Hungry Snakes Have Huge Hearts

To help snakes cope with enormous meals, scientists at the University of California have found that the heart of a python expands by 50%. And it's all thanks to a special protein that expands heart muscles. Snakes are well known for eating huge but irregular meals that keep them going for weeks. Scientists kept four Burmese pythons hungry for a month before giving them a tasty rat dinner that came to a quarter of their own body weight. They found that the snake's heart became flooded with a protein called heavy-chain myosin. This increases the size of the heart muscle and allows snakes to pump much more blood to the digestive system. They also get a 400 times increase in their metabolic rate while they break down the meal. Human hearts also have this protein, but it would take years of intense exercise to increase our heart size by that much. Snakes can do it in just two days.

6th Mar 2005

Smile Without a Cary in The World

Japanese researchers have developed a new filling material that does away with the dental drill by latching onto damaged tooth surfaces and integrating itself seamlessly into the tooth structure, producing an invisible mend. Decay occurs when acid produced by mouth-bacteria eats into the enamel surfaces of teeth, producing small pits. Dentists currently have to enlarge the hole, drilling away healthy tooth material, in order to provide an anchor for the filling material because it does not adhere perfectly to the enamel surface.
But the new material is a paste made of hydroxyapatite - a form of calcium phosphate - exactly the same substance that makes up the enamel itself. When the paste is added to a damaged tooth, within minutes, it seals off the affected area and bonds seamlessly to the tooth surface. Viewed under a microscope the repair is invisible. The researchers suggest that because the paste is quite acidic it initially dissolves some of the native tooth enamel, before forming new crystals which lock themselves into the tooth surface in a smooth, homogeneous layer. The results not only repair decayed teeth but can also strengthen them, preventing the problem from recurring.

6th Mar 2005

Nasa Scientists Thaw Out 30,000 Year-old Bugs

NASA scientists working on samples of Alaskan permafrost have discovered a new form of life that has been frozen in time for over 30,000 years. When the scientists thawed the ice under a microscope the newly-identified organisms, bacteria christened Carnobacterium pleistocenium, showed signs of life and began swimming around. The bugs, which date back to an era when mammoths and sabre-toothed tigers roamed the earth, were collected from a tunnel drilled through the ice near the town of Fox. Richard Hoover, who made the discovery, says that the findings raise the prospects of finding life on Mars because the bacteria were extracted from half-metre thick wedges of ice similar to structures seen on the red planet. Indeed, the Mars Express probe has recently revealed the presence of a giant frozen sea near the Martian equator, which could provide the ideal conditions for microbial activity.

6th Mar 2005

How a Calculator Works

Philippa Law interviews Dr Julian Allwood & Dr Lucy Green

Philippa - This week, I'm going to find out how a calculator works. The first thing I want to find out is how it turns on in the first place. Dr Lucy Green from Cardiff University.

Lucy - When you put a calculator into the sun, the sunlight will fall onto a special solar panel. There are photons in the sunlight that hit the material in the solar panel and knock electrons out. Those electrons are now free to move about and they form a current. So it's a way of getting sunlight and changing it into electricity to power the calculator.

Philippa - What's Einstein got to do with all this?

Lucy - Einstein was the person who allowed us to understand the photoelectric effect. He was the person who proposed that light isn't made of a wave but is made of small packets of energy. This was absolutely revolutionary and changed everyone's views about light. So instead of thinking about it as a continuous wave, now we can also think about it as tiny packets of energy called photons. Most things we see behave as we see them behave. The table I'm sitting at is just a table, and always will be a table. With light, it depends on the situation it is in as to the form it is in. It took a great mind like Einstein to be able to understand it.

Philippa - It sounds like solar panels are the perfect solution to everything. How come we don't get solar powered televisions and hair-dryers?

Lucy - Solar energy is fantastic and is a clean source of energy, but the only problem is that solar panels don't generate very much electricity. So it's alright for something like a calculator. A solar panel about the size of my thumb will generate about 50 milliwatts. If you think of a 50 Watt light bulb, you would need about 1000 solar panels the size of my thumb just to get one light bulb shining. So they don't generate much electricity and they can be very expensive.

Philippa - So far so good: we've managed to switch the calculator on. How on earth does it work sums out? Dr Julian Allwood from Cambridge University.

