The Energy of Life:. Guy Brown

it, using the figures for predictions, but have no idea what it is in itself. Energy seems just an abstract accounting concept like money quantifying the amount of movement that could be produced by a particular system. How boring! Yet, according to physics, energy is perhaps the most fundamental property of the Universe. Energy is the one constant conserved through all change. Everything can be created from or dissolved into energy, including even matter itself: which is demonstrated by atomic explosions and Einstein’s famous equation E = mc². In this rather abstract scheme of things, energy is the ultimate substance and fabric of the world, from which all else evolves and into which all else ultimately dissolves.

      But energy itself does not produce movement or change. So what does? Newton said all movement or change is brought about by forces. In our lives we experience only two types: gravitation and contact forces. Gravitational force pulls everything towards the earth’s centre and causes all heavenly (and not so heavenly) bodies to attract each other. Contact forces occur when we push or pull something; when I lift a chair; when a car hits a lamppost; or when a volcano explodes. Gravitational force exists because every bit of matter is attracted to every other bit, causing them to accelerate towards each other. All the contact forces are different manifestations of one immensely powerful force: the electric force. Electric force is the force of attraction or repulsion between all charged matter. Gravitational force and electric force account for virtually all movement and change in our universe. There are two other forces known: strong nuclear force and weak nuclear force but their range of action is so small, they can only be observed by breaking open the nucleus of an atom. Thus nuclear forces have no apparent effect either on biology or our everyday lives.

      Although gravitational force is important for large objects like us, it has no significance for small objects like cells. The electric force is – roughly – one thousand million million million million million million times stronger than the gravitational force and is the only force that matters at the level of molecules and cells. Gravitational force causes attraction – that is, two objects will accelerate towards each other. But the electric force causes either repulsion or attraction depending on whether the matter carries the same or different charges: opposites attract, likes repel. The electron carries a negative charge: the proton a positive charge. Everything, including our bodies, can be considered made up of different arrangements of protons and electrons. (There are also neutrons, but they have no charge, and behave like an electron and a proton stuck tightly together.) Everyday objects are made up of approximately equal numbers of electrons and protons. If this were not so, an excess of positive or negative charge would create a huge force pushing out (or exploding) the extra charge, leaving a roughly neutral group of electrons and protons. The power of the electric force is truly immense. If two people, standing at arm’s length, each had one per cent more electrons than protons in their bodies, they would be blown apart by an electric force sufficient to move the weight of the entire earth.