An Astronomy Park around Virgo! C O N T E N T S

NEWS FROM THE COLLABORATION 3 “h - The Gravitational Voice” is an internal Squeezing light to catch gravitational waves publication of the European Gravitational Observatory (EGO) and the Virgo Collaboration. FROM THE WORLD 6 The content of this newsletter does not The Japanese Large-scale GW Telescope: KAGRA necessarily represent the opinion of the management. LISA Pathfinder An Astronomy Park Editor: Carlo Bradaschia Editorial Staff: NEWS FROM THE SITE 13 Henrich Heitmann Gary Hemming The 2012 VESF School Martin Mohan The new EGO optics laboratory Séverine Perus The Biathlon 2012 Frédéric Richard

Production: Séverine Perus OUT & ABOUT 16 Copenhagen, a drama Published in electronic format on the EGO Web: www.ego-gw.it LETTERS TO THE EDITOR 20

E D I T O R I A L

While reading the following two articles on wind turbines in the April issue of Europhysics News: C. le Pair, F. Udo and K. de Groot: Wind turbines as yet unsuitable as electricity providers. http://dx.doi.org/10.1051/epn/2012204 and P.J. Eecen, H.A. Bijleveld and B. Sanderse: Wind energy research - development of advanced design tools. http://dx.doi.org/10.1051/epn/2012203 I was surprised to read such sharp opinions in such a widely diffused and normally “soft” magazine. Hence, I thought it would be interesting to hear the reactions of the EGO and Virgo folk and, as such, I advertised the two articles by e-mail. We publish in this issue of h, in the column “Letters to the Editor”, a subsequent exchange of letters and we mention the fact, upon the suggestion of Andrea Vicere’, that EPS and SIF are organising a school dedicated to the theme: http://en.sif.it/activities/energy_school/2012 with ‘energy storage’ being one of the central topics. We will be happy to receive and publish further comments on this hot subject.

C. BRADASCHIA Editor-in-Chief

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one. It does not take into account the fact that guitar strings (or the Squeezing light to catch electromagnetic field constituting a laser light wave) follow the rules of gravitational waves quantum mechanics. A quantum oscillator behaves in a quite peculiar way. We cannot That the expected amplitude of a for the VIRGO sensitivity is thermal determine exactly its “position” and gravitational wave is quite small is motion. But let us suppose that in a its “velocity” at the same time: a fact familiar to readers of h. So it not too far future thermal noise will accordingly with the so-called should not come as a surprise that be reduced by a large factor. Then Heisenberg uncertainty relation the catching a gravitational wave is a we will find that there is a kind of product of the indeterminacy of these difficult task. It is mainly a struggle noise which is linked in a very two quantities cannot be smaller against various noises which do their intimate way with the measurement than a value proportional to a best to mask the expected effect, a procedure used. We can call it optical fundamental physical constant called distance change between two noise or, for reasons that will be h. This has interesting consequences suspended mirrors. discussed in the following, quantum that I will try to illustrate with some noise. examples. Due to the smallness of the quantities The surprising point about quantum involved, measuring the position of noise is that it could seem that it a mirror with a ruler is out of gives a limit to the sensitivity that Figure 2 – The behavior of a question and the VIRGO way to do cannot be evaded for fundamental quantum ball oscillating at the that is by using interference. In a reasons, no matter how smart we bottom of a valley. The oscillation nutshell, a light wave (the laser are. This is called Standard Quantum is along the blue axis, while time beam) is sent to a far away mirror, Limit (SQL). increases along the red one. Each and the reflected wave is observed. color corresponds to a possible The information about the mirror’s When we think about a wave, we classical motion which starts at the position is contained in how many imagine something which is similar same position with a different initial times the wave oscillates before to the picture sketched in Figure 1. velocity. coming back. There is something which can oscillate, such as a guitar string, and Obviously the mirror moves for a the “position” and the “velocity” of lot of reasons unrelated to the a given piece of the string is well presence of gravitational waves, and defined at any time. The trouble with currently the fundamental limitation this picture is that it is a classical

Figure 1. The VIRGO way to measure the position of a mirror. The light sent to the mirror (in red) is reflected back (in green) to the observer.

In Figure 2 I represented the possible positions of a small “quantum ball” oscillating inside a valley as a function of time. In drawing the picture I supposed that initially the ball was found with pretty good accuracy displaced in the positive direction from the bottom of the valley. The initial ball velocity is thus uncertain, this uncertainty becoming larger and larger with the precision of our knowledge of the initial position. Several initial velocities will be possible, and for

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each of them the position of the ball the possibilities. As we are interested works. However increasing the laser will change in the following in a in measuring the displacement of power is not a painless option, as it different way. The uncertainty about the wave (that is, its phase), a leads to several issues which are not the position will grow reaching a measurement will select one of the easy to deal with. But let us suppose maximum after a quarter of the classical oscillations compatible with that these could be solved: still we oscillation period, and then it will the given indeterminacy. By looking find that quantum noise cannot be start to decrease and so on, at Figure 2 we see that there are reduced arbitrarily in this way. continuously oscillating between a several different phases which can The reason is simple to understand: maximum and a minimum. come out after the measurement, as it is clear from Figure 3, a evidenced as classical curves with coherent oscillator fluctuates both This “quantum ball” behaves quite different colors. In other words we in phase and in amplitude. When strangely, but maybe I set it up in have a quite large phase the laser is reflected by the mirror the wrong way. If we want to obtain indeterminacy. it acts on it with a pressure a more “classical” ball it is better to proportional to the square of its avoid a too accurate initial position For the coherent states in Figure 3 amplitude. If the amplitude measurement, which unavoidably things go somewhat better. Once fluctuates the pressure will also and triggers a large increase of the again the phase is not completely the mirror will be displaced from its uncertainty afterwards. determined, but its indeterminacy is original position in an unpredictable much less than before. I plotted two way, changing the phase of the reflected beam anyway. When the The knowledge about the position extreme possibilities for each wave (thin gray lines): this is an estimate laser power is low this effect will of a classical oscillator can be perfect be small, but the intrinsic phase in principle and it does not change of the limit on the sensitivity to the position of the mirror. indeterminacy of the coherent state with time. The most similar quantum will be large. On the other hand oscillation we can construct is the when the laser power is increased so-called coherent state, which is By looking carefully at Figure 3 we the intrinsic phase indeterminacy actually a quite accurate model for realize an important point: the phase will decrease, but the phase a laser beam. In this case the position indeterminacy of the orange curve indeterminacy induced by the shaken indeterminacy is not zero, but at is lower than the green curve’s one. mirror will increase. There will be least it is time independent. This is This seems to suggest a simple way an optimal intermediate power that showed pictorially in Figure 3: in to reduce phase noise: we could will give the lower phase the case we are interested in, the simply increase the field amplitude, indeterminacy obtainable, which is plot could represent the value of the by buying a more powerful laser. the Standard Quantum Limit laser field at a given point as a Up to some extent this certainly mentioned before. function of the time. The two colors correspond to two waves with different amplitudes, and at a given Figure 3. In a coherent state the knowledge we have about the amplitude of time the indeterminacy is the laser field does not change with time, and it is the better we can get with represented by the thickness of the this constraint. This is the best approximation we can have of our intuitive curve. (classical) concept of a wave.

We should keep in mind that there is no such thing as a “real” classical trajectory followed by the oscillator but hidden by our ignorance: at a given time the oscillator is in a quantum superposition of positions. I will not discuss here the fascinating subject of the meaning of this quantum superposition concept, which is a severe challenge for the common sense (1).

