Naked Science Question and Answer and Record Breaking Fireworks

05 November 2006

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Why scratch your head at science when Dr Chris, Dr Dave and Dr Kat are here to answer all you questions?! In this week's question and answer special, we discover why liquid washing tablets don't dissolve from the inside, why some genetic diseases only manifest in later life, is gravity constant, and why do men get hairy nostrils and ears when they hit sixty? There will also be a fireworks special in hounour of bonfire night including Dr Roy Lowry, who hold the record for firing the most rockets in five seconds, and Derek and Dave pull out an angle grinder for some sparkly Kitchen Science.

In this episode

Good News For Old, Fat Men

Now if you're old, overweight and male, then you could be given a new lease of life by chemicals found in grapes, wine and nuts - if you're a mouse that is. Researchers led by a team in the US have found that old male mice on a high-calorie diet enjoyed better health and lived longer if their diet was supplemented with resveratrol, a plant chemical found in those yummy plant-based foods. Over the past few years, other studies have found that resveratrol can help yeast, worms, fruit flies and fish to live longer. It's thought that the chemical switches on proteins known as SIRTs, that are involved in controlling the cell's metabolism and energy use. But this is the first time it's been shown to help mammals increase their lifespan. Unfortunately, a resveratrol pill isn't ready for humans just yet - the scientists warn that we don't yet know how much resveratrol we would need, and how safe it would be in those doses. But I'm sure the odd glass of wine wouldn't hurt, would it?

Flu in your Genes

It's the time of year for sniffles, and many of us tell the boss we're laid up with flu when we've just got a bad cold. But flu can kill, though it usually targets the very young and very old. Every so often we get an epidemic of flu, such as the one in 1918, that kills millions of people of all ages around the world. And doom-mongers are predicting another flu epidemic, which could be the dreaded bird flu. But why does flu kill some people and not others? Researchers at the Southern Illinois University School of Medicine in the States are trying to find out, by studying genes involved in making the immune system respond to flu attacks. The team studied two different genetic strains of mice who had been given a dose of flu, and found that the immune response in the two types of mice was different, and they activated different genes in their lung cells. The mice that mounted a bigger immune response were more likely to die from flu than the hardier strain. So this suggests that it's crucial genetic differences between the two strains that are responsible for determining whether the mice are likely to die from the flu. And because we're very similar to mice (some of us more so than others), it's likely that similar genes will be at work in us too.

Sperm Stopper

US researchers have produced a male "pill" capable of temporarily making rats infertile. Cheun-Yan Cheng, from the Centre for Biomedical Research in New York and his colleagues have found a way to block the maturation of sperm cells in the testis. Whilst sperm are forming they attach themselves to a class of supporting "Sirtoli cells", which nurture their development. Cheng's group have identified a compound, called Adjudin (1-(2,4-dichlorobenzyl)-1H-indazole-3-carbohydrazide) which can selectively inhibit this attachment process, preventing the sperm from developing and rendering recipient rats temporarily infertile. However, administered on its own, the agent caused liver and muscle damage in experimental animals, so the researchers have now found a way to selectively target the drug just to the testis alone. They have linked the Adjudin to an altered form of the hormone FSH, which normally locks onto receptors in the testis and triggers sperm formation. And because FSH receptors are not found anywhere else in the body only tiny doses of the agent are required to temporarily stop sperm production for over 4 weeks in rats given the new formulation. The effect wore off by 8 weeks after the drug was washed out from the body. The team are now exploring the possiblity of producing a skin-patch capable of releasing the drug through the skin to avoid the necessity to administer it by injection.

- Blasting Into The Record Books

The Naked Scientists spoke to Dr Roy Lowry, University of Plymouth

Blasting Into The Record Books
with Dr Roy Lowry, University of Plymouth

Chris - Tell us about your feat.

Roy - It is very tempting to tell you they are about size 9... It took about a year to put together. On the 16th of august, sixty of us spent the whole day putting rockets into frames, putting black match (string covered with gunpowder) underneath them, connecting the whole lot to a juicy looking red button, pressing the button and then watching the whole lot go skywards.

Chris - What was the point of doing this though?

Roy - The point was that I have a thing about science. I don't know about you, but I have been to parties where people ask me what I do, I say I am a chemistry lecturer and then their eyes glaze over. They say they weren't very good at science at school and they wander off to talk to an estate agent. I have fun doing my job - it is the best job in the world and I think it is about time we said you can have fun doing science. I spent about a year doing calculations to make sure this world record attempt would go off... and it did.

Chris - Has the Guinness Book of Records recognised your feat now?

Roy - It actually came back to me on Tuesday morning of this week, and I have a very impressive-looking certificate with my name on it. It takes them a while to make sure that we did it properly, but they got back just before November the 5th which was great.

