After that, if there’s any time, we’ll have a brief look at a new theory of physics that may integrate gravity and quantum theory. Gosh. And, of course, steam cars.

I’ll be on air after the 11am news. If you don;t want to listen live, shortly after the programme, you’ll be able to get it as a podcast or just download the audio as ogg or mp3.

Read on for my speaking notes, or after the broadcast you’ll be able to download the audio as ogg or mp3.

Q: Stargazing! Are you talking about the bid for the new telescope which New Zealand and Australia are doing?

A: We’ll get to that, but what really caught my eye was Neptune.

Q: Neptune?

A: Yes, it’s up at the moment. Now, I’m not a stargazer – I’m impressed by a good starfield as much as the next person, but I’m certainly not an astronomer. And I knew that Neptune is the hardest to see of the planets – quick recap, Neptune is the furthest from the Sun of all the planets which makes it very hard to spot.

Q: What about Pluto?

A: Pluto is further again from the Sun than Neptune, most of the time anyway, but it really doesn’t behave like a regular planet. It goes the wrong way round the Sun, it dives inside Neptune’s orbit sometimes, and it’s very small. A few years ago some august international astronomical body reclassified it as a dwarf plant, whatever that means, so there are only eight regular planets, with Neptune as the furthest.

Q: How did you know Neptune was visible at all?

A: A friend with far better astronomical knowledge than mine pointed it out to me. There’s Jupiter, he said – and I knew that, Jupiter is a bright object low in the North East at the moment – and look, there’s Neptune next to it.

Q: How did you know he was right?

A: I checked it on my phone. I used Stellarium software on my iPhone, which showed me the night sky in the direction I was looking and helpfully labeled all the planets and stars.

Q: That’s an iPhone thing, then

A: Not really. I used to have an entirely different phone called the Palm Treo – the descendent of the Palm Pilot pocket computers people used to have – and that had a star map on it, which knew where you were and what the time was and showed you what you could see. And there are equivalent available for other phones and computers.

Q: So it’s like a Planetarium?

A: Really quite like that. When I was young, growing up near London, I’d occasionally get to the Planetarium at Baker Street. That was spectacular and taught me a lot about stars. It was a really dramatic way of presenting astronomy. Unfortunately its now been completely taken over by the Madam Tussauds gallery next door, which is owned by the Dubai government, and no longer has anything to do with astronomy. The use the dome for showing films about celebrities. Cynics might suggest that all films are about celebrities, by definition.

And in Wellington there always used to be a small planetarium connected tot eh Carter Observatory – actually, I remember it used to be downtown next to the public library but that was demolished in about 1990 and moved up the hill. Anyway, the one up at the Carter in Kelburn is currently closed, waiting for enough donations to refurbish it, or that’s what the website says.

Q: But you can get computer software to do this?

A: You can indeed. It’s not as immersive as projecting onto the inside of a large concrete dome, but it’s still pretty impressive. And if you are lucky enough to live somewhere where you can really see the stars, like the back blocks of New Zealand, and you have a fancy phone which shows you what you can see, you can have a wonderful experience stargazing on a moonless night. Stellarium software, as its called, can let you identify what you are looking at outside your window, or predict what you can see at some other time or place. It can tell you when some object will rise or set.

Q: This is astronomy, not astrology, right?

A: Absolutely. Astrology is about the notion that the stars visible at anyone time have an impact on life on Earth.

Q: Where did that come from?

A: Astrology has actually got a sound foundation. Don’t get me wrong – I’m not saying that horoscopes have any validity – they don’t. But if you want to see how a heavenly body influences life on Earth, just think about the tides for a moment. If you look at each zodiac constellation, it rises at a different time of year depending on where it is in the sky. And the zodiac constellations rise at times when, in the Babylonian era, it was relevant to do certain agricultural things. So, Taurus the bull is the symbol of fertility, who came in the spring. An effect called “precession of the equinoxes” has changed the Earth’s rotation over the years so that the constellations now rise later than the Babylonians would have seen them two and half thousand years ago, but the principle is the same.

Q: So that’s how any of us can look at stars – what about the big telescope that was in the news last week?

A: That’s the SKA, or square kilometre array. That’s a bid rather than a reality, but it will be quite a stunning telescope if gets built. It will comprise a large collection of dishes, many of them in the Western Australia desert, and some in New Zealand. That gives what’s called a baseline of 5,000 kilometres, which means that the telescope will have a very high resolution.

Q: This is a radio telescope, then?

A: Yes. It’s hard to get optical ones much better on the surface of the Earth. You need a huge mirror, and you also need an area as free as possible from air pollution, and of course from light pollution. New Zealand has optical telescopes at Mt John, near Tekapo, and you do get a fine view of the stars from around there on a clear night. There are several really big optical telescopes high up on the big island of Hawaii, where there are virtually no street lights and very clear air. But the really good optical images these days are taken by the Hubble telescope which is in Earth orbit. There are some wonderful images from that online.

A radio telescope uses a different part of the radio spectrum from visible light. The radio waves it uses are generally less prone to interference from the atmosphere than visible light astronomy. And you have the trick of using multiple dishes some distance apart to get a better resolution, that’s called interferometry and it relies on analyzing the differences between what the different dishes are seeing to get a very detailed picture of what they are looking at.

Q: And what do all these telescopes tell us?

A: Wonderful science about the beginning of our universe – where we all come from, ultimately. After all, only hydrogen and perhaps helium were originally formed from the big bang – everything else comes from stars ‘cooking’ those light elements into the ones planets, our atmosphere, and even ourselves are made of. The old song says “we are stardust” – this is literally true!

Links

Farewell the London Planetarium. Let’s hope the Carter Observatory gets back in business soon.

The Zodiac constellations.

Free Stellarium software for Windows, Mac and Linux.

The Square Kilometre Array – the planned new radio telescope

We are stardust.

Read on for my notes, or after about 11:30 you can download the audio as ogg or mp3.

Clip 1: Invisible Man by Queen (first 10 seconds)

Q: you mean for real, or just being invisible on the Internet?

A: You aren’t invisible on the Internet. Well, if you are an expert who has done everything conceivable, you just might be, but I wouldn’t rely on it. The rest of us – not a chance.

No, I’m talking about real life invisibility.

Q: Science fiction?

A: Sounds that way, doesn’t it? And, frankly, it still is. But some quite rapid progress is getting made. There are two basic ways you can go about invisibility – the obvious and reasonably simple one is to cover the object you want invisible with LCD screens that show the scene behind the object. People are playing with that now.

But there is a much fancier approach using what are called “metamaterials”. These are materials that are constructed to bend light around them. They are still at an early research stage, but they could hold the key to real invisibility.

Q: How does that work?

A: Light is a wave, which is partly why we can reflect and refract it. It doesn’t always travel in straight lines. But to really manipulate light, you have to be able to construct materials which have a surface pattern on the same scale as the wavelength of light. Visible light has a wavelength of about 500 nanometres. That’s two million waves per metre. Our materials science isn’t really good enough to make reasonably sized objects with regular surface detail at that scale. But that’s likely to improve.

Radar waves – remember, light is just a kind of radio wave, and radar works using radio waves of a longer wavelength – they would be easier deflect around an object. There’s a lot of research going on around that, and I’d be surprised if a lot of it hadn’t already been implemented.

Q: You mean in “stealth” aircraft?

A: Yes, exactly. They are stealthy because they can avoid radar detection, but they’re not invisible to the naked eye. Maybe in the next few years it will become possible.

Play out to “As Close as This” – The Muttonbirds

Links

The godfather of invisibility explains – a great blog entry by journalist Peter Nowak, and how to make an invisibility cloak.

Foo is an amazing experience. It’s so energising to be there with scientists, geeks, and artists. And Nathan, Jenine and Russell do a fine job in organising it.

Part of the deal with Foo is that everyone presents (“no passengers”). I’m going to talk about “Hacking Government”. It seems that the geek community is quite bad at telling government what it wants, in a way that government actually responds to. Perhaps we can start to deal with that.

Go on, you know you want to.

Now, the same team has started a new project – BloodhoundSSC. They want to break their own record and get up to 1,000mph on land. Wow!

Read on for my speaking notes or download the audio as ogg or mp3.

Q: So, what have you for us today?

A: The land speed record, of course! But first, a couple of stories about the world’s favourite Scottish restaurant.

The first one is about a patent that the Golden Arches chain has just received in the US:

The present invention relates to a sandwich assembly tool and methods of making a sandwich, which may be a hot or cold sandwich, quickly by pre-assembly of various sandwich components and simultaneous preparation of different parts of the same sandwich. The sandwich assembly tool is composed of a member preferably having one or two cavities for containing a quantity of garnish. The cavities are used for the assembly of the sandwich. The tool may have a raised ridge adjacent one or both cavities for placement against the hinge of a bread component. Methods of making a sandwich] are disclosed. The methods may include one or more of the use of preassembled sandwich fillings, assembly of garnishes in advance of a customer’s order or while ether portions of the sandwich are being heated using the sandwich assembly tool, the simultaneous heating of a bread component and the sandwich filling, placing the bread component over the tool containing garnish, and inverting the tool and bread combination to deposit the sandwich garnish onto the bread component.

In other words, McDonalds has patented a machine for making a sandwich. Hmm.

Q: Can you do that?

A: Apparently. It even comes with a flowchart. You’d think that someone will take this on, on the grounds that its obvious and that sandwich have been around for years, but that’s an expensive lawsuit to fight.

Q: And the other story?

A: Ah yes. It seems there’s a couple called Philip and Tina Sherman who live, or lived, in Lafayette Arkansas. He left his phone in a McDonalds. He rang the staff there and told them to lock it up until he could come back for it. He was very insistent about that, and – this whole think is the subject of a lawsuit, so I had better start using words like “allege” – and it appears that someone on the restaurant staff’s curiosity got the better of them, and they went through the contents of the telephone.

Q: What was on the phone?

A: Apparently Tina had been sending racy pictures of herself to her husband’s cell phone. There was quite a collection. And, of course, there was her name, address and telephone number. The pictures and the contact details found their way somehow onto the Internet.

Q: What happened next?

A: The Sherman’s claim that this has ruined their lives and that they have had to move to get away from the unwanted attention. They have sued McDonalds for 3 million dollars.

Q: So, tell us about the land speed record

A: I first became seriously aware of the whole thing in about 1997 when some British guys were gearing up to try to run a supersonic car. The leader of the project was the existing record holder, a guy called Richard Noble, who had in 1983 set a record of 633mph – that’s a whisker over 1,000 kph – in 1983 in a car called Thrust2.

Q: was this a jet car?

A: Yes. It had a turbojet, which is what we would today regard as a very primitive form of jet engine. The engine came from an RAF lightning, some people may remember the classic angular Lightning with a pointed nose. It was one of those engines, and they were originally designed in 1945. So, a very old jet engine, but with it he beat everything to date.

Anyway, the Americans had held the land speed record since 1963 with the first record breaking jet car – that was called Spirit of America and was driven by a man called Craig Breedlove, and he’s still around looking at re-breaking the record. Before the first jet car, the record had been held by a succession of Britons driving ordinary piston engined cars, on the Bonneville Salt flats or at Daytona Beach. Those piston engined cars topped out at less than 400 miles an hour – which is still horrendously fast, of course, and it has been jet cars and a rocket car that have held the record since.

Then a series of jet cars driven by Americans held the record through the sixties, and rocket powered car took the record in 1970 and it stayed there until 1983 when Richard Noble took it with Thrust2.

Q: What happened to the first car called Thrust?

A: I think it died under testing on an aircraft runway in the UK.

Q: So, what happened after 1983?

A: Some of the Americans really wanted the record back, but they couldn’t beat Noble’s record. But it was clear that, sooner or later, one of them was going to take the record again, and Noble didn’t want that. So, he did the only sensible thing under the circumstances, and built a new car to break his own record. And in 1997, that was when I became aware of the whole thing.

Q: How did you fid out about it?

A: On the Internet, of course! The Internet was a lot smaller then, and it was unusual for people to use it seriously. And many, or most, of the people on it were geekier than the average Internet user today.

And people like me would check the web site for this project every day. I was fascinated by the whole endeavour and the sheer adventure of it. I followed them as they looked for a desert where they could run this thing, as they proved the technology in the car, and as they finally transported it to the Black Rock Desert in Utah where it finally did its record breaking run.

The Internet was key to them – even in those early days. When they ran out of money, as they did several times, they put messages on their website seeking small donations from fans, and they got those and kept the project running. It was a real example of a community built around the record breaking attempt, of people who wanted to see this thing succeed, but also were just reveling in the sheer attempt.

I well remember logging on to read that they had succeeded – they had got the car to go supersonic on land and broken the land speed record. To break the record you have to do two passes along a measured track, once in each direction, and there are various other structures. Essentially the record is a speed that is sustained for some time. ThrustSSC first went supersonic on a day that it couldn’t do two passes, but it claimed the record two days later, officially timed at 760 mph or over 1200 kph.

Q: Who drives these things?

A: ThrustSSC’s driver is a fighter pilot called Andy Green.

This isn’t the end of the story, though. The record still stands, but Richard Noble wants to take it further again. He’s planning a new record breaking car to be called Bloodhound SSC, with a rocket engine and a jet engine. They are targeting 1,000 mph for this car. Remember, the existing record is around 730mph. That’s a huge jump.

There are some pretty serious technical problems with this of course. One is about finding somewhere big enough to do it. Even with the car accelerating and decelerating at 2 to 3 g they need 10-15 kilometres of clear flat surface. The team is scouting round the world at the moment looking for somewhere.

Then there is the issue with going supersonic. The point about going supersonic is that the air doesn’t just get out your way like it does at lower speeds – you have to manually shove every molecule of air because now sound wave of your passing has reached it yet. That leads to some very tricky aerodynamics which aren’t well understood.

And then there’s just building wheels which hold together under the strain – the edges of the wheels will be trying to fly apart at 50,000g.

Q: Who is supporting this?

It’s being given a lot of support by Paul Drayson, a British Minister who’s also a racing driver himself. He’s at pains to point out that there’s no public money going into the thing, it will all be private sponsorship.

Drayson justifies this by saying it will rekindle interest in the engineering challenges and energise a new generation of Britons to take up science and engineering. They are using the world “adventure” about the whole thing. But I think the last work should go to Richard Noble, the man who has driven a record breaker and made the supersonic car. He tells a story of walking through one of the corridors of Parliament in the UK, and getting stopped by one of the Parliamentary Police, who told him how much he admired Noble for the record breaking and how it had made his son change his degree from something advertising related to engineering. That’s what Drayson and Noble both want to achieve.

Wikipedia on the Land Speed Record.

The website of the 1998 record breaker, ThrustSSC, and of the 2011 hopeful, BloodhoundSSC, and a BBC article about it all.

Read on for my speaking notes, or listen to the audio download as ogg or mp3.

Q: What is that?

A: It’s a rap about the Large Hadron Collider. It’s much better on YouTube, where you can see the visuals…

Q: Who made it?

A: A woman called Kate McAlpine. She’s a scientist at CERN where the Large Hadron Collider – the latest and greatest particle accelerator – is about to be switched on. She’s done a four minute YouTube rap, and the science in it seems to be spot on…

Q: And the music?

A: I think that’s in the ear of the beholder, don’t you? But the video is worth a few minutes of your time. Linked today, of course.

Q: You want to talk about the Large Hadron Collider this week. That’s more hard science than you usually talk about?

A: Yes. I’m quite clear about the difference. Technology is the way we do things, its recipes.

Q: recipes? Really?

A: Well, actually, yes. Recipes – in the usual sense of cooking recipes – are technology in my book. You know, you assemble these ingredients and do this to them and out pops something new that you might want to eat. Just like building or using gadgets.

Q: So there’s a recipe to build a mobile phone?

A: There certainly is, or rather, there are hundreds of recipes depending on the type of phone. And there are recipes for how to use them as well. And, like cooking recipes, people change the recipes and come up with new ones, and suddenly instead of prawn cocktail starters and bakelite rotary telephones we have sushi and iPhones.

Q: Sushi has been around for a long time…

A: It doesn’t pay to pick at the analogy too hard or it will bleed. But my point is, that technology is an aspect of culture, it’s the way we do stuff.

Q: And how would you define science?

A: Science literally means knowledge, as anyone who can remember their high school Latin knows. Science is more basic research. Sure, there’s a recipe to build a cell phone, but that recipe only exists because scientific research has built our understanding of physics and metallurgy to the extent that engineers can make a recipe.

Q: So we need the science before we can have the technology.

A: Absolutely we do.

