Lunar cycles are important to witches, who regard the full Moon as the most powerful time for casting spells and divination, and it’s when they gather to hold their Sabbath meetings. It’s the time when tainted humans turn into werewolves, and Steven Spielberg projects the silhouette of E.T. and Elliot on a bicycle flying on the night of Halloween against the backdrop of the full Moon.

With Moonstruck, Ernest Naylor takes a look at the extensive folklore and myths surrounding our celestial neighbour and compares them to the findings of science. In his opening chapter, he points out that when Galileo used a telescope to view the lunar surface he identified mountains and craters, which dispelled the long-held view that it was a perfect sphere. In turn, this discovery led writers like Francis Goodwin, the Bishop of Hereford, to imagine visiting its surface. From then onwards, the Moon was regarded as a place of seas and huge rugged mountains, and it is surprising to learn that it was not until 1968 that Kubrick’s 2001: A Space Odyssey was the first film to portray it correctly as having a relatively smooth and cratered surface. As this shows, old ideas, like John McClane, die hard.

In 1687 Isaac Newton scientifically established the gravitational influence between the Earth and the Moon, especially in terms of how this affects the rise and fall of ocean tides. What has taken much longer is an accurate appraisal of its influence on biological behaviour. Research has found some of this behaviour is indirect, with organisms responding to the changes in tidal heights and pressures which are influenced by lunar gravitation.

Experiments on direct influences have shown that, for example in the case of the bristle worm, spawning is put in motion by the intensity of the light given out by a full Moon. It is only in this century that a study of sandpipers showed that they orient their direction of travel to the position of the Moon, indicating that they possess a lunar-day biological clock. A similar mechanism also seems to trigger the spawning dances of the Platynereis dumerilii marine worm.

In the last chapter, The Moon and the Human Condition, Naylor shows the problems in pinning down how it affects us. Most human research has been conducted using statistics, and the findings seem to always contradict anecdotal evidence and assumptions about these linkages. Studies have found that there is no link between menstrual and lunar cycles in humans or related species, natural childbirths do not occur more often at the time of the full Moon, or that it causes ‘lunatics’ to go out of control. Equally, violent crimes, instances of epilepsy, and suicide rates do not conform to lunar cycles.

Studies have, however, indicated that death rates peak in the first and third quarters of the Moon, and that there are better survival rates for people undergoing aortic surgery just after a full Moon. Another significant survey has found that in laboratory conditions volunteers slept best at the time of a new Moon and less well during a full Moon.

The difficulty of determining a causal link between the Moon and behaviour has led to widespread scepticism by scientists. Despite this, Naylor is optimistic that we will find evidence for circalunar clock genes in more organisms, and that perhaps they are also embedded in our genes. If so, some of the ancient folklore, beliefs and legends about the Moon might have some truth in them after all.

Naylor provides a clear survey of the latest findings in this subject area, and a useful glossary is supplied for those not familiar with the terminology. The affects on humans bookend the body of the text that mainly concerns itself with marine organisms, not surprisingly, given that Naylor is Professor Emeritus at the School of Ocean Sciences, Bangor University, Wales. It would have been good to have a bit more detail on the human studies and some speculation on future research and what links might be feasible, but you can’t blame him for sticking to the facts rather than howl at the Moon.

MOONSTRUCK: HOW LUNAR CYCLES AFFECT LIFE / AUTHOR: ERNEST NAYLOR / PUBLISHER: OXFORD UNIVERSITY PRESS / RELEASE DATE: OUT NOW