Diet foods make children fat

US researchers have found that giving young animals diet foods can trigger obesity by encouraging overeating behaviours, suggesting that the same thing could happen to young children. Writing in the journal Obesity, University of Alberta researcher David Pierce and his colleagues have found that giving young rats the rodent equivalent of low-calorie foods affected their ability to learn how to associate the amount of energy in food with its taste. It seems that artifical sweeteners can fool the brain into assuming that all sweet things are equivalently low in calories, which can trigger over-eating when other non-diet foods are consumed. In the present experiments the age of the animals also seemed to be critical, because adolescent rats were not affected, possibly because they had already established the relationship between tastes and calories. "One thing is clear at this point," says Pierce, "our research has shown that young animals can be made to overeat when low-calorie foods and drinks are given to them on a daily basis, and this subverts their bodies' energy-balance systems." The results also fit with other recent findings including a University of Massachusetts study which showed links between diet drink consumption (amongst children) and obesity, diabetes and heart disease. "Diet foods are probably not a good idea for growing youngsters," Pierce cautions.

12th Aug 2007

Perseids Meteor Shower

If you happen to look up tonight you ahould be in for some cosmic fireworks. It is the peak of the Perseid Meteor Shower tonight and it is a new moon so the sky should be very dark so the meteors stand out really well, teh best conditions for the next 15 years in fact.

The Perseids are so called because they appear to be coming out of the constellation Perseus and occur at about this time most years. They are the dust and debris left from the comet Swift-Tuttle as it orbits the sun. The densest region of which that we are passing though tonight dates from 1862.

The perseid meteors are small lumps of dust or rock that hit the earth at 132 000mph. This means that they heat up immensely as they tear into the atmosphere, in a similar way to how your hands heat up when you rub them together.. They heat up to several thousand degrees celcius so hot that they glow white hot, creating a shooting star.

Although not as intense as tonight the perseids should carry on for the next couple of weeks, so find yourself somewhere away from the lights, lie down and look for the shooting stars.

12th Aug 2007

Wave goodbye to the reefs.

We often hear about coral reefs being the rainforests of the sea – both habitats are packed full of thousands of species and sadly both are being lost at ever more alarming rates.

And this week we’ve heard a piece of really bad news for coral reefs, because they may be disappearing much more quickly than we thought they were, and possibly around twice as fast as rainforests.

That’s according to a new study from John Bruno and Elizabeth Selig at the University of North Carolina in the United States.

They collected together over six thousand other studies going back to 1968 that documented how much hard coral was growing on particular coral reefs in the Indian and Pacific Oceans, in countries including Indonesia, Australia and the Philippines.

Hard corals are the building blocks of reefs – also known as scleractinia – they provide the main structure and habitat for all the other animals and plants to live on.  Measuring the percentage of the reef that hard corals cover is one of the best ways of gauging how healthy a reef is. [It’s a little bit like measuring how much canopy a rainforest has from either air born or satellite images, which is how scientists measure how quickly forests are being lost.]

The bad news is that the coral cover on reefs in the Indian and Pacific Oceans over the last 20 years has dropped by an average of 1% every year which might not sound a lot but it’s the equivalent of around fifteen hundred square kms every year.

The study also discovered that reefs in the Indian and Pacific oceans also began declining much earlier than we used to think – it was always thought that reefs on the other side of the planet in the Caribbean were in the worst state, but now it seems the Indo-Pacific is also fairing just as badly.

The cause of these declines could be a combination of global factors, like increased sea surface temperatures that trigger devastating bouts of coral bleaching, as well as more local pressures like damaging fishing techniques and the run off of sediments and pollutants from land.

But it’s not all doom and gloom. The researchers found that a number of reefs have in fact been increasing in coral cover, showing that it’s not too late, especially if we start taking direct action to stop the decline continuing at all these different levels from local to global.

Protecting reefs makes nothing but good sense.  Not only do the reefs of the Indo-Pacific contain huge numbers of species, the reefs also provide a crucial source of protein for people in many developing countries, they help protect coastlines from erosion and the generate important income in countries with burgeoning tourism industries.

12th Aug 2007

Nuclear Space Screw Tackles NEOs

Although space scientists are confident that they have mapped the majority of "near Earth objects" that could conceiveably collide with us, and found that we're safe for now, there's always the possiblity that something unexpected might happen. Like the asteroid Apophis, which will slip past the Earth in 2029, and then make a return visit in 2036. If it alters its course there is a remote one in forty-five thousand chance that it could hit us.

