The joy of trivia: ‘We wrote our book together to intrigue each other’

<span>‘We pushed ourselves to learn about things’: Beth Coates and Liz Foley.</span><span>Photograph: Paul Stuart/The Observer</span>
‘We pushed ourselves to learn about things’: Beth Coates and Liz Foley.Photograph: Paul Stuart/The Observer

It was the early 2000s, we were in our 20s and had both started as assistants at the same company. We bonded over excruciating induction sessions, where we had to reveal things like which cartoon character we most identified with (B: Danger Mouse; E: Marcie from Peanuts). We laughed a lot, but we also worked really hard – and pushed each other to do new things. Twenty years later, with six children between us as well as more senior jobs, we found ourselves bogged down by endless to-lists and the relentless pace of midlife. We realised we needed to rediscover and connect to the positives in the world around us. The answer lay in sparking each other’s curiosity.

Many studies have shown that having a curious mindset has real-life benefits, both for our bodies and our souls. Our brains have evolved to release dopamine when we discover new things, and dopamine boosts memory, creativity and forges new neural connections. Other research shows that having a driving sense of curiosity can break down barriers between people – particularly important in our increasingly polarised world – c uriosity helps us to build empathy, connectivity and respect for others.

We wrote our book, A Year of Living Curiously, to intrigue each other – if we could conjure a chapter with an answer to an unusual question for each day of the year that made the other one go “Ooh, interesting!” then it could stay in. Everything else had to go. Of course, we have our own idiosyncratic ideas about what’s interesting, so we knew we’d have entries on Scotland, sharks, Romans and etymology. But we pushed ourselves to try to learn about things that weren’t as easy for us, too, like quantum mechanics and mathematical sequences, and to distil them into enriching one-pagers. It’s not a stretch to say the joy of curiosity reminded us of our appetite for life, something we think should be nurtured 365 days a year. Here’s a taster for 12…

1. Who invented envelopes? In the 24th century BC, the Akkadian Empire rose in Mesopotamia (the fertile land between the Tigris and the Euphrates, now Iraq and parts of Syria, Iran, Kuwait and Turkey, which has been inhabited since 10,000BC). The Akkadians invented the postal system, using clay tablets and envelopes. So, next time you pop a birthday card in the post, remember to thank the Akkadians for their envelopes (happily, no longer made of clay).

2. Why are our hearts not heart-shaped? Humans have known what the real shape of a human heart looks like since at least the first recorded autopsy in about 300BC – and they don’t look terribly heart-shaped. The romantic heart motif emerged in the Middle Ages. One theory is that this shape came from artistic interpretations of written descriptions by scientists, such as the second-century Greek doctor Galen. Others believe it developed from the outline of ivy leaves, which were used to represent fidelity. One of the most widely discussed theories suggests that it developed from the seed shape of a now-extinct North African plant called silphium. The Greeks and Romans used silphium for all kinds of health concerns including as a contraceptive. It was so popular that some believe its seed shape became symbolic of sexual love.

3. Do you have kuchisabishii? In the darker months we often crave comfort food and feel compelled to mindlessly graze. The Japanese call this kuchisabishii, or “lonely mouth”. It can often be a symptom of a deeper feeling of disconnection and longing, so the next time you feel it, try calling a friend instead.

4. What is the tiny pocket on your jeans for? The tiny copper rivets you find on your jeans were invented by the Levi Strauss company for their first pair of jeans in 1873. They were used to hold pockets on firmly, making the trousers suitable as tough workwear. The little front pocket you still find on many jeans was also part of an original Levi’s 1890 design and was intended to hold pocket watches.

5. What was Henry VIII’s favourite instrument? King Henry VIII could play the lute, the lyre, the harpsichord and the organ, but this larger-than-life figure was particularly passionate about the humble recorder. By his death, he is said to have owned a whopping 76 of them.