Julian - That is a big question! The one thing a computer or a calculator can do is very simple: if you hold up two fingers, it can tell you whether there are two fingers there (in which case it says yes), or if you hold up more fingers or no fingers, it will say no. That in the end is all a computer can do. There's one variant in which the same question can be answered yes if any of the fingers are up. Those are the two operations which are at the heart of all computers. From that you can build up logic that will allow you to do addition and then multiplication and more difficult calculations.

Philippa - How does a calculator work out two plus two?

Julian - A calculator would represent two plus two as the binary numbers one - zero plus one-zero. Computers work only in binary. You can prove that it's faster for them to work only in zero and one rather than a wider scale of numbers. A computer would know that two was one-zero (10) and your other two was one-zero. Adding the first two digits, you've got zero plus zero. Its transistors would be able to say that that was zero and hold no fingers up. The next digits would be one plus one, and it would recognise that both of those were positive and both fingers were up. In that case, it would raise one finger in reply, which would lead to one digit being raised in the third part of the answer. So in binary, the answer to your question one-zero plus one-zero would equal one - zero-zero (100), which is four.

Example: The number 732 means 7 hundreds, 3 tens and 2 units. In the binary number system, there are only the numbers 0 and 1 to play with. Rather than working in units, tens and hundreds, it uses units, twos, fours, eights, sixteens, etc.

0 in binary is 0
1 in binary is 1
2 in binary is 10
3 in binary is 11
4 in binary is 100
5 in binary is 101

So, 10 (one-zero)
+ 10 (one-zero)
= 100 (one-zero-zero)

Because 0 + 0 = 0, and 1 + 1 = 10 in binary. So 10 + 10 (2+2) = 100 (4)

Philippa - So now the calculator has done the sum, how does it tell us that the answer is 4?

Julian - We still have the problem that all the calculator knows how to do are ones and zeros. Unfortunately people don't usually speak binary when doing their shopping! So it has to have a display that converts that number into something that you're familiar with. If you look carefully at the numbers on the display of a calculator, you'll see that the numbers are actually made up of a number of short lines. So the display is made up of a set of things that are also 'on' or 'off'. The calculator therefore has another calculation that says one-zero-zero (100) means four to a human, or that one-zero-zero means a number of lines turned on in the display.

March 2005

Hypnotism

Dr Peter Naish from the Open University and Dr Tannis Laidlaw from Imperial College London

Peter - Like many of the listeners, I was and still am intrigued by hypnosis. You imagine people being taken over in some weird and wonderful way. I am a psychologist and so was lucky enough to be able to go into research in this area. As with so many areas of science, I found that the truth was even more intriguing! As far as applications go, I'm interested in using it with phobias, its impact on memory and generally how hypnosis works.

Tannis - I look at mind-body types of medicine. I'm interested in people thinking about hypnosis and illness and the type of things that hypnosis can help with.

Chris - What's actually going on in the brain when someone undergoes hypnosis?

Peter - I want to begin by saying that some of my colleagues might give a slightly different story. It's still not absolutely proved what's going on. Scans have shown that something is going on in the brain, but it doesn't actually prove that there is some special sort of altered state there. Personally I think that there is something altered. One of our cleverest faculties as humans is to imagine. You can use it plan things and answer 'what if' questions. Some of the structures you use when you are imagining things must be the same as if it were happening for real. One of the abilities to go with imagining is the ability to know that you are only imagining it despite the same parts of the brain being active. So there's another bit of brain involved. It's right at the front of the brain where the two hemispheres fold together. It is known that people who have brain damage there have problems distinguishing between things they have just thought about from things that really did take place. We all do it sometimes, such as when we think 'have I locked the car or did I just mean to do it'? However, these poor people are trapped in this scenario all the time.

Brain scanning has shown that different parts of the brain get switched on or switched off during hypnosis depending on the task they're doing. Everyone who ever looks at brain activity during hypnosis always says that the anterior singlet gyrus is involved: this is the bit that I'm talking about. It is tempting to assume that what it is to be hypnotised is to be inventing your own reality but turning down the reality controls. This makes it seem real.

Chris - It therefore seems counterintuitive that you can hypnotise yourself, as you must realise that it's not real.

Peter - This leads quite nicely to the fact that people are in control when they are hypnotised. It is true that all hypnosis is self-hypnosis and the hypnotist is just there to guide the person along. The person being hypnotised has a hold on it at all times. Maybe losing a hold on it is what it is to be psychotic: schizophrenic hallucinations etc.

