Ask the Naked Scientists

What colour were human ancestors? What does a rocket push against in space to propel itself forward? Why does yawning make me cry? How do bats navigate? Can fuel cells run on alcohol? Why are 90% of people right handed? How genetically related would the children of two sets of identical twins be? Plus, noses grown on foreheads and how rotating antibiotic drugs can prevent bacterial resistance... L...

Why scratch your head if you don't know the answer? What about the Earth made the dinosaurs so big? Why does the Universe spin? Is the Sun seem brighter in the morning than the evening? Are autistic people particularly at home with computers? Why do effervescent tablets fizz only in water? Why do Parkinson's patients sleepwalk without difficulty? Plus, news of a decoy molecule that can treat dwarf...

How is an electron microscope tip made to measure 1 atom thick? Why do I sound different on a recording? Why does light slow down in some media? Why is soft water slimy? How do ants home in on my handbag? What makes my eyelids twitch? Plus, how scientists are exploring spider venoms as a source of new insecticides... Like this podcast? Please help us by supporting the Naked Scientists

How do robotic surgeons work? Do diamonds melt? What is heartburn? Can fish see colours, and what should anglers wear? What is brain plasticity? What would happen if an egg were dropped into boiling oil? What causes blushing? Why does holding the antenna of an AM radio improve reception? Like this podcast? Please help us by supporting the Naked Scientists

Is global warming a given? Can olive leaf extracts combat parasites? Is there a fake tanning pill? Why keep gas cylinders upright? How does digital storage work? Does reducing body temperture aid infections? How does the moon cycle affect human behaviour? Like this podcast? Please help us by supporting the Naked Scientists

Why is space dark; do bags of coins deter flies; why don't cats go grey; is GPS or an odometer more accurate; what was the effect of the Med drying up in the past; what does an ice-pack versus a hot-pack do for an injury; how might maternal diabetes affect a baby's future health, and should I let the tap run before drinking any water? Plus, urine-powered electricity supplies... Like this podcast?...

Why are we ticklish? What happens to blood when we die? Why are mechanical hearts hard to make? What's a burb? Can a mushroom crack tarmac? Why do helium balloons fly forwards in the car when I brake? Why does microwaved milk explode when I stir it? Like this podcast? Please help us by supporting the Naked Scientists

Do plants do maths? Has the Internet made us all more intelligent? Why did my milk freeze? Why do my hands get cold, but not my face? How did people realise Earth is round? What's red shifting? Why does squinting make it easier to see things? Why is water unreactive when hydrogen and oxygen are? What makes red shifting happen? Dr Chris answers more top science questions from South Africa... Like t...

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 its...

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 suppo...

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? Pleas...

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 Scient...

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 Sou...

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 Nak...

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