside from the physical properties of the universe, ‘information’ might be a fundamental property of such. The universe is slowly unveiling its secrets over time it seems. Is this the Hand of God?
For the moment, perhaps all we can content ourselves with is the knowledge that we seemingly are in the right place at the right time to be able to contemplate such.
If you wish to make an apple pie from scratch, not only must you invent the universe, but it has to be the perfect universe at that, it seems.