Helen - How much do we know about dreaming in relation to hypnosis? Dreaming is like being in another state and sometimes people can realise they're in a dream and control what happens next.

Tannis - That's called lucid dreaming. With hypnosis you don't go to sleep but go into a trance-like state that you are fully aware of. It's very rare for people not to remember everything that's happened. If you ask someone to have a dream, usually they will have a dream that they will remember and be able to control. In my experience, the people that have been able to do that with hypnosis have been able to do it again later. I would think that what they're doing is putting themselves into a self-hypnosis state and just recreating the kind of state they were in before. They can then have some control over their dreams.

March 2005

	Macrophages can clean up debris in the lungs. One of your guests the other week said that these phages can help the spread of lung cancer. How can this be? Ian
	That's a very good question. Macrophage literally means 'big eater' and are giant cells that do everything you might imagine a white blood cell would do. They have long rippling membranes that they extend like feet. When the find something that they want to eat, they extend these feet around the substance, engulf it and excrete lots of digestive chemicals into the substance and break it down. When we breathe in, we inhale millions of tiny particles of dust, chemicals and other substances. As they travel towards our lungs, they form a type of whirlwind and get stuck on a sticky layer of mucus on the edge of our windpipe. There are also lots of tiny hairs on the edge of our windpipe, which beat continuously and waft the mucus back upwards. Some particles obviously get trapped or go further in than normal. The macrophages act like hoovers and try to clean these up. However, sometimes the macrophages get a bit frustrated when they can't break them down, and so the particles get added back into the mucus to be either spat out or swallowed. It is interesting to note that people who smoke not only have higher rates of lung cancer, but also bowel cancer. It isn't immediately obvious why this is, but it's due to many of the particles being swallowed instead of spat out.
	March 2005

	How does a white LED work? Peter
	An LED is a Light Emitting Diode, and is a semi-conductor device which will glow if you pass a current through it. A semi-conductor is a material which in it's natural state won't conduct electricity well, but if you add tiny quantities of other materials it will conduct quite well. Normally each atom in the semi-conductor has 4 electrons and there are none free, but if you add a few atoms with 5 electrons there are some extra electrons which can move easily and carry a current (an N-type semi-conductor). Similarly if you add some atoms with only 3 electrons and then you get some gaps which other electrons can move into (a P-type semi-conductor). The electrons can now move a bit like the tiles in a sliding tile puzzle, but it is easier to think of a positively charged hole moving through the semiconductor.   N-type with a few extra electrons to carry current P-type which has a few electrons missing which can be thought of as positively charged 'holes' and can carry current.   .A diode is made if you join a lump of P-type semi-conductor to a lump of N-type. If you make the N-type region negative and the P-type positive, electrons and holes will move towards the junction and there are plenty of charge carriers there and a current can flow. But if you make the N-type region positive and the P-type negative then electrons and holes will be pulled away from the junction leaving the junction with nothing to carry current, so it becomes insulating and a no current can flow. Electrons and holes are pushed towards the junction so a current can flow. Electrons and holes are pulled away from the junction leaving it insulating. So what has this got to do with LEDs? if a current is flowing through the diode, you will get both electrons and holes in the same part of semi-conductor, this means that they can meet. When they do the electron can fill in the hole, releasing some energy, In an LED this is in the form of light.   The energy and therefore the colour of this light is fixed by the type of semi-conductor you are using, so normally it is all one colour, this is why LEDs are traditionally coloured. In fact it is much easier to make LEDs at the red end of the spectrum than the blue which is why blue LEDs have only recently become common. White light is of course  a mixture of colours and if you were to use LEDs on their own you would need 3 LEDs to make white light. Manufacturers have a cunning way around this problem, they use phosphors, these convert high energy blue light into lower energy colours such as red, yellow and green. So  by covering your LED with phosphors a blue LED can appear white.   Phosphors in the LED absorb blue/violet light and emit it as various different colours making  white light © Dave Ansell A white LED in action
	February 2008