Thankfully, University of Rome La Sapienza researcher Daniele Fargion has come up with a new strategy to tackle the problem head on - a nuclear powered rocket drill which burrows into the object and hurls the rock it digs out into space, pushing the asteroid off its Earth-bound course. This is an application of Newton'sThird Law - for every action there is an equal and opposite reaction. Flinging the drilled-out debris into space will give the object a kick in the other direction. Fargion's calculations show that over a ten year period this could deflect a 1 kilometre asteroid by upto 30,000 kilometres, enough to miss the Earth. But it's not all plain sailing. Asteroids are often loose aggregations of rocks and debris, which may prove difficult to drill into. Another problem is that they are also very often spinning, so the system would have to be programmed to spit out rocks only when the asteroid was pointing in the right direction. Undeterred, however, Fargion proposes testing the idea on our own moon, where his "screw rockets" could help to dig out underground shelters for future human use.

12th Aug 2007

Bye bye River Dolphin?

I don’t mean to be the harbinger of bad news – but it happens this week we’ve had another piece of important but incredibly depressing news from the aquatic world.

It looks like we might have to wave goodbye to the Yangtze river dolphin in China. Researchers from Zoology Society of London (ZSL) reported that during a two month expedition along the Yangtze river they found absolutely no trace of these dolphin.

The researchers have pointed the finger of blame at unregulated fisheries that accidentally caught the river dolphins, as well as the construction of dams and collisions with the huge amount of boat traffic that now ply the waters of the Yangtze river.  They proclaimed this as could be the first cetacean to be driven extinct at the hand of mankind and the first extinction of a large vertebrate for over fifty years – so it’s the first time a large, charismatic creature has disappeared from the planet that most of us will remember.

Facts about the Yangtze river dolphin:

• It was the only remaining member of an entire branch of the evolutionary tree, called the Lipotidae, a group of mammals that separated from other marine mammals around 40-20 million years ago.
• If any Yangtze river dolphins had been found during ZSL’s expedition, they would have been taken to an oxbow lake to begin a captive rearing programme.
• The Yangtze river dolphin had a long narrow beak which it used to feed on fish.
• The Yangtze river dolphin was top of the list on ZSL’s EDGE programme, which stands for “Evolutionarily Distinct and Globally Endangered species” – the world’s mammals were ranked in terms of how distantly related each one is to it’s nearest neighbour and how engendered they are.
• The extinction of the Yangtze river dolphin highlights the threats faced by other rare and endangered species in the river ecosystem which includes endangered freshwater porpoises, giant salamanders and Siberian cranes.

12th Aug 2007

Why Does Bubble Bath Change Colour

We were asked why it is that Mr Matey bubble bath changes colour when you mix it with water. We did an experiment to find out, and you could find out too!

What you need

What to Do

What may Happen

The bubble bath changes colour to blue in both hot and cold water so that can't be making the difference.

If you add bicarbonate of soda solution the bubble bath will change colour to blue - possibly an even deeper blue than with just water. If you add vinegar though it doesn't change colour at all and will stay orange. If you then add enough bicarbonate of soda you can make it go blue again (and make lots of bubbles).

What is going on?

The bubble bath has a dye in it called Bromocresol Green which is a pH indicator, it will change colour as you change the pH - how acid or alkali the solution is.  (Interestingly the one colour it never goes is green!)

Acids react with water to form H⁺ ions  (a hydrogen atom with it's electron missing - it actually sticks to a water molecule forming H₃O⁺) which are very reactive and are the reason that acids will react with so many things.  A pH indicator is just a molecule that will temporarily react with H⁺ ions and change colour, but if the H⁺ ions disappear it will change back.

pH is just a measure of how many H⁺ ions there are in a litre of water (although a strange measure because a low concentration of H⁺ is a high pH and vice versa).

So as you dilute the bubble bath, which starts off slightly acid, the same number of H⁺ ions are spread around through more water and they become less concentrated.  The pH then gets higher and the water becomes more alkaline, making the Bromocresol Green change from orange to blue.

