Why do dogs chase cats at every opportunity? Why do paper cuts hurt so much? Is a tortoise slower than a sloth? And which numbers should I pick to win the lottery?
These are just a few of the queries put to the “elves” of QI – hosted by Sandi Toksvig – by the listeners of BBC Radio 2’s The Zoe Ball Breakfast Show.
The researchers’ unexpected and frequently hilarious answers now feature in the book 222 QI Answers to Your Quite Ingenious Questions.
Here are a few of the puzzlers…
Q Is there any truth to the saying “Red sky at night, shepherd’s delight; red sky in the morning, shepherd’s warning”?
This saying has been around since biblical times and it actually does hold true for people living in many parts of the world.
In the UK, the weather usually comes from the west, so when you look towards a sunset, you’re looking at the weather to come.
If that forthcoming weather is pleasant, there’s a good chance it’s the result of what’s called a high-pressure system, which traps dust in the air. Sunlight scatters off the particles to create a red sunset.
In the morning, though, the sun is in the east. If you see red, the dusty high-pressure system is to your east and has already passed you. The weather following it is likely to be wet and windy.
Q Why is it that p a per cuts hurt so much?
Paper cuts are excruciating because we usually get them on our fingers. We have thousands of sensory receptors, or nerve endings, in each fingertip and tens of thousands in the rest of our hand.
They help our fingers detect things as tiny as fingerprint ridges, which are barely 0.4mm apart.
Test it yourself. Unravel a paper clip and bring its ends close together. Touch them to your fingertip, then to your arm. You should feel “two-point discrimination” on your finger but only one point on your arm, where sensory receptors are further apart.
The finger’s pain receptors, called nociceptors, are packed together like this too, so it’s no surprise fingers are among the most sensitive parts of our bodies.
Then there’s the paper. Under a microscope, you will see that the edge of a piece of A4 is jagged, as if covered in cactus needles. It’s closer to a chainsaw’s teeth than the straight blade of a knife.
This means that paper doesn’t cut “cleanly” but tears through the skin, damaging more nerve endings as it does so.
More annoying still is the fact that most paper cuts are shallow. Deeper cuts can sever nerve endings, which stops them sending pain signals to the brain. Paper, however, slices deep enough to trigger the nerves but not deep enough to shut them up.
Q Why do dogs chase cats?
It’s down to how each animal reacts to being surprised.
When a cat encounters a dog for the first time, its instinct is to run and hide. An unfamiliar animal might be prey or a predator, so they need space to work out whether to pounce or flee.
A dog’s instinct, on the other hand, is to chase new or exciting things, including cars, their own tails and cats.
So, when a cat and a dog meet for the first time, an animal whose main instinct is to run and hide is coming face to face with an animal whose instinct is to chase moving objects.
The result is often the classic cat-and-dog cartoon routine.
Q Why do people get left and right mixed up but not up and down?
Which way is left and which is right is quite arbitrary. It can change depending on which way you’re facing. Plus, you could be referring to your own left or somebody else’s. On the other hand, it’s easy to know which way is down. Just drop something.
Q What’s the strangest thing that anyone has ever stockpiled?
During the Cold War, the USSR kept a stockpile of steam trains. This was in case their modern trains were taken out of service by nuclear bombs, or there was a shortage of electricity or a supply issue with oil and diesel.
Q Which lottery numbers should I pick?
The real question is which numbers should you not pick? If you win with a common selection – such as 1, 2, 3, 4, 5, 6 – you’ll share the prize with more people, so start by ruling out the most common choices.
In the UK, the most popular numbers for Lotto players are multiples of seven: 7, 14, 21, 28, 35 and 42.
The second most common selection is multiples of five – 5, 10, 15, 25, 30, and 35 – while hundreds of players choose 4, 8, 15, 16, 23 and 42. These were the winning numbers of the character Hurley in the TV series Lost.
Picking numbers associated with special dates might seem like a good start but you run the risk that they won’t be unique.
Two players in Ireland once had to split the lottery jackpot because they both picked digits based on the birth, ordination and death dates of the same priest.
To make it less likely you’d have to share winnings, your best bet is to choose your numbers at random.
You should discard and redraw them if they have any obvious pattern (i.e. 10, 12, 14, 16, 18 and 20), if they’re all clustered together, or if they make a pattern when marked on the ticket (like a diagonal or vertical line).
The real way to avoid making a loss might be to not play the lottery at all. In the year ending March 2020, about 57% of money raised from tickets went into prizes, meaning there’s an average payout of 57p for every £1 spent.
Q Why does my stomach rumble?
The sound of your stomach rumbling is called borborygmi and while it tends to happen when you haven’t eaten for some time, it’s not
necessarily because you’re hungry.
The noise actually comes from your small intestine. When it’s not had any food for a while, it starts its cleaning process, which makes the noise you hear as a stomach rumble.
Q Which is slower, a tortoise or a sloth?
It’s the sloth that’s usually more slothful. They can manage only around 0.1mph, while your average tortoise can go at a breakneck 0.3mph.
Strangely enough, though, a sloth is a lot faster in the water than it is on land or in a tree and can swim at around 0.5mph.
So if a tortoise and a sloth were to compete in a triathlon, it would be quite an exciting race – at least until they got to the cycling part.
Q Is it just me, or are parking spots too small?
The real problem is today’s cars are too big. The standard parking space is exactly the same size as it was in the 1970s – 2.4m by 4.8m. That’s more than enough space for an older car but today’s are much larger.
In 2018, consumer group Which? found 120 models were too long to fit in a regular spot. Even standard-sized SUVs take up 90% of a regulation parking space, which doesn’t leave much room to open doors.
Q Why do we produce tears when upset?
There are three kinds of tears: basal, which lubricate your eyes; reflex, produced when an irritant such as dust gets in your eye; and psychic, which are emotional tears.
Nobody knows why we produce emotional tears.
In the 1600s, there was a theory that emotions such as love literally warmed your heart, which then produced steam to cool down. The liquid was released as tears from your eyes.
A more plausible modern theory is that crying encourages bonding, meaning we cry when sad or overwhelmed so others can pick up on these signals and provide support.
Q What’s the longest a light’s been left on?
A bulb at a fire station in California has been on since 1901.
It took a brief break when moved between two stations but the bulb, known as the Livermore Centennial Light Bulb, holds the Guinness World Record for the longest-burning light bulb.
- 222 QI Answers to Your Quite Ingenious Questions by the QI Elves is published by Faber in paperback, priced at £8.99.
