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Podcast TranscriptThe Naked Scientists: Science Radio & Science Podcasts |
| 2nd Nov 2003 | < Previous Show | Next Show > | ||||||
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How Many Plants To The Gallon ?
An American ecologist has calculated how much prehistoric plant and animal matter has gone into each gallon of petrol that we burn today. According to Jeff Dukes, from the University of Utah, a staggering 98 tons of prehistoric plant material (about the equivalent of 40 acres worth of wheat - stalks, roots and all) is required to produce each gallon of petrol. “Every day, people are using the fossil fuel equivalent of all the plant matter that grows on land and in the oceans over the course of a whole year”. And the amount of plants that went into the fossil fuels we burned since the Industrial Revolution began [in 1751] is equal to all the plants grown on Earth over 13,000 years”.
2nd Nov 2003
Cone Snails Under Threat
We may have become immune to the cries from environmentalists urging us to "save the rainforests" but scientists are now warning of serious consequences for medical research in the future unless we halt the destruction of natural habitats. Researchers working on tropical cone snails have found that these slimy hunters produce an enormous range of toxins which they use to kill their prey, like fish and worms. Each species of snail can make around 100 different toxic chemicals, adding upto around 50,000 toxins in total from all snail species. The scientists reckon these chemical could provide an amazing source of new drugs and have already found useful activity in a few- including a possible anti-epileptic drug and a medicine to treat lung cancer. These chemicals could also be used to treat strokes, head injuries, depression, heart problems and even incontinence, as well as being powerful painkillers. But the shallow tropical seas where the snails live are under threat from fishing, pollution, disease, housing and even global climate change. The snails are also taken for their beautiful shells. Unless the exploitation of the snails and their home is stopped, we may lose hundreds of drugs which could help future generations. 
2nd Nov 2003
Our Poles Are Melting
There’s grim news this week for the north and south poles… both of which are melting. In the north, Polar bears face an uncertain future as longer summers are causing thinning of the sea ice on which they rely for hunting seals. Scientists have used satellites to measure the sea ice thickness, revealing that the ice is 40% thinner than is was 40 years ago. The loss of ice could also speed up global warming, as less of the sun’s heat is reflected back into space by the ice. And down south, a giant ice shelf the size of Scotland is melting rapidly in warm Antarctic waters, according to research led by Scientists from the Scott Polar Research Institute in Cambridge. You may have heard of the Larson B - a floating ice shelf that fringes the east coast of the Antarctic peninsular -when a vast chunk of it collapsed off last year, well, now research has shown that it over the past few decades it’s been drastically thinning. The findings suggest that Antarctica may be more sensitive to the effects of global warming than was previously considered. And there are far-reaching implications of Larsen B melting… apparently the release of freshwater from it is more than 8 times the annual outflow from the River Thames, enough to potentially cause disturbance in patterns of global ocean circulation. There of course remains a great deal of uncertainly surrounding global climate change and scientific modelling of all the processes involved but whatever the implications, these are two convincing examples that some things are certainly changing.
2nd Nov 2003
Lefties Have Been With Us For Thousands of Years
Researchers studying 30,000 year old cave art left behind by our ancestors have made an interesting observation – that the proportion of left handers amongst the artists is the same as it is today – just over 20%. Charlotte Faurie and Michel Raymond and the University of Montpellier studied over 500 hand prints left on the walls of 26 caves in France and Spain. The prints were made by blowing paint from a pipe at a hand pressed against the cave wall. 25% of the impressions were of a right hand, indicating that the artist must have used their left hand to steady and aim the blowpipe. Left handedness seems to have a genetic basis [compared with a child born to right handed parents, a child born to one left handed parent is about 2x as likely to be left handed, and 2.75x as likely if both parents are left handed] but we still don’t understand why left handedness has remained so common and so stable for such a long time. One suggestion is that because left handedness is uncommon it gives individuals advantages over right-handers under certain situations like fighting.
