Half of all money spent on advertising is wasted. But we just don't know which half. In recent years, marketing professionals have been trying to use neuroscience to locate the "buy button" in our brain, which if pressed would make us buy their stuff. It's the holy grail: a way of knowing, in advance, which ads are going to work and are worth spending money on, and which ones would flop. The promise, from both marketers and some neuroscientists, is that our brains can, effectively, be hacked....

"Memory athletes" compete to see who can remember the most random numbers in an hour. Or else to memorise decks of playing cards. Memory training is big in China, where there are TV game shows for memory contests, and where parents pay good money to get their children trained in memorisation techniques. Everyone thought the Chinese were invincible, and that we were at the limits of what could be memorised - until 2019 when a group of North Korean teenagers arrived at the world...

Ever since the middle ages, pieces of the True Cross, and other relics such as saints' bones, have been sold to the gullible. But now the trade in bogus relics has moved online, to the fury of traditional Catholics. They are even more alarmed at the sale of "genuine" relics, which is also picking up pace as monasteries and convents close and their treasures come on the market. In theory selling a relic is an offence under Church law, warranting immediate excommunication. But what is a genuine...

There are millions of planets out there that could contain intelligent life. We can't look at them all, so which should we focus on? Using nothing but statistics, astronomer Fergus Simpson predicts the aliens will be living on small, dim planets, they'll have small populations, big bodies, and will be technologically backward. This goes against many astronomers' working assumption that the earth is typical of inhabited planets - and that our sun is an ordinary star in an ordinary galaxy....

As telescopes get better, astronomers are seeing more and more things in the night sky. Sometimes they can't explain them. Is it unreasonable to suggest that they might have found evidence of alien civilisation, or at least some form of extra-terrestrial life? Call it right and they could get the Nobel prize. Get it wrong and it could be career suicide. Only those at the very end of their career, with a well-established reputation, can afford to take the chance. Jolyon Jenkins reports on some...

Jolyon Jenkins investigates reports that people with severe dementia, or who haven't spoken for years, can sit up and have lucid conversations just before they die. Victorians called the phenomenom "lightning before death" and recently it's been described as "terminal lucidity". It seems incredible, but some in the medical community are taking it seriously. Producer: Jolyon Jenkins

Many animals can navigate by sensing the earth's magnetic field. Not humans, though. But might we have evolved the sense but forgotten how to access it? 40 years ago a British zoologist thought he had demonstrated a homing ability in humans. But his results failed to replicate in America and the research was largely discredited. But new evidence suggests that our brains can in fact detect changes in the magnetic field and may even be able to use it to navigate. Jolyon Jenkins investigates,...

Jolyon Jenkins explores Esperanto, the language designed to bring world peace and harmony. Invented in the late 19th century, Esperanto is simple to learn, with a logical grammar, a vocabulary drawn from European languages, and no irregularities. Its creator, Ludovic Zamenhof, hoped that it would become a second language that everyone could speak, eliminating international misunderstandings. For a while, Esperanto flourished, and there was even a tiny Esperanto-speaking state in what is now...

Who do you want to read your old emails when you die? Are the dead entitled to privacy?

Jolyon Jenkins attends an international whistling competition in Los Angeles to meet the people who want whistling to be taken seriously as a musical art form. The competition is organised by the "Whistling Diva", Carole Ann Kaufman, herself a former international whistling champion. "If it comes from the heart, it's art," she says. But even though there have been featured whistling instrumentalists, in the big band era for instance, whistling struggles to be thought of as more than a...

For centuries, people have dreamed of perpetual motion machines, and many ingenious inventors have tried to come up with devices that will keep going forever with no external input. All have failed. But in recent decades there's been a new take on the idea. A large community of people now believe that it is possible to build a machine that will create free energy. Not only will it keep going forever, but it will also be able to do useful work. They say that this does not contravene any laws...

Jolyon Jenkins meets the people who believe in trepanning - drilling a hole in the head. They do it for what they think are good medical reasons. Many ancient civilisations practiced trepanning, for reasons we can only guess at, but in modern times the practice dates from the 1960s and attempts by people in the counterculture to expand their consciousnesses. These enthusiasts thought they could get more blood into the brain if the skull was a bit more elastic, and therefore get "high"....

