domenica 25 febbraio 2007

Molecole su misura


Harold Kroto

C60, il supermodello molecolare

DI RENZO EDITORE

Il C60 è stato definito il composto più importante scoperto nel XX secolo: fondamentale per la chimica del carbonio e dei materiali, potrebbe un giorno condurre ad eccezionali applicazioni. Il suo scopritore, il chimico britannico Harold Kroto, con grande onestà ritiene che siano molte le scoperte importanti del secolo appena trascorso, nonostante il Premio Nobel vinto nel 1996.
Con la stessa modestia, l’autore ci racconta la sua esperienza umana e professionale, riconoscendo l’importante funzione che hanno avuto nella sua formazione esperienze all’apparenza banali, come lavorare nella fabbrica di palloncini del padre, giocare col Meccano e svolgere la professione di grafico.
Profondamente interessato alla divulgazione e alle discussioni scientifiche con la cosiddetta “gente comune”, Harold Kroto crede nella scienza come attività culturale e profonda comprensione del mondo. E ai giovani che vogliono seguire le sue orme consiglia di divertirsi nel proprio lavoro, di evitare la competizione perché non è produttiva e, una volta individuato il proprio obiettivo, di non mollare mai.
Harold Kroto, chimico inglese di origine tedesca, è stato ricercatore presso il National Research Council di Ottawa e i Laboratori Bell e dal 1967 insegna all’Università del Sussex. Si è occupato di spettroscopia elettronica e Raman, e di nanotecnologie. Nel 1996 ha vinto, insieme a Robert F. Curl e Richard E. Smalley, il Premio Nobel per la chimica per la scoperta dei fullereni. Impegnato nella divulgazione scientifica, è fondatore di una società di produzione di filmati scientifici per la BBC e attivo nella difesa dell’ambiente.

Recensioni e articoli

La chiave, la luce, l'ubriaco


Giorgio Parisi
La chiave, la luce e l'ubriaco
Come si muove una ricerca scientifica

DI RENZO EDITORE

“Mi viene in mente una vecchia barzelletta. Un ubriaco, di notte, si mette a cercare una chiave sotto un lampione. Arriva un tale che lo aiuta, ma, non trovando nulla, gli chiede se è proprio sicuro di aver perso lì la chiave. L’ubriaco risponde: No, non sono affatto sicuro, ma è qui che c’è luce”.
Con questo esempio scherzoso, ma non troppo, Giorgio Parisi ci spiega come si muove la ricerca scientifica fondamentale.
“Gli scienziati fanno le cose che riescono a fare. Quando si accorgono di disporre dei mezzi per studiare qualcosa che fino a quel momento era stato trascurato, allora s’impegnano per quella strada.” Se lo scopo è migliorare la capacità dell’uomo di conoscere e di controllare i fenomeni della natura, ogni problema, al quale si possano applicare teorie in corso di verifica, diventa immediatamente interessante ai fini della ricerca: ogni aspetto che viene chiarito può aiutare a comprenderne altri. Per il momento si tratta di ricerca pura. Le applicazioni, se verranno, arriveranno dopo.
In una conversazione animata e straordinariamente comprensibile, uno dei più importanti fisici teorici italiani ci aiuta a capire come è cambiata la fisica, di quali problemi si occupa oggi, che interazioni ci sono tra ricerca di base e sviluppo tecnologico, quali scenari futuri potrebbe aprire la sinergia tra la fisica dei sistemi complessi e la biologia.

Harold Kroto vince il Premio Italgas nel 1992

Sir Harold Walter Kroto
Winner for Chemistry

Harold W. Kroto was born at Bolton (England) in 1939. At present he is Royal Society Research Professor at the School of Chemistry and Molecular Sciences of the University of Sussex. He is member of the U.K Royal Society.
In the early seventies Professor Kroto and his co-workers initiated a research to investigate the preparation, characterisation and elucidation of the physical and chemical properties of new molecules and classes of molecules in which multiple bonds impart reactivity; in particular various spectroscopic techniques were applied to detect new species like phospho-alkane-alkynes, sulphidoborons, polyynes, etc. A fertile field of phosphorus chemistry has developed since this first pioneering discovery.

A direct consequence of the main spectroscopic programme was the discovery of the long-chain carbon molecules (cyanopolyynes) in space. Since the discovery was made, many more analogues chains have been detected in stars and in the interstellar medium. The new perspective that these molecules have yielded is leading to a revision of our understanding of the carbon content of space and to the conjecture that they were might form in chemical reactions in the circumstellar shells of red giant carbon stars.
The quest for an explanation of the origin of the carbon chains in space has led to interdisciplinary research programme in which have been welded main-stream synthetic chemistry, thermolytic decomposition, spectroscopy, microparticle and nucleation science and astrophysics.

The results of these studies have had spectacular conseguences, as the discovery in laboratory of the C60 molecule, the proposal of its closed spheroidal cage structure, named buckminsterfullerene, and most recently its extraction, isolation and the confirmation of its hollow cage structure, as well as the specification of the C70 molecule, another important member of fullerene family, with ellipsoidal cage structure.
This breakthrough has resulted in the birth of new, excting areas of carbon chemistry and materials science with most promising future consequences. There are revolutionary implications for fundamental aspects of organic and transition metal chemistry and boundless possibilities for new compounds with novel application.
For his relevant contributions to the development of this new field of research, the Prize Committee, unanimously, awarded Professor Harold W. Kroto the 1992 Italgas Prize for Chemistry.

