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Ask the Naked Scientists

698 episodes - English - Latest episode: 2 days ago - ★★★★★ - 60 ratings

How many organs could you donate and remain alive? How many planet Earths could fit inside the Sun? How high is a giraffe's blood pressure? Why is the sea blue? To find out, Ask The Naked Scientists!

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Episodes

Full tank or better to drive about half full?

March 11, 2022 03:31 - 19 minutes - 18.2 MB

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? P...

If identical twins marry identical twins...

March 01, 2022 10:21 - 18 minutes - 17.4 MB

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 u...

Are my feet ageing faster than my face?

February 20, 2022 10:11 - 17 minutes - 15.7 MB

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

Dark side of the moon for the James Webb?

February 07, 2022 07:17 - 15 minutes - 13.8 MB

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?

January 14, 2022 06:55 - 23 minutes - 21.5 MB

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 do I think I look different in photos?

December 24, 2021 07:11 - 26 minutes - 24.6 MB

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 does everything taste rotten after Covid?

December 17, 2021 12:02 - 26 minutes - 24 MB

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 supportin...

Can memories be artificially implanted?

December 04, 2021 02:27 - 25 minutes - 23.1 MB

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

Is Google Maps harming my sense of direction?

November 20, 2021 11:49 - 28 minutes - 25.7 MB

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 answer...

Why doesn't an injured spinal cord re-grow?

November 11, 2021 08:55 - 25 minutes - 23.7 MB

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

How long does Covid-19 vaccine immunity last?

November 03, 2021 12:42 - 22 minutes - 20.6 MB

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

How different are dog and human brains?

October 25, 2021 00:59 - 25 minutes - 23.5 MB

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

Are farts infectious?

October 15, 2021 10:00 - 26 minutes - 24.7 MB

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 thi...

Why are only some batteries rechargeable?

October 04, 2021 11:48 - 25 minutes - 23.3 MB

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 like Covid-19 mutate?

September 29, 2021 00:14 - 21 minutes - 20 MB

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

Can science bring back extinct species?

September 18, 2021 10:58 - 29 minutes - 26.9 MB

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

How does a water softener work?

September 11, 2021 09:04 - 26 minutes - 24.4 MB

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

Why does heat wipe out a magnet?

September 03, 2021 00:27 - 26 minutes - 24.3 MB

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

Can two light rays collide?

August 28, 2021 09:43 - 25 minutes - 23.4 MB

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! Li...

In computing, how does the cloud work?

August 21, 2021 08:57 - 26 minutes - 24.3 MB

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

Allergic to just one part of an animal?

August 14, 2021 09:20 - 26 minutes - 24.6 MB

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

Does digital data weigh anything?

August 06, 2021 08:50 - 24 minutes - 22.5 MB

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 ...

Are we at peak human Olympic performance?

July 24, 2021 08:58 - 23 minutes - 21.7 MB

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

Why does squinting sharpen vision?

July 17, 2021 09:07 - 25 minutes - 23.1 MB

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

Electric eels to power the national grid?

June 28, 2021 07:03 - 17 minutes - 16.2 MB

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

What happened to the Wankel Rotary Engine?

June 18, 2021 10:14 - 28 minutes - 26.5 MB

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...

Why don't tennis players get one massive arm?

June 16, 2021 08:38 - 26 minutes - 24.3 MB

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 h...

How do bees make honey?

June 07, 2021 01:37 - 20 minutes - 18.4 MB

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

Can dogs detect Covid-19?

May 28, 2021 11:23 - 19 minutes - 18.1 MB

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

Why sugared cucumber might taste like melon

May 21, 2021 08:40 - 23 minutes - 21.3 MB

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 S...

Why won't water burn?

May 08, 2021 08:56 - 16 minutes - 15.5 MB

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

Why don't animals have green fur?

April 30, 2021 03:51 - 20 minutes - 19.2 MB

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

Low platelets, but blood clots. Why?

April 19, 2021 02:05 - 19 minutes - 17.6 MB

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

Why halt the Johnson and Johnson Vaccine?

April 16, 2021 09:05 - 27 minutes - 24.8 MB

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

Flu and Covid-19 vaccines together?

April 14, 2021 04:51 - 26 minutes - 24.1 MB

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? ...

Why do masks stop Covid-19 but not smells?

March 26, 2021 05:50 - 22 minutes - 20.2 MB

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

If I've had Covid-19, do I need a vaccine?

March 22, 2021 02:48 - 21 minutes - 19.5 MB

Why are the EU posturing around AstraZeneca's Covid-19 vaccine, and what will be the consequences? And if you've already caught coronavirus, should you still get vaccinated if you are already immune? What is ataxia and how can it be treated? What causes rigor mortis and how long does it last? In Covid-19 genetic vaccines, how long does the foreign genetic material persist in the body? Plus why conspiracy theories and misinformation proliferated online are so toxic. Like this podcast? Please h...

Do catwalk models have more neck bones?

March 12, 2021 11:27 - 23 minutes - 21.7 MB

Why is the Moon moving away from the Earth, and what would have been the consequence of it being closer to us millions of years ago? Also, why does Covid-19 anosmia stop me smelling Vick's Vapour rub but I can still feel its effects? Do models have more neck bones to account for their longer necks? Why do some people float but others sink in the swimming pool? And how does lightning work: does it travel upwards, downwards, or neither? Like this podcast? Please help us by supporting the Naked ...

Will not having sex harm my health?

