This article first appeared in the 17 April edition of The Big Issue  under the title The Whole Truth. We live in a world of alternative facts. Paradoxically, these arise because political and religious leaders, driven by belief systems, base their actions on what they believe to be 'truths'. By contrast, science, shockingly to some, is not concerned with absolute truth. Scientists establish the best current theory, given the available evidence. These results are subject to revision as new evidence comes to light. Science is always provisional. This is why scientists often struggle when pulled into political debates. A good scientist avoids the absolute certainties politicians want to hear, and this is interpreted as weakness. The reason scientists do this is that are aware of their frames of reference. A ‘frame of reference’ is a physics concept - it's at the heart, for example, of relativity, and is about establishing the position from which we look at the world. ...

When writing about science we often have to fight against irrational ideas that seem to grow on people's minds like fungi. Yet early mathematicians had the opposite problem of requiring the irrational. This was the irrational in the literal sense - a number that is not made up of a ratio. According to myth, when one of Pythagoras' merry band discovered that the length of a diagonal of a square with sides of length one (the square root of 2) was not a rational number (a fraction that's the ratio of two whole numbers), he was drowned for spreading such a malicious concept. What's interesting, as I describe in my book A Brief History of Infinity , is that there is a remarkably simple proof that  √ 2 is irrational. It requires little more than an understanding of odd and even and goes something like this: Let's assume  √ 2 can be represented by a rational fraction - we'll call it top/bottom. To keep things simple, we are assuming that top/bottom provides the ...

Anyone who knows anything about the battle to preserve rationality in supporting the theory of evolution against marauding creationism will know of the 1925 Scopes trial - or 'the infamous Scopes monkey trial' as it is often known. What I didn't realize until reading John Grant's excellent rallying cry for embattled reason, Denying Science , was that the whole Scopes trial was a publicity stunt. It's not that there wasn't a serious issue to be fought. The trigger was the signing of an act prohibiting the teaching of evolution in universities and schools in Tennessee. But the Scopes trial was apparently one of those good ideas that civic leaders have when they've had a drink or three down the local saloon. Apparently the dignitaries of Dayton, where the trial took place, spotted that any such trial would bring a lot of cash into town. So they got together both the prosecution and the defence, and looked for a likely candidate as defendant. Scopes, a gen...

There will be much said positively and negatively about the late Margaret Thatcher over the next few days. But whatever your opinion of her policies and what they did for or to the country I have to say that, from the inside, the impact of privatization on at least one company was wonderful. I joined British Airways when it was a nationalised industry. It wasn't an unpleasant place to work - far from it - but, frankly, it was fairly low energy. I had an interesting job and I enjoyed it, but the overall feeling was of a company that had little unity and more interest in the status quo (down to the separate 'officers' mess' style management canteen) than, for instance, its customers. In the entire time I was working for a nationalized company I only saw a board member once, and that was in the run up to privitization. Privatization changed everything. There was a dramatic new energy - it really felt like somewhere exciting to be working. More to the point, the major...