From our point of view we can see a quantum superposition as a noise source: when we measure something about the oscillator we will find a result selected randomly among all

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But this solution does not work. As Figure 4 - The state of a quantum oscillator can be changed. On the left side there’s no such thing as a free lunch, four different states for an incoming laser beam are depicted. The beams we see that together with a reduced reflected by a suspended mirror are described by new states, which are phase noise there is an increased represented on the right side. Some classical oscillations compatible with the amplitude one (2). When a laser beam indeterminacy are superimposed in each case. in this “phase squeezed state” is reflected on a mirror, it shakes it a lot, and the reflected beam (on the right side in Figure 4) is in a state with an increased phase noise. This is the same effect that leads to the Standard Quantum Limit (see the first row of Figure 4) but worsened.

On the other hand if we try to use an “amplitude squeezed state” like the one which is represented in the third row of Figure 4, this will be reflected by the mirror without shaking it a lot. However a large phase noise will be present in the beam since the beginning: this is not a good option either. The simplest options do not seem to work well, but there is a large class of possible “squeezed states”. In the “phase squeezed” and “amplitude squeezed” states I described so far the probability of having a phase fluctuations is independent from the probability of having an amplitude one. In the general case we can introduce correlations between the two. And it turns out that doing this in a clever way we can obtain a “squeezed state” that, after being reflected by the mirror, has a phase noise reduced compared with the one of a “coherent state”. An example is represented in the last row of Figure 4. This opens the door to several interesting possibilities of evading the Standard Quantum Limit. In the last decade these have been extensively studied theoretically and It seems that there is no way to escape find something useful. tested experimentally. The level of from this, but this is not true. A hint noise reduction is continuously about a possible way out comes from The first option could be to use a increasing, and the key issue here is the “strange” quantum oscillation we squeezed state with less phase noise the ability of generating laser beams saw in Figure 2, which is a member compared with the one of a coherent with large squeezing (3). of a family called “squeezed states”. state. An object of this kind in fact This particular “squeezed state” is exists; it is appropriately called a Squeezed light will be applied in the no better than a coherent one as its “phase squeezed” state and is next generation of advanced phase noise is larger, but maybe with represented in the second row of gravitational waves detectors. It will some exploration it is possible to Figure 4, above. become in the future a more and

THE GRAVITATIONAL VOICE - JULY 2012 5 N E W S F R O M T H E W O R L D more important aspect in the design KAGRA was selected as the new of gravitational wave observatories. nickname for LCGT, which is associated with the Kamioka G. CELLA, Pisa Group Gravitational wave detector, and a new logo (see Fig. 1) was chosen (1) For those who are interested to a subsequently. In Japanese, the word non technical but careful introduction kagura means music and dance in I cannot resist the temptation of honor of Japanese gods. In this Fig. 1. Logo of KAGRA suggesting a book: G. Ghirardi, article I will briefly explain the Sneaking a Look at God's Cards, objectives, design, preparation, Princeton University (2007). It requires schedule, and organization of pendulum. Each stage also acts as a some effort, but it is worth of it. KAGRA. very low-resonant-frequency vertical isolator with the help of geometric (2) This is a general consequence of The objectives of KAGRA are to anti-spring effect, invented by the Heisenberg uncertainty relation, Riccardo DeSalvo. The mirrors of which can be rephrased by saying that detect gravitational waves and to establish a new astronomy - the arm cavities are cooled to 20K the product of the position error at a in order to reduce the thermal noise. given time and after a quarter of period gravitational wave astronomy - together with Virgo, LIGO, and For this purpose, sapphire substrates is constant, so if we reduce the first we and fibers will be used because of should increase the second. I encourage GEO in the context of the worldwide you to verify this on all the oscillations network. We are especially interested the material’s excellent mechanical in Figure 4. in detecting gravitational waves and thermal properties. The lower coming from neutron star binary stages of the SAS are set up in a coalescences. These detections cryostat (see Fig. 4), and are cooled (3) I will not discuss here in detail how by a pulse tube cryocooler via soft a squeezed beam can be generated. This together with simultaneous gamma- is done routinely today in optical ray observations will, for instance, heat links to the intermediate masses. laboratories. I want only to remark that allow us to determine whether The cryogenic thermal shield around when we reflect a coherent state on a neutron star binary coalescences are the masses and inside the beam tube mirror, the reflected beam will be in a truly an engine of short gamma-ray (up to 20 meters from the masses) squeezed state, as shown in the first bursts. We also expect to detect prevents the masses from being row of Figure 4. gravitational waves coming from exposed to the thermal radiation black hole binary coalescences, from the room temperature vacuum supernovae, pulsars, etc., although chamber and beam tubes. The the expected detection rate for such topology of a power-recycled Fabry- events is not well established. Perot Michelson interferometer, The Japanese which is used for most of the 1st- Large-scale KAGRA consists of a 3km long generation detectors, such as Virgo, Resonant Sideband Extraction (RSE) LIGO and TAMA300, will be Gravitational interferometer with the cryogenic enhanced by an RSE configuration, mirrors suspended from the Seismic for which an additional mirror is Wave Telescope: Attenuation System (SAS). The placed at the anti-symmetric port. detector will be built underground KAGRA in the Kamioka mine, 200m below the surface, as illustrated in Fig. 2. Fig. 2. Illustration of KAGRA located The vibration level at the site is a underground in the Kamioka mine. factor of 100 smaller than the surface, which After long and arduous efforts the together with the SAS, Japanese Large-scale Gravitational reduces the seismically- wave Telescope (LCGT) was finally originated mirror motion approved by the Ministry of drastically. The SAS Education, Culture, Sports, Science was developed based on and Technology in June of 2010. the Virgo Super- Although a significant amount of attenuator technologies, delay was caused by the Tohoku and in collaboration with Earthquake and its aftermath, the LIGO. As shown in Fig. excavation of the tunnel at the 3, the SAS consists of Kamioka mine was finally started an inverted pendulum on May 22, 2012. Meanwhile, and a multi-stage

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Fig. 5. Sensitivity limit of KAGRA.

This configuration allows us to and the observation range must be optimize the quantum noise, that is larger than ~180 Mpc. Here, a composed of shot noise and radiation signal-to-noise ratio of 8 for pressure noise, with regard to the gravitational waves incident normal chirp signal expected from a onto the detector is assumed. The compact-star binary coalescence. spectrum of the sensitivity limit of KAGRA is shown in Fig. 5, which KAGRA is required to detect gives an observation range of ~280 gravitational waves coming from Mpc. In reality, however, we neutron star binary coalescences anticipate that various practical more than once a year with deviations from the ideal design Fig. 3. Seismic Attenuation System probability of higher than 90%. To could impair this sensitivity limit. for KAGRA. The upper and the satisfy this requirement, the duty lower parts are separated by solid factor of KAGRA must exceed 80% rock. In Japan we started research and development for the detection of Fig. 4. Sketch of the cryostat and cryocoolers designed for KAGRA. gravitational waves with a laser interferometer around 25 years ago with the 10m and, later, the 100m delay-line prototypes at Institute of Space and Astronautical Science (ISAS), and then with the 20m Fabry-Perot prototype at National Astronomical Observatory of Japan (NAOJ). Encouraged by the successful results on those prototypes, we proceeded to realize TAMA300 at NAOJ and CLIO at the Kamioka mine facility of the Institute for Cosmic Ray Research (ICRR), University of Tokyo. TAMA300 is a power-recycled Fabry-Perot Michelson interferometer, where a simpler version of SAS was installed and its performances were successfully

