Can two light rays collide?

Loading player...
Is there such a thing as a true circle? Can two light rays collide with one another? What makes the sky look blue? Have aliens ever visited Earth? Will time travel ever be possible? What's the perfect pH for seed germination? Would a truck full of birds weigh less if all the birds took off? What's at the bottom of a black hole? Why is poo brown despite the fact we all eat different foods? This week the questions for Dr Chris come from the kids at Gaia Waldorf School, and they're very hard! Like this podcast? Please help us by supporting the Naked Scientists
28 Aug 2021 English United Kingdom Science

Other recent episodes

Why did the Lincoln Memorial Reflecting Pool turn green?

Why is Europe experiencing a heatwave? What happens if a being from a different dimension enters our dimension? Why are wombats able to produce square-shaped faeces? Can we live without sodium? Is there a scientific explanation for xenophobia? Why did the Lincoln Memorial Reflecting Pool turn into a green swamp?…
26 Jun 22 min

How do cats sustain a purr-fect purr?

Why does our hair stand up when we are scared? Does the animal kingdom experience colour differently? How do cats purr without running out of breath? Can certain types of medication cause tinnitus? What benefits does vaccination afford us? And why do some people struggle to recognise faces? Chris Smith…
19 Jun 23 min

Are there sounds around us that we can't hear?

What's the impact of sodium on our heart health? Are there sounds around us that we can't hear? Why do teeth have nerves and a blood supply? What controls our emotions? Can other primates and mammals have colourblindness? Why can't certain organs regenerate themselves, whilst others can? Dr Chris Smith…
12 Jun 21 min

Why does a slice of toast land butter side down?

Do dolphins and whales yawn? Is yawning contagious in animals? What progress has been made on brain chip implants? What is the difference between kidney thrombosis and renal vein thrombosis? Why does a falling slice of toast land butter side down, and does fall height matter? Is it unsafe to…
5 Jun 25 min

How does a headache tablet know where it hurts?

Does water boiled in a microwave oven taste different from kettle-heated water? How long does it take the body to absorb a drink of water? Does too much water cause a kidney problem? What are essential fatty acids? Why do farts linger longer in the shower? What's better for your…
29 May 24 min