WEIGHING THE SOUL: The Evolution of Scientific Beliefs
by Len Fisher
Imagine you are riding along on a bicycle and you throw a ball straight up in the air. Will it come down some feet behind you or back into your hand? About 30 per cent of people say behind you, which fits with common sense - ball goes up, you keep pedalling, ball falls behind you. But this is to ignore the counter-intuitive laws of motion set out by Galileo in 1638. Your ball has the same forward motion as you do and so it drops back into your hand.
Len Fisher, a media-friendly physicist and research fellow at Bristol University, takes us on a very accessible and entertaining tour of various historical moments where contemporary commonsense ideas about how the world worked clashed with scientific findings. The fact that nature turns out to be highly counter-intuitive - such as the famous prediction of the theory of relativity that as you speed up so time slows down - makes it hard to decide what research is ground-breaking and what is just daft.
In the early years of the Enlightenment, for instance, Charles II mocked the members of his Royal Society for wasting their time trying to weigh air, which turned out to be a very fruitful activity. However, subsequent attempts to weigh heat proved futile; it is now accepted that heat is a form of energy and energy, another “necessary mystery” as Fisher calls such findings, is weightless.
The “weighing the soul” of the title was the apparently daft project of an American physician called Duncan MacDougall, who carried out a series of experiments just over 100 years ago based on the theory that if there were a soul it should weigh something. He placed beds containing dying patients on a large set of scales and watched for a sudden drop in weight at the moment of death. Several experiments gave him a figure of three quarters of an ounce.
Modern scientists sniff at such a project, not least because they claim there are no rational grounds for believing that the soul exists. However, Fisher regards this as not exactly fair. While dismissing the soul, they are perfectly happy to believe in the existence of the “Higgs boson”, a particle that has never been detected or measured in any way but which is currently the best explanation for a big scientific conundrum: why does anything weigh anything in the first place? Why does gravity act on the mass of an object to create weight?
This particular hare was first set running by Isaac Newton as a direct result of his brilliant insights into gravity, which were so spot-on that scientists 300 years later could use them to navigate space rockets. However, what gravity was, or how it worked, remained a mystery. Newton also provided the impetus for another chapter on one of the most counter-intuitive ideas of all - that the basic nature of light is both a particle and a wave. His writings described light as a stream of “fiery particles” that struck the eye and produced vision.
About a 100 years later a British doctor called Thomas Young, who had been an infant prodigy (by the age of four he had read the Bible - twice), used Newton’s data to put forward the idea of light travelling in wavelengths and he backed it up with careful experiments. He was challenged by a man usually portrayed as a hero - the anti-slave campaigner and amateur scientist, Henry Brougham.
His attack illustrates how scientific “truths” can be defended as irrationally as political or religious ones. Brougham ignored the evidence and concentrated on personal insult and spreading unfounded rumours about Young being a plagiarist. The scientific establishment proved little more dispassionate, and it was 11 years before Young’s research won the day.
Weighing the Soul is a mine of delightful oddities, such as the origins of Galileo’s “scaling theory”, which is still used to estimate proportions when turning a model into an actual building. Early in his career Galileo was asked by the Pope to use his mathematical skills to work out the exact location and dimensions of Hell. His calculations showed it to be a cone-shaped structure with the point at the centre of the earth and the top a circle whose centre was below Jerusalem. The big structural problem was the unsupported roof, which spanned 5,000kms. Galileo claimed that the design used for the dome of the cathedral in Florence would do the job and was lavishly praised. In fact he rapidly realised that his calculations were wrong but kept it secret, only publishing the amended equations years later.
Given Fisher’s championing of the bizarre and offbeat, it is curious that he declares that one of his hopes for the book is that it will stimulate scientists to study environmentally friendly ways of transporting and storing energy. After designs for Hell, that seems terribly tame.
Weidenfeld Nicolson £12.99 224 pages