6. How do great white sharks breed? Witnessing the act is thought to be the Holy Grail of marine biology and there’s one fisherman in New Zealand who claims to have seen it happen in 1997. He described two sharks belly to belly, with the male biting the female to hold her in place – the ultimate love bite. In fact female sharks’ skin is thicker than the males’, and this behaviour might give us an evolutionary reason as to why.

7. Why do things taste awful after you clean your teeth? Everyone knows that orange juice tastes disgusting after you brush your teeth. This is because of the sodium lauryl sulfate foaming agent in many toothpastes. This chemical suppresses taste buds’ sweetness receptors and breaks up the natural compounds in OJ that reduce its bitterness. The good news is it only takes about half an hour for the effects of sodium lauryl sulfate to dissipate, and then you are free to glug joyfully at will.

8. What is stotting? Make no mistake, the British Isles are wet and some places get more than their fair share – the Lake District has about 200 days of rain a year. It’s no wonder that there are several words for rain in the Cumbrian dialect. “Mizzling”’ (very small raindrops), “spitting” (light, just visible rain), “syling” (from the Scandinavian word for sieve, so, as if through a sieve, and “stotting” (from the old Scottish and northern English word for bouncing) are all used in local lingo to describe differentmeteorological conditions from a fine mist to a drenching downpour.

9. Where did the word Bluetooth come from? Bluetooth was developed by the Swedish mobile phone company Ericsson and named after the Viking king Harald Blåtand (910-987AD), who, according to legend, was good at bringing people together – he unified and Christianised Denmark and Norway. The English translation of Blåtand is “Bluetooth”, and the technology’s symbol shows his initials in the old Nordic written language of runes. Harald apparently got his colourful name because of a dark, dead tooth in his mouth, rather than because he loved blueberries, as some stories claim.

10. How likely is a footballer to score in a penalty shootout? There’s nothing quite like the stress of a penalty shootout, and for this reason some psychologists have used it to better understand how we all respond to pressure. A number of factors emerged from the psychologists’ studies: the young tend to miss less often; fatigue counts – players who have been on the field for the whole match are more likely to miss the kick, as are those who take a kick quickly. One stat that highlights the extent to which pressure is a factor is that, if a player steps up to take a penalty that will win the shootout, and so the match, the success rate rises dramatically to 92%, whereas if they have to save their team from losing, the likelihood of scoring drops to under 60%.

11. How did Russia reluctantly give us rhubarb? Rhubarb originates in Asia and has been used in Chinese medicine for more than 5,000 years. But in the 17th century, Russia’s rulers took advantage of their role in the trade routes to Europe and created a monopoly by banning the sale of rhubarb seeds outside Russia – at one point, they were more valuable than gold. The Scottish physician, James Mounsey, is responsible for breaking this stranglehold. Mounsey had been a court physician to Peter III, who was allegedly murdered by his wife, Catherine the Great, in a coup d’état. After Peter’s death in 1762, Mounsey persuaded Catherine to let him return to Scotland. He smuggled several pounds of rhubarb seeds home out with him.

12. How were microwaves invented? As the US geared up to enter the Second World War, a man named Percy Spencer was working on developing combat equipment that would help the Allies. Percy worked on the magnetron, a tube in which electrons move in a heated spiral pattern, emitting radiation that could be used in radar. He inadvertently invented the microwave when he realised one day that, as he stood next to an active radar set, the chocolate bar in his pocket had melted. He tried it next on corn kernels, which began to pop, and an egg, which exploded. He filed a patent in 1946, for which he received the standard $2 from his company, which claimed his work. The first microwave was a beast – the size of a small car and pricey at about $5,000 (equivalent to around $68,000 today). But in the 1950s they took off in a big way. Percy never received more than that $2.

A Year of Living Curiously: 365 Things Worth Knowing by Elizabeth Foley and Beth Coates is published by Faber at £14.99. Buy it for £12.74 from guardianbookshop.com