Bananas are radioactive: Why printed encyclopedias for children are more important than ever

The real world is far more amazing than anything you can make up. Over the past 18 months, I have been editing the first Britannica children’s encyclopedia to have been published in a generation – and at every turn, my mind has been spinning with amazement at the extraordinary universe we live in.  

You may wonder what the point is in turning to a book to look things up when you can so easily go online. But there are some very good reasons why printed books are even more important these days than ever before. Will you remember what you read, with all those ads popping up and interruptions from social media? And is learning everything from a bright backlit screen really such a great idea?  

In a world of fake news, learning how to trust information and determine the truth is more vital than ever for children. This encyclopedia is written and designed in a way to engage young people – and it gives them an overview of all the expert knowledge that they won’t always get from looking things up piecemeal. When you are young, you don’t know exactly what you are interested in and this book presents a whole spectrum of fascinating topics for them to discover more about themselves and the world we live in.

Britannica has been in the business of publishing encyclopedias longer than anyone else. The first came out in 1768, more than 250 years ago. But the recently published Britannica All New Children’s Encyclopedia is the first printed children’s volume they have produced since 1984. 

It’s not divided up into an A-Z look-up format, like encyclopedias of old. Nor it is divided into separate subjects like you find at schools. Instead, it is structured as a journey through time and space – a proper reflection of reality – that goes from the beginning of the universe to the present day in eight chapters: Universe, Earth, Matter, Life, Humans, Ancient Times, Modern Times and Today’s World & Tomorrow. 

What’s more, there are real experts behind every page. You get to meet them at the end of each chapter – and find out why they are so passionate about their subjects. Finally, its subtitle is “What we Know and What We Don’t” – that’s because many of the most interesting questions don’t have answers. At least, not answers that experts can agree on. Is there life on other planets? Why is there more matter than antimatter in the universe?

Below are some of the most amazing and bizarre facts I discovered while editing this new children’s encyclopedia.  

The Universe 

• A star-making nebula cloud the size of Earth would only weigh the same as a small sack of potatoes! This is because all the dust and gas in a nebula is really light. However, when the dust and gas stretches over many lightyears, there is enough mass and gravity for the nebula to collapse and form new stars

• The computer in each Voyager spacecraft has only about 70 kilobytes of memory, the same as a very low-resolution internet picture. With that, they’ve explored the solar system and beyond for more than 40 years

• The first rockets were made by the Chinese using bamboo tubes. The tubes were packed with gunpowder and attached to arrows fired by bows. During the Battle of Kai-Keng in 1232, the Chinese used ‘arrows of flying fire’ to repel the Mongols

Earth 

• The Moon looks round but that’s only the end we can see. It is actually shaped more like an egg. Scientists think Earth’s gravity pulled the Moon out of shape when the Moon’s thin crust floated on hot molten rock. Even today, Earth’s gravity tugs on the Moon, causing it to bulge 

• You can calculate the height of a mountain by boiling a kettle The boiling point of water reduces by 1°C every 304 metres you climb. This is because the boiling point of water depends on pressure, and pressure drops as you climb. The higher you climb, the faster water boils

 • Without Earth’s natural greenhouse effect, our whole planet would be like Antarctica – the coldest place on Earth. Temperatures would drop by around 33°C, and the world would be covered in ice. Life as we know it would not be able to survive

Matter  

• Dr Charles Henry Mae calculated that there was enough iron in the human body to make a medium-sized snail      

• Bananas are radioactive. They contain just enough potassium to set off some radiation alarms. Scientists measure low-level radioactivity in food in terms of Banana Equivalent Doses or BEDs. Fortunately, a BED is far too weak to ever harm you, even if you ate millions of bananas.

• Researchers have made diamonds out of peanut butter. Peanut butter is rich in carbon. Carbon is also the mineral from which diamonds are made. German scientists were studying how crystals form beneath Earth's surface. They squeezed the peanut butter under high pressure to remove any oxygen. A rogue gas upset the experiment, but not before diamonds had emerged.

Life        

• More than 99.9 percent of species that ever lived are now extinct. Some disappeared because of competition for food, others because their habitat changed. Volcanic eruptions wiped out some. Others went extinct when an asteroid hit the Earth. More recently, human activities have driven animals to extinction.

