QUANTA AND CONTINUUM

Do Not Adjust Your Clock!

OU tutor Graeme Nash has pointed out to us that the answer we gave to question 16 in the FUSION Quiz (see the Spring 2004 Newsletter) is incorrect. The answer given quotes an article in an earlier Newsletter (Winter 2001) which stated that the tidal effect of the Moon is slowing down the Earth's rotation, and thereby adding half an hour to the length of a day every ten million years. Graeme has informed us that this should read 100 million, not 10 million. So no need to put in for a pay rise just yet then! We apologise for this error, and thank Graeme for drawing our attention to it.

Are you interested in space?

Karen Hurren is looking to start up a branch of UKSEDS (UK Students for the Exploration & Development of Space) within the OU. The national web site address is www.uk.seds.org. If you are interested please email Karen.

OU launches CEPSAR!

A new interdisciplinary centre at the OU brings together world-class researchers from three different departments: Earth Sciences, the Planetary and Space Sciences Research Institute (PSSRI), and the Astronomy Research Group in the Department of Physics and Astronomy. The Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR) studies the origins, systems and processes with respect to the evolution and chemistry of materials that form the stars and planetary bodies, the processes and natural systems that shape the environment of our habitable world now and in the past, and the essential properties of a Solar System that allows life to develop on one of its planets. See http://cepsar.open.ac.uk for more information.

FUSION Astronomy Weekend Images Online

Steve Fossey of UCL's Mill Hill Observatory has put some of the images obtained by participants at our Astronomy Weekend in March 2003 on the web. Members can view the images at www.ulo.ucl.ac.uk/~sjf/OU.

Rewrite of SM355

Stuart Freake, the OU's PhysSci Programme Director, tells us that the planned rewrite of SM355 Quantum Mechanics is underway, with the first presentation in 2007, following hard on the heels of SMT359, the new electromagnetism course, which will get its first presentation in 2006. The Science Faculty has approved the 'Business Plan' that all courses now need to submit before getting the go-ahead. The current intent is to code the course SM358, with the provisional title The Quantum World. Unlike SM355 the course will not use a set book, but it will require the same maths preparation (MST207, or its replacement MST209 from 2005), and will include some of the exciting new applications of quantum mechanics.

Physical Science on First Class

According to Michael Watkins, Physical Science Programme Manager at the OU, there is a new First Class conference especially for students studying, or thinking of studying OU Physical Science courses. It has been set up as the main place for students to look for news about current and future Physical Science courses and awards, and to find out what your fellow students think about the programme in general. There is also a sub-conference (Physical Science Student Chat) intended as a forum for related student discussion. Please feel free to place questions there to your fellow students such as: "I'm thinking of studying S282 next year. What's it like?" "Can anybody who has studied S357 and SM355 in the same year comment on the workload?" "Is it useful to have studied S194 before S282?" This conference is not intended to replace conferences for specific courses - rather it is meant as a forum for Physical Science curriculum issues. You can reach this conference in just two clicks from your normal desktop by selecting Open University and then Science. One message in the conference explains how to make the conference appear on your desktop automatically.

Einstein (Not Enough Time)

Peter Bowles tells us that the Institute of Physics has found a DJ who's made a big underground tune called Einstein (Not Enough Time) It's at www.vadercrewkiller.com/ audio/mp3.einstein.mp3.

The M500 Winter Weekend

The M500 Winter weekend is at Trevelyan College, University of Durham from Friday 7th to Sunday 9th January 2005. Full details at www.m500.org.uk/winter.htm.

Ask-a-Boffin

Is the mass of the universe infinite or finite?

Ray Ash asks: Is the mass of the universe infinite or finite? If it is finite then how can we reconcile this with the infinitude of space? If it is infinite then how can we envisage a Big Bang happening with infinite mass in one location?

