.. Prentice• delivers moons on cue V0Y-agersup-p-orls MONASH Uranus theories A senior lecturer in the Department of Mathematics has risen to world REPORTER prominence after successfully predicting the findings of the Voyager probe in its recent encounter with the planet Uranus. Dr Andrew Prentice accurately ed, whirling faster still and sloughing off AMAUll. FOR THE UIIIVERSm predicted the locations of a new moon doughnut~shaped rings of gas from its and a new satellite belt, the chemical equator at precise intervals. Registered by Australia Post - publication No. VBG0435 compositions and densities of the The rings were abandoned where the moons, and that the magnetic field of centrifugal force of whirling, which the planet would be found to be at an pushes material away from the prolo­ angle to its rotational axis. sun's centre - that same force which He also provided an explanation of throws you around in a car as you turn a the astonishing 8 km high cliffs on the corner at speed - exactly matched the surface of the moon Miranda (centre gravitational force pulling material pages). towards the centre. He did so on the basis of his contro- In the Prentice model, the formation versial model of the formation of the of the ·outer planets and their attendant solar system. moons is seen as a re-fun on a minor His initial success in defining the loca- scale. tions of the previously unknown moon and satellite belt received widespread Turbulence publicity in the United States and Bri­ The theories of Laplace were discard­ tain, and he became one of only two ed generally by astronomers, because scientists interviewed on national public there seemed no good mechanism for radio in the US over Voyager's Uranus the shedding of the rings, and their con­ flyby. solidation into planets. Since the confirmation of Prentice's But Prentice thinks he has found the pronouncements on the densities and answer in "supersonic turbulence" - a chemical compositions of the moons of concept first suggested by the Dutch Uranus, the editor of the prestigious physicist, Dr Dirk ter Haar. with whom scientific journal, Nature, has asked him Prentice worked at Oxford University. to contribute a review article on his Supersonic turbulence is a powerful theory. form of convection, the circulation that occurs when warm fluid rises and cooler Proto-sun fluid rushes in to take its place. "At the moment, my model is the In this case, hot eddies of gas are seen only one that can satisfactorily explain as shooting out from the centre of the the formation and composition of the whirling proto-sun or proto-planet entire solar system - and that's not too towards its edge at greater than the bad," he said. speed of sound. The Prentice model is based on the Their place is taken by cooler gas fall­ 190-year·old ideas of the great French ing towards the cente. astronomer and mathematician, Pierre Few of Prentice and ler Haar's col­ de Laplace. leagues, however, actually believe in In the early 1970., long after supersonic turbulence, which means that Laplace's ideas had fallen into disfavor, until now the Prentice model has not Dr Prentice became convinced that they been widely accepted. constituted the best explanation for one Initially it was published only after of the simplest and most curious facts of being rejected some 10 times. the solar system - all the planets travel That is why the latest test of the in the same direction on nearby circular models' predictive power was so impor­ orbits almost all of which are in the tant for Dr Prentice. January, Dr Prentice delivered a paper km. The reporter was mightily same plane. And his success has gone a long way containing his Uranus predictions to the impressed. Laplace pictured the solar system as towards vindicating the concept. American Astronomical Society which A few days later. Voyager found a emerging from the contraction of a hut­ "For the one value of supersonic was meeting in Houston. belt of satellites spread around an ter, whirling proto-sur. which once turbulence, we have been able to explain The Voyager encounter was to be in average distance of 68,(0) km from covered the whole of the space now oc­ the composition of the entire solar late January, but already preliminary in­ Uranus. cupied by the planets. system," he says. formation was beginning to filter back. So Dr Prentice had predicted the posi­ This contracted as it cool- Soon after re"ching Dr Prentice took the floor feeling tions of these two to within 3 per cent ­ more than a little nervous. well within his margins for error. He had just heard a radio report that Not all his colleagues fared so well. A a new Uranian moon had been team from the Massachusetts Institute discovered, but he had no details of of Technology predicted a new satellite where it was