Science News
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Could a lost love stress your skin? Researchers have found that the emotional stress of a break-up compromises the skin's ability to repair itself making it more vulnerable ... |
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Anyone who has spent ages rummaging around in their bag for their keys on a dark evening, usually in the rain, will appreciate a new self-illuminating solar-powered ha... |
Questions

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I've always wondered what causes your feet to stink. Is it from your feet sweating, or do other things come into play?
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It may shock some people, but your feet actually squirt about half a litre of sweat into your socks and shoes every single day. You also shed in the order of about 40 000 skin cells every minute or so from your body. Over a lifetime that adds up to a few stones in weight of dead skin. Now this is perfect bacterial food, so you have a combination of a warm, damp place with lots of food. This makes your feet a thriving emporium of bacteria and fungi. When these eat the skin in your shoes, they produce volatile substances that smell. It's these substances that come whiffing up to your nose. People who wear trainers a lot end up locking their feet in and let them stew. The way around it is either to use odour eaters or wear sandals, as this lets your feet ventilate. Alternatively, you can wear leather shoes, as this helps your feet breathe more naturally.
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I'm in contention with someone at work, who is saying something that I don't believe is true. He maintains that if you hold your breath, it changes your bone composition in such a way that it allows your body to accept a low current, such as putting your finger in a light socket without being hurt.
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The reality is that if you take a deep breath, the only things it's going to do is affect the volume of your lungs, and affect your blood pressure and heart rate. When you take a deep breath in, it triggers a reflex that makes your heart rate go up a little bit, but that's about all. It won't affect anything to do with your bones and it certainly won't affect whether you can tolerate being electrocuted. If you put your fingers anywhere near mains electricity, you have a very real chance of being killed. You must tell this person to stop spreading silly rumours, because he's going to get someone killed at some point.
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When you let the water out of the bath, why does the water spiral down the plug hole?
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The shape of the plug has something to do with it, because you get a kind of whirlpool effect. The size of the whirlpool is affected by the size of the the plug hole. Some people believe that the direction of the whirlpool is down to the Coriolis Effect, the conservation of angular momentum which applies to moving things - like air and fluids - as the Earth turns in space. But simple calculations show that actually the Coriolis force is too small to account for the direction that water goes down the plughole, so the whirlpool produced when the plug comes out must be a product of the shape of the sink and the drain hole.
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What's the difference between an epidemic and a pandemic?
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We really shouldn't be using the word pandemic. It basically means a global outbreak. Really, flu is the only one that is pandemic. It can start anywhere and can sweep around the world. An epidemic can mean an outbreak in Norfolk and then maybe spreading to London but not going too far into Europe. So an epidemic is usually restricted, but a pandemic sweeps the whole world.
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Why do we cough up phlegm?
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Actually, not a lot of people do. Most of the phlegm that you produce ends up in your stomach. On the way to your lungs, all of your airways are lined with a sticky substance called mucus. It's there to mop up things like bacteria, viruses and particles of dust and dirt from the air. The linings of your lungs have tiny thread-like projections on their that beat. They all beat in the same direction which creates a current which pushes the mucus out of your lungs and up to your throat. Now if you get a lot of mucus, sometimes you cough and it can come flying out of your mouth. But most of it goes down into your stomach. That's very important, because as it has all the nasty things you've breathed in locked up in it. These are carried down into your stomach where stomach acid kills all the bugs. What's left then goes into your intestines. In the walls of your intestines the dead bugs and dirt meet special patches called Peyer's patches, and that's where your immune system learns what's doing the rounds in the air around you, what sorts of things it has to mount an attack against, and what sorts of things it has to ignore. So normally you swallow most of your phlegm, but if you have excess production, coughing it up helps to get rid of it.
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What's the longest period someone has had the flu for?
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It's something like three or four days. In someone your age Lydia, it would probably be four or five days. But we've known people who've had it much longer, maybe even eight, nine or ten days. That's really bad luck though!
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Why do you sneeze when you look at the sun?
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It's called the photic sneeze reflex. It's a defined entity and about 20% of the population have this, when you look at a bright light after coming out of a dark room and you have this irresistible urge to start sneezing. This has been investigated by the US military because they were a bit worried about their fighter pilots flying towards the sun and going into a sneezing fit. They don't know exactly what's happening at the nerve level, but what we think is happening is that there's a bit of cross-wiring going on. When you look at the sun, your pupil closes up and it gets much much smaller in order to stop as much light getting into your eye. But sometimes this can get a bit muddled up with the bit of the brain that thinks that your nose must be irritating. This triggers a sneeze instead. In the old days, people used to think that when you look at the sun, it made your eyes water and the tears trickled down your nose, making you sneeze. They did some experiments to test this and found that the tears would trickle too slowly to make you sneeze, so we think at the moment that it must be cross-wiring.
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Does the number of virus particles you have in your body affect the severity or duration of an illness?
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I think that answer is that the fewer virus particles you have in your nose at one time, the longer the incubation period is likely to be. So it will be the same severity, but it will take longer to get to that point.
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You said earlier that you would weigh 13 tonnes if you lived on Jupiter. Would your bones be able to withstand that, or would you end up like a pancake?
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Standing on Jupiter would be like having a bus standing on your head, as you'd weigh so much. So the bones in your feet which are set up to withstand 50 kg of weight pushing through them, would now have to withstand 13 tonnes. I don't think even the nest hip replacement would be able to withstand that kind of load. So you would be as flat as a pancake.
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My wife has had a letter from the doctor about a flu jab. But it also - that if she has an egg allergy, she's not to attend. Why?
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This is because the flu vaccine is grown in eggs, so there will be a smidgen of contaminating egg in the final vaccine. If she's allergic, she might get a reaction so it's best not to go along.
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| Interviews
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Chris Smith interviews Dr Paul Digard from the Division of Virology at the University of Cambridge
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Professor John Oxford, The Royal London Hospital
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Professor Pat Troop, Chief executive of the Health Protection Agency
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Fact or Fiction
Your new blood cells are made in your liver
 
It's False
· New blood cells come from the bone marrow.
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Chocolate grows on trees
 
It's True - the cacao tree
produces cocoa which is refined and used to make chocholate.
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People photocopying their buttocks are the cause of
1% of all photocopier breakdowns worldwide
 
It's False
- The noble art of derriere 'photocopyography' actually
accounts, worldwide, for a massive 23% of photocopier
breakdowns !
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You breathe in nitrogen to survive
 
It's False - We
depend on oxygen in the air for our survival. There are
some bacteria that can use nitrogen, but no animals !
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IQ - the measure of intelligence - stands for Intelligence
Quota
 
It's False - it actually stands for intelligence
quotient and is used as a measure of the population's
reasoning power.
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Hyperthermia is when the body gets too hot
 
It's True
· Hyperthermia is excessive body heat which can
be triggered by infections and hot climates, and certain
drugs. The opposite effect - hypothermia - sets in when
your body temperature falls too low, and it can kill you
because the chemical reactions that power your cells slow
down to such an extent that there is not enough energy
being produced to keep you alive.
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Your intestines are over 30 metres long
 
It's False
- the small intestine is about 5 or 6 metres and the large
intestine is about 1.5 metres so the total length is about
7 metres, not 30.
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If you were a space traveler standing on Jupiter you
would weigh the same as you would on Earth
 
It's False
- A person who weighs 50 kg on earth will weigh 13,200
kg - that's over 13 tonnes - on Jupiter. This is because
your weight is a measure of the pull of gravity between
you and the body you are standing on. Jupiter is larger
than Earth and larger planets have more gravity than smaller
ones. So on Jupiter gravity pulls you harder towards the
planet meaning you would weigh more there than on Earth.
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When an aircraft takes off your body momentarily weighs
less because of the acceleration of the plane
 
It's False
- Your weight actually increases when you take off because
the plane is accelerating you away from the surface of
the earth. On the other hand when you fly through turbulence
and the plane suddenly drops, producing that awful stomach-in-your-mouth
feeling, your weight decreases because you are momentarily
in free fall.
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Seawater contains about 20% salt
 
It's False - it's
actually 3.5%, or 3-and-a-half times more concentrated
than your body fluid, which is why drinking sea water
won't quench your thirst, dehydrates you more, and is
a generally bad idea !
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