Paul Ruffle answers: As Block 11, section 2.5 of S103 Discovering Science advises, we have to put aside our everyday preconceptions as to the Universe having an edge or centre. Both space and time came into existence at the Big Bang, so we can not speak of the Big Bang as taking place at a location in space (or time). Observational cosmologists can estimate the mass of the Universe, but whether it is infinite or finite is a matter of debate. For example, if we picture a two dimensional world, we can grasp the idea of our three dimensional Universe not having a centre. Imagine 2D creatures who live on a 2D plane or surface. If their universe is flat or negatively curved (hyperbolic), their surface would go on forever, being infinite and unbounded (edgeless). However, if they lived on the surface of a sphere, their world would be finite and unbounded - they could set out on a journey and eventually come to the point they started from. In either case there is no centre to their universe. Likewise, regardless of the shape of our 3D Universe (flat, positively curved or negatively curved) there is no centre or special place. Janna Levin's excellent book How the Universe got its spots discusses these ideas in greater detail.

Absolute Zero Revisited

Fiona Mitchell's recent question about temperature prompted a vigorous exchange of emails between Jim Grozier and Paul Ruffle:

Jim: I've been thinking about Fiona Mitchell's recent question about temperature. I wondered if what she was getting at was, if zero K corresponds to no motion, is there a maximum temperature corresponding to the maximum velocity c? But if so, it doesn't work because the kinetic energy of a relativistic particle is mc² x γ and as v tends to c, γ tends to infinity so the corresponding temperature (which would be this quantity divided by Boltzmann's constant) also goes to infinity.

Paul: Being pedantic, the relativistic energy expression includes both rest mass energy and the kinetic energy of motion. The kinetic energy is: E_k = mc² - m₀c² (where m₀ is the rest mass). This defines the kinetic energy of a particle as the excess of the particle energy over its rest mass energy. For low velocities this expression approaches the familiar non-relativistic kinetic energy expression: E_k ~ 1/2mv².

In the context of a Boltzmann distribution, temperature is a macroscopic quantity that only applies if the particles interact and exchange energy. As we saw in S381, relativistic electrons in an initially collapsing cloud make the cloud too hot and no longer in equilibrium and hence unable to collapse further. Given that particles with mass can not attain c, they can be persuaded to posses very high E_k (as in a particle accelerator), but could only be described as having a very high temperature if they are contained in some way so as to interact. Splitting hairs I know, but infinite temperature is not the opposite of absolute zero. According to QM, objects cooled to absolute zero do not freeze to a complete standstill, but that they jiggle around by some minimum amount.

Jim: That's why 0 K is unattainable.

Paul: Is it? According to the AIP's Physics News Update the zero-point motion in a Bose-Einstein condensate has been quantitatively measured, allowing researchers, in effect, to study matter at a temperature of absolute zero (www.aip.org/enews/physnews/ 1999/split/pnu433-1.htm). So there is still the zero point motion at absolute zero. Splitting hairs again!

Ed: Jim and Paul are both right, if you overlook the missing term (-mc²) in Jim's formula. Paul is using m to denote "relativistic mass", m = m₀γ; Jim's m is the same as Paul's m₀.

Membership Report

by John Pollard

FUSION is now well into its fourth year and membership levels remain healthy having risen every year so far. The year-end membership was 294 in 2001, 381 in 2002 and 407 in 2003. At the end of June this had increased to 419. Of the current members 191 joined during 2001, 102 joined during 2002, 77 joined during 2003 and so far another 49 have joined during 2004. However 96 members chose not to renew their membership in 2002 with another 78 leaving during 2003; a further 35 have allowed their membership to lapse this year.

One in four of our members are female and members' ages range from 20 to 80 with a mean age of 45. 87% of members use email to communicate with FUSION while only 21% claim to use the OU's First Class conference system.

Although most current members are OU undergraduates at levels 2 and 3, 28 are members of the OU's Physics & Astronomy Dept. and 26 are Associate Lecturers; some are former OU students who are now studying or researching as postgraduates at other universities.

This year's most popular OU courses (based on feedback from 234 members) are S207, S357, S282, S381, SMT356 and MST207 (see below for a full breakdown). At least 308 FUSION members are also members of the Institute of Physics with 236 of these having joined the IoP through FUSION.

345 members are listed in the May 2004 FUSION Regional Contact List. This is an opt-in list that is intended to facilitate communication between FUSION members on matters of mutual interest and to act as an informal source of support for members during their OU studies.

Although the current membership base is strong the FUSION committee is not complacent and welcomes feedback from members who have suggestions or who are willing to organise activities, visits or events or to contribute Newsletter articles. Please send your suggestions to membership@oufusion.org.uk.

FUSION Membership by OU Region

OU Region	FUSION Members
South	18.9%
East	11.5%
London	11.0%
South East	9.3%
Scotland	6.9%
North West	6.7%
South West	6.7%
West Midlands	6.4%
East Midlands	6.2%
Ireland	4.3%
Wales	3.8%
Yorkshire	3.8%
North	2.6%
Overseas	1.9%

FUSION Membership by OU Course

OU Course*	FUSION Members
S207	40
S357	24
S282	23
S381	20
SMT356	19
MST207	18
SXR207	11
S103	9
S283	9
MS221	7
SMXR356	6
SXR208	6
MST121	5

*courses being studied by five or more members.

Rendezvous on an Alien World

At about 10.30 am on January 14th 2005, a man-made "flying saucer" will begin a two hour parachute descent through the atmosphere of Titan, Saturn's largest moon. One man will be paying it particularly close attention - John Zarnecki, Professor of Space Science at the OU's Planetary & Space Sciences Research Institute (PSSRI). The Huygens mission to Titan has taken up a sizeable chunk of Zarnecki's career, from original conception in 1988 to next year's splashdown (or crashdown - see below!)

Those who have studied S281 (and, hopefully, S283 in more recent times - surely they wouldn't dare leave it out?) will remember the TV programme Design for an Alien World, which showed him putting together his group's bid for the Surface Science Package, discussing the project with fellow-scientists, and working in the lab with his PhD students designing and testing the various instruments.

Towards the end of the programme we see Zarnecki alone in a deserted lab, reminiscing about who worked where and on what ... but all the students had gone on to other things, and Zarnecki himself was soon to follow, moving to the OU when the department at the University of Kent closed. But Huygens was on its way by then, aboard its mother-ship Cassini. The seven year journey to Saturn included flypasts of Venus (twice), Jupiter, and even the Earth, so that the maximum amount of energy could be extracted using the principle of gravity-assisted propulsion, the rest coming from a plutonium-powered thermo-electric generator. (Saturn is so far from the Sun that it only receives a hundredth of the solar flux incident on the Earth - so solar panels could not provide enough power).

Discovered in 1655 by Christian Huygens, Titan is the only object in the Solar System whose surface we have never seen. This is because it possesses an atmosphere - indeed, the only nitrogen-rich atmosphere outside the Earth. As well as being perhaps 80% nitrogen, Titan's atmosphere also contains many hydrocarbons, including long chain polymers which are thought to have formed as a result of the action of light on methane:

2CH₄  +  hν  →  C₂H₆  +  H₂ (etc)

If the methane had existed only in the atmosphere, it should all have been converted to other hydrocarbons by now. So the fact that it is still present indicates that there must be a source of methane on Titan - either in liquid form, as seas or lakes, or perhaps solid. (The surface temperature on Titan, 80K, is close to the triple point of methane). No-one knows what lies beneath the clouds - and so Huygens is equipped with an impressive range of instruments, some which of will function in a liquid environment, with others more appropriate to a solid surface - including the penetrometer, shown in the programme being dropped into a bucket of sand (which apparently came from the local branch of B&Q!). Other instruments will sample the atmosphere on the way down.

The mother-ship Cassini in orbit among the rings of Saturn.

Contrary to reports in the popular press about a "kamikaze mission", Huygens is not expected to be destroyed by the impact even with a solid surface, as its terminal velocity, thanks to the parachute, will only be about that of a human being jumping out of a tree. It will carry on transmitting to Cassini for two hours, until the mother ship disappears over the horizon. Then Cassini will relay the data to Earth, and - who knows? The result may well be the birth of a new science, extraterrestrial oceanography!

If you have Internet access, you can follow the progress of the Cassini/Huygens mission by visiting www.esa.int/SPECIALS/Cassini-Huygens. Cassini entered Saturn orbit on 1 July 2004; separation of Huygens from Cassini is due on Christmas Day.

The above report by Jim Grozier is based on a talk given by Prof Zarnecki at the Institute of Physics London & South-East Branch in May 2004. For details of IoP branch events, see http://members.iop.org/branches.html.

Who am I? - Understanding the Fundamental Character of a Neutrino

by Kai Zuber

This at first glance psychological looking question does not only bother human beings but also experimental particles. The question is related to the character of our fundamental particles, namely quarks and leptons and their behaviours as particles and antiparticles. Again at first thought, there doesn't seem to be any problem, because all quarks and charged leptons can be distinguished according to their charge. As an example the positron, a positive charged electron, is the antiparticle of the electron. In addition, all of these particles can show up left-handed or right-handed, depending on whether their spin is in the direction of their momentum or opposite to it.

Members of such a four state system, e.g. left and right handed electron and positron, are called Dirac particles. All quarks and charged leptons are Dirac particles. But what about neutrinos? Is a neutrino also a Dirac particle? How do we define an antineutrino? Currently in the following way: if an electron is produced in an interaction, the original particle must be a neutrino, if a positron is produced it must be an anti-neutrino. Is this sufficient, because this definition is based on left-handed (neutrino) and right-handed (anti-neutrino) states in the interaction? What about right-handed neutrinos and left-handed antineutrinos, they could exist, but would not show up in any known interaction (except gravity of course).

Well, since its very beginning neutrinos are the big unknown in particle physics. Unlike most other particles they were not discovered experimentally but postulated theoretically. The reason was the observation of a continuous electron energy spectrum in beta decay. The only way to explain it at that time was a violation of conservation of energy, the Holy Grail of Physics. The desperation led Wolfgang Pauli in 1930 to the hypothesis of a new particle to save energy conservation. This new particle disappears from the apparatus, but carries energy, so the sum of the energies of the electron and the new particle is always constant. Actually, he called this hypothetical particle, neutron, because it should have no charge and interact only very weakly. He also stated, that he has done something terrible, postulating a particle which will never be discovered. Soon after, the real neutron was discovered, and Enrico Fermi renamed the particle neutrino. It took about another 25 years until neutrinos were discovered experimentally. For a very long time it has been assumed they are massless, a property also implemented in the successful Standard Model of particle physics. Only in the last decade convincing evidence has been found for a non-vanishing rest mass of the neutrino.

Our current understanding of beta decay is a process, where a neutron decays into a proton, an electron and - to conserve lepton number - into an anti-electron neutrino. Already in 1935 Maria Goeppert-Meyer discussed the process of double beta decay, where two neutrons decay into two protons, two electrons and two anti-neutrinos. This process of two simultaneous decays is very much suppressed and requires that single beta decay is forbidden. Nuclear physics tells us that only nuclei with an even number of protons and an even number of neutrons (so called even-even nuclei) can do this process. The further requirements of forbidden beta decay actually lead to only 35 isotopes in nature which can decay this way. Being a rare process, the theoretical expected half-lives are around 10²⁰ years and beyond. As you can easily check, measuring such a half-life is a difficult task, which is part of the field of low-background physics, a part of physics working in a very clean environment and deep underground in mines and tunnels to search for rare events.

Fig. 1: Left; The neutrino accompanied double beta decay as allowed in the standard model. It is the simultaneous decay of two neutrons into two protons, two electrons and two antineutrinos. Right; The neutrinoless double beta decay is lepton number violating and needs new physics. No antineutrinos are emitted. The emitted antineutrino will be absorbed in the same nucleus as a neutrino, hence requiring that neutrino and antineutrino are the same.

But what does this have to do with the neutrino character? Already in 1938 Ettore Majorana came up with a two component theory of the neutrino, having only a left-and a right handed component. So all our observations could be described by such a two state object as well, but this would imply that neutrinos and antineutrinos are identical! An immediate consequence is that lepton number violation is no good concept anymore, something not foreseen in the Standard Model. A year later Furry proposed the process of neutrinoless double beta decay, where two neutrons decay into two protons and two electrons. Clearly this process violates lepton number by two units. You can consider it in the following two steps: First a neutron decays emitting a right-handed anti-neutrino, which in some magical way must be absorbed by a second neutron as a left-handed neutrino (Fig. 1). To fulfil this condition, therefore neutrinos must be identical to anti-neutrinos and in addition, to match the helicities neutrinos must have a mass. So, this is the major importance of neutrinoless double beta decay: It is only possible if neutrinos and anti-neutrino are the same and are massive. Actually, it is considered to be the gold plated process to probe this fundamental character of neutrinos. If neutrinos are Dirac-particles like the other fundamental particles neutrinoless double beta decay will never be observed.

So let's go and search for it. If you measure only the sum energy of the two emitted electrons, the signal is pretty nice, namely a peak at the position of the decay energy, while in the neutrino accompanied decay, you will get a continuous energy spectrum, because the two escaping neutrinos take energy away (the argument goes in the other direction to that of Wolfgang Pauli).

As it turns out, to explore a neutrino mass in the region of about 1 eV, you have to measure half-lives in the order of 10²⁵ years! Typically one kg of an average element just contains about that number of atoms, so even in this case you would only expect 1 event per year. Not to mention that you are only interested in a specific isotope whose natural abundance is not 100%. This is by no means an easy task, actually it's among the rarest processes ever explored. The major worry are of course disturbing events, which could mimic your double beta decay or spoil the region of your signal. Hence, such searches cannot be performed on the surface, but must be done deep inside the earth, in tunnels or mines, because too many particles from cosmic rays are flying around in the atmosphere. To be a little bit more specific let's concentrate on one specific isotope, Germanium-76, where both electrons together would result in a peak at the sum energy of 2039 keV.

Fig 2: Working clean is everything! Shown is part of the Heidelberg-Moscow collaboration installing the Ge-semiconductor detectors inside a very clean lead shielding of about 10 tons. Special care is taken not to bring in any impurities. Also the four detectors are visible in their copper housing, because they operate at 77 K. The whole setup is installed in the Gran Sasso Underground Laboratory (Italy) and there is at least 1400 m of rock as shielding in all directions.

The beautiful thing is, that Ge crystals are used as semiconductor detectors with an excellent energy resolution, so the expected peak would be pretty sharp. Ge-76 is intrinsic in the crystal, so your source and your detector are the same (the detector is decaying). Having such a beautiful device and installing it in a tunnel is still not sufficient, what else do we have to worry about? The usual suspect is natural radioactivity, coming dominantly from the omnipresent uranium and thorium decay chains. Therefore a shielding of several tons of lead must be built around the detectors to shield against gamma rays, coming from this background source. In addition, the air must be removed because it contains radon. But the real crucial point to make such an experiment a success is to work extremely clean during installation (Fig. 2). Not a single bit of impurity should be brought in, in a year long selection process any used material is tested for its radioactivity. Materials are used, which spent 400 years on the floor of the Mediterranean on Spanish ships or such from before the second world war, to avoid the pollution of the atmospheric atomic bomb test. (In this way, wine producers have been caught cheating, because wine with an official vintage of around 1910 showed tritium from the bomb testing!)

So what's the status of the searches? Indeed Ge experiments are the leading experiments, especially the Heidelberg-Moscow experiment. They have driven the lower half-life limit up to about 2 x 10²⁵ years, quite outstanding. The latest development is, that a subgroup of this collaboration, has recently claimed they have found the peak. Because of its outstanding importance, very likely a Nobel prize winning discovery, this caused a lot of excitement in neutrino physics. However, the peak is very weak and has a rather low statistical significance, hence there is a lot of scepticism about its existence. What to do? Clearly building another experiment to probe the peak. A few of them are on their way, but it will take some time until they can probe the claimed peak. The only one with significant UK involvement is COBRA (Cadmium-telluride O-neutrino double-Beta Research Apparatus), an experiment using CdTe semiconductors, and led by the University of Sussex (with further UK collaborators at the Universities of Birmingham, Liverpool, Warwick and York, and the Rutherford Appleton Laboratory). So, stay tuned there is a lot more to come!

Kai Zuber has been doing neutrino physics for 15 years (with and without accelerators). He did his PhD in 1992 in Heidelberg working on the Heidelberg-Moscow experiment and then spent several years at Gran Sasso Laboratory, DESY and CERN. Currently he shares his time between Oxford and Sussex Universities, and is a member of the Sudbury Neutrino Observatory SNO collaboration and spokesperson for the COBRA experiment. He also plays the guitar.

EVENT REPORT

Behind the Fence at Windscale

by Jim Grozier

We are always being told about the crisis in physics - fewer physics graduates means fewer physics teachers, and therefore even fewer studying the subject in the next generation, and so on, in an ever downward spiral.

One of the obstacles to any attempt to reverse this trend is the bad press physics has had as a result of its unfortunate association with one of the curses of the modern age - the atomic bomb. If only, I thought as I skirted the razor wire fence in my 45 minute walk from the railway station to the north gate at Sellafield, there had been no atomic bomb - perhaps even nuclear power would have got a fair hearing. After all, the debate on nuclear power has always been dominated by preconceptions and misconceptions on both sides, together with a spectacular failure to apply a sense of proportion, particularly where the risks are concerned. Certainly there would not be all this security, complete with armed police who looked as though they were about to arrest me for suspicious behaviour!

But that was wishful thinking. Just how wishful was graphically demonstrated to me after I had reached the gate and joined the rest of the group, who had arrived by car. For it was July 9th, and this was the FUSION visit to Windscale in Cumbria, the UKAEA part of the site, which did not change its name when the reprocessing plant became Sellafield several years ago. Here are some of the very earliest reactors; and the enigmatically named Pile 1, the subject of our first tour, illustrated very clearly the link between nuclear power and the bomb.

It is rather comforting to reflect on just how long it takes for your average megalomaniac to purify uranium by the method of separation of isotopes to the degree required to make a bomb. (If you want to know how long, do S280!) However, if he or she has a nuclear reactor available, it is much easier, because there is then a ready made supply of plutonium.

Nuclear fission in a reactor consists of a series of reactions, in each of which a nucleus of ²³⁵U, the lighter and more unstable isotope, splits into two, emitting neutrons which, after being slowed down by a moderator, produce further fissions in other ²³⁵U nuclei. For a sustainable chain reaction it is only necessary for each fission to produce, on average, one additional fission. But the average number of neutrons emitted by a disintegrating ²³⁵U nucleus is about two; the extra neutrons will be absorbed by the far more numerous ²³⁸U nuclei, transforming them into a heavier uranium isotope, which then beta-decays to plutonium:

²³⁸U + n  →  ²³⁹U  →  ²³⁹Np + e^- +  →  ²³⁹Pu + 2e^- + 2

So all you have to do is remove your fuel after a while and reprocess it to extract the plutonium. This was the sole function of Pile 1, and its sister plant, Pile 2. No energy from the reaction was used to make electricity; each reactor was air-cooled by gigantic fans which blew a ton of air per second through the core and straight up the chimney into the atmosphere. They even had a very clever device for extracting the plutonium in regular amounts - each fuel element, which was inserted into the core horizontally, was actually made up of a large number of interlinked sections, and as the element was pushed through the core the plutonium-rich section emerging on the other side would drop off and fall into a conveniently-placed pond for collection by automated "skips". It was important that each section spent just the right amount of time in the core, because otherwise the fissile plutonium would eventually absorb more neutrons to produce less reactive isotopes:

²³⁹Pu + n  →  ²⁴⁰Pu etc.

In 1957, Pile 1 caught fire, releasing radioactive isotopes such as iodine-131 and polonium-210 (the latter was being produced in the reactor for use in the initiators of atomic bombs) into the atmosphere. After the fire had been put out, both Piles 1 and 2 were shut down. Much of the fuel in Pile 1 had by this time been removed, as was all the fuel in Pile 2; but fuel elements that had been damaged by the heat could not be moved. Nearly fifty years later, these fuel elements are still in the reactor, along with the control and shut-down rods, which have been sealed in. UKAEA are involved in a clean-up programme, but they are still at least five years away from any serious decommissioning.

In the afternoon, after being treated to a nice buffet lunch by our hosts, we turned to a slightly later, and slightly more peaceful, development - Windscale's prototype Advanced Gas-Cooled Reactor, WAGR (the famous "giant golf-ball" which features in all the photographs, even those which purport to be of the reprocessing plant!) which was built in order to finalise the design for what became the UK's second generation nuclear power stations (six were built and are still operating). The WAGR decommissioning is being done by a very clever machine, built and controlled by even cleverer humans; nothing is left of the radioactive core, but the "escape hatches" have been thoughtfully left in place in case there is an emergency of a slightly more humdrum nature than that for which they were designed. We were disappointed, however, to find, on leaving the building, that they lead to conventional fire-escape staircases, and not fairground slides!

In S280 we were taught that the decommissioning costs of a nuclear reactor are estimated in advance, and built into the quoted cost of producing electricity during the plant's lifetime. But it was not at all clear how realistic these estimates had turned out to be. At least two members of our group thought that the actual decommissioning costs would bear little resemblance to the original estimates, making nuclear power simply not an economically viable option. So, even assuming that we eventually become wise enough to stop making bombs, there may not be a case for nuclear power unless we turn to it in desperation in order to prevent global warming. Yet back in the 50s and 60s, nuclear power was clearly thought to be the power of the future - this was the overwhelming impression I got from UKAEA's research site at Winfrith, which FUSION visited last year. It is just inconceivable that the physicists there would have worked so hard and so meticulously if they had had an inkling of the stigma that would soon become associated with their chosen field.

Perhaps the best hope - for physics as well as for the planet and all its inhabitants - lies with the physicists working in UKAEA's other branch - the Fusion Research section, based at Culham, and their colleagues who will build the "next step" device, ITER. I remain confident that they will eventually show the world that physicists are capable of inventing something that not only cannot be used for destructive purposes, but just might save us from the environmental catastrophe currently being stoked up in coal and oil furnaces all over the world.

STOP PRESS: The fence just got higher!

After many attempts to organise a FUSION visit to a nuclear power station, specifically the one at Sizewell in Suffolk (with thanks to Chris Seaman for her efforts), it has come to light that the Government has put a stop to ALL visits to nuclear power stations, citing the threat of terrorism as the reason.

One cannot help wondering exactly what damage a terrorist is supposed to be able to do to a 2-metre thick concrete containment vessel, especially if airport-style security measures were installed to prevent him or her from taking any weapons onto the site!

This over-reaction will only serve to ensure that those who oppose nuclear power through prejudice or lack of information will continue to do so, and in fact may begin to believe that the nuclear authorities have something to hide, and are just using terrorism as an excuse. And, to be honest, how do we know they haven't?

PHOTO REPORT

Visit to the Mullard Radio Observatory in Cambridge

Research student Tak Kaneko describing the Arcminute Microkelvin Imager. AMI, an array of small dishes, will search for Sunyaev-Zeldovich silhouettes in the cosmic microwave background radiation which indicate the presence of galaxy clusters in the early universe.

The group listens as our guides Bodie and Dominic explain the workings of one of the telescopes. L-R: Delphine Murray, Jim Grozier, Alex Clark (with Chris the Bug), Wendy Mayhew, Janet Cook, Bill Willows, James Dallard and Ian Murray. Photos: Kim Vignitchouk.

The Magic of a Name

Rolls-Royce and its Aero Engines - by John Taylor

It is 100 years since the first meeting, in the Midland Hotel in Manchester, of Henry Royce and the Hon Charles Rolls, the founders of what was to become the aero engine division of Rolls-Royce. Since this time life has changed from travelling by horse to flying round the world in 400+ passenger aircraft powered by engines each delivering up to 95,000 lb of thrust. Although a global company, the main aero engine centre at Derby is always called Royce's by the employees in recognition of the true engineer of the partnership.

Royce, in partnership with Ernest Claremont struggled to establish a company that produced, amongst other things, electric cranes of high longevity. But it was the strange, lovable Rolls, a motoring enthusiast, who had the vision of a motor car which was to become a household name for quality and reliability.

The need to service a growing demand for its products caused the company to open a factory at Nightingale Road in Derby in 1908, chosen because low priced electricity was available. However the partnership ended in 1910 with the tragic death of Rolls. He had the dubious honour of becoming the first Englishman to die in an aircraft accident. Royce, himself in ill health, kept the business running, often from his bed, by a fertile mind and new design ideas.

C. S. Rolls and Henry Royce.

The opportunities of war meant that the engineering skills of the company could be used to develop a safe, reliable and easy-to-manufacture engine, named the Eagle, which powered the Vickers Vimy on the first non-stop transatlantic flight. It was the second world war which saw the development of the Merlin engine introduced into the Spitfire fighter and Lancaster bomber that was to play such an important part in the conflict and the future of Rolls-Royce. The development of the first jet fighter to see active service and the first gas turbine powered airliner to fly, paralleled the development of the most luxurious cars in the world, power plants for warships and tanks as well as power generation installations.