	I was hypnotised and thought I was a Dutch girl from 1815. Was this my former life? Paul
	The thing about the hypnotised mind, like any other mind, is that nature abhors a vacuum. If you take someone back to before they were born and then say, 'who are you?' one answer might be 'I'm no-one because I haven't been born yet'. However, the nature of the question itself implies that there is an answer. The brain is very fertile and this is the reason why police don't use hypnotism to obtain details from witnesses. Asking someone about a robbery and the car number plate is fraught with danger. People think they are answering truthfully but have in fact constructed a story from lots of things in their brains. I could tell you a story about being a Dutch girl but it doesn't mean I ever was. By turning off the reality centre in the brain, your threshold for telling that what you are saying is nonsense is reduced. Another analogy that might be helpful for memories in general is to think of islands poking through a lake. Occasionally as memories fade, it is as if an island has subsided a bit. With a little judicious lowering of the lake level, maybe you could get them to poke through. If you do that in any big way, you get irregularities from the bottom of the lake that never were genuine memories. As they start poking through people think they are remembering something even though it's totally fictitious. Unfortunately, there's no way of telling the difference.
	March 2005

	I really need to give up smoking but I just can't seem to do it. I have chronic pain after an operation, chronic bronchitis and my health is deteriorating, but I get depressed when I give up. Smoking to me is very much like a crutch. Could hypnotism help me? Carol
	I've taken a lot of people off cigarettes in my time. Using hypnosis to get rid of this nasty habit is quite effective in the short term. Usually people have to be fairly motivated, but I think with chronic bronchitis your motivation is probably rising. You have got this fear of getting rid of something that is giving you pleasure and so I suppose that is going to be something you will need to think about a great deal. However, using hypnosis can help with your motivation. I also just want to say something not related to hypnosis. There is a peak in desire when you want to have a cigarette. If you can look at your watch when you want a cigarette and wait for five minutes, you may find that after five minutes the peak of that desire has actually gone. You have then saved yourself one cigarette, and that has nothing to do with hypnosis. I don't recommend going longer than five minutes because there's something inside us that makes us feel deprived, thus making us want it even more. As for your chronic pain, hypnotism can help if you go to a properly qualified practitioner. You could find that it could help with smoking and pain. To find a hypnotherapist, go online and do a search for BSECH. They have a website with names of properly qualified practitioners.
	March 2005

	I went to a hypnotist to stop smoking in the early 1980s and it worked for about a year. I went away on holiday and bought a packet of cheap cigarettes and that got me back onto smoking. Would it help if I went to a hypnotist again? Christina
	The idea of being back on cigarettes just by smoking a bit is very common. I used to think that New Year celebrations were the most dangerous thing for recovering smokers because people have a few to drink and are in a smoky atmosphere. However, it is only one incident. You have proved that you can give up for a whole year and so I would have said that you should put that one cigarette behind you and start again. Slipping back into smoking is very common, but as you were so successful using hypnosis the first time, I would recommend that you try it again.
	March 2005

	What are the dangers of hypnosis? Would it help with my anxiety disorder? Ronald
	Hypnosis can help with anxiety, although sometimes the thought of going to a hypnotherapist can make them anxious. However, they have nothing to be nervous about if they go to a properly qualified person. Among professionals, we always say that someone shouldn't treat someone with hypnosis if they wouldn't be competent to treat it without hypnosis. With an anxiety problem, you would probably be thinking about going to see a psychologist. If that psychologist knows how to do hypnosis, he may think about using that as an additional tool. This can help with the effectiveness of the treatment normally given. There is nothing harmful about hypnosis in itself as long as you go to someone properly qualified.
	March 2005

	I was hypnotised when I was 25. I'm now 67 and I've smoked once in between. The session cost me £4 and was worth every penny! Brian
	That's great!
	March 2005

	Can hypnosis help tinnitus? It was brought on by two very stressful incidents. Tinnitus is when you get noises in the ears and head that you cannot get away from. It sounds like a loud electrical transformer hum and then it will alter to a loud fizz. Pauline
	Stress can definitely exacerbate tinnitus and I know because I have tinnitus myself. There is a lot that can be done with hypnosis to allay anxiety and stress reactions. It's definitely worth a try.
	March 2005

	I was hypnotised over 30 years ago and it cost me £5. At the time I was very angry with the hypnotist because I didn't feel like I'd been on another plane at all. The first thing I did when I walked out was have a cigarette! However, after that first cigarette I never had another one again. Hypnosis didn't meet with my expectations but it did seem to work. Joyce
	To my mind, the hypnotists missed out an important thing at the beginning. It's well worth telling people that hypnosis does not produce odd feelings. People can get up and open their eyes if they wanted. It does not do magical things.
	March 2005