Ask the Naked Scientists

How much ice are glaciers losing annually? What makes eyes itch? Is yoga beneficial to health? How do solar sails work? Do we have dominant feet? Why is a rainbow the shape it is? Plus, news of why breastfeeding could help your offspring to climb the social ladder... Like this podcast? Please help us by supporting the Naked Scientists

Why does yawning produce tears? Why do noses tend to run on a cold day? Is methylated spirit good for mosquito bites? Why do computer screens sometimes produce after-images on your eyes? Can blocking blood vessel growth cause cancers to stall? Is cola good for bloat? Is it really colder just as the sun rises? More top science questions from South Africa, as well as news of how the cornea keeps itself clear of blood vessels... Like this podcast? Please help us by supporting the Naked Scientists

How do continental plates move? Is the weather worse at weekends? What does your brain choose to ignore? Why do wet fingers wrinkle? Are bullets fired into the air dangerous? Are premonitions real? Why does the Sun seem larger at sunset? Like this podcast? Please help us by supporting the Naked Scientists

How much radiation would an astronaut encounter on the way to Mars? What causes loss of appetite during a fever? Why does camera red eye happen? Can we reproduce in space? Is mercury in dental fillings safe? How old are the atoms in the body? What causes tides? What's the point of male nipples? Why do trees lose leaves in winter? Like this podcast? Please help us by supporting the Naked Scientists

What is genetic diversity? What causes colourblindness? Why does a microwave turntable sometimes rotate in the opposite direction? How are genes linked to behaviour? How accurate are different dating methods? Where does sleep in your eyes come from? And how does an aeroplane wing work? Join Dr Chris for another top clutch of questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists

What attracts malaria-infected mosquitoes to people? How happens to the brain during adolescence? Why are bubbles always white? Would a sealed box containing an exercising person get lighter? What does a launching rocket push against? Why is water from the hot tap initially cold? What actually is a random number? And is there a formula to calculate the size of a parachute? Like this podcast? Please help us by supporting the Naked Scientists

Does cold exposure cause colds? What consitutes safe drinking water? Why do distant lights and stars flicker? What is sleep walking? What causes bipolar disorder? How does sound travel in air? Plus, news of a vaccine to help crack heroin addiction. Join Dr Chris for more top science questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists

Does what we eat alter how we smell? Why does the severed tail of a lizard still wriggle? How does the nervous system re-wire itself? What's in snake and spider venom? Do fuel-saving devices for cars really work? Plus news of how honey helps bees to fight off infections, and pesticides... Like this podcast? Please help us by supporting the Naked Scientists

Why do adults smell more than children? How are bionic implants contributing to longevity? What is progeria? How do touch screens work? Why do anti-HIV drugs cause fat redistribution? Why does power = volts x amps? What actually are dark matter and dark energy? Join Dr Chris for the answers to more cool questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists

Does holding a car remote to your head make it work better? Why does a boat float? Are triple rainbows real? What's a near-death experience? This week we also look at a new scientific study into why - and when - breast milk transmits HIV to a baby... Like this podcast? Please help us by supporting the Naked Scientists

Are babies born to swim? Can you escape from a black hole? Can an egg with a double yolk yield two chicks? What causes nightmares? Why do we gesticulate when we speak? Why is the Moon visible by day? Dr Chris takes on more top questions from South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Naked Scientists team, Ben Valsler, Chris Smith and Ginny Smith joined the 702 crew and a studio audience live in Johannesburg to talk science, build vacuum bazookas and challenge listeners' mathematical minds... Like this podcast? Please help us by supporting the Naked Scientists

Do satellites collide? Can albinism be diagnosed on a scan? What causes the timing of the equinox to vary? Do bullets fired in the air still kill people? Can we make a human from just a genetic code? Why doesn't glue stick to the container? What's left underground once oil has been removed? And why can't we tickle ourselves? Join Dr Chris for another round up of the best science questions from South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Who was John Snow? Why do things shrink in the wash? How does carbon dating work? Is intelligence down to mitochondria? Why does the banner also bank behind a banking aircraft? And how does the human body develop in utero? Dr Chris answers more top science questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists

Does a cloudy day aggravate arthritis? Was the biblical flood real? How does a gastric bypass work? Will a knife in water go blunt? Where do the skeletons on sunken ships go? Why do cats have an extra fold of skin in their ears? And why transmit electricity at high voltage? Dr Chris joins Redi Thlabi for thirty minutes of quickfire Q and A... Like this podcast? Please help us by supporting the Naked Scientists