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verified. CLIO, the 100m cryogenic observation run in 2015 to check Engineering Office (SEO). KAGRA prototype interferometer, was built the data acquisition system and council consisting of the directors to demonstrate the cryogenic analyze the obtained data. We hope of ICRR, KEK, and NAOJ and other technologies required for KAGRA. that we can achieve a sensitivity important members determines At room temperature CLIO has good enough to join the worldwide critical issues on the project. achieved a sensitivity limited by network of gravitational wave KAGRA also has Program Advisory both the suspension thermal noise detection. Then we will proceed to Board (PAB) and External Review and the mirror thermal noise. By bKAGRA. Board (ERB). PAB consisting of senior members in the GW and neighboring field (including European members: Benoit Mours and Bernard Schutz) reviews mainly the management aspects of KAGRA, while ERB consisting of researchers with high expertise in the GW field (including European members: currently Raffaele Flaminio, Andreas Freise, Roberto Passaquieti, and Benno Willke, and formerly Alessandro Bertolini) reviews mainly the technical aspects of KAGRA. KAGRA employs the underground location and cryogenic mirrors, which are key technologies for the 3rd-generation gravitational wave detectors, such as the Einstein Telescope (ET). Therefore, KAGRA is not only one of the 2nd-generation detectors, aiming for the first direct detection of gravitational waves, but Fig. 6. Sensitivity of CLIO operated with the two front mirrors at room also plays an important role for (grey trace) and cryogenic (red trace) temperature. (Takashi Uchiyama, future generations to further develop et al., Phys. Rev. Lett. 108 (2012) 141101) gravitational wave astronomy. Hence, we are naturally collaborating with the ET project cooling of the two front mirrors a It is an RSE interferometer with a by exchanging young scientists with reduction of thermal noise could full SAS and sapphire mirrors at the ET-LCGT interferometric successfully be demonstrated (see cryogenic temperature. We hope to Telescope Exchange of Scientists Fig. 6). This was a crucial milestone finish the installation and (ELiTES) program led by Michele for the success of KAGRA. commissioning to start an obser- Punturo on the ET side and with the vation run around 2017 - 2018. student fellowships on the KAGRA After the tunnel is completed, which side (we also plan to submit a is expected to happen in March of The KAGRA project is hosted by proposal equivalent to ELiTES). 2014, we plan to build KAGRA in ICRR with strong support from the two stages: initial KAGRA High Energy Accelerator Research KAGRA is still in the initial stage (iKAGRA) and baseline KAGRA Organization (KEK) and NAOJ, as of the project, but we truly hope that (bKAGRA). iKAGRA is a simple well as from more than twenty we can achieve a good sensitivity Fabry-Perot Michelson domestic and more than ten as soon as possible to join the world interferometer with a modest international institutes/universities. network of gravitational wave vibration isolation system and fused KAGRA is led by Principal detection. silica test masses at room Investigator, Takaaki Kajita, who is temperature. We decided to start also the director of ICRR and the Professor Seiji Kawamura with iKAGRA to gain some useful Executive Office (EO). The EO Institute for Cosmic Ray Research University of Tokyo experience for a km-class manages fourteen subsystem groups Subproject manager of KAGRA interferometer and also to learn with the help of the Project Member of GWIC technical challenges for bKAGRA. Management Support (PMS) group We plan to conduct a short and mostly through the Systems

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LISA Pathfinder: achieving near-perfect free-fall for gravitational wave astronomy

Free-fall and gravitational wave detection

A gravitational wave is “felt” as acceleration caused by noise of the with millions of solar masses that a tidal effect, a position-dependent detector as a displacement sensor, merge at frequencies far below the acceleration that stretches and and, second, any true residual terrestrial observation band. contracts, just as the gravitational acceleration of the test particles Achieving – or not achieving – the field of the sun and moon is caused by spurious forces unrelated target acceleration noise floor observed in the swelling of the ocean to the gravitational wave. For this determines the LISA resolution at at opposite sides of the Earth. A second reason, the free-falling test and below several mHz, and thus gravitational wave detector’s simple, particles are also known as also the number of astrophysical but difficult, task is that of measuring “geodesic reference” test masses, as sources that we can observe, to what the minute tidal deformation that a they ideally serve as references of distance, for what length of passing gravitational wave produces purely gravitational orbits. observation time, and how well we on a constellation of free-falling test will know their sky positions. particles. For LISA, the maximum tolerable deviation from perfect free-fall is Given the impact that free-fall will In terrestrial laser interferometer quantified by a residual acceleration have on gravitational wave science, detectors like VIRGO and LIGO, noise with a noise power spectral it is reasonable to ask can we -15 2 1/2 aimed at sensitivity in the range of density below 3 10 /s /Hz . This really use an apple-sized test mass 10 Hz to audio frequencies, the test translates to a background of as a reference of pure free-fall with particles are suspended end mirrors spurious acceleration low enough such precision, well below a femto- several km apart, which are in free- to allow, in several hours time, g (“femto” means 10-15)? Probably fall except for calibrated suspension resolution of a gravitational yes, according to analysis and earth- and control forces. For ultra-low differential acceleration with based measurements of the small frequencies, from nano to microHz, amplitude 10-17 g – where g = 9.81 forces that can perturb the test mass several dozen neutron star pulsars m/s2 is the well known acceleration orbit. However, a complete answer scattered across the Milky Way can due to gravity at the Earth’s surface to this question awaits the results of serve as test masses, with – with oscillation periods from 5 LISA Pathfinder, the “Einstein gravitational wave strain detectable minutes to several hours. geodesic explorer” mission. in the Doppler-shifted arrival of their Coincidentally, this requirement for radio beacon “clock” pulses at low acceleration noise is similar to earthbound radio telescopes. For that needed, around 10 Hz, for LISA Pathfinder gravitational wave detection in the Advanced VIRGO. intermediate 0.1 to 100 mHz band, LISA Pathfinder (LPF) is a the LISA – Laser Interferometer European Space Agency (ESA)-led Space Antenna – mission concept LISA will observe binary systems of compact objects – solar mass mission aimed at achieving, and foresees roughly-kg test masses measuring, sub-femto-g free-fall orbiting around the sun in a nearly black holes, neutron stars, and white dwarfs – at a point in their evolution with the core hardware that will be equilateral triangle with several used for LISA. It will launch in million km side length. millions of years before their orbital frequency reaches the audio 2014, from French Guyana, into the frequencies range detectable by 1st Lagrange point roughly 1.5 These detection techniques are all VIRGO, minutes before their final million km toward the sun, with the forms of differential accelerometry. merger. More unique to LISA are aim of guaranteeing the differential The gravitationally-induced relative gravitational waves from compact accelerometry resolution that is acceleration of the free-falling test objects falling into the massive black needed to open the window of space- bodies is measurable, but it is in holes at the centers of galaxies and based gravitational wave direct competition with two main coalescences of the massive black astrophysical observation in the next noise sources: first, the fake effective holes themselves, binary systems decade.

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radiation pressure that would otherwise dominate its residual acceleration. The remaining sources of force noise relevant at the femto- g level include cosmic ray charging of the test mass and stray electrostatic fields; test mass magnetic impurities and the interplanetary and spacecraft magnetic fields; Brownian motion from residual gas impacts; fluctuations in nanoNewton-level applied electrostatic control forces; spacecraft self-gravity fluctuations.

