Chasing The Sun by Linda Geddes (book review)
I haven’t reviewed any science books here for a while so been looking for some for your consideration. For starters, we have Linda Geddes’ book ‘Chasing The Sun’. Appropriate for this time of the year until you read the sub-title, ‘The New Science Of Sunlight And How It Shapes Our Bodies And Minds’. Don’t think in terms of just getting hot but how your body needs sunlight to survive.
Basically, our bodies respond to sunlight in different ways. You wake earlier in the spring and summer because daylight is earlier and sleep later in the autumn and winter. However, you’re also responding to your internal circadian rhythms, which can vary from person to person, showing who are the night owls and the early birds. I tend to be somewhere between these two extremes, depending on the work needs being done. I had hoped to find something about enforced powernaps which if I don’t do, suffer longer ones to catch up but think it relates to the circadian cycle. The index doesn’t note these but it might come under a different name. If you want to understand how your body reacts to sunlight, other than tanning, this book should pique your interest.
Geddes examines various people who have lifestyles to match the sunlight from the Amish to shift workers and even experimented on herself and family by reducing artificial light sources. I use a natural light lamp in my living room, hopefully to keep me awake, but it doesn’t stop my natural desire for powernaps. Reading about the problems people who have try to stay awake for long times. Don’t. It can be fatal.
Her exploration of people where countries have less light and even New York where the skyscrapers have everything below them in the shade and an effect on the population should get you worried. Its not helped by so many of us living indoors than getting out more. There is also so much showing how are hormones are affected by sunlight so not getting enough is not helpful for your life. Doesn’t mean you need to get sunburnt but choose times to get outside. The lack of light when young in East Asia and Australia also leads to many becoming short-sighted is definitely worth considering. I do think some people are likely to be myopic but not as widespread. The importance of Vitamin D is also pointed out. Considering how heavy the clouds we have in the UK in the summer as well as the winter months, I’m sure we aren’t getting enough from sunlight so tend to supplement with Vitamin D tablets the year over now. Although she doesn’t as much, Geddes is indicating you need more than just sunlight so all things need to be balanced out.
Seasonal Affected Disorder, otherwise SAD, had to come up. My comment in the previous paragraph applies just as much. I’m probably borderline in this but I find, other than my Vitamin D tablets, having a natural light which gives a blue wavelength does a lot of good. You might see the blue on the first day but your brain quickly gets used to and ignores it.
What was more startling was how the time of day can affect the type of prescribed medication you take. Geddes even goes as far as the best time for operations which makes me wonder if surgeons are aware of this.
The last section deals with jetlag and adjusting to summertime, as with the UK and other countries, to get the most sunlight. There is a connection to them both as the latter can also feel like jetlag. Geddes points out how to adjust when flying across the world which is essentially adjusting your inner circadian clock, although I do have to wonder if people can sleep a full 9 hours in flight. At least, that’s something I won’t ever have to worry about.
Obviously, there’s a lot more in this book than I’ve pointed out here. Without the notes and index sections, there’s 202 pages of reading that covers a lot of ground. Geddes looks at examples of extremes and how people cope with them, either by experience or training, like with astronauts. It does leave room for further exploration, like how some people can drop to sleep anytime, light or not.
Considering how much we live with sunlight in all our lives, this book shows how much we under-estimate how much it does in our lives.
GF Willmetts
August 2025
(pub: Wellcome Collection/Profile Books, 2022. 241 page indexed small enlarged paperback. Price: varies. ISBN: 978-1-78125-833-0)
check out website: www.profilebooks.com