Chris - You must have faced some criticism for doing this, as some people would say this was a waste of energy and time. Did anyone complain? Roy - I got a total of about half a dozen e-mails. The main criticism was please don't frighten our cats and dogs which I fully understand. But we did it as part of the UK firework championships, held in Plymouth every year, so it was a noisy night anyway. I had one or two raising concerns on environmental grounds, but I had to point out that old fashioned firework technology produces molecules that have been around so long that almost everything can be dealt with by natural systems.

Chris - Were these fireworks going to be chucked away anyway?

Roy - We were generously donated a batch of nearly 60 000 rockets, because they were outlawed for use by the general public - they were too small to be used. So we were acting as a disposal mechanism.

Chris - If they hadn't been disposed of by you what would the alternative have been?

Roy - The alternative to setting them off is to soak them in water, which means that the potassium nitrate (saltpetre) will dissolve out leaving just charcoal. This would be put on a landfill somewhere and then become methane, which is a very powerful greenhouse gas. You're better off burning them.

pottery making, artisan, maker movement

- The Dead Sea Scrolls and Cuban Jewellery

The Naked Scientists spoke to Chelsea Wald and Bob Hirshon from AAAS, the Science Society

The Dead Sea Scrolls and Cuban Jewellery
with Chelsea Wald and Bob Hirshon from AAAS, the Science Society

Bob - First Chelsea will tell us the science of one of the most famous archaeological finds of all time - the Dead Sea Scrolls.

Chelsea - The Dead Sea Scrolls have been called the greatest jigsaw puzzle in human history, because the 2000 year old Jewish religious scripts were found in about 40 000 pieces. For years scholars have tried to fit the pieces of animal parchment by matching their shapes, colours and written contents. Now scientists are getting help from the skin's DNA. Aldolfo Roitman the Dead Sea Scroll curator at the Israel museum in Jerusalem explains how it works.

Aldolfo - Once the DNA is recovered, the idea is to find the ID of the parchment so we can then see if the fragment fits with any of the others with the same ID.

Chelsea - Roitman also says that DNA will tell you what kind of animal the parchment came from. This is important because some animals were considered pure and used for holy manuscripts and others profane wouldn't have been used in holy places. They are also trying to match the manuscripts to some animal bones they have found which may solve the long standing mystery of where the scrolls were made.

Bob - At a 500 year old Cuban burial ground local archaeologists and their colleagues from UCL in London have found surprisingly opulent jewellery made from surprisingly humble materials, they were brass shoelace tags called aglets, which were traded with local people for gold. But field director Jago Cooper explains that back then gold in Cuba was abundant and not very valuable, instead the social elite decked themselves with a copper based alloy called guanin.

Jago - And when the Europeans turned up the brass objects then had with them were very similar to guanin and represented a high social status.

Bob - Caught off guard the Europeans traded whatever brass trinkets they had to hand or in this case on foot.

Chelsea - Thanks, Bob. Next week we'll talk about the Sun - Earth connection and its effect on some GPS receivers as well as the rise and fall of species. Until then, I'm Chelsea Wald.

Bob - And I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists…

- Do plants and trees communicate?

Do plants and trees communicate?

Do plants and trees communicate?

There is a form of chemical communication that goes on. There was some research done recently where they looked at plants having their leaves pulled off, and they found that the plants scream chemicals to signal that this damage has occurred. There are a number of chemicals produced. One of them is called ethylene (H2C=CH2) and that is a signal that tells the plant that it is being damaged to grow some more. It also makes fruit ripen. Bananas produce lots of it and so can help other fruit to ripen much faster. There is also communication between plants and the fungi in the soil (a mycorrhizal relationship). Fungus is very good at extracting water and minerals from the soil, and it swaps these with a plant, which will provide it with sugars to give it energy, so both benefit. People used to think that there were two species of thistle, a dwarf and a tall thistle, but they were both the same species, just with different fungi, referred to as Hartig nets, growing around their roots.

- How do insects manage to fly in the rain?

How do insects manage to fly in the rain?

How do insects manage to fly in the rain?

It depends on the insect. The large ones like butterflies don't; they hide somewhere dry such as under a leaf as a raindrop would do them a lot of damage and make them much heavier. On the other hand tiny insects such as midges are so small that they will tend to get blown out of the way with the air rushing around the raindrop as it falls.

- Why does your urine smell after eating asparagus?

Why after eating asparagus does your urine smell so strong?

Why does your urine smell after eating asparagus?

There must be a chemical in the asparagus that is absorbed into your blood through your gut, and then filtered out by your kidney into your urine. Scientists don't know what the chemical is, but it must move quickly as people can smell it in their urine after only half an hour. Interestingly some people claim not to be able to smell the difference.

- Do white blood cells multiply by mitosis?

Do white blood cells multiply by mitosis?

Do white blood cells multiply by mitosis?

Yes that is the normal process of cell division and they are made from stem cells in your thymus and bone marrow etc.

