Topics

- You can make the London Underground less unpleasant by making it overground. Sir Joseph Paxton, the creator of the Great Exhibition, proposed having a railway entirely encased in glass, which he called The Great Victorian Way. It would loop all around central and west London. It would not only consist of a railway, but on either side there would be shops, music, and houses. There would also be three river crossings in what would be a ten-mile girdle of London, 108ft high and 72ft wide. It was never made because it was too expensive, but it did lay the groundwork for the Circle Line.

- XL Tangent: The first tube station was Baker Street, although Alan says you cannot have a first one and that you need two.

- XL Tangent: In order to lighten up the Underground during its early days, in 1906 they built a machine that would whitewash the tunnels. It travelled at night and would spray two miles of tunnel at a time, using 850 gallons of paint. There is a person today working on the London Underground whose job it is to watch paint dry. Josh once had a job on the London Underground where he would go around with a clipboard and check that all the electric adverts were working.

- Tangent: Every single Underground line used to be run separately, which meant that the two directions of the Circle Line were owned by two separate companies: the Metropolitan Railway Company and the District Railway Company. You had to buy your ticket from a different office depending on which direction you were going in. Unscrupulous ticket sellers might send all the way around the line in their direction, even if you only wanted to go a few stops in the opposite direction.

- XL Tangent: The Underground announcements were recorded by a husband-and-wife, Elinor Hamilton and Phil Sayer. Phil died in 2016, leading to Elinor making a statement saying: "We're sorry to announce that this service terminates here."

- XL Tangent: Many London Underground stations are on a slight hump due to breaking. The train comes into the station slightly uphill, and then at the other side you go slightly downhill.

- XL: Sandi offers 100 to anyone who can clearly explain to me why the Large Hadron Collider underground is because there is not enough room above ground. The LHC consists of 27km of tunnel, and if it was above ground it would result in a lot of expensive real estate to buy and maintain, so it was cheaper to put it underground. Also, there was already an existing tunnel for another particle collider, the Large Electron Positron Ring, which was available to use.

- XL Tangent: Alan was invited to and visited the LHC. He was given a nice lunch, and Alan was asked why he was invited, and they said: "Don't you follow us on Twitter?" Alan didn't follow them, and thus assumed they mistook him for another Alan Davies. The staff told Alan they were already disappointed that the LHC wasn't bigger. The staff tried to explain to Alan what happened at the LHC, but he had forgotten it all by the time he got back to the hotel.

- XL Tangent: Particles travel around the 27km of the LHC over 11,000 times per second. Theoretically, you could get to the moon and back in three seconds. Scientists are trying to get these protons to come together, almost like two needles coming at each other at a distance at a distance of 10km and hitting head on. The reason is to try to understand the universe at its earliest moments. The LHC is maintained by CERN, which also gave us the internet, as World Wide Web inventor Tim Berners-Lee was working there at the time.

- XL Tangent: Up until the 1990s, most houses had a particle accelerator in them, as cathode-ray tubes in televisions are a form of particle accelerator.

- The panel are shown a photo of a giant cave and are asked who dug it. It was created by elephants in Kenya. There are nearly 20 caves on the side of Mount Elgon which were excavated by hungry elephants. The elephants grind their tusks up against the cave wall, carving a foot-long grove from the bedrock, breaking it up and eating the rock to gain minerals. This is form of salt mining. One cave called Kitum has been excavated over 160m deep, and was almost entirely made by elephants. The photos used were taken by a biologist called Ian Redmond, who is in the audience. Mount Elgon is an extinct shield volcano, which has a low profile so it looks like a shield boss. However, the Maasai name for it is Ol Doinyo Ilgoon, which means Breast Mountain.

- XL Tangent: Baby elephants are often seen eating their mother's poo because they do not have the necessary bacteria to digest plant life, and the only way you can get this bacteria is by eating the faeces.

- Sandi asks if anybody knows of any other interesting holes around the world. One is at the University of Kent, which was built on top of an underground rail tunnel, namely the Crab and Winkle Line that ran between Canterbury and Whitstable. It was the world's first steam-powered passenger railway, running from 1830 to 1952.