All of these noise sources, and others, will be tested on LISA Pathfinder. The most threatening sources are those acting on the test mass surface due to the surrounding electrostatic, magnetic, vacuum, and thermal environment; these sources can be well-characterized on ground with torsion pendulum Figure 1 Illustration of the LISA Pathfinder science payload, featuring the two measurements of small forces with 2-kg Au/Pt test masses, separated by a Zerodur optical bench with interferometry suspended LISA-like test masses hardware to allow a relative acceleration measurement. inside of the relevant flight hardware. Finally, Brownian noise, stray electrostatic fields, noisy Space allows much larger test temporal variations in the Earth’s control forces and other sources particle separation than the km-sized gravity. As both the sensitivity level targeted by LPF are relevant to a interferometry arms possible on and low frequencies required are broad class of experiments with earth. It eliminates the force noise difficult to reach in an Earthbound reference test masses, including introduced by suspending the test laboratory, an in-orbit experiment Virgo. Thus, the LPF investigations mass in 1 g – indeed it eliminates like LPF is necessary to build a physical model of the limits the need to touch the test mass at convincingly demonstrate the to achieving perfect geodesic motion all – and radically extends the time measurement science needed for for experimental gravitation. scale over which the test mass can space-based gravitational wave be considered in free-fall. It also astrophysics. Figure 2 shows a conservative allows us to safely distance the test prediction for the LPF acceleration masses from the Earth’s locally The idea of LPF is to drastically noise performance, based on noisy gravitational field from shrink a single LISA arm to fit into extensive ground testing of both the moving water, rock, air, and life. a single spacecraft, with two free- interferometry sensitivity and force These are the reasons why we need falling test masses separated by 40 noise sources. In addition to to go into space to detect cm, and then perform a laser improving upon the official mission gravitational waves at frequencies interferometer measurement of the goal, the expected performance below 1 Hz. residual relative acceleration meets the LISA acceleration noise between the two test masses. The goal at all frequencies above 1 mHz. Space does not remove, however, sensitivity to gravitational waves is In so doing, LPF should guarantee the residual interaction with the co- lost in the factor 109 reduction of the the core LISA scientific return, orbiting satellite and the local test particle separation, but the including high precision observation environment around the test mass. relevant noise sources for the stray of gravitational waves from a Additionally, the LISA acceleration TM acceleration remain and will be number of known white dwarf noise goals are three orders of detected at the femto-m/s2-level. binary systems in our galaxy. Also magnitude beyond what is currently shown are current upper limits to achieved by the best space The co-orbiting satellite, in addition surface forces acting on the test differential accelerometry to housing interferometry hardware, masses, based on torsion pendulum experiments, such as the GOCE shields a LISA or LISA Pathfinder measurements with prototype flight mission, which measures spatial and test mass from the fluctuating solar hardware, indicating that LISA

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would allow gravitational wave observation, even if the flight performance were no better than that already demonstrated with our more modest ground instruments.

Challenging economic times and evolving science programs inside both ESA and NASA have increased the error bars relevant to the launch date of LISA and have reopened discussion of many aspects of the mission – including the orbits, the optimal size and number of laser links for the available budget, the nature of the collaboration between different agencies, even the use of the name “LISA” itself. The astrophysical science case and performance requirements remain unchanged, however, as does the measurement technique and key Figure 2 Expected performance for the LPF acceleration noise upper limit hardware. LISA Pathfinder is (black) compared with the LPF and LISA mission specifications. Also shown financed to fly, and it represents, in are the acceleration noise levels required to observe gravitational waves from Virgo terminology, the a number of known galactic white dwarf binary systems and torsion pendulum commissioning phase for the final upper limits on the contribution from test mass surface forces. [Presented at space gravitational wave the Marcel Grossmann 12 Conference in July, 2012] observatory, whether or not it is named LISA. We hope to provide an update, with data from the orbiting LPF spacecraft, in just a For more information on LISA Pathfinder, see: couple of years! http://www.rssd.esa.int/index.php?project=LISAPATHFINDER&page=Index and http://www.esa.int/esaSC/120397_index_0_m.html. William Joseph Weber Università di Trento 19 June 2012 For the evolving LISA concept, see: http://elisa-ngo.org/.

Decoindustria? Decoindustria, which a plant devoted to the treatment of is situated between Chiesanova and contaminated liquids. It was closed An Astronomy the Virgo North End Building, was by the Italian magistracy for illegal Park

by Sara Baglini

I live in Santo Stefano a Macerata, in the vicinity of EGO. My thesis to obtain the “architect” degree at the University of Florence was inspired by two outstanding structures in the territory. One is EGO and the other is the remaining structure of Decoindustria. We already know about EGO but what about

THE GRAVITATIONAL VOICE - JULY 2012 11 N E W S F R O M T H E W O R L D management of poisonous waste. “Gira.sole Luoghi di by students and researchers. At Scienza” ground level all the common The idea took shape of converting The original landscape was utilities: kitchen, library, reading the industrial plant to something characterized by the horizontal lines hall, pub. On the upper floor rooms nice and useful for the community. of fields, interrupted by cypress rows and small apartments will be Virgo was the inspiration for the and a few farm houses. The new available for longer stays. proposal to create a national Science landscape will be dominated by the Park dedicated mainly to astronomy. existence of the EGO observatory The Planetarium and the Museum Virgo would play a strong role in and by the large industrial complexes will preserve the size and the shape attracting people while the converted for public use. of the two largest tanks of the old attendance would be enhanced by The needs of students, researchers industrial plant. Their pure the location along the linear and tourists will be taken into geometrical shape corresponds very metropolitan area, which is expected account within the framework of a well with the new safe technology in the future to connect Pisa with science oriented development which replaces the dangerous Florence. stimulated by local universities, original. In the Planetarium, research institutions and high equipped with I-Max technology, The idea has been endorsed by the technology spin off industries. there will be room for projections Cascina County Council which is and science inspired shows. In the already engaged in the challenging In addition to a Planetarium and an Museum there will be laboratories decontamination of the Astronomy Museum the Astronomy for hand-on experimental activity. Decoindustria site. It has become a Park will include a Hostel for visiting The large instrument prototypes and real design by the architects Sara classes and a Guest House for the free fall demonstrator presently Baglini and Danilo Gentili. For the researchers temporarily working at hosted at EGO will be moved to the realization it will be necessary to EGO. garden outside. obtain funds at regional, national The Hostel and the Guest House and European level. will be designed reproducing the The four natural elements can be architecture of old country houses discerned in this natural science site: Designing the Park with common wide yards to be used • Fire: the stars projected in

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the Planetarium cupola Board has proposed a topical school, from controls to diffuse light and • Air: the central open space for the first time focused on thermal noise, covering most of the in the Museum building experimental issues related to the issues that characterise the upgrade design and construction of Advanced to Advanced interferometer. • Earth: the garden soil and Interferometers: this has turned out Overall, the students were subjected the lining coating the cylindrical to be good intuition, as the numbers to an amazing 996 slides in 27 hours! buildings confirmed: we had 18 participants, Also for this reason, the guided tour • Water: the fountain basin in mostly PhD students (and some post- of the Virgo facilities was the central court. docs). They represented 9 different particularly appreciated, and raised nationalities over two continents a lot of interest and curiosity. (France, Germany, Great Britain, The Planetarium Greece, India, Italy, Poland, Spain A nice dinner topped the social The entrance is through a classical and Ukraine), and they arrived from programme and strengthened dromos (entrance to ancient Greek 13 different institutions, from 7 friendship ties: rumour has it that tombs) slowly descending countries and 2 continents: Siena, the after dinner socialisation lasted underground. The visitor will be Camerino, Pisa, Roma 1 and 2, till late into the night (or should we guided from the obscurity of AEI, Glasgow, IEES, Artemis, LAL, say early morning?!). Logistics was, ignorance to the virtue of wisdom Leiden, Warsaw and MIT. as usual, quite efficient and effective, along a spiral slope surrounding the despite the concurrent meeting of 75 seat Planetarium. The outside of One striking feature was the high the EGO Council that absorbed most the cupola, a full sphere, will number of women participating: 7, of the energies and time of the EGO reproduce the Earth’s surface, a record for any VESF School! All staff. Our thanks to EGO and its transforming the walk to the entrance the students were well prepared and Director, to the computing people of the Planetarium into a “journey motivated: many of them are already and to the secretariat, for a smooth around the world”. active in the Virgo collaboration, and trouble-free school! some might join in the future, others are involved with GEO or even with In summary, an experimental school, The Astronomy Museum LISA. The wide central space is partly both in the sense of a new occupied by a large crystal sphere programme and of a syllabus containing a tree sprouting from a The course was held by 14 lecturers focused on the experiment, which water basin. It is a symbol of nature of high profile, recruited in 5 turned out to be a success! penetrating the building, an outside different countries (+ EGO). Most of them are actively working on symbol contained inside a shell. At M. BASSAN ground level there will be a book Advanced Virgo, but we also had 2 shop, a media center, a bar and other representatives from the LSC. The services. Astronomical exhibits, sky lectures, spread over 5 days, ranged Picture below: school participants with over topics from sources to Massimo Bassan (school co-director) pictures and videos will be exhibited and Stefan Hild (lecturer). on the two upper floors. suspensions, from lasers to cavities,

The 2012 VESF School

In the week of June the 18th to the 22nd, EGO hosted the first VESF School on Gravitational Wave (GW) Advanced Detectors.

