The Greatest Show on Earth Read Free Page B

if I ask something like ‘Should we be good?’ I almost always get an answer. Anything vague, especially involving conventional moral judgements, these aliens are extremely happy to respond to. But on anything specific, where there is a chance to find out if they actually know anything beyond what most humans know, there is only silence.
    
    
    
    
    Fermat’s Last Theorem, like the Goldbach Conjecture, is a proposition about numbers to which nobody has found an exception. Proving it has been a kind of holy grail for mathematicians ever since 1637, when Pierre de Fermat wrote in the margin of an old mathematics book, ‘I have a truly marvellous proof . . . which this margin is too narrow to contain.’ It was finally proved by the English mathematician Andrew Wiles in 1995. Before that, some mathematicians think it should have been called a conjecture. Given the length and complication of Wiles’s successful proof, and his reliance on advanced twentieth-century methods and knowledge, most mathematicians think Fermat was (honestly) mistaken in his claim to have proved it. I tell the story only to illustrate the difference between a conjecture and a theorem.
    As I said, I am going to borrow the mathematicians’ term ‘theorem’, but I’m spelling it ‘theorum’ to differentiate it from a mathematical theorem. A scientific theorum such as evolution or heliocentrism is a theory that conforms to the Oxford dictionary’s ‘Sense 1’.[It] has been confirmed or established by observation or experiment, and is propounded or accepted as accounting for the known facts; [it is] a statement of what are held to be the general laws, principles, or causes of something known or observed.
    
    
    A scientific theorum has not been – cannot be – proved in the way a mathematical theorem is proved. But common sense treats it as a fact in the same sense as the ‘theory’ that the Earth is round and not flat is a fact, and the theory that green plants obtain energy from the sun is a fact. All are scientific theorums: supported by massive quantities of evidence, accepted by all informed observers, undisputed facts in the ordinary sense of the word. As with all facts, if we are going to be pedantic, it is undeniably possible that our measuring instruments, and the sense organs with which we read them, are the victims of a massive confidence trick. As Bertrand Russell said, ‘We may all have come into existence five minutes ago, provided with ready-made memories, with holes in our socks and hair that needed cutting.’ Given the evidence now available, for evolution to be anything other than a fact would require a similar confidence trick by the creator, something that few theists would wish to credit.
    It is time now to examine the dictionary definition of a ‘fact’. Here is what the OED has to say (again there are several definitions, but this is the relevant one):
    
    Fact: Something that has really occurred or is actually the case; something certainly known to be of this character; hence, a particular truth known by actual observation or authentic testimony, as opposed to what is merely inferred, or to a conjecture or fiction; a datum of experience, as distinguished from the conclusions that may be based upon it.
    
    
    Notice that, like a theorum, a fact in this sense doesn’t have the same rigorous status as a proved mathematical theorem, which follows inescapably from a set of assumed axioms. Moreover, ‘actual observation or authentic testimony’ can be horribly fallible, and is over-rated in courts of law. Psychological experiments have given us some stunning demonstrations, which should worry any jurist inclined to give superior weight to ‘eye-witness’ evidence. A famous example was prepared by Professor Daniel J. Simons at the University of Illinois. Half a dozen young people standing in a circle were filmed for 25 seconds tossing a pair of basketballs to each other, and we, the experimental subjects, watch the film.