Scientific Springfield - The Science of the Simpsons

Michael Hopkin: If you are looking for science on TV, you probably would not turn to a show about a dysfunctional cartoon family whose main intellectual thinker is an 8-year-old girl, but if you look closely, The Simpsons' is one of the most scientifically literate shows around and that is perhaps unsurprising given the fact that the shows head writer, Al Jean studied mathematics at Harvard. I asked him whether there are any parallels between cartoons and maths.

Al Jean: I look at comedy writing mathematically. You know it started like a proof for you trying to find the ideal punch line for a setup and when you get it, it is a very elegant feeling and it is a little like a feeling of completing a proof when I was doing math in college.

Michael Hopkin: And he is not alone, in fact, most of the established writers on this show have a scientific pedigree and it is a pretty impressive roll call.

Al Jean: Yes, Ken Keeler who wrote for The Simpsons and Futurama has a mathematical Ph.D., Bill Odenkirk who writes for The Simpsons has a Ph.D. in chemistry, George Meyer a long time Simpsons writer, I cannot remember what his major was, but it was definitely in the sciences and Stewart Burns another Simpsons and Futurama writer had maths degree, and you know when we are alone, you know, we sort of talk about math, but again we have learnt that there is a wider world and we do not always like, expose others to it. We do it in a subtle way.

Excerpt from The Simpsons:  "I know. Well, this perpetual motion machine she made today is a joke. It just keeps going faster and faster. Lisa, get in here. In this house, we obey the laws of thermodynamics."

Michael Hopkin: There is also a scientific theme running through the new movie alongside typical Simpsons' absurdities such as Homer falling in love with a pig. The plot also features the looming threat of climate change prompting Lisa to present an Al Gore-style lecture entitled 'an irritating truth'. In fact, throughout the shows 400-episode history, it has often fallen to Lisa to speak up for scientific rationalism, perhaps most notably in the episode in which she attacks Springfield's decision to abandon the teaching of evolution. It made me wonder whether the writers have a specifically pro-science agenda.

Al Jean: Our general agenda is to display both sides of an issue and to let the viewer make up his or her own mind. In that particular case, I believe evolution is so scientifically well founded that it is hard to have any sort of intelligent alternative joy.

Excerpt from The Simpsons:  "Creationism, but that is not science."

"It is now. This helpful video will evade all your questions. Eyes screenward."

"So, you are calling god a liar an unbiased comparison of evolution and creationism. Let's say hi to two books; one a bible was written by our lord. The other, the origin of species was written by a cowardly drunk named Charles Darwin,"

"This is slander. Darwin was one of the greatest minds of all time!"

"Then, why is he making out with Satan?"

Michael Hopkin: Of course, The Simpsons also has fun with scientists' social image especially in the case of the painfully awkward professor Frink, who one suspects would trade in all of his inventions such as the sarcasm detector, the frog exaggerator, and mood pants for the chance just to get a girlfriend, but more seriously and as someone who has spent time in the scientific community, Al Jean worries about the negative portrayal of science and scientists in much of the mainstream media.

Al Jean: Well, it is sad because, you know, in my life I have seen science viewed as sort of the saviour for everything and it has almost come full circle, you know, because nothing can completely solve everybody's problems, the disappointment when that happens is extreme and now people are, you know, casting scientists as villains or, you know, not listening to them, which I think is tragic, you know, 50 years ago, Albert Einstein was the epitome of scientists among the public and regarded as a hero and there is not anybody comparable today and I think it shows how science has, you know, have been made to appear in a, you know, more ambiguous way.

Michael Hopkin: That is not to say that contemporary scientists have not appeared on the show. Over the years, The Simpsons has featured scientific luminary such as Stephen Jay Gould and Stephen Hawking and the writers have not been afraid to give them scripts that delve into the relevant subject matter.

Al Jean: There is nothing, you know, purer than mathematics of all the things I have ever studied.  People seem really thrilled that we have had Stephen Hawking on the show and no one could be more thrilled than I.

Excerpt from The Simpsons:  "Oh! Stephen Hawking!"

"The world's smartest man."

"What are you doing here?"

"I wanted to see your Utopia, but now I see it is more of a Fruitopia."

"I am sure what Dr. Hawking means..."

"Silence I don't need anyone to talk for me, except this voice box. You have clearly been corrupted by power. For shame"

"Larry Flynt is right! You guys stink!"

"I don't know which is the bigger disappointment, my failure to formulate a unified field theory or you."

Michael Hopkin: So, if you worry about science getting a bad reputation on TV, you can take solace in the fact that Springfield at least is on your side. That is assuming of course that you think science is worth caring about. 