In the year when work on Advanced Virgo and Advanced LIGO has kicked off, the VESF Executive

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detectors, the TDM. (Thermally 1. Plans of the new lab can be seen Deformable Mirror). Since its in Figure 3. The new EGO creation, the amount of activities in optics the lab has constantly increased, The two rooms, Optics Labs 1 and reaching complete saturation. In 2, correspond to the old laboratory. laboratory addition to the permanent optical The addition of two new rooms setups installed in the facility, the doubles the total space of the lab: 43 m2 of the lab were also used to Optics Lab 3 hosts three new optical store various optical materials, tables and will be devoted to the devices and spares, leaving no room most demanding applications in for new setups or space for terms of cleanliness, Optics Lab 4 The “old” EGO Optics Lab was mounting, cleaning and inspection will be used for storage and some created in September 2007 in the of optics. space will be devoted to noise new building to cope with the studies with, for example, a setup growing needs of on-site testing and dedicated to mechanical prototyping of new optical systems characterisation of optical mounts. for the maintenance and upgrade of Virgo. The most important modifications of the infrastructures are linked to The main part of the lab was cleanliness issues. Indeed, the “old” specifically dedicated to the laboratory was created in a space completion of the R&D for the High that was supposed to host some Power Input Optics (HPIO) to offices, and the materials used where prepare for AdV. Figure 1 shows the far from adapted to a clean enclosure hosting the 200W laser environment. Despite all efforts to source and the dedicated high power Figure 2. maintain the old lab “as clean as optical setup. In addition to R&D possible”, Figure 4 shows the state studies, the setup was intensively Besides, new activities are foreseen of an optic exposed for a few days used to develop recent Virgo+ to its hostile conditions. upgrades such as improvement of in the next few years since the EGO the SIB Faraday isolator, realisation Optics Group is in charge of the INJ of high power in-vacuum beam subsystem for AdV, which means in dumps for the detection system, particular the development of 2 large study of high power diaphragms optical benches. The HPIO R&D setups have to be maintained over the next 2 years as the final Faraday Isolator and other components will be built and characterised before integration into AdV.

It was therefore decided in 2011 to enlarge the lab by “absorbing” the space dedicated to the electronics Figure 4: A few days of dust exposition laboratory that moved to Building in the old lab.

Figure 1: High power room of the “old” optics lab A second part of the lab (see Figure 2) was used for all other activities with setups dedicated to measurements such as diffusion, reflectivity, absorption, polarisation and some more exotic activities Figure 3: Plan of the such as the development of a new new laboratory adaptive optics system for GW

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Therefore, considerable effort was second to fourth places, the arrival made to modify rooms 1, 2, 3 in sequence changed quite a lot order to limit this issue. More in The Biathlon between the first half (the athletes detail, the ceiling, originally made coming back from the North Arm) of plaster, was replaced with plastic 2012 and the final result. plates. Then, the walls were painted with a special paint and a PVC floor Despite the difficult weather was installed. In addition, the With respect to past years (in 2011 conditions, the winning time was existing air conditioning was it rained shortly after everybody had comparable with that of past years modified to control the temperature moved to the canteen), this year the (2011: 35’13’’; 2010: 36’29’’). of rooms 1 to 3 and clean filters Biathlon took place during a where installed on different AC particularly hot period. outlets. H. HEITMANN This might have deterred h Reporter a few potential athletes from participating, but nevertheless four teams were formed, ready to participate in the competition.

The table below shows the Heading for the final leg of the run, measured times after half after receiving the baton from the the Biathlon (athletes cyclist. returning from the North Photo courtesy of Marc van der Sluys. arm, grey) Figure 5: A view of one of the new and the final rooms, Optics Lab 3. times (white).

Infrastructure works started in The winning February 2012 and finished last May. team was the First impressions of the new lab are newly created very good and people find it for the PartenoPisa; but moment a very convenient place to being a blend of work. Figure 5 shows a view of the the traditionally new room Optics Lab 3 where some victorious setups for AdV, such as BMS Napoli (poetic: improvement and RFC Partenope) and characterization, were already Locking teams, installed. As one can see from this its victory was figure, in only one month, this new not a real room already starts to be crowded... surprise. For the

B. CANUEL EGO Optics group

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Copenhagen, a drama

In this issue we use the production literature in relation to the required to achieve an objective of of the play 'Copenhagen' by Michael development and production of both this kind to be 'enormous'. He Frayn at the Church of San Zeno in nuclear energy and weapons. He continues by explaining how this Pisa on the 15 of June, which was was also keenly involved in the was actually a useful situation: supported and promoted by EGO, themes of peace, the future and anti- along with the Foundation Pisa and nuclear activity, publishing, among “This situation seemed to us to be the Comune di Pisa, as a springboard numerous other titles, a critique of an especially favorable precondition to look at the event on which the the nuclear industry with 'The as it enabled the physicists to play is based, its author and the Nuclear State' in 1970 and even influence further developments. For, setting in which the performance standing as Green Party candidate had the production of atomic bombs was given. in the Austrian presidential elections been impossible, the problem would of 1992, eventually won by Thomas not have arisen at all; but had it Klestil. Following the 1956 been easy, then the physicists The Bohr-Heisenberg publication he was contacted directly definitely could not have prevented meeting by Heisenberg, who wished to their production...The actual givens clarify a handful of points that of the situation, however, gave the The play itself is based on a meeting emerged following the latter's physicists at that moment in time a that took place in occupied Denmark reading of the text during a period decisive amount of influence over in September 1941 between the of short illness [3]. It is from this the subsequent events..” [3] physicists Niels Bohr (1885-1962) exchange of letters, which took place and Werner Heisenberg (1901- between November of '56 and In this context, Heisenberg states 1976), while the latter visited January of '57, and subsequent that they, note the fact that the letter Copenhagen with fellow physicist events that the dynamic of the affair uses 'we', rather than 'I', thought that Carl Friedrich von Weizsäcker. What emerges. a discussion with Bohr 'might be of actually took place at that meeting value'. During that meeting will probably always be lost in the Heisenberg's original letter covers Heisenberg states that he asked Bohr mists of time, but, in subsequent an array of different issues, from the whether he thought it justifiable that years it has been possible to political convictions of a colleague scientists work on the 'Uranium formulate a general idea – perhaps to discussions on the 'Uraniam problem' during war-time, 'ideas' is a more precise way of problem', and the concept of active considering the grave consequences putting it – of what was discussed. resistance within a totalitarian such work might imply. He The issue of the content of the dictatorship. He even goes as far as continues by saying that Bohr discussion first emerged with the to note that he has actually read 'immediately grasped the meaning publication of the book 'Brighter almost all of the works by the of the question' and describes his than a thousand suns: A personal English novelist Anthony Trollope, response as being 'startled'. He then history of the atomic scientists', rather than Tobias Smollet, as had says that Bohr immediately which contains the first published been reported by Jungk in his text. demanded: account of the Manhattan Project However, it is his subsequent letter, and the German atomic bomb motivated by a request for further “Do you really believe one can project, by Robert Jungk (1913- information solicited by Jungk in utilize Uranium fission for the 1994) in German in 1956. Jungk, reply to the original correspondence, construction of weapons?” [3] who was born into a Jewish family that the Copenhagen meeting is in Berlin and was studying at its addressed. Heisenberg then becomes a little university when Hitler came to more coy, stating that he 'may' have power, emigrated to Paris and In his reply, Heisenberg describes replied that 'I know' that, at least in studied at the Sorbonne in 1933, how the physicists in, what he terms, principle, it is possible. He then before spending the period 1936- their 'Uranium Club' had reached describes how Bohr was so 'shocked' 1938 in Prague, publishing an anti- the conclusion that not only would at what he had heard and that the fascist paper. From '38, with the it be possible to produce energy from explanation for this reaction must entrance of the Nazis into Prague, a uranium and heavy water reactor, have been that Bohr believed he fled to Switzerland, where he but also that a decay product of 239- Heisenberg was trying to tell him remained until the end of the war in uranium would be produced which that Germany had made great strides 1945 [2]. He described himself as a could be used as an explosive in an towards the manufacture of the 'scientific journalist' [1] and atomic bomb. However, they bomb. produced a considerable volume of perceived the technical resources This letter certainly gives rise to a

