Why do some people grind their teeth? Can someone's heart keeping beating when they're dead? How does the brain interpret words? How do we know how long something has been dead for? Dr Chris Smith and Relebojile Mabotja have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

How much do wildfires contribute to carbon release? How do bones heal themselves? Why do weeds seem to grow faster than other plants? Why do some animals float, but others sink? Why do ducks like spinach? How did we evolve different blood types? Why do some people's temperature go down when they're feeling ill? How many of our metals come from space? Why do snails come out in the rain? Dr Chris Smith and Clarence Ford have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

Does laying on your left side clean your organs? Are faces the only difference that different populations have, and why do we notice facial differences? What happens to the body when your body drops drastically? How does the body react to extreme trauma? Why do we get blemishes on our skin? Could you transplant muscles around the body? How do you seek help after a suspected rabies bite? Dr Chris Smith and Krystal Orderson have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

The Platinum Jubilee; aerodynamics and physics of tailgating vehicles; why planets and the moon are all in the same orbital plane; how ants lead their nest-mates to a food source; animal extinction; how light can reveal what something is made of; do transplant recipients inherit genetic diseases from their donors; and would someone with an arm transplant leave a different DNA fingerprint with their new hand? Dr Chris Smith joins 567 Cape Talk's Lester Kiewit to talk the answers through... Like this podcast? Please help us by supporting the Naked Scientists

What are stars made of? How do ants breathe? How does a person catch chickenpox? Why are sunsets and sunrises red? What are planets made of? How many bones in a human body? How do Earthquakes occur? IF the Earth's round, why don't we fall off? Why doesn't sand dissolve? How does a bird fly? This week Lester and Dr Chris are with the kids at the AKA snapshot study group to find out what they want to know... Like this podcast? Please help us by supporting the Naked Scientists

Shortages of cooking oil, risks of being hit by lightning and can lightning travel through your plumbing; why boats have round portholes; what's the memory capacity of a human brain; can we measure happiness; do animals feel happy and sad like we do; what gives farts their unique characteristics, and why do stars twinkle? Lester and Dr Chris have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why do some animals sleep standing up? And do fish sleep? Why are elderly voices higher pitched than younger voices? Why does the outside temperature drop just before the sunrise? Why do I feel pain in my ears during a plane takeoff, and why does chewing gum help? Do cats and dogs recognise their siblings? Why is yawning contagious? Do dogs get depressed? And why doesn't our own snoring wake us up? Dr Chris and Abongile Nzelenzele have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Can trees produce more than 1 type of fruit? Why do some flowers only have a scent at night? What makes fruit taste sweet? How does the Google search engine work? How do motorcycle tyres grip the road? How are some children geniuses? What is myasthenia gravis? What's the difference between a sickness, a disease, an illness, an affliction, a malaise and a disorder? How does reverse swing work on a cricket ball? And how do tides work? Dr Chris Smith and Lester Kiewit have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why are humans still born with bits we don't need - will evolution do away with them? Did an onion make me cry less because it was cold from the fridge? Do animals get diabetes like humans do? What is the physics of a rainbow? Where does lightning come from? What did cloning Dolly the Sheep mean for me? And is Covid-19 nature redressing the balance? Dr Chris Smith and Relebogile Mabotja have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Nominative determinism; can cold showers ward off coughs and flu; what's von Willebrand's Disease; if smoking causes cancer how does it cure salmon; why can some people roll their tongues; what's "Agent Orange"; in television, how does a green screen work; do crocodiles age more slowly than we do; what is Helicobacter pylori? Chris and Lester have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Is it better to keep the tank topped up to full, or should I drive around on half empty: what's better for my car and fuel consumption? Why might althletes take an ice bath after exercise? If I go out with wet hair, will I really catch a cold, or is that a myth? Do babies sleep better in a cooler room? What's the difference between an electrical blackout and a brownout? Is the expensive face cream better than the cheaper one? Lester Kiewit and Dr Chris have the answers... Like this podcast? Please help us by supporting the Naked Scientists

What happens, genetically, when a black and a white human partner have children? And if a pair of genetically identical twins marries another pair of identical twins, are their kids genetically brothers and sisters? Do birds have ears? And if you lose one of your special senses, do other senses strengthen to compensate? What's the reason for human handedness? And does a blood transfusion recipient carry the genes of the blood donor? Dr Chris has the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why does my kiddie object to wearing shoes? What is spacetime and how does time dilation work? What is entanglement, otherwise known as spooky action at a distance? Are my feet ageing faster than my head? When a person dies, does their energy pass into their offspring? How does hyperloop technology work? Relebogile Mabotja and Dr Chris Smith have the answers... Like this podcast? Please help us by supporting the Naked Scientists