How did horse meat end up in the food chain? Is baking foil bad for you? How big are viruses? How are urine and sweat produced? How do hydrogen vehicles work? And how do we measure the height of things above sea level? Join Chris Smith for this week's crop of top questions from Talk Radio 702, South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Why do ovaries run out of eggs and what affects egg quality? Why does diesel smell nice but burning engine oil is unpleasant? Do genes from genetically modified organisms get into eggs and sperm? Does lead affect behaviour? What causes motion sickness? Join Dr Chris for another run of science questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists

How does alcohol cause liver cirrhosis? Can we make matter massless by removing Higgs particles? How did spiders evolve web-making skills? What is insulin resistance? What does fluoride do? And do scars sustained by adults manifest in their offspring? This week Dr Chris takes on more questions from Talk Radio 702 South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Are helium-filled balloons less likely to pop? How does a cordless toothbrush charge? Is there much mercury in compact fluorescent bulbs? Why do tired toddlers rub their eyes? Is lactose intolerance more common than it once was? And is it possible to trigger earthquakes artificially? Dr Chris answers this week's burning questions on Talk Radio 702, South Africa... Like this podcast? Please help us by supporting the Naked Scientists

What is involved in blood doping in sports? Can beetroot make urine red? Can mosquitoes transmit HIV? How do dung beetles use the Milky Way to navigate? Do sneezes stop your heart? Can you hear a supernova? Could plants grow on Mars? Why do ants keep drowning in my drink? Why do we not notice Earth turning? And can flour relieve burns? Dr Chris takes on another batch of top science questions from South Africa. Like this podcast? Please help us by supporting the Naked Scientists

How box jellyfish venom exerts its lethal effect, will the World end, how were the pyramids aligned, why does humid air feel hotter, why does a hot water stream slow after the tap is opened, what causes lights to twinkle, why do humans have language, is there a way to make more twins, where do stepped-on snails go, and why do diabetics sometimes smell like pear drops? Dr Chris tackles another crop of top questions... Like this podcast? Please help us by supporting the Naked Scientists

Carp with compasses, why we have earwax, what causes CIDP, can genes re-write their own code, do bananas in brown bags stay fresher longer, does hot water sound different, why veins look blue and what is coarctation of the aorta? Like this podcast? Please help us by supporting the Naked Scientists

Why do we age? Why do frogs end up in the swimming pool when it rains? Are mosquitoes attracted to some people more than others? What is epigenetics? What causes Bell's Palsy? How do frogs find water? Do tyres on the roof repel lightning? Answers to more great science questions from South Africa with Dr Chris... Like this podcast? Please help us by supporting the Naked Scientists

Do blood donors live longer, is water safe in plastic bottles, is Earth gaining weight and are space probes sterile? Plus, how fireflies have helped engineers make even brighter LEDs. Like this podcast? Please help us by supporting the Naked Scientists

What causes hurricanes? How does plastination work? Why do we go grey? Does grunting make muscles work harder? Do parallel universes exist? What causes hot flushes? Are there any IQ tests for babies? Do plants benefit from being talked to? Join Dr Chris for this week's round up of top science questions from South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Why aren't bubbles coloured like the soap they came from? Does holding a remote control to you head make it work better? Why has exercise reduced my alcohol tolerance? Is it by design that the names of all continents start and finish with the same letter? Why don't eyebrows go grey at the same time as head-hair? Do things taste different on opposite sides of the mouth? Why remove metal objects before a medical scan? And why does running water make me want to wee? Join Dr Chris for the answers to this week's questions as well as news of a way to correct mitochondrial enzyme defects... Like this podcast? Please help us by supporting the Naked Scientists

How do atoms change inside stars? How did Felix Baumgartner accelerate to over 800 miles per hour? What is inside a black hole? What decides the sex of a baby? What causes jetlag? Could we use the movement of seawater inside the Earth's magnetic field to make electricity? Why is the sea salty? Plus, are women born to flirt? Dr Chris has the answers... Like this podcast? Please help us by supporting the Naked Scientists

