<p>When listener Sakura’s husband came home from his morning walk in Cambridgeshire, UK, he told her about a massive rainbow he’d seen. But when he showed her a picture, she didn’t think it was particularly large. So how big is a rainbow really? Are they always the same size? And if some are bigger than others, is there a limit? </p><p></p><p>To find the answers, presenter Marnie Chesterton meets independent rainbow expert Philip Laven in a pitch-black studio to simulate how a rainbow is formed. He demonstrates how they are created by sunlight, reflecting and refracting in millions of little water droplets. </p><p></p><p>But what does that mean for their size? Raymond Lee, retired professor from the US Naval academy, says that rainbows are not objects and don’t have a linear size, just a specific angular size that’s relative to the person seeing it. But Marnie doesn’t give up so easily – some rainbows still look bigger than others. </p><p></p><p>In her journey to discover other ways to size up a rainbow, Marnie hears from Australian aerial photographer Colin Leonhardt who stunned the world with a beautiful picture. Next, assistant professor Ping Wah Li from The Chinese University of Hong Kong explains why it’s possible to come across more than one rainbow at a time. </p><p></p><p>And finally, atmospheric scientist Harald Edens shares another way to consider size, as well as how much he struggles to explain the complexity of rainbows to his four-year old daughter. </p><p></p><p>Presenter: Marnie Chesterton </p><p>Producer: Florian Bohr </p><p>Editor: Ben Motley</p><p>Photo: Rainbow of Dreams - stock photo stock photo Credit: Laurent Fox via Getty Images)</p>