The Recovery Trial, a nation-wide clinical study in the UK, helped identify treatments for Covid 19 in the early months of the pandemic. Tim Harford speaks to Professor Martin Landray of Oxford University whose team established the randomised trial.

Tim Harford interviews Milo Beckman - a young mathematician, still in his twenties, who has written a book called ‘Math without Numbers’. Milo explains why he wanted to strip out digits to make it easier to describe the beauty of mathematics.

Mexico City’s official Covid 19 death toll did not seem to reflect the full extent of the crisis that hit the country in the spring of 2020 - this is according to Laurianne Despeghel and Mario Romero. These two ordinary citizens used publicly available data to show that excess deaths during the crisis - that’s the total number of extra deaths compared to previous years - was four times higher than the confirmed Covid 19 deaths.

Bayes’ Rule has been used in AI, genetic studies, translating foreign languages and even cracking the Enigma Code in the Second World War. We find out about Thomas Bayes - the 18th century English statistician and clergyman whose work was largely forgotten until the 20th century.

In 2020 there were 1.8 million reported Covid deaths. So far this year, we’ve had 1.2 million. We’re currently seeing around 12,000 deaths a day across the world. But while some areas are seeing falls in numbers, others such as India are seeing a surge.

This week Tim Harford tries to answer the question: Will there be more global deaths this year from Covid 19 compared to last year?

If we brought together all the Covid 19 vaccine needed for the whole world, how much space would it fill up? An Olympic size swimming pool? We do some back of the envelope sums.

Plus - we look at the increased risk of clots from pregnancy. Last week we looked at the increased risk of getting a clot from taking the combined contraceptive pill and compared it to risk of possible rare clots identified following the Astra Zeneca jab. How does pregnancy compare?

The Astra Zeneca Covid 19 jab remains in the headlines because some regulators have concluded that it may raise the risk of a very rare type of blood clot, albeit to a risk that is still very low. In the past few weeks a number of countries have said they will limit its use to older age groups. But people are drawing comparisons to the contraceptive pill which is well-known to increase the risk of clots and asking why this level of risk is tolerated. Is this comparison fair?

The impressive speed records of a well-known gamer called Dream for the video game Minecraft have come under scrutiny. Many say that Dream has completed speed runs in such a fast time that it doesn’t seem possible. Are these suspicions correct? We speak to stand-up mathematician Matt Parker who has looked at the probabilities on the elements of chance in the game to see if these records seem plausible.

On this week’s programme we talk to Clare Griffiths from the UK’s coronavirus dashboard and Alexis Madrigal from the Atlantic Magazine’s Covid Tracking Project in the US.

Many countries recently decided to suspend the use of the AstraZeneca coronavirus vaccine over fears it was increasing the risk of blood clots. The European Medicines Agency and the WHO called on countries to continue using the vaccine but regulators in individual countries opted to be cautious, waiting for investigations to take place. But why?

Tim Harford explores the risks of blood clots and weighing up whether it was necessary to suspend using the vaccine.