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sense of frustration on the part of Bohr frequently expressed concern included in the Danish language Heisenberg; a sense of about the development of atomic version of the text, also published inconclusiveness; of an unfinished weapons and is even quoted as in 1956, which was apparently taken piece of business. He puts this down having later said, “That is why I out of its original context and gave to the fact that he knew that Bohr went to America. They didn't need the impression that Heisenberg had was being closely monitored by what my help in making the atom bomb.” used his meeting with Bohr to claim he terms 'German political [7] Following a meeting with that, for moral reasons, he had operatives' and as a result, he was Oppenheimer, in which it was sabotaged the German atomic bomb forced to be circumspect in his apparently decided to send Bohr to project. [9] Bohr, upon reading the statements: speak to Roosevelt about the text, took exception to this possibility of sharing information description of events and, as a result, “I tried to keep the conversation at with the Russians, in order to speed proceeded to write a series of letters, a level of allusions that would not up work, Roosevelt seemingly most of which were never sent, to immediately endanger my life...In proposed that Bohr should discuss Heisenberg, in order to express his my subsequent attempt to correct the idea with Churchill, to gain disagreement. These letters – eleven this false impression I must not have British agreement. Churchill, documents in all – are available via wholly succeeded in winning Bohr's however, of course not renowned the Niels Bohr Archive, the website trust, especially because I only dared for his overtly friendly sentiment of which states that, “The documents to speak in very cautious allusions towards the communist system, supplement and confirm previously (which definitely was a mistake on recorded “It seems to me Bohr ought published statements of Bohr's my part) out of fear that later on a to be confined or at any rate made recollections of the meeting, particular choice of words could be to see that he is very near the edge especially those of his son, Aage held against me.” [3] of mortal crimes.” [8] Bohr.” and that they were released in their entirety on the 6th of He felt that this impossibility to The remainder of the letter dedicated February 2002, “in order to avoid communicate fully was at the root to the meeting deals with what took possible misunderstandings”. [10] of the misunderstanding. Certainly, place in a less distinct manner, The documents had been subject to he was correct in believing that Bohr exploring rather issues in relation to a clause proscribing their release was under surveillance. At the end the state of developments in until fifty years after the death of of September 1943, Bohr, whose Germany and the USA at the time. Bohr, which means that they should mother was Jewish, received It is interesting however, to note not have been released before 2012. warning of his imminent arrest by how Heisenberg goes to However, this clause was revoked, the Gestapo as part of a planned considerable lengths to stress that in agreement with Bohr's family, deportation of all of the Jews in he is uncertain of all that he recalls given the intense interest in the Denmark. He and his wife owing to the passage of time – Heisenberg meeting provoked by subsequently fled to Sweden by sea remember this was 15 years after Frayn's play. [11] [4] as part of what has become the event - and to a conscience of known as the 'Rescue of the Danish an unspoken sub-text to the meeting, All but one of the eleven documents Jews' – an historic event in which which rendered it difficult to clarify in the archive are either drafts – the Modstandsbevægelsen (Danish precisely what took place: sometimes incomplete - or notes Resistance Movement) with the help and are even sometimes in the hand- of many ordinary Danish citizens, “Everything I am writing here is in writing of Margrethe – Bohr's wife evacuated the vast majority of the a sense an after the fact analysis of - or Aage Bohr, rather than Bohr country's Jewish population by boats a very complicated psychological himself. The remaining document of varying sea-worthiness to situation, where it is unlikely that is in the form of a telegram, sent by Sweden. As a result of these actions, every point can be accurate. - I Heisenberg in response to 60th 8,000 people's lives were saved. At myself was very unhappy over this birthday greeting from Bohr. The the end of the war, 99% of conversation...Even now, as I am Director of the Niels Bohr Archive, Denmark's Jewish population had writing this conversation down, I Finn Aaserud, notes in the survived the Holocaust. [5] Before have no good feeling, since the introduction to the documents that long he was taken by military wording of the various statements they are to be treated with caution, aeroplane to Britain, where he was can certainly not be accurate all being written at least sixteen introduced to the secret atomic bomb anymore, and it would require all years after the event. In addition, project, before being transferred to the fine nuances to accurately they have all been translated into the Los Alomos base in the United recount the actual content of the English, which means that, “As with States, where he worked on the conversation in its psychological any translation, the precise choice Manhattan Project under the shading.” [3] of corresponding words and phrases pseudonym 'Nicholas Baker' for has been difficult”; a difficulty security reasons. [6] Interestingly, An extract of Heisenberg's letter was accentuated by the fact that the

