In the early days NASA did worry about astronauts’ diets and going up into space for various reasons. One is that if you have gut flora or bacteria that break foods down into gas: if you eat foods that they like breaking down and turning into gas, then there’s a worry that you could end up making a lot of gas and that could be quite unpleasant in your spacesuit. That was the theory, so diets were selected to be what’s called, ‘low residue,’ and fairly stomach-kind.

But in fact experience has shown that, after many, many space missions that’s probably not necessary. So you can go for pretty much anything that can be desiccated down to dried-out astronaut food.

There’s no trick to it necessarily. It’s not entirely what it looks like. Basically there are three components.  The first thing to consider is that when you’re walking across fire, understandably, you do it a bit quickly.  So you’re actually minimising the time that any particular part of your body is in contact with the fire. This is the same reason that lizards scoot about in the desert on hot rocks. The quicker they move, the less they’re going to burn themselves.  There are two other things: the fires are lit and left to burn until they become like a barbecue.  The top layer of that is ash.  Ash is actually a pretty good insulator against the direct heat underneath.  So you can feel the heat above it but the burning heat won’t get through so much.  Also carbon is the component of the coals.  Carbon is a very poor conductor of heat so the burning at the bottom of the fire pit won’t come up so much. So it’s not as hot as it looks and also you go across it very fast.

There is another theory that because you’re a bit nervous, just as you would get sweaty hands, your feet sweat a bit and you effectively surf across the top of the coals on a cushion of steam which also helps to keep the temperature down.

It can be both because the spinal cord isn’t just a one-way street.  It’s got information coming out of the brain, down to what we call motor neurons, the motor nerves that supply your muscles.  At the same time information’s coming in from your body, going up the spinal column, into your brain, telling your brain where your body is in space, how fast different muscle groups are moving and where they are and whether the movement you’re just made has been completed.  So if you’ve damaged the spinal cord you can damage just the sensory fibres and that means you can’t feel your body but you could potentially still move.  You can damage just the motor fibres which means although you can feel your body you can’t make any movements.  More usually it’s impossible to be that discrete when you make a lesion in the spinal cord.  For example, people dive into the swimming pool where it’s too shallow and they impact on their neck.  They break their neck, it severs the spinal cord and it disjoints all of the fibres coming up from the body: telling your brain what your body is doing/what it feels like, as well as the fibres coming out of your brain that tell you muscles to move.  This means you can’t feel your body nor make it move, so it’s very unpleasant.

We put this question to Cristina Lazzeroni, Particle Physicist from Birmingham University:

Cristina:   Yes, we would like to make black holes with the large atom collider.  It would be very interesting because there are lots of things we don’t know about them and we could study them.  And no they would not destroy the entire universe because they would be very, very localised and they would last such a short time they would not destroy anything.

Chris:  Why wouldn’t they grow huge?

Cristina:   Because they will decay and die instantaneously like anything else.

We put this question to Ben Allanach, Theoretical Physicist from Cambridge University

Ben:  They’re are theoretical possibility as you can find out from solving Einstein’s equations but if you actually look into them you can’t really see how they would form.  They seem to be unstable.  They’re like black holes but stuff comes out of them rather than the other way around.

Chris:  So they’re the reverse?

Ben:  Yeah

Chris:  So would the stuff that came out be antimatter?  Because in our universe all the stuff we can see is matter.

Ben:  It would be any matter and antimatter and light would come out.  They’re unstable so I don’t think they can form.