Author: BBC World Service

CrowdScience listeners David and Tatiana have long been captivated by an unusual dinner table discussion: the peculiar change they’ve noticed over the past 16 years in the sunlight streaming through their bedroom window in Ostend, Belgium. They’re convinced that the room has not only become sunnier but that the actual angle of sunlight has shifted.

Intrigued by their observations, we head to Ostend. Our mission: to investigate three of their theories, enlisting expert help along the way.

Theory 1 – A celestial anomaly? René Oudmaijer at the Royal Observatory of Belgium considers whether our shifting position in the solar system might explain the change.

Theory 2 – Movement in the Earth’s crust? Alejandra Tovar from the Geological Survey of Belgium examines tectonic data to see if the Earth’s crust is moving enough to alter the angle of sunlight.

Theory 3 – Subsidence? Structural engineer Kath Hannigan helps us inspect the building for signs that it may be sinking or twisting.

And we explore one final theory of our own, enlisting memory expert Julia Shaw to examine whether it could all be a trick of the mind. Will the team crack the case?

Presenter: Caroline Steel Producer: Harrison Lewis Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Studio Manager: Sarah Hockley

(Photo: CrowdScience listeners David and Tatiana standing in front of a window in their house)

Russia has fined Google more than two undecillion rubles, which is more than 20 decillion dollars. How much you ask? 20 decillions is a 20 with 33 zeros behind it, more money than there is in the entire world!

This unpayable fine inspired us to look at extremely large numbers, from the amount of cells in our body, to infinity hotels and beyond. Plus, two-time world memory champion Jonas von Essen teaches us how to memorise these supermassive numbers.

Also, we unpick a dubious influential biodiversity statistic that has no basis whatsoever, and we look at the scientific tools of ghost hunting.

Plus, to round it off, presenter Marnie looks at a sport with more possible moves than there are atoms in the Universe. Can you guess what it is?

Presenter: Marnie Chesterton with Tristan Ahtone and Candice Bailey. Producer: Florian Bohr with Alice Lipscombe-Southwell and Imaan Moin. Sound engineer: Rhys Morris

Many coronaviruses exist in nature that we don’t know much about. We don’t even know how and whether most of them might bind to human cells. Research published in Nature, by scientists at Wuhan and Washington Universities, describes a new way of designing novel receptor sites on cell cultures so that many types of coronavirus may now be cultured and studied to ascertain their risk to humans. Cambridge virologist Ravindra Gupta, who is not one of the authors, gives Science in Action his take on the risks versus the reward.

Dotted around the remains of Pompeii, visitors are often struck by the plaster casts of some of the victims’ dying moments. During recent restoration of several of these casts, scientists were able to extract DNA samples from bones which had previously been enveloped by plaster since their initial discovery. As Alissa Mittnik of the Max Planck Institute for Evolutionary Anthropology describes, some of the findings confound our previous narratives about their lives, relationships, and even their genders.

Rozenn Pineau, a plant evolutionary geneticist at the University of Chicago in Illinois, has been investigating the unique evolutionary history of the world's oldest (and biggest) tree - "Pando".

And finally, the oldest known tadpole is described from a 160 million year old Argentinian fossil by biologist Mariana Chuliver.

Presented by Roland Pease Produced by Alex Mansfield, with Eliane Glaser Production Coordination by Jana Bennett-Holesworth

(Image: Illustration of Covid-19 coronavirus binding to human cell. Credit: Kateryna Kon via Getty Images)