Big Bang?

Energy:  What Exactly Is It?

© Davy Jones

No matter how much you push the envelope – it will always be stationery

About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion was known as the Big Bang.  At the moment of this event all of the matter and energy was contained at one point.  What existed prior to this event is completely unknown and is a matter of pure speculation.  (LaRocco)

The above paragraph is an excerpt from an article, entitled, ‘The Big Bang – It sure was BIG’!  Note the comment – all of matter and energy was contained at one point – not - all of matter and energy was created at one point. 

There’s no great mystery in this statement of course, it is a simple matter of physics – energy - as we know, cannot be created or destroyed - it can only be transformed!  The arguable word in the sentence is the inclusion of ‘matter’ being contained at this point.  However, given that energy and matter are, according to Einstein (E=mc2), one and the same, the semantics of the sentence are perhaps neither here nor there.  What is possibly more important in this reflection is the fact that many people actually refer to the Big Bang as the point at which the universe was ‘created’!  That basic misinterpretation muddies the cosmic waters before any logical thought as to the conceivable possibilities surrounding the greatest of all mysteries, can be considered.  Just to underline the immense implications contained in this short paragraph, one should also consider; all energy and matter must mean and include – dark energy and dark matter – or quite simply – the basic constituents for everything thereafter!  

My thoughts as I read through the above article drifted to the most basic question – ‘what exactly is energy’?  On the face of it, a simple and certainly most obvious question, which would soon be resolved by a little research?  (I have been known to make naive suppositions from time to time).

Within a short while I found myself frustrated at every new Internet page.  Information categorising energy in its various forms – thermal (heat) – chemical – electrical – radiant – nuclear – elastic – sound – mechanical and luminous (light), abounded.  All of the indicated forms of energy can of course be divided into the two generic groups of kinetic and potential energy. 

The Internet also provides an overabundance of data relating to the above classifications, detailing where, when, how, and why they occur.  There is also much made of the fact that energy is a physical measure that expresses the amount of work that can be achieved by a force; it then follows that all forms of energy are measurable through the use of mathematical symbols.  A lot of interesting facts and figures – but no concrete explanation of exactly what energy is! 

Eventually, I stumbled upon a Science Forum discussion page that seemed to offer ‘something’ I could finally nail down!   The opening question appeared to offer precisely the information I needed: ‘What exactly is energy…without using symbols and metaphors’?  There was no doubt about it – as I waded into the opening comment – the first participant began by stating the obvious – that molecules move, they are ‘hot’ and have lots of kinetic energy.  But, then asked: what exactly is energy?

The discussion progressed along similar fumbling lines to my research – going through all of the categorisation mentioned above, including the mathematical concepts involved.  Several comments into the forum I came across the first glimmer of hope in the following comment: …’energy is the capacity to do work of some sort.  It is categorically not a substance in itself that pervades the universe’. Naturally a swift rejoinder to this comment followed, which suggested that if the previous writer thought energy was just an abstract concept – they should try sticking a fork into an electrical socket.  Whilst amusing – this comment still didn’t assist me in my quest to define ‘energy’ per se.  We all know that ‘electricity’ is a form of energy.  And, as with just about every form of energy I can think of, in certain circumstances, too much of it can do extreme damage to the fragile human atomic structural arrangement!  At its worse – we call that damage – death – that being, in terms of physics, just another ‘changed state’ in a seemingly endless process!

The next comment suggested that ‘everything’ was energy because all matter, irrespective of state is a form of energy.  A fair enough comment – but it still didn’t answer the basic question!  It is amazing how trains of thought can become bogged down when dealing with oddly esoteric questions.  Further again into the discussion the term: ‘creation of the universe’ inevitably raised its head.  The very use of the word – creation – of course, suggests a creator – and therefore moves the discussion from a purely scientific one to a philosophical and spiritual one.  This manipulation of any discussion seems to be the ultimate human response when frustration and a lack of logical answers set in; a third party is introduced that conveniently provides all the answers.  Even the illustrious Einstein is recorded as resorting to the same conclusion at one very frustrating moment in his quest for answers.

Despite this natural diversion, the discussion continued in a reasonably focused direction.  Some participants were beginning to show obvious signs of frustration – evident in their comments becoming more personal and derogatory towards other forum participants.  Much was made of the fact that energy determines the path of change – energy is evident through observable change – and the amount of energy determines the rate of change. 

All pertinent points – but still none that addressed the original question: What exactly is energy?

Towards the end of the discussion there were a few comments relating to molecules and particles, and the movement of these ‘producing energy’.  Finally, a respondent came up with the following explanation:  Energy, he said, has no reality apart from its mathematical dependence on measurable variables.  The respondent noted that an object’s kinetic or potential energies are not measured – but the associated state variables are - velocity and position respectively. (Sic)

This answer was expanded upon, by one I assumed to be the convener, who warned that whilst it wasn’t an easy question to answer – that didn’t make the question impossible to answer.  He indicated most physicists know exactly what energy is, and continued thus: the concept of energy is ultimately a tool – invented by humans – to understand the world around us.  He stated that whilst this was not a definition of energy – the whole point was – energy can be MANY things and it is this vagueness that makes the concept useful.

As an example, he cites the notion of length – which is close to our primitive perception; length – we understand as being that there is, “here” and “there”.  The concept of energy, however, he describes as being a higher order type of tool.  It doesn’t correspond so simply to our direct experience in that no one can point to a primitive notion and state that it is an example of energy.  Therefore – energy – is simply an abstraction.  However, it does enable a unified description of diverse phenomena.  Energy, as such, is simply a tool and an additional way to organise our understanding of the universe. 

The writer wraps up by providing what he describes as an exact definition of energy: “Energy is the generator of time translations”.  Having given this murky definition, he explains that – this is why no one gives the exact definition of energy, because it takes years of intensive training just to comprehend what such a statement really means!

In this instance, I can only agree.  Having put myself through this meticulous research process, I now wonder what ‘diverse phenomena’ are?  I’m sure no one will ever bother to explain it to me – simply because I wouldn’t understand - even if they bothered! 

So, at the moment of the Big Bang – all diverse phenomena were present – or were they?

Any readers’ comments on this small reflection would be most welcome; particularly if a convincingly simple answer is forthcoming.

Refs:

Encyclopedia, W. T. F. (1999). Energy. Retrieved February 18, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Energy#Forms_of_energy.

LaRocco, C. E. A. The big bang it sure was big. Retrieved February 18, 2011, from University of Michigan: http://www.umich.edu/~gs265/bigbang.htm.

Sciforums, P. (2006). What exactly is energy. Retrieved February 18, 2011, from SciForums.com: http://www.sciforums.com/showthread.php?t=54423.