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documents are drafts, notes and often presented, but the conclusion 2. The Right Livelihood Award, unfinished. [11] remains the same – indecisive. Given http://www.rightlivelihood.org/jungk. the lack of conclusive proof, it is html. Rather than offer an interpretation possible only to read and re-read the of the letters here, which is obviously available documents, looking for 3. Two Letters from Werner Heisenberg to Robert Jungk, the author the axis on which this story pivots, suggestions, building hypotheses of "Brighter Than a Thousand Suns" and making a vain attempt to reach and loading more or less significance [+ a reply by Jungk] (English a conclusion that is perhaps un- onto statements that may or may not translation), http://werner- reachable and un-knowable, it is really be of any import. This really heisenberg.unh.edu/Jungk.htm. perhaps more advised to simply does seem to be an area of history point the reader in the direction of of which we will never really be 4. Copenhagen (play), the documents themselves. They can able to know precisely what http://en.wikipedia.org/wiki/Copenha be found within the pages of the occurred. The issue was, however, gen_%28play%29, 2012. Niels Bohr Archive website and are further clouded in March 2006, available here – following the intervention of the 5. Rescue of the Danish Jews, http://www.nba.nbi.dk/papers/intr Croat physicist and philosopher, http://en.wikipedia.org/wiki/Rescue_ oduction.htm. Regardless of the Ivan Supek (1915-2007), who had of_the_Danish_Jews, 2012. extent to which the documents been a friend and student of 6. Pais, Abraham, Niels Bohr's actually clarify the issue, they do Heisenberg. Supek claimed that Times, In Physics, Philosophy and give the impression of a wish to Margrethe Bohr had informed him, Polity, Oxford: Clarendon Press. ISBN address or render clearer exactly in confidence, that von Weizsäcker, 0-19-852049-2, 1991. what happened on that evening back rather than Heisenberg had actually in 1941. been the protaganist in the meeting: 7. Long, Doug, The atomic bomb and beyond, http://www.doug- One further piece of interesting “Heisenberg and von Weizsäcker long.com/bohr.htm. information is provided through a came to Bohr in German army summary of events by Bohr's son, uniforms. Von Weizsäcker's idea, 8. Rhodes, Richard, The Making of the Atomic Bomb. New York: Simon Aage, quoted in the book, Niels probably originating from his father and Schuster. ISBN 0-671-44133-7, Bohr: His life and work as seen by who was Ribbentrop's deputy, was 1986. his friends and colleagues, edited to persuade Bohr to mediate for by Stefan Rozental and released in peace between Great Britain and 9. Niels Bohr, 1967, in which he addresses the Germany.” [13] http://en.wikipedia.org/wiki/Niels_Bo meeting directly: hr, 2012. So, 65 years after the event, yet “In the book “Brighter than a another alley opens up down which 10. Niels Bohr Archive, Release Thousand Suns” by Robert Jungk it one might potentially lose oneself. of documents relating to 1941 Bohr- Heisenberg meeting, is asserted that the German Enter Michael Frayn - stage left, one http://nba.nbi.dk/release.html, 2002. physicists submitted a secret plan is tempted to say - and the words he to my father, aimed at preventing puts into the mouth of his 11. Aaserud, Finn, Release of the development of atomic weapons Heisenberg: documents relating to 1941 Bohr- through a mutual agreement with Heisenberg meeting. Introductory colleagues in the allied countries. “No one understands my trip to comments, This account has no basis in the Copenhagen. Time and time again http://www.nba.nbi.dk/papers/introdu actual events, since there was no I’ve explained it. To Bohr himself, ction.htm, 2002. mention of any such plan either and Margrethe. To interrogators and during Heisenberg’s visit, or during intelligence officers, to journalists 12. Bohr, Aage, “The War Years and the Prospects Raised by the Atomic a later visit to Copenhagen – also and historians. The more I’ve Weapons,” pp. 191–214 in Stefan mentioned by Jungk – of the German explained, the deeper the uncertainty Rozental (ed.): Niels Bohr: His life and physicist Hans J.D. Jensen. On the has become. Well, I shall be happy work as seen by his friends and contrary, the very scanty contact to make one more attempt.” [14] colleagues, Amsterdam: North-Holland with the German physicists during Publishing Company, p. 193, 1967. the occupation contributed – as already mentioned – to strengthen G. HEMMING 13. http://jutarnji.hr/clanak/art- the impression that the German 2006,3,19,supek_intervju,17440.jl?ar authorities attributed great military tpg=1, in Wikipedia, Ivan Supek, importance to atomic energy.” [12] 1. J. Calder, Obituary: Robert Jungk, http://en.wikipedia.org/wiki/Ivan_Su The Independent (http://www. pek, 2012. independent.co.uk/news/people/obitu And with that, we return to the ary-robert-jungk-1414618.html), 18 14. Frayn, Michael. Copenhagen. beginning. The evidence has been July 1994. New York, New York. Anchor Books:

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Random House, Inc. 2000. to get them to do what the author columnist and screenwriter, the wants them to do, while still bibliography is considerable. But allowing them to have their own one thing in particular stands out Michael Frayn lives as well. He has written both from the various available sources drama and prose and been successful – interviews, reviews and so on - Michael Frayn was born in Mill Hill, in both, while his work ranges from for an article such as this, and that London in 1933, grew up in Ewell, farce - the writing of which he is the fact that, as he says in his own Surrey and was educated at Kingston describes as being 'particularly words, “I very much like laughing”. Grammar School. His father, a deaf difficult' - to philosophical, often in asbestos salesman, would bring the same play. His most famous home samples of the material, with productions have been Noises Off, The Church of San Zeno, which the young Michael would a farce about a play within a play, Pisa play, hammering nails into them and Copenhagen and Democracy, a drama about the end of Willy so on, completely oblivious of its The setting for the production of toxicity. Frayn's sister, Jill, would Brandt's chancellorship of West Germany and the unmasking of his Michael Frayn's Copenhagen was later prematurely pass away the deconsecrated Church of San suffering from a lymphoma, secretary, Gunter Guillaume, as a spy. Zeno in Pisa. One of the oldest probably caused as a result of this churches in the city, the abbey was early and sustained exposure to re-opened in October of 2000, asbestos dust. His mother, having In relation to Copenhagen, he says that he “worked very hard to find following a protracted restoration survived the War, died of a heart and is now used for exhibitions, attack in November 1945. out everything that was known...I've tried to respect the historical record, concerts and the occasional play. It in so far as it exists, but then what can be found on Via San Zeno, near He was idealogical as a schoolboy to Piazza Santa Caterina and is near and, while at school, set up an I've tried to do is imagine what was in the heads of the two.” With regard to the homonymous doorway to the independent communist cell with a old town, which gives onto the classmate. Following school, he to the potential pitfalls of this approach, he recounts an interesting intersection between Via del learned Russian, while on a two year Brennero and Via Vittorio Veneto. military service, and then studied at anecdote in relation to the opening night of the play in New York, in Dated as far back as 1029, the church Cambridge, where he read Moral was part of a monastery complex Sciences (Philosophy) at Emmanuel itself a tense evening, following which he met one of the audience - and also hosted a hospital until the College. While at the university he, 15th century. The church passed to along with a group of Russian- Werner Heisenberg's son - who informed him that his – Frayn's – the order of the Camaldolese monks speaking friends, set up what he in the 12th century. believes was the first student Heisenberg was nothing like his exchange programme with Moscow, father, who never expressed feelings although this brought him into for anything other than music, but contact with the intelligence services that, however, he understood how a which, as he wished to maintain his play requires characters to be more independence, caused him to forthcoming in order to function withdraw. His earlier communist properly. tendencies soon wore off, however. He states that he learned Russian to As well as his own fiction, Frayn study Russia better, but that “The has translated work by both Chekhov interest in Russia remained, the and Tolstoy into English and says communism wore off pretty that one of the aspects of Chekhov's quickly”. work that he most admires is his modesty, in the sense that he is Upon graduation, he began to work absent from it. In this context, the as a reporter for the Manchester nearest Frayn has come to writing Guardian and has since commented about himself is in 'My Father's that “Newspapers were where I felt Fortune, A Life', a memoir about the PERSONNEL MOVEMENTS most at home”. Having worked for life of his father, written to satisfy the curiosity of his daughter about both the Guardian and the Observer, Departure Frayn began to write fiction, which her antecedents, in which he of he describes as being not unlike course appears as a significant part Gaelle Parguez 'industrial management' – citing the of his father's life. Engineer left the Vacuum team end need to strike a balance with the of June 2012. characters of a play or book in order So, playwright, novelist, reporter,

