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I've just finished a first draft of my book about information theory, neuroscience and their implications for philosophy. Unfortunately, it's missed this year's "holiday reading" window, but maybe next year?

Nevertheless, this is an ideas column and I feel the urge to offer you an edited excerpt, which may assist you in arguing about religion down the pub (you'll excuse the lack of direct relevance to computing this once, I hope). The story so far is there's been a Big Bang and there's now a universe full of hot stuff whizzing around. One such lump of hot stuff is the sun, and we all live on a ball of rock and water in orbit around it. Now read on...

Life on Earth exists, as Roger Penrose has so lucidly explained, not because of energy received from the sun but because of low entropy radiation received from the sun. The Earth re-radiates as much energy back into space as it receives from the sun each day: if it didn't it would become ever hotter and would've evaporated millions of years ago.

However, it re-radiates in the infrared at a lower frequency than the yellow sunlight it receives and, because each lost infrared photon carries away less energy than an arriving sunlight photon, more of them are needed - hence their entropy is higher. We live in this entropy gap between incoming sunlight and outgoing heat radiation, and ultimately on the fact the sun shines brightly against the black background of space - if all the incident radiation were of uniform

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energy and came equally from all directions, there'd be no entropy gap and no possibility of order (that is life) arising anywhere. The non-uniform distribution of matter and radiation permits a local lowering of entropy and enables living organisms to arise and reproduce themselves by assembling simpler molecules into large orderly structures.

Once life arises, evolution generates life forms of ever increasing complexity, many of them equipped with some kind of sense organs that confer the ability to sample their surroundings - such organs greatly assist in finding food, avoiding predators and locating mates. This sampling involves the transfer of information rather than matter, although always via some material medium: for example, vision samples light reflected from external objects; hearing samples pressure waves created in air by the motion of external objects; touch samples the pressure exerted on the body by direct contact with external objects.

Only taste and smell require ingestion of external chemical substances, in tiny quantities. The end result is a stream of electrochemical impulses in the organism's nervous system that is purely internal, but which encodes information about the external world.

The external world is full of unevenly distributed, moving matter that exhibits forms (shapes, colours and so on) imposed by the basic attractive forces of physics. Living organisms sample these forms via their sense organs, store and process them encoded as electrochemical signals. These forms are manifest in matter itself, whether or not any living being exists to see, hear, or feel them. They're not subjective. Later on, organisms evolved brains that could store these samples and recall them as memories, enabling them to partially predict the future by comparing current samples with remembered ones to discover repeating patterns. The brain of Homo sapiens alone confers an ability to use language to communicate these samples to others, and to support self-consciousness - the ability to sample our internal states and discuss them.