News
US researchers have found a way to non-invasively track the movements of cells around the body, a discovery which could help scientists to better understand how some cancers spreadand how the immune system works. Assaf Gilad, from Johns Hopkins in Baltimore, developed a way to entice cells to produc...
New research out this week hints at a ray of hope in the battle against malaria – and it seems the answer could be a rather simple ingredient – mosquito spit. Every year somewhere between one and three million people die of malaria and the search for an effective vaccine is a huge challenge fa...
Interviews
If you thought Concorde was fast, think again. Scientists are looking to make hypersonic engines that could travel from London to Syndey in a few hours.
Bird and insect flight is still not fully understood. So scientists are now using video backpacks for eagles and virtual flight simulators for flies to work out exactly what's going on.
Bob and Chelsea hear about the music of the ocean, including scientists that listen to whale communication, and how the Blue Danube is helping the visually impaired to see the magic of aquariums.
Rising carbon dioxide levels usually make us think about the atmosphere, but new research shows that carbon dioxide dissolving in the ocean could have devastating effects on shellfish and other marine organisms.
Kitchen Science
Hot air balloons are the most elegant way to fly - build one from normal kitchen materials.
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Questions
Why do water bottles shrink when they freeze?
I would say that it’s the air inside the bottle also contracting. Air gets bigger as it gets warmer and smaller as it gets colder, so although you’re right that water expands when it freezes, the air will shrink down. If you have a good seal on your bottle so that no more air can creep in, I think that it might crumple when it got colder. The material of the bottle itself might even contract when it gets cold, which would crumple the bottle into a distorted shape.
Do swallows roll 360 degrees?
The quick answer is that it might be the case. Most birds don’t do that because they actually keep their head horizontal in flight, so if you turn 360 degrees you end up turning your head around. The only bird I know that definitely does it is the raven, but swallows are very manoeuvrable so I guess it’s perfectly possible that they do too.
Can curry reduce parasites?
There was a bit of research done on this. In 2004 some people looked at coriander, the thing that you use to perk up a curry. They managed to find a molecule in there called dodecanal, which is a 12-carbon hydrocarbon with an oxygen on the end. They found that it’s very good at punching holes in the membrane of bugs like salmonella, so it works a bit like a detergent. It’s got this long oily chain that it sticks into the membrane of the bacterium and then this water-loving bit at the other end that opens up a hole in the bug’s wall. The hole allows the contents of the cell to leach out and the bug dies. So how much coriander would you need to achieve that effect? Well when they got an amount of coriander greater than the amount of curry you would eat, then you could get enough of this dodecanal to get approximately the same effect as the antibiotic gentamicin. So it can work but not at the concentration that we’re seeing in curries.
Why do men have nipples?
It’s an evolutionary thing. If you look at how we develop in utero, for the first few weeks male and female babies look absolutely identical. It’s only subsequently that you start, under the power of the hormones pumped out, to change and alter your anatomy. But because you develop a lot of these surface structures and appearances when you’re very early on in development, you’ve got them whether you need them or not. There is one example that I’ve managed to find that’s a male and uses it’s breasts to potentially breast feed as they certainly lactate. That’s a Dayak fruit bat and they live in Indonesia. The male produces about a tenth of the amount of milk that the female does.
Should coffee be stored in the freezer?
The main reason you want to freeze it is to keep in all the volatile chemicals and aromas. If you keep it in a warm place then the volatile chemicals come out of the coffee and it won’t taste as good.
Could you return nuclear waste to the mines it came from?
I think there are a number of problems. One of the problems is making sure that when you’re putting stuff in the ground you don’t build a bomb by accident. This is in the sense that this stuff would be in a reasonably active state and so if you put everything together you might get reactions propagating. The second question is whether a mine is the best geological place to put something that could potentially have major health implications. If it gets into water and then into people, it could have major implications for human health and the environment. You may need a more stable geological site. This is why scientists have not really decided how to make the best repository. There is one site, which is over in America, but I don’t think anything’s in it yet. People are putting a lot of thought into this because you don’t want to make the wrong decision. Some of this stuff remains radioactive for 250 000 years, so the place you put it must also be stable for 250 000 years. Putting it back in a mine might be dodgy if you want my personal opinion.
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