Why is skin the mouths of animals pink? Why doesn't water immediately fall out of clouds? How do we use light to send information into space? Why did a stomach explode after a liquid nitrogen cocktail? What are chimaeras? How will Felix Baumgartner get to the edge of space for his free-fall jump? Why is your breath both hot and cold against your hand? Why are the entry doors to an aeroplane always on the left side? And why do toenails seem to grow more slowly than fingernails? Join Chris for another rampage through the best science questions South Africa has to offer! Like this podcast? Please help us by supporting the Naked Scientists

Is the Earth about to gain a new tectonic plate? What is pompholyx and what are the treatment options? Why does sunburned skin blister? Why does boiled water taste different? Is there anyone who can still make a pencil from scratch? Why won't sugar solutions freeze? Why does my dog yawn when it gets up? Does famine affect genes in future generations? Like this podcast? Please help us by supporting the Naked Scientists

How is the effectiveness of environmental interventions measured? What's the scientific definition of nothing? Why do farts smell worse in the shower? What happens when an aircraft breaks the sound barrier? What should I drink with lunch? What's happening with ITER? How are flu vaccines made? How do hair transplants work? Like this podcast? Please help us by supporting the Naked Scientists

Why does a local anaesthetic make my face feel fat? How do worms get into food? Would a taxi driver find a map of a new city easier to learn? From where did the asteroid belt form? Why is the lower lip more prone to chaps? What makes birds decide to sing at 5am? Can we make a spacestation inside an asteroid? Do you believe in UFOs? Another crop of top questions from 702 listeners gets answered... Like this podcast? Please help us by supporting the Naked Scientists

How did NASA get their cameras to work in the cold on the moon? How does a cordless electric toothbrush charge itself? What is adult respiratory distress syndrome? Where does the amniotic fluid around a baby come from? Why are Olympic races run anticlockwise? Why is sunscreen advised even on cloudy days? What is more accurate, my speedometer, or the speed recorded by my GPS? And why do my sunglasses make LCD displays look strange? This week Dr Chris takes on more of your science questions... Like this podcast? Please help us by supporting the Naked Scientists

Is a heater more efficient than a lightbulb? Why does your tongue stick to ice? Do planes alter the weather around airports? What's a headache? Do dreams alter your metabolism? Is medicine making the population less fit? Is teething linked to diarrhoea? Why don't aircraft tyres explode? Join Dr Chris for this week's round up of intriguing science questions and answers from Talk Radio 702... Like this podcast? Please help us by supporting the Naked Scientists

Why does my GPS think my car has moved in the garage at night? Can humans survive a space-ride to Mars? Why are epsom salts worth their salt? What is a black hole and what is inside it? How do the equations for special relativity and kinetic energy relate? Why is Pluto where it is in the solar system? Why have right and left headphones? Join Dr Chris for this week's brain-stretching science phone-in on 702. Like this podcast? Please help us by supporting the Naked Scientists

How do nerves conduct electrical impulses? How long does it take a bee colony to make a beehive? Why are there 360 degrees in a circle? How does special relativity work? What happens to a live insect if you swallow it? Is there a north, south, east and west in space? What happens to a diesel engine when the fuel shuts off? Dr Chris needs your help this week, because he's not an apiculturist or a mathematical historian... Like this podcast? Please help us by supporting the Naked Scientists

What's the point of making medicines fizzy? Why should salt have a sell-by date? Is boiled water as good as distilled for my iron? Do we actually only see half a movie? Where do foreign bodies dislodged from the eye go? Is lactose intolerance becoming more common? What causes morning sickness, and is it a risk for mother and baby? Join Dr Chris for this week's round-up of top questions from Talk Radio 702, South Africa... Like this podcast? Please help us by supporting the Naked Scientists

This week, what causes anencephaly and exencephaly? Can electric cars recharge themselves from their wheels? How do astronomers determine the composition of exoplanets? Why do things move when I switch eyes while looking at them? Why do animals of the same species all look identical? Can we get dinosaur DNA out of amber? Do hands and feet get fat when a person puts on weight? Join Dr Chris for the latest round up of top questions from Talk Radio 702, South Africa. Like this podcast? Please help us by supporting the Naked Scientists

This week, the cause of vitiligo, whether pork is linked to a sore throat, what happens to a flame in microgravity, what causes albinism, what is dark matter and why can't we see it, why doesn't the sea sink into the seabed, why is window-cleaner fatal for flies, what determines diastolic blood pressure and why are some babies born prematurely? Dr Chris takes on more top questions from the listeners of Talk Radio 702... Like this podcast? Please help us by supporting the Naked Scientists