- Is it really possible to drive onto a trailer like Knight Rider?

Is it really possible to drive a car onto a moving trailer like Knight Rider did?

Is it really possible to drive onto a trailer like Knight Rider?

There is no reason why not. As Galileo noted, the important thing is your relative speed not the absolute one. So if the trailer is doing 60mph and the car 70mph, once the car is on the trailer it will only be doing 10mph relative to the trailer. So it would be like driving onto the trailer at 10mph. The one problem you could get is that if you don't make the transition with your foot on the clutch, the wheels will go from 70mph to 10mph while the engine is still trying to push them at 70. This will either cause a lot of burnt rubber or bits of your engine to fall out.

- Is firework smoke dangerous?

When fireworks are released into the air they turn into smoke and dust. Is there any danger from this?

Is firework smoke dangerous?

If you are close enough to breathe in a significant amount of the smoke from fireworks, you are too close. Most of the things in the smoke are the same as you would find in wood smoke. In Disneyland they have a large firework display every night over a lake, behind their castle. They commissioned a study to look at any pollution caused after 250 shows a year for 30 years. Even with modern techniques they couldn't actually detect any pollution, so it is probably ok.

- How many different things can we memorise?

How many different things can we memorise, what is the most anyone could memorise?

How many different things can we memorise?

There are some people who can memorise immense amounts and others who forget what they had for breakfast. The difference is down to your genes, we have a million million neurons in our brains and your memory works by making connections between these stronger by a process called long term potentiation. This happens in a part of the brain called the hippocampus and also the amygdala, but we don't know how memory actually works. What we do know for example, is that if you learn lots of languages, particularly from a young age, the part of the brain involved with language (the language cortex) gets bigger.

- Where does the microwave background radiation come from?

Where does the microwave background radiation come from, how was it made and why is it still around?

Where does the microwave background radiation come from?

The microwave background radiation is left over from the big bang. Originally the whole universe was so hot it was a plasma and the electrons had so much energy they were wandering about separate from the nuclei. About 300 years after the big bang the universe cooled enough for the electrons to get trapped by nuclei-forming atoms. This released an immense amount of energy in the form of light. Originally this would have been in the form of X-rays or ultra violet with a wavelength of less than a thousand trillionth of a metre. As the universe expanded, the light was stretched too, to the couple of millimetres it is on average now. Microwave background radiation is still around now because the universe is very empty and it hasn't all hit anything solid yet.

- Why is memory triggered by smells and music?

Why is memory triggered by smells and music etc?

Why is memory triggered by smells and music?

Smell molecules trigger nerve cells in your nose. These cells then connect to a structure called the olfactory tract and this links up to areas of the brain that are very close to where memories are laid down. This is in a primitive part of the brain, which controls animalistic behaviours such as emotions, sex drive and general arousal. So scientists think that smell can trigger all these other emotions. Also, memories don't seem to be laid down as a video clip, but are distributed all over your brain. So remembering something is like doing a jigsaw puzzle or a collage; the more pieces you have the easier it is to find more.

- Why do hairs grow in my nose?

When I got towards retirement age, I started to get hairs growing out of my nose and my ears. Why?

Why do hairs grow in my nose?

Unfortunately, blokes seem to get hairier as they get older. It's to do with testosterone - the hormone that makes us uniquely male. It makes hair grow on some parts of the body, makes your skin greasier, and makes hair fall out on the top of your head. The hairs in your nose and ears do have an important job, as they filter out large lumps of dust or fluff that would damage your lungs. Testosterone just makes them grow thicker and longer. It seems to be an exposure effect so over time we get hairier and hairier, and there is not a lot we can do about it apart from investing in a nose clipper.

- Why do genetic diseases sometimes only develop in later life?

Why do genetic diseases sometimes only develop in later life?

Why do genetic diseases sometimes only develop in later life?

Although the gene could be turned on from birth and doing damage all the time, it may take a long time for the damage to cause a major problem. For example, if you have a gene for a blood disease that creates something to block up blood vessels, it could take fifty years before it has accumulated enough to actually block them. There is another disease called Huntingdon's disease, where the gene is active from birth, and produces a protein that builds up in a cell. Like a rubbish bin, you can keep adding rubbish until eventually it overflows and causes a problem, so the disease only hits when you get to 40 or 50 years old.

- Is gravity around the planet constant?

Is gravity around the planet constant? If you have a spinning ball and put a penny on it, it will be thrown off at the equator but not at...

Is gravity around the planet constant?

Gravity is nothing to do with rotation. If the earth were a perfect sphere, gravity would be the same in all directions. As the earth is actually slightly flattened, gravity will be slightly larger at the poles. What the rocks are below you also makes a difference. If you are on a very dense piece of rock, gravity will be slightly higher. Of course, if you are interested in how much you will appear to weigh, centrifugal force will also have an effect so you will appear to weigh less than you would do if the earth wasn't spinning.

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