Q: Is that how you justify the money that gets spent on science? What about things that will never be useful?

A: Two things to say about that: first of all, it’s pretty hard to predict what’s going to be useful up front. Pure mathematical research is an often-cited example of something that has no applications; but pure maths underlies the codes we use on the Internet to protect banking transactions. And it helped the British crack the German Enigma codes during the Second World War, which may well have turned the tide of the war. Same argument with the Americans in the Pacific war.

But the other thing as to why we do science – we do it because its fun, for some clever people anyway, to find out more about how our universe, our world, and our bodies are put together. Let’s celebrate the fact the some people are gifted with the intelligence and determination to find things out and make it as easy as possible for them. It just makes the word a better place.

Q: Like Leonardo da Vinci?

A: Absolutely classic example of man whose genius spanned several spheres of endeavour. And, back then, we didn’t separate science from other fields of enquiry, so no-one got onto Leonardo’s case and said – look, you’re paid to invent helicopters or something and can you please stop wasting time with a paintbox?

Q: But modern science is very specialized.

A: It’s sad, but it probably has to be. There is so much scientific knowledge now available that even to hold it all in one head is impossible. To do original work requires a sharp focus. But there’s still serendipity going on where you bring a lot of clever, scientifically-trained people together and let them follow their interests. The World Wide Web, for instance, came out of a computer project at CERN, the giant particle accelerator on the Swiss border. A cynic – someone who didn’t appreciate science – might say that CERN had wasted all the billions thrown at it over the years, but I’d have to point at the World Wide Web and say that paid for all of it many times over!

Q: Pity for them that they didn’t patent the Web

A: Damn good thing they didn’t! Otherwise it would have been monopolized by some large company and never would have taken off the way it has.

Q: Back to CERN, the particle accelerator. What does that do?

A: CERN is an institution which does fundamental research into what the universe is made of. The latest experiment is the large hadron collider – hadrons are a class of elementary particles. Many of the particles we are familiar with are hadrons – protons and neutrons, for instance. They are the type of subatomic particle which have mass. And the collider accelerates streams of these to velocities incredibly close to the speed of light and smacks them into each other to see what happens.

Q: They can’t get faster than the speed of light, can they?

A: No, Einstein said that, and we’ve not proved him wrong yet. Instead, as you put more and more energy into things to make them go faster they just get microscopically closer to the speed of light, but they still have the energy, and it’s the collision energy that interests researchers – they are on the track of a really big particle that some theories predict, called the Higgs Boson. They hope that if they set up a collision with sufficient energy they’ll get a Higgs Boson out of it.

Q: And what is a Higgs Boson?

A: According to a really attractive particle physics theory, called the Standard Model, the Higgs Boson is the one particle that gives everything else mass. If that theory is right, the Higgs explains how gravity links to the other forces we see in nature.

Q: Has it been found yet?

A: Not by the biggest particle accelerator that’s currently running – that’s at Fermilab in Chicago, but the LHC is capable of far more energy. The machine’s first proper run will be in the next few weeks. And, no-one really knows, even if the Higgs exists, just how much energy it’s going to take to make one. And that’s because we don’t know how much one would weigh – you’ve heard of Einstein’s most famous equation – E = mc2 ? That says that energy and mass are the same thing, but that a huge amount of energy is equivalent to a very small amount of mass. That’s how stars like the sun work – they literally burn their mass through nuclear reactions to give out energy. And the LHC is trying to do the opposite – put enough energy into one place and see what can get created.

Q: How do they get these particles moving so fast?

A: Magnets, basically. Not just your little horseshoe ones, either, but ones like you get in an MRI scanner. For those listeners who’ve never been near an MRI scanner in a hospital – they are amazingly magnetic. The staff won’t let anything metallic in the room. There’s all kinds of videos on YouTube of loose oxygen bottles or even hospital gurneys being sucked toward the machine and thrown into it with incredible force. You wouldn’t want anyone to be inside the machine if that happened, which is why they are so careful.

