I have just downloaded cryptlib which is a software library containing encryption algorithms made accessible to those who don't wish to get involved in the nitty-gritty of computation. What led me to do so was the desire to back up my stuff without having to plug in auxiliary devices, that is to back it up via wireless internet which means to, or via, 'the cloud'. Now 'my stuff' is stored in Truecrypted files which are 4000MB in size (or sometimes bigger) and backing up one of these files via WiFi would take a while and it would be desirable for every little update or alteration I made. My idea therefore was to split up the big files into segments and back up afresh only those segments which have altered since the last backup, or (simpler but not tying in with the way Truecrypt works) separately encrypt each file I work with and back up afresh only those which I have worked on recently. The main thing I wanted to do with cryptlib was not so much encrypt files as produce a trustworthy hash value to verify the files backed up (and perhaps to assess which files - or segments of the big files - have altered since last time).
This has led to me thinking about what the point is of life, or - because I'm pretty sure there is no point as such - what there is of significance to life, or in the universe. And myself, I think it's information. Some people are more physical, and do physical things to look after their bodies (play sports, for example) or do things which bring physical pleasure to their bodies; but the way my brain and body are, I am more mental than corporal.
I'm still working out just what 'information' is, but broadly speaking homo sapiens is constructed - more so than other animals - for processing it. Human processing of information has as a large component of it simplifying or summarising information. Part of this is pattern recognition: we observe things in the world around us which we categorise towards the end of processing all instances in a category much the same. Tables can be treated all very similarly, and so can dogs. Of course a lot of what makes for interest in life is that things even within a category are not identical: there is symmetry but imperfect symmetry.
Another way of saying it is that human processing of information is a battle against increasing entropy. This applies also to life in its physical aspects. The fact that animals reproduce versions of themselves - similar but not identical - is on the face of it a contradiction of the law which states that entropy (a measure of randomness or chaos) always increases. Of course it isn't in fact a contradiction because in putting things into order a lot of waste heat is emitted and that is an increase in entropy. I'm not so much thinking of hot air here as steam, that is in converting hot vapour into an ordered to-and-fro motion of a piston a steam engine is considerably less than 100% efficient.
Jedenfalls, this is what life is and specifically it's what human life is: on this planet circumstances have arisen whereby a lot of order comes into existence - order measured at a certain level of abstraction - at the same time as the creation of a lot of heat. I am with Sartre in noting that order - a piece of music for example - doesn't exist within the physical universe and as such for some of us more than others order has more significance than heat.