What does the discovery of the Higgs particle mean? How do flies land upside down on the ceiling? What happens when we divide by zero? Why do healing wounds itch? Does my washing dry by osmosis? How do fibre optics work? What causes a headache? Like this podcast? Please help us by supporting the Naked Scientists

Is the moon brighter overhead? Why do babies have higher heart rates? Do men snore more than women? What is peripheral neuropathy? Why are our organs wet inside? How do electric eels work? Why do wires tangle? What is the basis of a skin graft? This week Dr Chris takes on more tough questions on TalkRadio 702, South Africa... Like this podcast? Please help us by supporting the Naked Scientists

What gives a flame its colour, and what is the hottest part? What limits the height of a skyscraper? How does post-exposure prophylaxis for HIV work? How do they put the lines on a clay tennis court? Why do some songs cause goose-pimples? Why are some people better at withstanding temperature extremes? And can lightning be collected as a power-source? Join us for the answers and some lively chat from Talk Radio 702, South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Who was Phillip Tobias, how do self-focusing binoculars work, are muscle transplants possible, what is the bone structure of a snake, what happens when several sounds interact, will we still be evolving in the future, why is air transparent and what comes up when you clear your throat? Dr Chris has the answers to this week's crop of questions from Talk Radio 702 South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Do birds have a sense of smell? Are penicillin allergies permanent? How do vultures identify dinner? Does light travel forever? Is alcohol added to cooked food safe for an alcoholic? Do viruses have viruses that prey on them? How do bees track down my beer? Are some people genetically programmed to commit crime? Can two twins have different fathers? How did the power of speech first evolve? Dr Chris Smith has the answers... Like this podcast? Please help us by supporting the Naked Scientists

What makes dog poo turn white? Is water really wet, or does it just wet things? What was the nuclear impact of Fukushima? Where did my big ants go? Do microwaves alter water? Is the world changing shape? Where do corrugations in dirt roads come from? How did the Universe come by its water? Will my wife really end up looking like my mother-in-law? Join Dr Chris for another crop of top questions from 702, South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Are premium-priced fuels really worth the extra cost? Why are males born with nipples? Is a male contraceptive pill in the offing? Do all animals get the same number of heartbeats? Does any one organ failing cause death? Can aeroplanes run on diesel? Why does silver tarnish? What causes lightning? Is mental illness curable? Join Dr Chris for the answers to this week's crop of queries from South Africa. Like this podcast? Please help us by supporting the Naked Scientists

Why do I bruise more easily now I'm older? Why do some wind turbines spin in reverse? Are UV sunbeds worse for young skin? Ozone therapy, or quackery? Why do I want to eat chalk? Is blood the same in all animals? And alongside the answers to the best science questions 702 listeners have to offer, Dr Chris also reveals new radio-controlled cells... Like this podcast? Please help us by supporting the Naked Scientists

What substances are in snake venom? Where is sea-level measured? Are any of my cells the original ones I was born with? Are we seeing the effects of global warming? How does planetary precession work? How do bullets do damage? How can you tell when a melon is ripe? Why are men so stubborn? Plus, how fossilised raindrops are shedding light on what Earth's atmosphere was like 3 billion years ago... Like this podcast? Please help us by supporting the Naked Scientists

What causes jaundice in newborn babies? What is vitiligo? How do liquids behave in space? What causes cardiac arrests? What would happen if Earth span in reverse? What is Bell's Palsy? What are quarks? And how do hiccups occur? Join Dr Chris for this week's crop of questions from South Africa's Talk Radio 702 Like this podcast? Please help us by supporting the Naked Scientists

Does alcohol affect men and women the same way? Do other animals menstruate? Does intensive training affect a woman's fertility? Is it bad for birds to drink from my swimming pool? Should I shower during a thunderstorm? What causes a febrile convulsion? What is photocatalysis? Who gets gallstones and what are they? Why do whales have horizontal tails? Join Dr Chris on Talk Radio 702 for this week's select crop of top science questions... Like this podcast? Please help us by supporting the Naked Scientists

What does the genetic fingerprint of Ozti, the 5300-year-old Alpine iceman, reveal? Why do the bubbles in a glass of Guinness appear to be defying the laws of physics? Could we replace food with pills? Why did a dead bee still sting me? Is there any evidence that Voodoo does do anything? Why do balloons go bang? How do ducklings recognise their mothers? And why are planets round? Join Dr Chris for this week's crop of top science questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists