Kat:  I think this is all to do with the vestibular system, if that’s the right word.  I’m sure Chris will pick me up on this from Australia if I’m wrong.  Basically, inside your ears you have a system of interconnecting tubes that are all at right-angles to each other.  In each plane: up down, left and right that are filled with fluid.  They tell you which way is up and which way is left and right in your head so you know if you’re standing up or lying down.  If you spin very fast the fluid in these canals will spin round.  If you stop very suddenly, as in stopping an office chair, you stop but the fluid in your ears is still going.  Your brain gets all confused.  You think you’re still spinning but your eyes are telling you that you’re not spinning so it manifests as feeling very sick.

Ben:  Isn’t this why people feel sick in long car journeys at all?

Kat:  Exactly, it’s when you get an imbalance between what your ears are telling your brain and what your eyes are telling your brain. You get confused and that makes you feel nauseous.

I think the answer to that is they actually use a special technique when they spinning round.  If you watch a dancer who’s spinning round very fast they’ll flip their head round, very quickly so their head is actually fixing on one point and then flipping round very fast.  Is this called spotting?  This is what we think it’s called.  Your head’s actually mostly stationary and you’re flipping round and focusing on one point so it affects your ear system a bit less.

This is because of osmosis.  What happens is that water will move into your cells.  That makes sense of how skin swells up but it doesn’t necessarily make sense that your skin’s wrinkly.  You'll notice when you have a bath you don’t get wrinkles all over.  You get wrinkles on the soles of your feet, on your hands: especially your fingers.

This is because you have a layer of protective keratin.  Keratin’s a kind of tough stuff, it’s what claws and nails and so on are made of.  This means that the skin here is much thicker than elsewhere on your body, and this thick layer is made of dead, keratinised cells.  This takes up more water than the thinner skin elsewhere, and so swells up, and goes wrinkly.

It’s been stored in your body which is that fantastic body temperature of 37 degrees.  It’s like keeping something in an incubator, it’s nice and warm.  When it comes out, it’s still warm.  Because your skin is cooled by the air, anything at 37 degrees feels hot against your skin.  You’ll notice this if you put your hand in some water that is 37 degrees, it doesn’t feel the same.  It feels warmer than blood heat.