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Il libro di divulgazione scientifica pubblicato in Italia da Harold Kroto ha il seguente titolo: Molecole su misura, Di Renzo Editore

Orazio Svelto vince il premio Italgas nel 2000

Orazio Svelto
Winner for Science and Technology for Information Systems


New Lasers for Optical Communications

Prof. Orazio Svelto: A first scientific enterprise of Prof. Svelto and his colleagues is the invention of the first continuously-operating diode-pumped erbium - ytterbium glass laser which, due to the high quality of the output beam, opens up quite interesting new possibilities for optical communications, in particular for free space communications, and for metrology.

A second scientific enterprise is a scientific discovery that is revolutionizing the field of ultrafast optics. Prof. Svelto has conceived, designed and successfully experimented the novel technique of pulse-compression in a hollow fibre filled with a noble gas, argon or krypton,which represents the non linear element producing pulse-compression.

Using this hollow-fiber compressor he has been able to generate laser pulses with ultrafast duration down to the value of 4.5 femtoseconds, with pulse-energy of 70 microjoules. This is a world record in pulse duration, as recognised by prestigious journals such as Optics Letters (April 1997), which represents the fastest physical phenomenon artificially produced by man; a record of great importance, not only because this result is based on the relatively simple use of hollow fibre, but also because the energy of these ultrafast pulses is about 10,000 times greater than the energy of pulses of the previous record of pulse duration.

The achievement of Prof. Svelto was obtained in the Centre Of Quantum Electronics of the Italian National Research Council at the Department of Physics of Milan Polytechnic, in the period 1995 - 1998. The new technique introduces very important scientific and technological results:

1) in the area of optical communications, utilising optical communication links at very high speeds, in the 0.1 - 1 THz regime, with very promising applications to the Internet of the next generation;

2) in physics research, particularly in optics, with ultrafast and ultra-intense optical pulses and high intensity fields, since it is now possible to obtain, in the focus of a lens, peak intensities up to 1018 W/cm²;

3) in the area of the generation of X-rays, through the high-harmonic generation, obtaining soft X-rays down to the water window (20 - 40 Angström), with a high impact for new technologies for biophysical studies, with applications to extreme UV lithography, with relevant results in the technology of microelectronics and the development of ultra large-scale integrated circuits.

A number of wonderful new discoveries and applications in science, engineering and everyday life will be obtained by using these fundamental new inventions of Prof. Svelto.


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E' stato appena pubblicato un libro di divulgazione scientifica, di Orazio Svelto, dal titolo - Il fascino sottile dei laser - Di Renzo Editore

Giorgio Parisi vince il premio Italgas nel 1993

Giorgio Parisi
Winner for Physics

Giorgio Parisi was born in Rome in 1948 and graduated in Physics at the University of Rome in 1970, under the direction of Nicola Cabibbo. From 1971 to 1981 he worked at the Frascati National Laboratories. In this period he worked also at some scientific Institutions abroad: Columbia University (1973-1974), Institut des Hautes Etudes Scientifiques (1976-1977), Ecole Normale Superieure (1977-1978). In 1981 he became full professor at the University of Rome where he had at first the chair of Institutions of Theoretical Physics and now the chair of Quantum Theories. Professor Parisi received the Feltrinelli Prize for Physics from the Academy of Lincei in 1987 and the Boltzmann Medal for thermodynamics and statistical mechanics from the International Union of Pure and Applied Physics in 1992.

He is corresponding member of the Academy of Lincei since 1987 and foreign member of the French Academy of Sciences from 1992. The scientific and research activity of Professor Parisi concerns in particular elementary particles physics, phase transitions theory and statistical mechanics, mathematical physics and strings theory, disordered systems (spin glass and complex systems), neuronal circuits and theoretical immunology, computer theory for the evaluation of hadronic mass spectrum, statistical physics of non-equilibrium systems.

The most important contribution by Professor Parisi belongs to statistical mechanics and concerns his spin glass theory. He established the statistical and thermodynamical properties of these systems, which are characterized by disordered interactions among their elementary components. Spin glasses represent the prototype of all amorphous systems. In 1979 his work leaded to the mathematical solution of the simplest of such systems, that is the system in which every component can interact with all the others. This solution represents the reference point for the study of amorphous systems. Professor Parisi showed that the phase transitions in amorphous systems are characterized by an order parameter which is not simply a number, as in the simplest systems (for example the magnetization in ferromagnets), but a measure of probability defined in the interval [0,1]. Parisi's solution of spin glasses is the result of a wonderful combination of a deep physical and mathematical analysis. The difficulty of the problem is in the fact that in the amorphous systems it does not exist a clear tendence of the difference parts to draw up in order to minimize the energy: the minimization of the energy between a couple of elements increases the energy of other couples. This characteristic is called "whipping" and is common to many applied problems in the field of optimization. The applications of the methods developed by Professor Parisi and his school showed the depth and the importance of these discoveries and opened one of the most original and useful way of thinking - of which Professor Parisi is the certain leader - in the study of a wide class of complex systems.

For his relevant contributions given to the development of fundamental and applied physics in several research fields the Prize Committee unanimously awarded Professor Giorgio Parisi the 1993 Italgas Prize for Physics.

Il solo libro di divulgazione cientifica pubblicato da Giorgio Parisi è: "La cchiave, la luce, l'ubriaco" - Di Renzo Editore