Picking Robert F. Kennedy Jr., a known vaccine sceptic, as the Secretary for Public Health might not be the most ‘out there’ thing the Trump administration has done but it certainly raised some eyebrows.

Every two years, the UN release their predictions for the future population of humanity – currently expected to peak in the 2080s at around 10.3 billion people.

One of the things they use to work this out is the fertility rate, the number of children the average woman is expected to have in her lifetime. When this number falls below 2, the overall population eventually falls.

The collected data – that covers up to the present day – shows a fertility rate that’s falling fast. But the predicted rate for the future immediately levels out.

To explain what’s going on we speak to Patrick Gerland, who runs the population estimates team in the United Nations Population Division.

Presenter / producer: Tom Colls

In the early 2020s, a conspiracy theory started circulating online known as the “dead internet theory”.

This suggested that, instead of a vibrant digital super-community where people freely share things like cat videos and conspiracy theories, the internet was instead basically dead - an AI dystopia controlled by the deep state, where almost everything you see and interact with is generated by computers.

In this episode, we investigate one specific claim about the number of these bots on the internet - the idea that more than half of internet traffic is bots. Where does this claim come from, and is it true?

Presenter/producer: Tom Colls

Warren Buffett has announced he is stepping down as CEO of his company, Berkshire Hathaway.

Buffett is one of the richest people in the world, and is widely held up as the greatest investor who ever lived. He’s also been remarkably critical of other masters of the financial universe.

Tim Harford talks to Financial Times journalist Robin Wigglesworth, author of the book Trillions, about Buffett’s money making method, and how he used a massive bet to make a point about hedge funds.

Presenter: Tim Harford

An interruption to your regular podcast feed: the first episode of a new BBC Radio 4 series investigating the steep rise in autism diagnoses.

The Autism Curve looks into the data that has prompted arguments - and conspiracy theories - about what’s behind the rapid rise. It goes on to explore changes in what autism is, who gets to define it, and whose experience counts.

In this first episode, Ginny Russell discusses her 20-year study that showed an astonishing eightfold rise in new autism diagnoses in the UK on an exponential curve. And Professor Joshua Stott explains how a surprising discovery at a dementia clinic led him to calculate that that enormous rise in diagnoses may still undercount the country’s autistic population by as much as 1.2 million.

Listen to the rest of The Autism Curve here: https://www.bbc.co.uk/sounds/play/m002bszl

Archive: BBC; CSPAN; Fox News; CNN.

Presenter: Michael Blastland

On the 29th April US President Donald Trump took to the stage in Michigan to celebrate his first 100 days in office.

This is a milestone in American politics, but is everything he claims the administration has achieved true?

The BBC’s US National Digital Reporter Mike Wendling joins us to fact-check President Trump’s claims on immigration, the stock market, fentanyl and….eggs.

Presenter: Lizzy McNeill

Netflix’s psychological drama Adolescence has started a debate about teenage boys and misogyny in modern society. It tells the story of a seemingly normal young boy, Jamie, who is arrested after the brutal murder of a girl in his class.

The series focuses on how young men are being radicalised against women by various podcasts, blogs and forums that make up the anti-feminist movement, the so-called ‘manosphere’. These podcasts often give men tips about how to be an ‘alpha’ male and promote the idea that feminism has set back men's rights. They use a range of material to back up their claims, including statistics.

Here are More or Less we’ll all about the facts. Every day we use a toolkit of known proofs to try and answer our listeners’ questions. But who do we have to thank for this toolkit and how did they set about proving the unknown?

What is the cash value of a human life?

That’s the question at the heart of The Price of Life, a book by journalist Jenny Kleeman.

Presenter: Tim Harford

What is the error in the calculation Donald Trump used to work out his new tariffs?

What happened when the government ordered a recount of bobbies on the beat?

When is a tax freeze not a tax freeze?

And do redheads really have a 25% higher tolerance to pain?

Tim Harford investigates some of the numbers in the news.

This episode was originally broadcast on the 9th April.

Presenter: Tim Harford