What causes monkeypox? Would an organ donor's DNA be in your body? Why does alcohol abate the symptoms of a hangover? Can you get bird flu from bird poo? Why do birds bob their head when they walk? Where does the word 'humour' come from? Is there a scientific basis on the laws of attraction? Dr Chris Smith and Clarence Ford have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

How does the James Webb Space Telescope work, and what will it reveal to us? How do spring and neap tides work, and what determines the times of tides? What causes hot flushes and night sweats? And why park the James Webb Space Telescope out in space - why not on the dark side of the moon? Lester Kiewit and Dr Chris Smith are back in action! Like this podcast? Please help us by supporting the Naked Scientists

What's the best shaped ice cube, the study suggesting a pan-coronavirus vaccine might be on the cards, why a temperature of 30 degrees C feels hot despite being below human body temperature, what effect have wars had on human population, where has the flu gone to in recent wnters? Join Dr Chris to find out! Like this podcast? Please help us by supporting the Naked Scientists

Why cockroaches invariably are found dead on their backs; what happens to old and previous Covid-19 variants; why do I see myself differently in photographs compared with when I look in the mirror; how do chickens produce eggs; what powers deep space probes; why do some people snore, especially after a few drinks; and why is yawning contagious? Dr Chris Smith and Lester Kiewit have the solutions! Like this podcast? Please help us by supporting the Naked Scientists

Why, after a dose of Covid-19, am I left with a new taste sensation resembling rotten onions? Why does bleached hair look blond, not white, and does salt water decolour the hair of surfers? How do I get rid of unwanted facial hair? Why is the hole my dog digs bigger than the dirt or sand that came out of it!? Why do mosquitoes prefer me to my wife? Does lighting a match do away with the smell of poo? Dr Chris and Lester Kiewit have the answers... Like this podcast? Please help us by supporting the Naked Scientists

What boils fastest, a glass or plastic kettle? Do animals adapt to their surroundings? Why do I feel sleepy when I take a trip to the coast? What's an itch? Why can I hear my husband snoring, but not me doing it myself? Can we artificially insert memories into the brain? Why do the colour of the sea vary in different locations? Why is entropy not a force? What is in it for a virus? Like this podcast? Please help us by supporting the Naked Scientists

This week, what's the bottom line on sanitising surfaces against Covid-19? Why, wonders Lester, am I so sluggish for the first few hours of the day? And can you train your chronotype to be a better morning person? Does it make a difference if you sleep on your left or your right? Why is gambling addictive and is addiction a genetic trait? Can pornography be addictive? And will resorting to apps like Google Maps impact my sense of direction? Join Dr Chris Smith and Lester Kiewit for the answers... Like this podcast? Please help us by supporting the Naked Scientists

The chemistry of fireworks, can I safely eat one year old Christmas cake, why we don't fall out of bed at night, what the Universe is expanding into, the reason we have to remove laptops from bags at airports, why the spinal cord won't spontanteously regenerate, sleep apps, and the science of forgetfulness all go under Lester and Dr Chris's microscope for analysis this week! Like this podcast? Please help us by supporting the Naked Scientists

This week we join young learners at Christel House school who ask us about the duration of immunity to Covid-19 post-vaccine and post-infection. Also, menstrual synchrony and whether it's fact or fiction, craniofacial abnormalities and the developing baby, the threat humans face from Artificial Intelligence (AI), why we're conscious and why we sleep. Dr Chris Smith and Lester Kiewit have the answers... Like this podcast? Please help us by supporting the Naked Scientists

What gases are present in lava? What happens when hot magma meets cold water in the sea? How different is an animal's brain to my own? How much of my intelligence is down to genes, and how much is the environment in which I grew up? Do photons weigh anything? Is there a cancer pandemic? And will a spoon in the neck of the bottle keep champagne fizzy? Dr Chris and Lester Kiewit tackle your burning questions... Like this podcast? Please help us by supporting the Naked Scientists

This week, James Croll and Mulitun Milankovic's contributions to planetary climate cycles; what it takes to knock a planet off-axis; where do clouds falling off Table Mountain go; does a discharged battery weigh less than a charged battery; the cheese reaction and bad dreams; why some foods go through undigested; why are planets round; birds recognising their own flocks; Captain Kirk heads to space; is a bad smell potentially infectious? Lester Kiewit and Dr Chris have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Dr Chris Smith answers listener science questions; what factors impact the onset of glycosuria? Might we have contaminated Mars with organisms from Earth? Why did the universe form the way that it did? Like this podcast? Please help us by supporting the Naked Scientists