Excerpt from The Simpsons:

"Science! What has science ever done for us? TV off"

August 2007

"Whats Science Ever Done for Us?" What the Simpsons Can Teach Us About Physics, Robots, Life and the Universe

Chris -   “What’s Science ever done for us” is also the title of a new book that’s out at the moment. It’s been written by Professor Paul Halpern, he’s from the University of Philadelphia. He joins us now. Hello Paul.

Paul -   Hello Chris.

Chris -   Thank you for joining us on the naked scientists to tell us about your book. Why have u written this? And don’t say to make money because that was Boris Johnson’s answer on Radio 2 the other day.

Paul -   Well I noticed throughout the years that the Simpson’s features marvellous Scientific references on the show and features scientific guests and many illusions to people such as Neil spore, Einstein, Darwin and Newton…I thought it was about time to look at the Simpson’s episodes and explore the real science behind the series.

Chris -   Well, few people have the sort of insight into how you’ve done this,  it’s nice this because you get a taste of the Simpson’s upfront and then you get how it’s relevant to science in the second part of the chapter.

Paul -   That’s right in each chapter I look at how an episode of the Simpson’s handles the science then I look at the background behind it. For example, in one episode Lisa invents her own perpetual motion machine and Homer gets obsessed by it and shouts at her: “Lisa, in this house we obey the laws of thermodynamics.” So I take off from that episode into an exploration of whether or not perpetual motion is possible and I explore the laws of thermodynamics. So I find it provides a great intro into some interesting science.

Chris -   Now, how does the Simpson’s sit with you as a professional physicist engaged in research in a US university?

Paul -   Well, physicists that watch televisions tend to enjoy series like the Simpson’s because it’s one of the few series, it’s not the only series, to have scientific references on the show and it does a number of fun and very sophisticated things with science. For example, exploring higher dimensions, looking into the possibility of time travel, bringing up genetics, robots, artificial intelligence… it’s just amazing how much interesting science there is in the show.

Chris -   I thought it was hilarious when Homer Simpson managed to end up crossing a tomato and tobacco plant to make an addictive form of a tomato

Paul -   That’s right it’s called Tomacco and the interesting thing is he uses plutonium to make this hybrid

Chris -   And he gets it where..?

Paul -   [laughs] He manages to get it shipped in from his nuclear plant, it’s no problem for him since he works in this plant so he just manages to phone up his friend and get some plutonium shipped into his farm that he’s trying to grow crops on. He grows this tomacco and produces this tomacco plant, which is highly addictive.

Helen -   I don’t know if this is in your book but one of my favourite bits in one of the shows is when they discover that Homer, as a young child, pushed a crayon up his nose and into his brain and that’s why he’s… ‘Homer’ shall we say. They take it out and he becomes very intelligent and then they decide in the end to put it back again. Do you think, is there any reality in having a pencil in your brain and changing your behaviour?

Paul -   Well it’s interesting. The Simpson’s brings up a number of theories throughout the years on why Homer is so different than the people in his family, for example Lisa, who is much brighter and in one episode they attribute it to genetics. Then, in the episode called ‘Homer’ which is a parody of Flowers for Algernon, they suggest it’s an accident that Homer had as a child where he had the crayon lodged in his brain and that it affected his intelligence, but the strange thing is once they pull out the crayon he’s very unhappy. He preferred being not so bright

Chris -   I think that goes for a lot of people in some cases though doesn’t it? I mean, not that everyone would have a crayon jammed up their brain but some people find that ignorance is bliss don’t they?

Paul -   That’s right sometimes u can know too much about a subject and you might not be happy about it, you’ll be well informed but perhaps not particularly happy about if say you know that something dyer is going to happen

Chris -   Well Paul, I have to say I thoroughly enjoyed your book. It had me sniggering at midnight last night so thank u for sending us a copy. Thank you for joining us on the Naked Scientists to tell us about it. It’s out now is that right?

Paul -   That’s right. Yes. Thank you very much. It’s my pleasure.

Chris -   It’s been a pleasure to have you on the programme. Thank you

Paul -   Bye

Chris -   That’s Professor Paul Halpen. He’s written a book called “What’s Science ever done for us”. It’s all about how the Simpson’s, as we’ve been exploring, actually has its firm roots in science and you can get it in all good bookshops right now.

August 2007