The Science of Discworld IV by Ian Stewart & Jack Cohen Terry Pratchett Read Free Book Online Page B

atthe same time as the planets, but has not been subjected to the same complicated processes as the material of the Earth. Meteorites are a ‘frozen’ record of the early solar system.)
    Independent verification has come from Earth’s own rocks; in particular, tiny particles of rock called zircons. Chemically, these rocks are zirconium silicate, an extremely hard material that survives destructive geological processes such as erosion, and even metamorphism, where rocks are heated to extreme temperatures by volcanic intrusions. They can be dated using radioactive decay of uranium and thorium. The most ancient zircons yet observed – small crystals found in the Jack Hills of Western Australia – are 4.404 billion years old. Many different lines of evidence all converge on a similar figure for the age of our planet. This is why scientists are adamant that contrary to the claims of Young Earth creationists, a 10,000-year-old planet is completely inconsistent with the evidence and makes absolutely no sense. And they have come to this conclusion not through belief, or by seeking only confirmatory evidence and ignoring anything that conflicts, but by
trying to prove themselves wrong
.
    No other system of human thought has the same kind of self-scrutiny. Some come close: philosophy, the law. Faith-based systems do change, usually very slowly, but few of them advocate self-doubt as a desirable instrument of change. In religion, doubt is often anathema: what counts is
how strongly you believe things
. This is rather evidently a human-based view: the world is what we sincerely and deeply believe it to be. Science is a universe-based view, and has shown many times that the world is
not
what we sincerely and deeply believe it to be.
    One of Benford’s examples illustrates this point: James Clerk Maxwell’s discovery of electromagnetic waves travelling at the speed of light, implying that light itself is a wave. Human-centred thinking could not have made this discovery, indeed would have been sceptical that it was possible: ‘The poets’ and philosophers’ inability to see a connection between sloshing currents in waves and luminoussunset beauty revealed a gap in the human imagination, not in reality,’ Benford wrote.
    Similarly, the Higgs boson, by completing the standard model, tells us that there is far more to our universe than meets the eye. The standard model, and much of the research that led to it, starts from the idea that everything is made from atoms, which is already far removed from everyday experience, and takes it to a new level
. What are atoms made of?
Even to ask such a question, you have to be able to think outside the box of human-level concerns. To answer it, you have to develop that kind of thinking into a powerful way to find out how the universe behaves. And you don’t get very far until you understand that this may be very different from how it appears to behave,
and
from how human beings might want it to behave.
    That method is science, and it occupies the second of Benford’s categories: the universe as a context for humanity. In fact, that is where its power originates. Science is done by people, for people, but it works very hard to circumvent natural human thought-patterns, which are centred on
us
. But the universe does not work the way we want it to; it does its own thing and we mostly go with the flow. Except that, being part of the universe, we have evolved to feel comfortable in our own little corner of it. We can interact with little pieces of it, and sometimes we can bend them to our will. But the universe does not exist in order for us to exist. Instead, we exist because the universe is that kind of universe.
    Our social lives, on the other hand, operate almost exclusively in Benford’s first category: humans as a context for the universe. We have spent millennia arranging this, re-engineering our world so that things happen
because we want them to
. Too cold? Build a fire. Dangerous