• The great white shark never stops swimming. It must keep moving so that oxygen-rich water continually enters its mouth and passes over its gills. If the shark stopped swimming, it would drown.

• Hundreds of dog breeds have evolved from one ancient species of wolf. This is because humans have selectively bred them for different purposes, such as hunting, herding, and cuteness. The latest “designer dogs” are crossbreeds such as the cockapoo, a cross between a cocker spaniel and a poodle.

Humans              

• Goose bumps helped our human ancestors stay warm. When it is cold, the skin responds by raising the hairs. This traps air to keep the skin warm. This does not work for humans today because we have lost most of our body hair. But our ancestors were a lot hairier than we are! 

• Scientists found 5,700-year-old DNA in a piece of gum.  They analysed the DNA and then asked an artist to produce a picture of the person who chewed the gum, based on their findings. They called her Lola, for Lolland, in Denmark, where the gum was found. The gum DNA was the first complete extract of DNA from something other than bones or teeth.

• The shiny coating on jelly beans comes from an insect. The covering is shellac, produced by the female Indian lac insect that lives on trees in India and Thailand. When heated and filtered, the substance turns into flakes, which are then dissolved in a chemical called ethanol. This produces a glaze that hardens when it cools.   

Ancient & Medieval Times 

• During mummification, the brain was removed through the nose. It was once thought that this was done by poking the brain with a stick and then hooking it out through the nostrils. Most scientists now think it was done by stirring the brain with a stick through the hole in the skull. The brain, which is squishy, would then turn to liquid and drip out through the nose

• Studying poo helps scientists know more about the Norte Chico people. Fossilised poo shows that the Norte Chico ate corn and seafood such as anchovies. Potatoes, sweet potatoes, and guava fruit were important, too. Tools with pollen from maize plants still on them indicate that the Norte Chico farmed corn. They also grew cotton

• Salt was worth nearly as much as gold! Used to preserve food, salt was brought mainly from the northern camels and traded for gold from gold mines in what is today Senegal, Western Mali, and Guinea. The Ghana Empire, which flourished from the 600s–1200s CE, also grew rich by collecting taxes on trade goods carried through its territory 

Modern Times 

• Akbar the Great, an Indian who ruled from 1556 to 1605, owned 101 elephants. Many of them probably formed part of his army – Mughals rode into battle on armoured elephants. The huge animals charged at enemy soldiers, who risked being trampled underfoot if they attempted to get close enough to fight.

• According to legend, the fearsome pirate Blackbeard wore lighted matches in his hair. The slow-burning matches (used to light ships’ cannons) were said to have surrounded his face with fire and smoke! Blackbeard was one of many pirates who terrorized settlers in Virginia, North Carolina, and the Caribbean. Ruthless villains, they often attacked English and French ships headed back to Europe and stole the trade goods onboard.

• Henry Brown shipped himself out of slavery in a box. He escaped to Pennsylvania inside a 90 x 60 x 76-centimetre box. Members of the Underground Railroad aided his escape. This organisation of free blacks and white people operated a network of secret routes and safe houses. Besides Henry ‘Box’ Brown, it helped between 30,000 and 100,000 enslaved people escape into free states and Canada

Today & Tomorrow 

• It would take 200 years for the average US worker to earn enough to become a billionaire. To look at it another way, many of the super-rich earn the average yearly salary of US$50,000 (£40,000) in less than a minute

• Scientists discovered graphene with the help of sticky tape. Graphene is made from carbon. It is very thin and very light, yet it is 200 times stronger than steel. Researchers discovered graphene in an unusual way. They used sticky tape to strip layers of carbon from graphite, the same material that is found in lead pencils. They continued until they had a really thin layer of carbon atoms – graphene

• The first artificial kidneys were adapted from washing machines! Our kidneys filter our blood, ridding it of toxic substances. If the kidneys stop working, people become ill. In 1966, Dutch doctor Willem Kolff noticed that the movement in a washing machine rinsed out stains such as blood. Inspired, he built an artificial kidney, using a washing machine to cleanse the blood of waste products. Patients use such machines to do the work of their kidneys

'The Independent’s’ readers can purchase copies of ‘Britannica All New Children’s Encyclopedia’ at a special price of £19.99 plus a £4.95 delivery charge.  Click here.