Series G, Episode 12 - Gravity
- You can get from where you are to anywhere else in the world in exactly 42 minutes and 12 seconds by travelling through the Earth. Theoretically speaking, if there was a hole that went through the planet and you jumped down it, it would take you 42 minutes and 12 seconds to fall through to the other side because of the gravity. The maximum speed you can travel at depends on where the tunnel is. This tunnel does not have to grow straight down the middle of the Earth. It can be placed anywhere, and it would still take you the same time to come out of the other end. This is known as a "Gravity train" and while it is not feasible on Earth, it might be on the Moon because it has no molten core, but it would take 53 minutes to travel through it because the gravity is weaker. The people who worked out the information regarding the 42 minutes and 12 seconds were Sir Isaac Newton and Robert Hooke, in a series of letters between them.
- While Aristotle believed that heavier objects travelled towards the Earth quicker than lighter ones, Galileo realised he was wrong by calculating it, not by demonstrating it. He later did some experiments using ramps, but he never dropped anything from a great height. Galileo worked out that half a tonne of coal would fall at the same speed as one tonne of coal. Galileo worked claimed correctly that Aristotle's reasoning, if a lighter object was attached to a heavier object, then either the added weight would make the whole thing travel faster or the lighter object would slow the heavier one down, meaning it would be going faster and slower at the same time, which is impossible. Apollo 15 astronaut David Scott demonstrated that Galileo was right by dropping a hammer and a feather on the Moon, which both landed at the same time. (Forfeit: Dropping cannonballs of the Leaning Tower of Pisa)
- In 1784, Britons George Biggin and Letisha Sage performed not only the first hydrogen balloon flight, but could also be argued to be the first members of the "Mile High Club" by having sex in their balloon. It was organised by an Italian called Lunardi who was meant to go with them, but he got out thinking the balloon would not support three people. He got out just as it took off in St. George's Fields, and as the balloon flew over Piccadilly people could see Sage on all-fours, although she tried to make excuses claiming she was not having sex. The balloon travelled 14 miles, landing in Harrow. The incident became a huge scandal, with people asking having sex in a balloon was possible at all. The wager books, which contain lists of all the bets made in London clubs, contained one bet which read: "Lord Cholmondeley has given two guineas to Lord Derby to receive 500 guineas whenever his lordship 'plays hospitals' with a woman in a balloon 1,000 yards from the Earth."
- The thing to say to a gossypiboma is actually something to say to a surgeon, and normally something like "Get it out!" A gossypiboma is something that a surgeon leaves inside your body, like a piece of cotton, although it could be anything. In the USA, there are 1,500 cases a year of things being left inside the body by surgeons. 54% of foreign bodies are left in the abdomen or pelvis, 22% in the vagina, 7.5% in the chest and 17% in other places like the spinal canal, the brain and the face. One man had a six-inch surgical clamp insdie him, but the surgeons realised that the man already had an operation to remove a clamp. He had two in there and the previous surgeon never thought to find the other one. The reason given by surgeons for why this happens is because in unprepared medical emergencies there are unplanned changes in the operation and thus people forget about what things were used. Also, they blame patients with high body mass indexes because it is harder to find stuff inside someone who weights more. While "gossypiboma" is the most common term used by surgeons, because it relates to cotton, if a surgical instrument is left inside the body it is called a "foreign body granuloma". Perhaps somewhat cheekily, when a foreign body is discovered, they refer to it as being "retained" by the patient as if it was the patient that took it rather than the surgeon leaving it behind. (Forfeit: Mind your own business)
- XL: An underwater weighting machine is more accurate in calculating body mass index than one on the surface. The body mass index (BMI) is equal to your weight divided by your height squared. However, the system is very faulty. For example, if you are very muscular, the BMI would say you are overweight, while if you were a marathon runner with a slower metabolism the BMI would say you were underweight. Therefore, for really accurate measurements, you are weighted underwater. Under the BMI, you are considered overweight if your BMI is over 20 for men and over 30 for women. (Forfeit: Whale weigh station)
- XL: Stephen asks a question which he asked Alan last year, who told Stephen that it would make a good QI question: "Why, when you slow down, do you become more unstable on a bicycle?" The answer is a mixture of torque and the caster effect, which is when the back wheel acts on its own and self-centres. To turn a bike left, you turn the handle bars slightly right in what is known as counter-steering, which makes it difficult to go around kerbs. If you want to test it, ride a bike, take you left hand off, and then turn the handle with your right. Although you can only push them left, you will go right. The physics of bicycles was not understood until 1970 by David Jones.
- Shooting a gun straight up into the air in a celebratory mood is a bad idea because the bullets have to come down, and they come down with some force. While it is unlikely they the person firing the gun will get hit, because a single gust of wind will blow the bullets away from the them, the bullet may still land on someone nearby and crack their skull. A typical 7.62mm round would typically reach a height of nearly 2.5km, taking 14 seconds, and then it would take another 40 seconds to come back down again at a speed of around 70 metres per second.
- Supposing you invaded London, but the "oppressors" had fled to the Welcome Break Motorway Service Station at Scratchwood, which are the first services if you got out of London via the A1. If you were in the City of London but have cut off all telecommunications so you cannot give instructions to anyone outside, you could stop your oppressors using the guns on HMS Belfast, which are pointed at Scratchwood Services. If you go on board as a tourist, you will see a sign telling you that they are pointed at Scratchwood Services.
- XL: Fosbury flopped because it lowered his centre of gravity. All the jumps before that in the high jump - the scissors, the Eastern cut-off, the Western roll and the straddle - placed their centre of gravity above the bar. The Fosbury flop, introduced in 1968, places the centre of gravity below the bar, meaning you can jump higher for no extra effort. The world records for the high jump were set in 1993 for men and 1989 for women, so it looks like they are getting harder to beat.
- If a cloud rained wine, it would have to be the size of a bus in order to dispense your daily recommended amount of wine (250ml).
- There are five bullets in a gunslingers revolver. One is always empty for safety reasons. Wyatt Earp claimed that he always left the sixth chamber empty because the hammer rested on the chamber and so he knew it would not backfire by mistake. (Forfeit: Six) Correction: Earp's gun actually had a 'quarter-cock' position, which holds the hammer completely clear of the cartridge, meaning Earp knew that it was safe.
- If you cook a stake and you see a red liquid come out of it, that liquid is myoglobin. It is a protein used to help muscles work during sustained activity. (Forfeit: Blood)
- Rich Hall and Alan Davies: 3 points (Alan's eleventh victory and first joint victory)
- Bill Bailey: -8 points
- Barry Humphries: -36 points
For correction, see QI Qibble Blog.
- Friday 12th February 2010
- BBC One
- 30 minutes
Cast & crew
|Stephen Fry||Host / Presenter|
|Alan Davies||Regular Panellist|
|John Mitchinson||Question Writer|
|Justin Pollard||Question Writer|
|James Harkin||Question Writer|
|Molly Oldfield||Question Writer|
|Katie Taylor||Executive Producer|
|David Morley (as Dave Morley)||Executive Producer|
|Jonathan Paul Green||Production Designer|