This week, where Vitamin D comes from, if lab-grown protein is vegan-friendly, how mammals evolved to dive deep underwater, how genes can be used to track evolution, how chillies create a burning sensation in the mouth, whether feet change shape as we age, what makes a battery rechargeable, and why tropical seas tend to be blue and clear. Dr Chris Smith and Lester Kiewit have the answers... Like this podcast? Please help us by supporting the Naked Scientists

What makes a virus mutate? Why does bladder control become so much harder to achieve the closer I get to a toilet? How does sneezing work? How are vaccines quality controlled and assured around the world? What happens to Covid-19 vaccines if the cold-chain is broken? Dr Chris and Africa Melane have the answers... Like this podcast? Please help us by supporting the Naked Scientists

This week it's time to join another local school to answer their burning science questions including can we bring back extinct species from the dead; is the Universe infinite; can we replace cells and tissues in the body; will science solve Alzheimer's Disease; are humans getting taller; how do viruses like Covid-19 evolve and change; why do black holes matter; and, an easy one to finish on: what's consciousness!? Like this podcast? Please help us by supporting the Naked Scientists

What causes r-rolling difficulties otherwise known as rhotacism? Also, why do we have to stay still in an MRI scanner, why is calcium a metal, what makes water hard and how does a water softener work, what is the impact of a caesarian birth on health and why, what's the reason dementia affects short but not long term memory, and how does gravity work? Join Lester and Dr Chris for the answers to this week's crop of questions... Like this podcast? Please help us by supporting the Naked Scientists

This week we ask whether we're about to start spoiling other planets with our space forays, if there is antimatter in the human body, what causes cluster headaches, whether microwaving can ripen avocado, what causes long-sight, how atomic clocks operate, the basis of entropy and thermodynamics, why heat wipes out a magnet, and whether cleaning surfaces is a good idea for combating Covid-19... Like this podcast? Please help us by supporting the Naked Scientists

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

Why do I shiver when I wee? How does carbon dating work? What can I not tickle myself - is that similar to why I mind my own farts less than someone else's? Does breath-holding block tickle sensations? How does "the cloud" work in computing? Why are sunsets red, and what is the green flash? Why would a telegraph pole by the road vibrate of its own accord? Dr Chris and Lester have the solutions! Like this podcast? Please help us by supporting the Naked Scientists

Can you be allergic to one part of an animal but not another? What's the point of dreaming? What happened before the Big Bang? What's in wine that causes hangovers, and is this an allergic reaction? Are we seeing into the past when we detect light from far away in space? Why does driving through a long tunnel or across a bridge make me feel giddy? Lester and Dr Chris make your head spin with the answers! Like this podcast? Please help us by supporting the Naked Scientists

How do African animals withstand extreme cold in the Kalahari? Does the data we're all generating and storing weigh anything? How does relativity relate to the real world? Why do we run Olympic races in the direction we do? Is the ozone hole disappearing now? Were left handers less able to defend themselves back in history? Is a germinating seed making new matter? And will volcanoes eventually empty the Earth of magma? Lester and Chris have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why do some forms of heater seem to warm a room up faster? What's the different between Alzheimer's Disease and dementia? Are aluminium cooking utensils a risk factor for Alzheimer's? Can magic mushrooms control dementia, or other mood disorders? How do we know what's inside the Earth, and did we collide with another planet during Earth's past? Are microwaves a risk for cancer? Is there a limit to human Olympic performance? Like this podcast? Please help us by supporting the Naked Scientists

Are skin tags an indication of diabetes? Why don't cattle flee from fire? Do apples stimulate your appetite? Why are some cats great at hunting, and others not? Why doesn't dust fill up our lungs? What is the sediment at the bottom of frozen wine? When did our tail become a coccyx? What causes ringworm? What drives the magnetic field? Dr Chris Smith and Krystal Orderson have all the answers... Like this podcast? Please help us by supporting the Naked Scientists

In this week's show, recorded before the Euro 2021 final, Dr Chris explains why Inuits survive on polar fare with impunity but Shackleton's crew developed nutritional deficiency when they were stuck in the Antarctic. Also, why laser beams are bad for goalkeepers, if energy drinks are dangerous, why squinting sharpens vision, if there humans with better senses than average, and what is meant by the percentage chance of rain? Like this podcast? Please help us by supporting the Naked Scientists

Can electric eels power the national grid? What does 5% alcohol in a beer really mean? Does alcoholic hand cleanser ruin your fingerprints? Why does warm water on cold feet feel scalding hot? Is behaviour genetic - do I inherit my mood from my dad? Join Dr Chris and Azania Mosaka as they unravel the answers... Like this podcast? Please help us by supporting the Naked Scientists