or whether it squared up would be found at precisely 76,222 ± 8 with his model. km from the planet, exactly halfway bet· After he had delivered his paper, an ween the newly discovered bodies. interested reporter from the Boslon "It's a risky business. this predicting. Globe approached him and together "They couldn't have chosen a worse they rushed to the nearest newsstand for spot," he says. details of the newly discovered moon. But it was not all smooth sailing for Dr Prentice had predicted new satel­ Dr Prentice either. lites or satellite belts at 68,OClO km and Mathematical models are highly 89,(X)() km from the centre of Uranus. dependent on the quality of the informa­ The new moon measured in at 86,(X)() • Continued page 6 "Know then thyself, presume not God to scan The proper study of mankind is man." So said Pope, so I'll tell how Where'er I went, from birth till now I came across a strange tall bloke With ginger hair and wreathed in smoke. Who robots loves, and music, too ­ I'm sure you'lI find he's known to you. Who is the man 'shrined in this rhyme? For the answer turn to our page nine. MONASH REPORTER 1UtOTFD$A~ Whols New n Educalion, Rffieorch~and CommlXlity Service. No.l-BS --- ~ -- ... - . ~ HUIIIMft- t o .. NO\IUIiMIUt IS. '1115 From. the inform.ation office in '86 MONASH REPORTER is one of ceeding issues 3fe published on the Keith Bennetts, or the secretary, tion of news clippings dealing a number of publications and ser­ back page of each edition. Ruth Keeler. They can be contacted with Monash and the education vices provided by the University's in­ Another major publication is on ext. 2087. scene generally. This is formation office. MONASH REVIEW, a periodical THE MONTH AT MONASH, the distributed two or three times Although a part of the Vice-Chan­ devoted to publicising - mainly off­ advertisement listing University weekly to aIt departments. cellor's section, the office exists to campus - the University's events to which members of the • This is Monash, the annual service the needs of the campus as a achievements in teaching, research public are invited, is another infor­ visitors' guide to the campus. The whole. and community involvement. mation office responsibility. Compil­ 1986 edition is now available. First, MONASH REPORTER. __ It is edited by TIm Tbwaites, who ed by Georgia Tsioukis, the ad ap­ • Press releases and publicity mat­ ters generally. The office is pleas­ This is primarily an internal publica­ can be contacted on ext. 3087. pears around the turn of the month in The Age and a number of subur­ ed to assist in the preparation of tion, published nine times a year. and SOUND is another information ban weeklies. In normal circum­ releases and to advise on publica­ distributed throughout the campus office publication. Sub-titled 'The stances, copy deadlines are 5 p.m. on tions. and affiliated off-campus official broadsheet of Monash Uni­ the third Thursday of the preceding The office also is involved in main­ institutions. versity', this modest journal appears month. The extension to dial is 2002. taining liaison with the Monash It is edited by Lisa Kelly who can on average 35 times a year. There are Other information office services Graduates Association and with be contacted on ext. 2003, and who no fixed deadlines, and items for include: school tours of the campus. Georgia would welcome contributions, letters publication will be accepted at any Tsioukis is the person to contact and ideas. Copy deadlines for SllC­ time by the information officer, • Press Cuttings, a regular compila­ about these. Picture parade of first 25 years The Visual Arts Gallery will hold two special exhibitions this year to mark the University's 25th Anniversary. Contributors will include John The first, Selections/rom the Univer­ Rickard (History), Conrad Hamann, sity Art Collection, opened this week Margaret Plant and Jenepher Duncan and will continue until Friday. April 11. (Visual Arts), Martin Canny (Botany) The second will be a largely photo­ and David Bradley (English). graphic exhibition of the University's The exhibition will be held during the cultural, political and social history. 25th Anniversary celebrations, and will It is being mounted jointly by the be officially opened on Tuesday, gallery, the departments of Visual Arts May 20. and History, and is being drawn from at (Contributions of photographs from least 10 different photographic collec­ private collections - memorable events, tions around the University. faces, student activities, and others ­ A special publication, funded by the will be appreciated. They should be sent, Silver Jubilee Committee, will be pro­ together with a date and brief explana­ iii duced in conjunction with the exhibi­ tion of the contents, to the Deputy are, from left: John Rickard.