- Tangent: Josh asks when something stops being a tunnel and start being underground. Zoe suggests that if you dig through a mountain that is a tunnel, but if you dig under it then it is underground. However, Dan says that this is all still under the mountain's ground, which leads to Sandi giving him two points.

- XL: The contents of the most dangerous pond in Suffolk include spent uranium rods. Sizewell Nuclear Power Station currently produces 3% of the total electricity for the UK, and has been running for 27 years. To get rid of the spent rods safely, they put it are the bottom of a pond or swimming pool to cool them off. Water is a really good shield against radiation, and in theory you could probably swim this pond. The rods are then loaded into metal canisters which are then welded shut. They are then placed in large concrete casks, and finally they are put in a specialist dry fuel storage building. The rods have to be stored for up to a million years before they are safe.

- XL Tangent: We have known about uranium since 1789. It was discovered by German chemist Martin Klaproth, who named it after the planet Uranus.

- XL Tangent: Zoe's mother phoned her up recently and said to her: "The sky is beautiful at the moment. You can see Uranus from my window." Zoe says she might have, because she Zoe does walk around semi-naked with the blinds up, and her mother lives in the next street along, so with a clear sky could probably see Zoe's anus from there.

- XL Tangent: After the Cold War ended, the USA acquired lots of Russia's nuclear weapons, and they used the uranium in their own power stations. For 20 years, 10% of American electricity came from old Soviet bombs. A ton of enriched uranium produces the same amount of energy as 145,000 tons of coal, and produces no greenhouse gases.

- The most skilled urinators on the planet are all women. "Urinator" is an old term for a diver, coming from the Latin "urinor", meaning "to dive". No-one knows why the Romans called it that, but some say it is commonplace to feel the need to urinate when you dive. The most skilled urinators are the Haenyeo women of Korea. They have been diving for seafood off the island of Jeju since the 17th century, but the practice is dying out. In the 1960s, there were 26,000 Haenyeo women, but today there is about 5,000, and 98% of them are aged over 50. The women dived because they are warmer, having more subcutaneous fat than men. Because the women produced most of the income, a semi-matriarchal society developed on Jeju, with the men raising the children, doing the housework, and paying dowries to the family of the bride. However, the men still had the political power.

- Tangent: You do not feel warmer if you urinate underwater. What happens is that you would feel the benefit just for a few seconds. The reason you want to urinate is that when you dive into water that is colder than the surrounding air, your blood vessels narrow. All the extra blood moves to your torso, and your body interprets this as a fluid overload, and signals to the kidneys to produce urine. But then your blood vessels will expand again, and then the fresh cold water enters your wetsuit, which makes you even colder. Also, because urine is acidic, you will probably rot the crotch of the wetsuit.

- XL Tangent: Other female diving groups include the Sulu divers of the Philippines; the Paumotuan of French Polynesia, who can go 120ft without a scuba tank for two minutes; and the Ama divers of Japan, who have a tradition of pearl diving that is over 2,000 years old.

- XL Tangent: Urinating in your wetsuit will not attract sharks. Tests by National Geographic revealed that urine does not interest them.

- Urchins, or rather sea urchins, commonly have hats on their bottoms. The urchins wear stones, seaweed and shells on what looks like the top of their bodies to people, but actually the topside of sea urchins contains their anus. They use the hats to protect themselves from sunburn, as ballast against ocean currents, as camouflage and as protection. The urchins put their hats on by using their tube feet, which have suction cups on the end.

- Tangent: One part of the sea urchins body is called the Aristotle lantern, which is their mouth. Aristotle noticed that there was a lantern called the horn lantern, which was popular in his day, and he noticed its similarity to the mouth of a sea urchin. The mouth of a sea urchin contains five teeth pointing in all directions and they can drill holes in solid rock. One species responds to threats by releasing hundreds of tiny venom-filled jaws which can continue to bite a predator long after the urchin has left.

- Tangent: Zoe has eaten a sea urchin. In Greece, they cut off the top of the urchin, and you scoop up the insides. People probably should eat more sea urchins because they eat so much kelp, with them having eaten 90% of the Californian kelp forest. Biodiversity can be improved by eating sea urchin gonads. Sandi then gets out some sea urchins which have been prepared for herself, Dan and Zoe to eat. All three eventually eat them. The Japanese regularly eat them as "uni", which is part of sushi. These testicles contain both sperm and eggs in them.

