News
Scientists have developed a system that offers patients paralysed by spinal injuries the prospect of regaining the ability to move.
The breakthrough is the work of Chet Moritz and his colleagues at Washington University in Seattle. Writing in this week's Nature the team describe how they hav...
Do you dream in black and white or in full glorious technicolour? Your answer could well depend on what sort of TV you watched as a child, because a new study has provided more support for the theory that people who only watched black and white TV and movies as children also dream in black and white...
Scientists have brought a 1950s science experiment back to life, and with it discovered a lot more about how life on Earth got stated in the first place.
In the 1950s UCSD scientist Stanley Miller made history when he recreated the conditions of the early Earth by mixing some water, methane,...
Coral reef fishes that spend their lives picking clean other, bigger fish provide a more honest valet service when they work in pairs, showing that it pays off to be cooperate and behave.
That’s according to a study in the journal science this week from a team led by Redouan Bshary from the Univers...
Questions

How do blind people dream?
Chris - I know this because people have told me. My friend who I mentioned earlier was blind from birth and he tells me that his dreams were mainly words and sounds. In other words the kinds of things that you’re exposed to that you have experience of experiencing. He would just experience those.

Why is there so much radiation in space?
Chris - The answer is that in space there’s nothing to stop the radiation and so there’s a million mile an hour maelstrom of cosmic radiation which is streaming off our own sun. If we didn’t have the magnetic field of the Earth to deflect it away then it would be basting us in radiation. It would also be plucking away our water and our gases on our planet and we’d end up like Mars ultimately did. It isn’t a safe and nice hospitable place in space. It’s not just because of the use of fusion.

How much juice is left in fuel rods?
Steve - Nuclear power plants aren’t doing fusion, they’re doing fission which is splitting big nuclei up: uranium. In a nuclear power plant you only use a very small fraction of the uranium so there’s something like 50 times more energy left in there that we’re unable to tap except through what’s called fast breeder reactors which we don’t currently do.
Chris - How do they work?
Steve - This is a long question. They work by using the fast neutrons from nuclear reactions, from uranium, to attach to the inert part of uranium (uranium 238) to make plutonium. Plutonium can fission like uranium 235. That’s a complicated answer.

Why does the sun take so long to burn out?
Steve - The sun’s doing fusion very slowly. It doesn’t have to do it any faster to keep itself held up. If the sun did fusion faster it would expand and then the fusion would go slower and it would contract back down again. If the sun was doing fusion too slowly it would contract until the fusion got fast enough to hold it up. The sun is just self-regulating and that’s why it’s going to last 5 billion years.

Can fuel from nuclear power plants be recycled?
Steve - With the current designs we have fusion power stations. These are conceptual. We haven’t built one yet. With the current designs we burn deuterium which we extract from sea water and we burn lithium which you get from salts. There’s millions of years-worth of this fuel. The by-product is helium which you can put in kid’s balloons if you really like. They don’t have any long-lived wastes from this. It’s really an ideal way to make energy.

How will ITER work?
Kate - ITER as Steve pointed out is a completely different device. It’s a big magnetic donut and it confines plasma for a length of time whereas the thing about lasers is the Reactor would be slightly different. You have to inject these fuel pellets and compress them. In order to support a 4GW reactor you’d have to do that four times a second. The designs of the two system s are very different. That’s not to say we don’t have overlap and they’re not complementary. They are, we have some of the same technology challenges.
Kitchen Science
Create plasmas from a humble grape in your microwave.
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Interviews
John Bailey joins us to explain the problem with Japanese knotweed, and how this alien species could be kept under control by another alien species...
Electricity from fusion could be a great alternative to traditional coal-fired power stations, supplying cheaper, cleaner power. But how does it work? Steve Cowley joins us to explain the physics of fusion...
The Joint European Torus, or JET, is the biggest fusion experiment in the world right now - but how does it keep fusion reactions going? Meera went along to explore the technological challenges...
So what's the next step towards making fusion power a reality? Steve Cowley explains the plans for the International Thermo-nuclear Experimental Reactor, better known as ITER...
How could lasers be used to achieve fusion? Kate Lancaster joins us to explain all...
QotW
Is it best to let batteries discharge, or keep them topped up? Which method gives the longest living battery, and does the type of battery matter?
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