March 08, 2021 02:37 - 23 minutes - 21.9 MB

Why do we fall asleep when we don't want to? Will going without sex harm your health? Why do aircraft resort to black boxes when they could send data to satellites? Why don't brakes overheat and lock on? Can you create a 1 degree angle? And why does Earth look flat for people on the surface when we all know it's not really flat? Join Dr Chris Smith and Talk Radio 702's Azania Mosaka for the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why haven't we evolved not to age?

February 27, 2021 11:05 - 26 minutes - 24.1 MB

Good news on the Covid-19 vaccine front from the UK, why South Africa isn't using AstraZeneca's vaccine, is the Universe under threat from "strangelets", why has evolution not solved the ageing problem, why ice sticks to an empty glass, the PCR test for Covid-19, and how to stop cats killing wildlife... Like this podcast? Please help us by supporting the Naked Scientists

Why does Covid come in waves?

February 15, 2021 02:06 - 19 minutes - 17.6 MB

Will loud music deafen my dog? Why are some dog breeds more docile than others? Why do Covid-19 outbreaks follow cycles of boom and bust? What gives a person their "second wind"? Why do ants invade my kettle and other electronic devices ? Is ant invasion in you home a sign that the place is dirty? Why have I got vibration sensations in my foot? Join Dr Chris Smith and 567 Cape Talk's Saskia Falken to find out... Like this podcast? Please help us by supporting the Naked Scientists

Can teeth fillings tune in to radio waves?

February 05, 2021 10:04 - 22 minutes - 20.7 MB

This week we talk vaccines for Covid-19, especially the Novavax trial results, and hear why it might be possible to tune into radio waves with your teeth. We also discuss Covid and cytokine storms, bubbles in the Milky Way, where the sharks go during a tsunami and how radioactivity is used to power spacecraft... Like this podcast? Please help us by supporting the Naked Scientists

Are the Covid-19 vaccines safe?

January 26, 2021 03:44 - 21 minutes - 19.7 MB

This week, Dr Chris and Kieno Kammies talk Covid-19 vaccinations, explore whether ivermectin might be a helpful coronavirus drug, explain how maggots get into wounds, unpick what's in the Covid-19 vaccine, and talk nanoparticles... Like this podcast? Please help us by supporting the Naked Scientists

Am I a snake: my yawns spray saliva!

January 22, 2021 08:48 - 20 minutes - 19.2 MB

This week, journey times to Mars, how stars come by the matter inside them, why some people feel compelled to eat paper, how coronavirus antibody levels correlate with Covid-19 severity, whether water really goes down the drain in different directions on opposite sides of the Earth, and why a yawn produces a spray of saliva. Join Dr Chris Smith and Azania Mosaka for the answers. Like this podcast? Please help us by supporting the Naked Scientists

Can you swallow upside down?

January 18, 2021 01:23 - 20 minutes - 18.9 MB

This week, Aza catches coronavirus, Covid-19 vaccines, viral variants and where are the mutations in the SARS-CoV-2 genome, can you still swallow when you're upside down, how was Einstein proved right, and what causes cramp? Dr Chris Smith has the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why do you float on the Dead Sea?

January 11, 2021 10:12 - 27 minutes - 25 MB

How do energy drinks give you a buzz? Why do planets orbit on a plane? Should we test for Covid-19 infection before we vaccinate? Do energy drinks cause diabetes? Why do you float on the Dead Sea? How does the Plimsoll Line on a boat work? When does Covid infectivity cease after death? What's your first and last organ to die? How do planets orbit? And what's the best way to get rid of rat poison? Join Dr Chris Smith for all the answers... Like this podcast? Please help us by supporting the Na...

Why car indicators flash at different rates

December 18, 2020 07:55 - 15 minutes - 14 MB

How do point of care tests for Covid-19 work? Are they any good? How infectious are people asymptomatically infected with Covid-19? Why do different car indicators flash at different rates? How do accents work and where do they come from? How many Earths could fit inside Jupiter, and what is the "giant red spot"? Does wearing a facemask have any negative health impacts? Do hailstorms only happen in the daytime? Join Dr Chris Smith and Tshego Modisane for the answers... Like this podcast? Plea...

Why is it dark in space?

December 08, 2020 09:49 - 24 minutes - 22.1 MB

An update on the Pfizer vaccine for Covid-19, the lotto likelihood of sequential winning numbers, why swallows congregate around motorway bridges, the logistics of keeping the Covid-19 vaccine cold, and why is it dark in space? Also, why is there a Covid-19 vaccine in 10 months but no HIV vaccine after 4 decades, would we still have tides without the Moon, and why is the Moon white since the sky is blue? Join Dr Chris and 567 CapeTalk's Kieno Kammies for the answers... Like this podcast? Plea...

Why shave sheep in winter?

December 04, 2020 08:58 - 24 minutes - 22.2 MB

Why shear a sheep in winter when it's cold? And can animals count? Why do geese and turkeys chase people? Also, how does coronavirus infection alter our sense of smell and taste? How do artificial sweeteners work? And when it comes to survival of the fittest, what constitutes "the fittest"? What brings asteroids onto a collision course with the Earth? Dr Chris joins Kieno Kammies to answer this week's crop of farmyard-inspired - and other - questions... Like this podcast? Please help us by su...

Can we taste through our fingers?

November 27, 2020 05:30 - 21 minutes - 19.4 MB

Why did touching something make me taste metal? Also, what's the best liver detox, why does listening to loud music stop a stammer, does music help attention deficit disorder and is sunrise to the south even in the southern hemisphere. We also wonder whether perpetual motion is possible, why the sun can make some people sneeze, why ice cubes sometimes crumble, and how some fruits encourage others to ripen. Join Dr Chris Smith and Kieno Kammies for the answers... Like this podcast? Please help...