- Tangent: There is a hockey team at the Rhode Island School of Design called the Nads, so called because everyone can shout: "Go, Nads."

- XL Tangent: In the Indian Ocean and the Red Sea, the carrier crab often carries urchins around and uses them as hats. Both creatures get protection, with the crab getting protection using the urchin's spikes, and the urchin gets carried to new feeding grounds. Sometimes small fish will burrow into the spines to avoid being eaten.

- On old Gemran U-boats, the name of the bit that usually pokes out of the water is called the snorkel. Most of WWII subs spent most of their time above the water, not beneath it. Until 1943, all U-Boats were surface ships, and they only went down for small periods of time. The first properly submersible, the type 21, was only built in 1943, and that was because Allied radar could locate surfaced submarines. In order to avoid detection, they borrowed a technique from the Dutch navy, called the "snuiver" or "schniffer". This pipe allowed the ship to inhale air to run the sub's diesel engines. The Germans called this pipe the "schnorchel", which is where we get the word "snorkel" from. This pipe was fitted with valves that could automatically shut in rough weather. However, if it slammed shut, then apparently the engines rapidly sucked air from inside the cabin, which was a big problem for the crew. (Forfeit: Periscope)

- Tangent: The worst thing about life on a German U-boat was the food. During a six-week trip with a crew of 50, you need 12.5 tons of edible material. There are only two toilets on board, and a lot of the food on board was stored in one of them. The chef also had only two burners to work with, and also needs to make sure the food is stored in such a way to make sure the U-boat remains balanced.

- XL: The correct way to pronounce the title of the film Das Boot is "Das Boat". This pronunciation is much closer to how the Germans would say the title. The people who made the film created a full size U-boat for the exterior shots, and kept it in La Rochelle harbour. However, one morning it went missing, because somebody had rented it to Steven Spielberg who used it in Raiders of the Lost Ark. (Forfeit: "Das Boot")

General Ignorance

- The chemicals which give you a high after exercising are called endocannabinoids. Studies in the 1970s showed that exercise increases the level of endorphins in the blood, but endorphins cannot cross the barrier between the blood and the brain, so they cannot affect our mood. Another study later, which blocked endorphin receptors in people found that their mood still improved. It was discovered that exercise also increases levels of endocannabinoids in the blood, cannabinoids being the psychoactive ingredient in cannabis. (Forfeit: Endorphins)

- Tangent: Zoe was once beaten on the line of a half marathon by a man dressed as a clown in a cardboard car. She was also once beaten to the line by a man dressed as a gonad, who was raising money for a testicular cancer charity.

- If you were suspected of being a witch and thrown in a river, the two possible outcomes were you floated and thus guilty, or you sank and were rescued. Innocent verdicts were decided long before the person drowned, so as the accused sank down towards the bottom of the river, it was clear that she was not going to the float and thus she was saved. The idea is that water, used in baptism, will repel sin, and if you floated then you were full of sin. These trials were officially used up until the 13th century, but by the time the witch hunting craze takes off in around the 15th century, it was only locals taking the law into their own hands who did this. If a person was allowed to drown, you would probably be charged with murder. (Forfeit: Death)

- Tangent: There is a ducking stool still in Canterbury, over the river Stour. However, its position is at a section of the river which is only two feet deep.

- XL: The prehistoric age in which iron was first used was the Bronze Age. The Iron Age probably started in the early Bronze Age. People were able to use iron from meteorites during the early Bronze Age. The earliest known iron artefacts are Ancient Egyptian iron beads from about 3,000 BC. In Tutankhamun's tomb, an iron dagger, a bracelet and a miniature headdress were discovered, all of which are believed to have come from meteorites. He lived in the late Bronze Age. (Forfeit: Iron Age)

Scores

- Josh Widdicombe: -3 points
- Alan Davies: -4 points
- Zoe Lyons: -9 points
- Dan Tiernan: -12 points