Now, these magnets are superconducting electromagnets. A regular electromagnet works by forcing an electric current around a circular path with creates a magnetic field – it just does, that’s a law of physics – but to get a really strong magnet like we are talking here, you need a huge current which would cook the magnet and anybody near it. A superconducting magnet works the same way with a big electric current flowing in a circle, but the material its flowing through is superconducting – it offers no resistance at all to the electric current. That’s important, because it lets you put a really big current through. The thing about superconductors is that they only work at around ten degrees above absolute zero – that’s spectacularly cold, liquid helium temperatures. So, you have to keep these things very cold. And if a part of the magnet ever gets too warm, the whole magnet suddenly warms with a big bang as all the energy in its electric current is suddenly converted into heat.

Building these magnets – and the whole of the rest of the Large Hadron Collider – is a great example of technology. And they are necessary for the fundamental scientific research which will ultimately lead to more technology. Science and technology are joined at the hip, but they are different things.

There’s an enormous amount more to the technology of the collider. The collider is all underground, in a 27 km ring that spans France and Switzerland. The machines that detect the product of collisions are very high tech, and there are of course computers to die for to analyse the vast amount of information it generates.

Links

As always, you can discuss this broadcast at it.gen.nz.

The Large Hadron Rap on YouTube – go on, you know you want to!

Another YouTube – a superconducting magnet quenching.

The Large Hadron Collider’s home page, and an article about it in the Herald.

Cartoonist XKCD’s take.

Go on, you know you want to.

Q: Quantum computing?

A: Strange-sounding, isn’t it? Quantum physics is easily the strangest branch of science. Its all about small things like electrons and photons. It seems that when we start doing experiments on individual electrons and photons they just don’t behave like larger objects do.

Q: How so?

A: It is deeply strange. Everything is what is called quantized. You find that the properties these objects are restricted to a few choices for no very good reasons. For instance, electrons in atoms can have only a few specific energy levels – the levels depend on the type of the atom – rather than any number you can think of, as you would expect in the world we are used to. And there’s the famous uncertainty principle that says that we can’t actually know everything about a particle – its almost as though the act of looking at it changes it, which is pretty much the case. And there’s the Pauli exclusion principle which says that no two electrons in an atom can be in the same state. Nobody knows why but it appears to be true. And then there’s problem that started the whole of quantum off – particles seem to be in one place at once, as you’d expect, but they also act as though they are waves that everywhere at once. Richard Feynman, one of the greatest physicists ever to have lived, said that no-one understands quantum physics.

Q: If no-one understands it how is it useful?

A: It is because we can exploit what we do know. Perhaps the most useful effect is so-called tunneling. Tunneling says that an electron or some other object of that size might cross a barrier that you’d think would stop it. Let’s think of an analogy. If you have a cat locked in a room, and there’s no way for it to get out, you can be certain that it will be there when you come back. Put an electron in a box, and it might or might not be there you come back – and we know the probability. If you put a hundred electrons in that box, we know how many will be there when you come back. Try that with cats and all hundred would still be there, although there might be a fair bit of fur lying around!

Q: The electron does behave strangely…

A: Quite. The rules for really small things are not the same as they are for large objects like cats, people or buildings.

Q: How small do things have to be to behave like this?

A: Each of us might have 10^26 electrons in our bodies – that’s a one followed by 26 zeros. That’s how small we are talking. We are composed of these tiny things that observe such strange rules, but the strangeness happens only on the tiny scale and we can’t see it. By quantum rules, it’s perfectly possible that this microphone might just suddenly leap a metre to the left – each of its constituent particles could do exactly that at the same time – but the probability is ludicrously low because there are so many particles which would all have to do it at once. So you the strange quantum picture of what happens to very small things quite consistent with the classical view of objects moving under Newton’s laws that we are used to.

Q: Classical?

A: A scientist’s way of sneering at a theory which we know to be only part of the truth.

Q: You just used the word “theory”. Is all this just a theory?

A: Yes and no – a scientist uses the term theory to mean a set of rules which explain what you can observe in the world around you. Quantum is a theory, relativity is a theory, Newton’s Laws are a theory – it just means a system of explaining things that actually works. Any kind of theory that has been around for more than a few years is likely to be pretty solid, because its easy to disprove theories that don’t work and impossible to prove theories that do work. Successful theories tend to build on and extend theories that have gone before, like Einstein built relativity onto Newton’s Laws. Quantum theory is built on Newton, too, and there are great labours going to merge it with relativity.

Q: OK, so small things behave oddly. What has that got to do with computers?