Across Britain, thousands of people have stopped paying council tax, water rates and speeding fines. They think they have the law on their side, thanks to the 1215 Magna Carta treaty between King John and the Barons. They argue that the present Queen has breached her obligations under the treaty and so has in effect deposed herself and even become a traitor. As a result, all laws passed by parliament are invalid, the courts are shams, and government officials are imposters. Instead, they...

Jolyon Jenkins meets the people who want to swim a mile through freezing cold water. This isn't like a quick dip on New Year's Day - it takes about 40 minutes to swim a mile. As the swimmers battle the second law of thermodynamics, only the fit, or fat, will make it. Some swimmers acclimatise by sitting in icy paddling pools in their gardens and sleeping without bedclothes. Others pile on the calories to build bulk. But apart from the danger of hypothermia, the risks are legion: cold shock...

Jolyon Jenkins investigates the network of private Christian schools in Britain that teach that evolution untrue, homosexuality is wrong, and that wives should submit to their husbands. These schools use the Accelerated Christian Education (ACE) curriculum, originally devised by a fundamentalist Texan who thought that all education needed to assume the literal truth of the bible. The entire curriculum, including science, makes continual reference to God's plan. It promotes creationism, and...

For 50 years, one of the most powerful psychoactive drugs, LSD, has been illegal in Britain. The authorities do not want you to alter your state of consciousness. In 2016, the government passed a law banning all psychoactive substances except caffeine, alcohol, and nicotine. But can you enter altered states of consciousness without drugs? Since the 60s, experimental "psychonauts", deprived of psychedelics, have been trying. Sensory deprivation, flotation tanks, hyperventilation, and light...

In a new documentary series uncovering stories from the left field, Jolyon Jenkins reports on the extreme treatments bald men are putting themselves through. They are commissioning laboratories in China to manufacture unproven, untested, and potentially dangerous drugs to cure their hair loss. Is it a hiding to nothing or will they succeed where the drug companies haven't? Men have always gone bald but now they're not putting up with it. An explosion of online forums has created a "hair loss...

Annie, 35, wants a baby, but she doesn't have a partner. If she could afford it, she could go down the official and regulated route to a fertility clinic and get pregnant using donor sperm. But that could cost thousands of pounds. So instead, she's gone online and entered the world of unregulated sperm donation. Jolyon Jenkins investigates this shadowy world. It's illegal to sell sperm, but some men are making a living doing so. Others offer free sperm in return for "natural insemination",...

Jolyon Jenkins meets the people zapping their brains with DIY electrical devices, lasers and electromagnets. They want to learn faster, dream better, and even have spiritual experiences. Some of it might even work. There's evidence that putting a weak electric current through your skull can help you learn, and induce a "flow" state. The US military is experimenting with devices that seem to help snipers improve their marksmanship. One woman who tried it says that what she found was that...

Build a better mousetrap, so the saying goes, and the world will beat a path to your door. But is it true? There are over 4,500 mousetrap patents but this doesn't stop inventors coming up with new designs - even though the basic spring-loaded trap was designed in the nineteenth century and, you might think, is unimprovable. Jolyon Jenkins talks to people who dream of riches from mousetraps, and one who has even managed it. And he invents his own, ultra-humane, hi-tech trap. Will it impress...

Jolyon Jenkins reports on the world of electronic voice phenomena (EVP) - the community of people who believe that the dead can speak to us through radio transmissions and white noise. The technique was introduced to the English speaking world by a mysterious Latvian, Dr Konstantin Raudive, who travelled to Britain in 1969 with recordings of Hitler, Churchill and Stalin speaking from beyond the grave. The method is now a mainstay of paranormal investigators. Jolyon unearths tapes from 40...

Jolyon Jenkins reports on the men fighting a liberation war against what they see as female tyranny, and the separatist "men going their own way" - who've given up on women. Such men take their principles from the film "The Matrix", in which only those who take the "red pill" see the true nature of reality, while those who take the "blue pill" live in ignorance of the true state of affairs - which, in this case, is that society is organised for the benefit of women, and that men are seen as...

Jolyon Jenkins reports on one man's attempt to create a new nation - a libertarian utopia - in what he says is unclaimed land between Serbia and Croatia. He has money and supporters, and half a million people have signed up for citizenship. But it's not been easy for Vít Jedlicka, Czech politician and president of "Liberland". Since he planted his flag on these marshy 7 square kilometres on the banks of the Danube in 2015, his supporters have been arrested, fined and jailed. He himself has...