Researchers have developed a medical imaging technique which reveals where in the body HIV lies hidden, even when people have their infection well controlled by antiviral drugs. The team at the University of California, San Francisco hope this will lead to better treatments and even cures for HIV. As Timothy Henrich told us, they are also going to use the technique to investigate the notion that Long Covid is caused by the coronavirus persisting deep in the body's tissues.

Also in the programme, Roland Pease reports from the vast particle accelerator in Switzerland where the famous Higgs particle was discovered ten years ago. The scientists there are preparing to begin experiments with an upgraded Large Hadron Collider to learn more about the particle and the fundamental nature of the Universe.

Roland also talks to Frank Close, physicist and author of 'Elusive' - a new biography of Peter Higgs, a scientist as elusive as the particle named after him.

Finally an international team of archaeologists have revised the ancient history of the chicken, with a new programme of radiocarbon dating and analysis of buried bird bones. Humanity's relationship with the bird began much more recently than some researchers have suggested. Naomi Sykes of Exeter University and Greger Larson of Oxford University tell Roland when, where and how the domestication began and how the birds spread from Southeast Asia to the rest of the world.

And, Humans can walk for miles, solve problems and form complex relationships on the energy provided by three meals a day. That's a lot of output for a fairly modest input. Listener Charlotte from the UK wants to know: how are we so efficient? And how does human efficiency compare to that of machines?

CrowdScience presenter Marnie Chesterton pits her energetic wits against everything from cars to wheelchairs to find out how she shapes up. Cars can travel many hundreds of kilometres a day if you give them a couple of tanks of fuel. But the only fuel Marnie needs to walk to work is a cup of coffee. She gets experts to help her work out who does the most efficient job.

Marnie also explores whether humans are born equal when it comes to fuel efficiency. Does the energy from one banana get converted into the same amount of movement from person to person? And how does she compare to an Olympic athlete? Marnie gets put through her paces to find out how efficient she really is.

Image: VRCPET body scan reveals HIV's hideouts