This week, what happened to the Wankel Rotary Engine; why does air become thinner at altitude and thicker at depths; and why do I need to blow my nose vigorously when I first wake up but not at other times of the day? Also, what are the best pollinators, what's the evidence for macro-evolution, why do many great discoveries get discovered at the same time by independent workers, and what happens in the brain during hypnosis. Join Dr Chris and Lester Kiewit for the answers... Like this podcast? Please help us by supporting the Naked Scientists

Which is better, male or female? Why does one nostril sometimes seem to work better than the other? Why do some birds hop but others waddle? What's monosodium glutamate and what does it do to food? Why are other people's farts harder to tolerate? What causes multiple pregnancies? Why do we sometimes feel cold? And why don't professional sportsmen, like tennis players, not end up with one massive dominant arm? Join Dr Chris Smith and Lester Kiewit for the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why might it feel colder at daybreak compared with during the night? What's the best gap between doses for Covid-19 vaccines? What causes albinism and can albinos do anything to make their skin darker? What are stretch marks? And how do bees make honey? Join Dr Chris and Azania Mossaka for the answers... Like this podcast? Please help us by supporting the Naked Scientists

This week how medical detection dogs are sniffing out Covid-19 with 94% success rates, the force powering the expansion of the Universe, how a master key works, whether parallel universes are more fact than fiction, what was Dr Chris's favourite science subject at school, what causes bad dreams, what triggers early labour, and should a Covid-19 recoveree get vaccinated? Like this podcast? Please help us by supporting the Naked Scientists

This week, expiry dates on vaccines, what is a smell and how does the body's olfactory (smelling) system work? Why does the smell of fruits change during the ripening process? Why might sugar on cucumber taste like melon? Do some people inherit genes that mean some smells are inapparent to them? When clouds disappear, where have they gone? How does a cell phone touchscreen work? And why do car exhausts seem to last longer these days? Like this podcast? Please help us by supporting the Naked Scientists

This week, the Covid-19 crisis in India and why it's happening, we discuss why water, despite being replete with hydrogen and oxygen which burn readily, is incombustible, we talk through the safety profile of the coronavirus vaccines, find out why shaking the remote control can apparently bring dead batteries back to life, and touch on the ageing process. We also bid farewell to Kieno, who is departing for pastures new... Like this podcast? Please help us by supporting the Naked Scientists

This week, why it's more comfortable to look at the Sun on the horizon compared with when it's directly overhead, why dogs pee on upright objects, where mosquitoes go in winter, is it normal to have one foot bigger than the other, and what's the best way to breed tall children? Ray White and Chris Smith take on your science questions... Like this podcast? Please help us by supporting the Naked Scientists

If the AZ vaccine causes blood clots, why do affected individuals have low platelets, which should make clotting less likely? Also, when the Earth wobbles on its axis, does the Moon's orbit also change? How many genes of mine will my offspring carry? Could we dump nuclear waste in space? Why do disinfectants claim to kill 99.9% of bugs? Where do they get that number from?! Dr Chris Smith and Azania Mosaka have the answers... Like this podcast? Please help us by supporting the Naked Scientists

Dr Chris Smith chats with Relebogile Mabotja and her listeners about their science questions. Today: do older people yawn less frequently? And should you avoid zero sugar fizzy drinks whilst pregnant? Like this podcast? Please help us by supporting the Naked Scientists

Chris Smith and Kieno Kammies discuss the latest on blood clots and Covid-19 vaccines, including the US and South Africa decisions to halt use of the Johnson and Johnson vaccine. Also, are the vaccines a risk for people with aneurysms, what causes recurrent nosebleeds, can we mix flu and coronavirus vaccines, why the heart is so tied up with emotions, and does not having sex harm your health? Like this podcast? Please help us by supporting the Naked Scientists

Should I get vaccinated despite previous Covid-19 infection? Can I get a combined flu and Covid-19 shot? Why can't my pharmacist give me a Covid jab in South Africa? Is a Covid-19 vaccine safe for someone with a history of Guillain-Barre syndrome? Can you find out what Covid-19 variant has infected you? Did they really find Jack the Ripper? And why do dogs and cats turn around in circles when they first get into bed? Join Dr Chris Smith and Kieno Kammies for the answers... Like this podcast? Please help us by supporting the Naked Scientists

The people that don't believe Covid-19 is real, how ants smell out sources of food, how soda water makes you burp, a way to banish ants, what would you change about the human body, why masks stop Covid-19 but not smells, and how long is the recovery time from bone fusion surgery? Join Dr Chris Smith and 567 Cape Talk's Kieno Kammies for the answers... Like this podcast? Please help us by supporting the Naked Scientists