2nd Nov 2003
Right Flippered Walruses
News last week was released that Walruses are right handed or should I say flippered, and prefer to use them to forage for clams on the sea bed. Apparently the bones in the walrus’ right limb are longer than the left, just like we see in right handed people. This adds walrus’ to the growing list of animals that seem to have a preference of using one hand or flipper, over the other, which includes Chimps, monkeys and crows. Apparently even humpback whales use either the right or left side of their jaw when snatching prey and habour seals use their right flipper to beat the sand and scare out of hiding the sand eels that they like to eat.
2nd Nov 2003
Vibrating Insoles To Help Wobbly Grannies
As people get older, they get a bit wobblier on their feet, especially if they have had a stroke or suffer from diabetes. This can cause accidents like falls, which in the brittle-boned elderly can be serious and disabling. Scientists have now developed vibrating insoles, which dramatically reduce wobbliness in both young and old people, at least when they’re just standing still. The reason it works is quite complex, but basically we constantly adjust our bodies to make sure we stay upright, like balancing a pole on one finger. This process uses lots of tiny muscles and nerves, which are always reporting back and adjusting. But as we get older, it gets harder to activate these nerves so this feedback gets a bit blurred and balance is affected. The vibrating shoes are thought to add a level of background noise to the balance nerves- contrary to what you might think, in the nervous system noise actually helps real signals to get through more clearly. This amplifies the signal from the nerves, making it easier to send the messages to the muscles to adjust balance. It remains to be seen whether the new shoes can cut down on wobbles when walking, or prevent falls but the scientists are hopeful for a steadier future.
2nd Nov 2003
Mobile Phone Health Risk Debate
Mobile phones give off electromagnetic radiation. Although these radiation fields are quite weak, we use our phones a lot so we have a high level of exposure. In Finland, 80% of people have a mobile, so researchers looked into the health risks, testing the effects of phone radiation on cultured cells and small animals. The phone waves appeared to stress the cell cultures, but didn't increase the likelihood of cancer in animals. But in combination with other nasties like UV light, there may be cumulative effects. When they tested phone radiation on peoples' brains they found an effect on the electrical activity of the brain, but this didn't affect brain function. The scientists are now trying to find out nexactly how much radiation we really receive from our mobiles, and how much it can penetrate into our brains and bones. In the meantime, it's best to limit your exposure- but that's probably not what the phone-mad world wants to hear.
2nd Nov 2003
American Scientists Find Napthalene Eating Bugs
Scientists in America announced this week that they have found a strain of bacteria that might help to clean up toxic residues from old industrial sites. Polaromonas naphthalenivorans can break down napthalene in coal tar contamination. Although naphthalene is not the most toxic component in coal tar, the microbiologists say their discovery might eventually help to speed the cleanup of hundreds of 19th and 20th century gasworks throughout the United States where the manufacture of gas from coal for homes and street lighting left a toxic legacy in the ground. Previously microbiologists had discovered a bacterium (Dehalococcoides ethenogenes) that biodegrades the industrial cleaning compound trichlorethylene (TCE). Billions of D. ethenogenes microbes are now at work at a New Jersey Superfund site and other TCE-polluted locations.
2nd Nov 2003
Reseachers Discover How Baby Dolphins Keep Up
Young dolphins swim alongside their mothers in the open sea for up to 3 years, but it has always been a mystery how they manage to keep up. It turns out that the young calves use much the same trick that cyclists use on the Tour de France – they exploit their mother’s slipstream to help pull them along. Israeli aerospace engineer Daniel Weihs studied dolphins at the US National Marine Fishery and found that young dolphins swim about 30 centimetres away from their mothers body. As the larger dolphin swims she pushes a wave of water out of the way around her which also flows around the calf reducing the amount of work it has to do by 65%. The pressure difference created as the water is deflected around the mother and calf also pushes the 2 animals tightly together. It’s in fact so strong that some female dolphins have been known to poach other mothers calves by swimming past rapidly and sucking the babies towards themselves !
2nd Nov 2003
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