A: Computers work by manipulating electrons. That’s the crux of the matter. And as computers get more and more powerful, they do this getting their parts smaller and smaller, which means that they are dealing with relatively few electrons in any given part.

Q: This is all inside the silicon chips, right?

A: Yes, exactly. If you take cover off a modern PC you’ll see somewhere in the middle what looks like a group of metal cooling fins with a fan attached. Underneath that is the chip which drives your computer. They get hot, which is why all the ironmongery is attached. Older, slower machines often have the processor chip plainly visible. Now inside that chip are hundreds of millions of components. The size of these components gets smaller every year as manufacturers try to squeeze more onto the chip. Currently the scale of these components is about 0.1 micron, and a micron is a millionth of a metre.

At that size you are manipulating small numbers of electrons and quantum rules very definitely apply.

Q: How do you design things to work with such strange rules?

A: It’s pretty specialized stuff as you can imagine. There is some serious mathematical heavy lifting involved. One of the leading people in this area is a New Zealander called Professor Michael Kelly. He works at Cambridge University in England – he taught me some of this stuff when I was an undergraduate. I think he comes back to Wellington from time to time.

All modern computers use quantum effects in their chips because they have to – there’s no ignoring them at that scale. But there are some really “out there” possibilities that quantum offers if you go looking for trouble, so to speak.

Q: Like what?

A: Another one of the amazingly strange things that quantum theory predicts is that things can be in many states at once – as though an electron were in many places at once, but the act of looking at it forces it to choose as it were and from then on its only where you saw it. This bizarre behaviour is what drives the Schrodinger’s Cat thought experiment. Schrodinger – who incidentally was a strange character himself who did all his best work on weekends with his mistress in an alpine chalet, you have to wonder what she thought of him spending his time on quantum mechanics instead of on her – he said, let’s imagine we have a cat in a closed box and with the cat is a machine which will gas the cat if some quantum event happens. If we don’t look at the quantum object in question it is half in one state, half in the other. As soon as we look it is one or the other. The question is: before we open the box and look, is the cat alive or dead?

Q: If the cat’s in a closed box it will suffocate!

A: Well, yes, but what Schrodinger was getting at was a way to magnify a quantum event with all its attendant weirdness into the domain that you and I inhabit. So quantum theory would seem to say that the cat is both alive and dead until we look inside the box, then it’s one or the other.

Q: What does happen if you try the experiment?

A: I don’t think it would be ethical to try it! Anyway, this weird way in which quantum objects can be many things at once – it’s called superposition by the way – can be harnessed to solve a problem which has bedeviled mathematicians for centuries – prime numbers. More correctly, it can be used in theory to factorise large numbers which is nearly the same thing. Now that’s a big problem in some quarters, because – you remember how we talked about how we use codes on the Internet a few months ago?

Q: Yes – weren’t prime numbers involved there?

A: Yes, the difficulty of factorizing large numbers is the cornerstone of some of the codes in use on the Internet today. And there are signs that a quantum computer can be used to do that job using something called Shor’s algorithm, although no one’s managed to build one yet.

Q: And the implications if they do build one?

A: Quite a lot actually – the codes we use for e-commerce are suddenly insecure and that’s a problem, but one I expect we could cover for that by switching to a new cryptosystem based on something different – there’s a technology called elliptic curves which could be used.

Q: How does that work?

A: It relies on a class of mathematical functions that are very easy to write down and fiendishly hard to solve. There is a vague relationship to the mathematical description of an ellipse, which is where the name came from.

But the real problem if someone makes a working quantum computer would be the amount of secret material – really secret, government classified national security material that has been broadcast in the past and recorded by people who would love to know what it said.

Q: Are there people out there really collected coded radio signals?

A: Absolutely there are. We are talking government-to-government stuff here, and they have a lot of resources, and if any of them have succeeded in cracking the prime-number based codes they certainly aren’t about to tell you or me.

Links

As always, you can discuss this broadcast at it.gen.nz.

A introduction to quantum mechanics at Wikipedia, and an article about the strange Erwin Schrodinger. Also an interview with the brilliant Oxford mathematician Roger Penrose as he describes the broad sweep of modern phyisics.

An article about quantum computing and a description of how one might one day be used to break codes

Wikipedia on elliptic curves that might one day replace prime number based codes.