Jeff Bezos reportedly changed the name after a lawyer misheard it as “cadaver”. He chose Amazon because it is the world’s largest river and started with an A.

“Brain”, written by two brothers in Lahore, Pakistan, infected the boot sector of floppy disks. It even contained their names and address.

Before video games, Nintendo made hanafuda playing cards in Kyoto. It also tried a taxi company and instant rice before becoming a games giant.

Harald “Bluetooth” Gormsson united parts of Denmark and Norway in the 10th century. The technology was named after him because it unites devices; the logo combines his initials in runes.

On typewriters, “Return” moved the carriage back to the start of the line. On early computer keyboards, “Enter” submitted data. Many keyboards still label them differently.

It means “Completely Automated Public Turing test to tell Computers and Humans Apart”. Solving them once helped digitise old books and street numbers.

The first iPhone launched in 2007 with only Apple’s built-in apps. The App Store arrived a year later in July 2008 with around 500 apps.

Motorola’s Martin Cooper called a rival engineer at Bell Labs from a street in New York using a prototype handheld phone that weighed about 1 kg.

On 3 December 1992, engineer Neil Papworth sent “Merry Christmas” from a computer to a Vodafone phone in the UK — widely considered the first SMS.

Early hard drives for personal computers held a few megabytes and cost hundreds or thousands of dollars. Today a gigabyte costs a tiny fraction of a cent.

The Indian tectonic plate is still pushing into Asia, lifting the Himalayas. Measurements suggest Everest rises by a few millimetres per year, though earthquakes and erosion also change its height.

Words and phrases such as “eyeball”, “bedroom”, “lonely” and “break the ice” are first recorded in his plays, though some may simply be the earliest surviving written use.

Engineers at Bell Labs gave the # key on telephone keypads the playful name “octothorpe” in the 1960s. It is also called the number sign or pound sign.

The word comes from Latin “salarium”. A popular story says Roman soldiers were paid in salt; historians say the link to salt is real but the exact origin is debated.

The word “tittle” comes from medieval Latin and also appears in the phrase “to a T”, which some believe comes from “to a tittle” — meaning exactly.

A “peppercorn rent” is a token rent, historically a literal peppercorn, used to make a lease legally binding. Some leases still use it today.

Levi Hutchins of New Hampshire built a personal alarm clock in 1787 that rang only at 4 a.m. — the time he wanted to wake up. He never patented it.

It was built for the 1889 World’s Fair with a permit for 20 years. It survived partly because it proved useful as a radio transmission tower.

The cashew nut hangs below a fleshy “cashew apple”. The shell contains an irritating oil, which is why cashews are always sold shelled and processed.

Apple flesh contains lots of air pockets, making the fruit less dense than water — which is why apple bobbing works.

The Maya and Aztecs used cacao beans as a form of currency. Cacao drinks were prized, and beans could be traded for food and goods.

A pineapple plant usually takes 18–24 months to produce a single fruit, which is one reason they were once a luxury symbol in Europe.

In the 1830s an American physician promoted tomato ketchup as a cure for indigestion and other ailments, and it was sold in pill form for a while.

Peanuts grow underground in pods and belong to the bean and pea family. Almonds, cashews and pistachios are not botanical nuts either; they are seeds of fruits called drupes.

Early cultivated carrots were purple or yellow. Orange varieties became popular in the Netherlands in the 17th century and spread worldwide.

Experiments suggest pigeons can pass forms of mirror self-recognition tests after training, and they can also distinguish between many images and even letters of the alphabet.

These Mexican salamanders can regenerate limbs, parts of the spinal cord and even heart and brain tissue, which makes them important in regeneration research.

Elephants can detect low-frequency rumbles and ground vibrations through sensitive cells in their feet and trunk, which may help them sense distant herds or storms.

Their wings rotate at the shoulder and beat in a figure-eight pattern, letting them hover, fly backwards and even briefly upside down. Small species beat their wings dozens of times per second.

Both have seven cervical vertebrae. A giraffe’s are simply enormous — each can be around 25 cm long.