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The e-mail from Gilles Bogaert has strong winds and this “solution” full power operation during the same Hi Carlo, is not possible for the Mediterranean period. According to the data about wind turbines as electricity countries, where the winds are delivered by the NEI (Nuclear providers, usually weaker than 4m/s (for Energy Institute, a policy http://en.wikipedia.org/wiki/File: example see the European wind map organization of the nuclear energy Wind_in_Denmark_1977_2011_la in Fig. 49 of the ET design study: and technologies worlds-wide rge.png https://tds.ego-gw.it/ql/?c=7954). industry, certainly not an Wikipedia explains to me that Furthermore, if you see Fig. 26.2 of independent institution), in a seven Danish wind turbines provide the above-cited book, the year period (2000-2007) the whole already 28% of the 2011 electricity fluctuations of the Energy produced nuclear plant system in the USA had production (and the goal of the by wind in Ireland aren’t mitigated a capacity factor of 87%. In the Danish government is 50% in by the country-size plants, and then figure the overall trend in the USA 2020). expensive smart grids are needed to in the last 40 years is reported. It is suprising that for the case of fill the energy holes or to redistribute Danish wind, the authors of the peak Europhysics News refer to a 2009 production. This is report which has been heavily mainly done by criticized. energy-exchange Gilles Bogaert, Nice, 8.06.2012 with neighboring countries (as Denmark does) The answer by Michele Punturo that produce Dear Bogaert, Dear Carlo, energy through an I believe that THE solution for the easily tunable energy problem doesn’t exist, but source (like only components of a global natural gas, oil, strategy. I found very interesting the carbon and hydro- reading of a book, freely available electric). on web, written by a physicist: David Regards, JC MacKay and titled “Sustainable Michele Punturo, Energy - without the hot air” Perugia 11.06.2012 One more answer by Michele (http://www.withouthotair.com). Punturo It is interesting because it makes the A comment from Andrea Vicere’ Hi Andrea, attempt to compute an energy budget Hi Michele, I fully agree that smart grids and (consumed energy vs produced that's right and I believe in fact that energy storage are crucial energy). As suggested by the title, nuclear energy is the only source technologies to be developed in the the author tries to demonstrate how which could allow in the mid term future. Just to quantify the problem it is possible to use “green” energies, (the next 20 years) to keep the of energy storage, in order to but being a physicist and using current level of energy supply while strengthen what was stated at the numbers and not adjectives, it has a reducing dramatically the CO2 foot beginning of the discussion on “wind hard job to fill the gap between print. However, also nuclear energy turbines as a sustainable energy available “green” energy and the isn't a solution in the long term source” let’s make a simple needs of our modern society (the because we will run out of cheap computation. conclusion, if there is a conclusion, uranium sooner or later, and nuclear A European citizen consumes, on is that we have to reduce drastically fusion isn't round the corner. So as average, 689W (an American our energy needs or, even if it is you said a mix is necessary, and in 1363W!!!). Let’s consider a country well hidden in the text, use nuclear the long term one could expect that with 60M citizens (like Italy or the energy). There is an interesting the storage of energy will be a crucial UK): the average power evaluation of the energy produced component of the grid, much more consumption is ~41GW. Let’s through wind turbines in Ireland than it is now, in order to increase suppose that you want to produce¼ (with some reference to the Danish the capacity factor of wind or solar of that energy with wind turbines, situation); they obviously produce farms. without accessing energy produced a lot of energy, but to have a relevant Cheers, Andrea by other countries in an easily role with respect to the needs of a 15.06.2012 tunable way. Hence about 10GW of country with the population density the energy is produced with wind of the UK, comparable to the EU An answer by Michele Punturo turbines (corresponding to 30-40GW average (and not obviously to Let us define “capacity factor” as of installed power). If you look at Denmark), you need to cover a huge the ratio between the energy wind availability, in a windy country, fraction (~the entire surface of produced by a plant in a period of such as Ireland or the UK, there are Wales) of the country with wind time and the amount of energy it periods of 10 days without wind. turbines plants. Note that the UK could have produced at continuous Let’s be optimistic and limit

THE GRAVITATIONAL VOICE - JULY 2012 20 L E T T E R S T O T HE E D I T O R ourselves to 5 days without wind. Thanks for your email; it is always Netherlands active in sustainable Hence you need to store useful to cross-check the numbers. energy - this after having left 10GW x 24 x 5 = 1240GWh of I used the numbers and the GreenPeace and working with the energy. statements in page 162 of the IPCC). Below I give you a brief Currently, the only serious way we previously-cited book. I cross- impression of the Dutch approach have to store that energy is using checked the references used in that to wind energy. the so called “pumped storage” book and I found a series of It is well-known that there is a long (hydro-electric plants used in interesting info. When economics tradition of windmills in The reversed mode). To produce 100 enters into evaluations, numbers are Netherlands. The Dutch have been GWh using such a plant you have more difficult and unstable. First of building windmills for centuries and to store 210M cubic meters of water all the global known reserves are with these windmills part of the and let it fall from a height of 200m increased (2009 data) to 5.5Mtons, country itself was built. Besides land (considering an efficiency of 90%). but it depends on the extraction cost. drainage, mills were used for This is a lake 10m deep and 21km^2 An indicative plot is reported here industrial purposes, such as corn in surface, about 3 times the lake of http://www.world- milling and sawing. As a nation we Montedoglio, that caused so much nuclear.org/info/inf75.html. have a strong emotional connection trouble to the population in According to the IAEA there are an to windmills and we are proud to Valtiberina. Then, you need 12 of additional 5 Mtons available, but it show them to tourists. While 1194 these (3xMontedoglio) lakes just to depends on the extraction cost. What of these historical windmills are still cover ¼ of the energy needs for 5 remains true (in your email, and in operation, the vast majority of days in Italy! Possible, but quite wrong in mine) is that the directly them has disappeared (the Dutch difficult! Another possibility is using available reserves are enough for database lists 15914 of historical batteries . Better solution ~80 years (160 considering the windmills). However, recently Let’s jump to Uranium availability. additional reserves stated by the windmills started a comeback, The known conventional reserves IAEA, but with the current rate of mainly driven by the quest for in the ground of Uranium are (in the usage!). I found confirmed the sustainable energy. At present there World) 4.7Mtons, the Uranium in increase of performance (x 60) given are about 1900 turbines installed on- the Phosphate deposit (more by fast breeder. shore with a capacity of 2.0 GW. expensive) are 22Mtons and in the It is always useful to discuss these Since the power of a wind turbine Oceans 4500Mtons (2005 data). interesting subjects. Ciao, Michele is given by the kinetic energy of the Let’s use just the easiest and smallest air incident per unit of time (and source of Uranium. According to A short comment thus proportional to ½ Av it is what is stated in the above-cited Hi, quite sensitive to wind book, this is enough for about 1000 An additional comment, about the speed. It would make sense to place years of energy production with the authors, De Groot actually, windmills in areas with high wind (2005) rate of usage. Instead, if each I am surprised to see he was formerly speed, e.g. along the coast, but in inhabitant of the Earth reaches an appointed by the Shell Dutch practice they are placed in-land in energy consumption comparable to company: remote areas. This is motivated by the European one, the reserves will www.clepair.net/windsecret.html what is called the “perception of the be enough for about 160 years. Gilles Bogaert, 18.06.2012 incorporation in the landscape” Obviously there could be the usual which is Dutch-speak for factor 2 error in the computation, Jo van den Brand, 24.06.2012: “minimizing the number of people but the once-through nuclear reactor Windmills in Holland complaining”. The consequence is is not the only available technology. This contribution was triggered by that in reality this 2 GW capacity Fast breeder reactors could produce Carlo Bradaschia, who noticed a has an efficiency of not more than a factor 60 more power with the paper on wind energy by C. le Pair, 18%. To ensure that sufficient energy same amount of excavated Uranium; F. Udo and K. de Groot in is available during the other 82% of they exist (http://en.wikipedia. EuroPhysicsNews 43/2 2012. Kees the time, we are now building 3 large org/wiki/Breeder_reactor) but the le Pair was director of the Dutch coal-fired power plants. In 2010 the technology is still not fully under funding agency STW (which Dutch approach to realizing wind control or better, is quite risky. supports technical sciences) and Fred energy became quite aggressive by But 60x160 years of energy Udo was a senior scientist at Nikhef allocating a subsidy of 5.4 billion availability is quite appealing. and is now retired. These authors Euro (4,395.8 million Euro is already Finally, there is also Thorium. India question the rational of placing committed) for the construction of has the capability to use Thorium multi-gigawatt windparks offshore offshore wind farms. While this and their reserves are estimated to without a good buffer and storage nicely appeals to sentiments on be enough for 1000 years. system. I happen to agree with them Dutch history of windmills, and the and recently had the pleasure to sea, it is worthwhile to question the (Andrea found an error in the explain this on Dutch national economic value of such an computation) television (in a debate with the investment in times of crisis. The Ciao Andrea, number one person in the promise is a capacity of 700 MW.

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