The expansion of the commercial aviation industry in the late 50s and 60s saw an intense competition across the Atlantic for the lucrative aero-engine market but there were simply too many players and it became a period of merger, consolidation and rapid technical development. Royce's took on the might of the US, not only at a time of uncertainly about the strength of the dollar, but also US protectionism - the president of Eastern Airlines, Eddie Rickenbacker, proclaimed "I won't have a limey engine at any price".

The scale of the advance was enormous - as was the size of the proposed new engine. The future for Royce's lay in a radically new design of engine, the RB211, which incorporated unique features such as: the largest turbofan ever built by Rolls-Royce; a revolutionary three shaft engine design; modular construction; and the extensive use of a composite called Hyfil. Such original ideas enabled Rolls-Royce to offer not only commercial guarantees, but commitments on the cost of parts, noise, smoke, fuel consumption and performance levels that could not be matched by the competitors. It was a golden opportunity that resulted in Britain's biggest export order.

These guarantees came to haunt the development of the engine. There were notable technical problems that could not be solved in the timescale promised. In particular the faith in an unproven Hyfil fan blade meant that a last minute redesign using titanium was required - and there was just not enough time. On February 4 1971 the board declared "It is no longer possible to continue with the present contract, Rolls-Royce has therefore called in the receiver". The feeling in the country was one of stunned disbelief - it was almost as if Great Britain had gone bust.

The three shaft RB211 engine design.

Herculean efforts were needed just to stay solvent. The author remembers pay freezes and frequent audits to check that new pencils were not taken from stores until the old ones were less than two inches long! (Even pencil extenders, at unknown cost, were manufactured to enable use until the pencil literally fell apart).The car division was sold off to provide cash, and it is frequently forgotten that Rolls- Royce, as a British company, no longer makes motorcars.

But cream rises, and the insistence of the engineers to maintain quality standards - at all costs - eventually started to pay returns. Trust returned in that the airlines continued to give business to Rolls-Royce. This was not entirely altruistic; they understood the need to maintain a healthy aero engine competition in order to drive cost down.

The replacement for the Hyfil fan blades, a unique wide chord titanium design that has been used ever since, started to pay back the faith of the airlines - in dollars - and the RB211-535 became the first Rolls-Royce engine to be launched on a Boeing aircraft. Other arms of the business were also prospering. The supply of energy in all its commercial forms became the company's business. Power generation, oil pumping, military aircraft and ships have represented a diversification sadly lacking in the early years. The years of Margaret Thatcher as British Prime Minister prompted a brave, but necessary, return to privatisation.

After 16 years the management was able to dictate its own future - and the future looked bright. RR engines were in service with 270 airlines around the world, 110 armed services and 175 industrial customers. Its gas turbines powered the naval vessels of 25 countries. As a private company Rolls-Royce was determined to compete with an engine in every market sector and this was a key strategic decision to produce a family of engines such that the high initial investment could yield commonality of design, maintenance techniques and logistic support and thus offer benefits of low cost of ownership. A critical breakthrough saw a magnificent order from American Airlines in 1988 and the company at last came of age.

Fiercely proud of their engineering skills, pride in their company, the ability to work to programme needs and not to timepiece schedules have been the hallmark of employment at Rolls-Royce over the last 35 years (as the author will vouch!). Times have been difficult. Aircraft accidents, oil price increases, military actions and terrorist attacks have instantly driven the market down, sometimes overnight.

Few engineers and scientists elect to leave the technical challenges of working at the real sharp end of such a demanding environment. Examinations of competence are tested daily and the industry is intolerant of mistakes and shoddy practices. Napoleon is reputed to have demanded of his generals "ask me for anything but time", but this is the main driving force for meeting ever demanding customer requirements. Programme management has driven ever harder as deadlines loomed and the need to maintain unique standards of quality is frequently tested.

The author has been both Programme Manager and Quality Assurance manger over the past 35 years. If there was ever a poacher turned gamekeeper! But it has been the individual pride of the scientists and engineers at all levels that has ensured that most go home, however late, with a feeling of a "job well done". It was no accident that the history of the company is entitled "The Magic of a Name"

John Taylor is a retired former employee of Rolls Royce. Although he has a BSc, he is currently brushing up his science by studying S103. He also serves on the FUSION Committee. All pictures courtesy of Rolls-Royce plc.