7_54 ____________ CQRRESPQNDENCE----N_AT_u_RE_v_o_L._32_s_z6_FE_'B_Ru_A_RY_t_9s7 sediments, the latter being the more per­ Antimatter underestimated manent sink for CO,. Perhaps floating lagoons made to trans­ SrR-The first published account of suc­ To develop such weapons would add con­ port sewerage could be towed like ice­ cess in immobilizing antiprotons in an siderable impetus to the current arms bergs (used for soft water irrigation), to electromagnetic trap has been the subject race. We call for an immediate ban on all chosen sites, where the surface waters of a recent leading article in News and antimatter-related research, especially as would be fed by trickle and slow release Views (Nature 324, 299; 1986). Although this work is fundamental to many third­ methods. Natural upwelling of nutrient­ this article gives a good overview of the generation nuclear weapon systems. rich bottom waters of the ocean greatly scientific meaning of this historical ANDRE GsPONER increase their production of living organ­ achievement, it gives in our view a rather JEAN-PIERRE HuRNI isms, (J.H. Ryther Science 166, 72-76; misleading perspective on its likely mili­ Independent Scientific Research Institute, 1969) and artificial methods could be de­ tary significance. 15, Charles-Galland, veloped to extend this process. It is true that for some applications of Ch-1206 Geneva, I look forward to a time when it is poss­ antimatter, such as antiballistic missile or Switzerland ible by careful balancing of the nutrition of spacecraft propulsion, relatively large pH of the biosphere in these and other amounts of antiprotons are required. For ways to treble its content of unoxidized C, most other cases, the useful amounts are SDI boycott as has been accomplished on farms and usually much smaller. For example, we SIR-Your leading article (Nature 323, gardens around the world in the course of have calculated that less than a microgram 746; 1986) questioning the wisdom of a a few decades. of antiprotons is sufficient to trigger a boycott of the Strategic Defense Initiative R. PARR thermonuclear explosion or pump a pow­ (SDI) misses the point. Scientists who Arrington Bridge, erful X-ray laseru. oppose SDI funding do not accept the Arrington, Royston, But antimatter is not only the most port­ premise that knowledge is worth gaining Hertfordshire SG8 OAE, UK able of all high explosives, it is also the for its own sake, irrespective of the ulti­ only feasible portable source of muons. In mate social consequences. We can wait to every antiproton annihilation, on average obtain some knowledge and its gains. First among equals three muons are produced. These could Of course academic researchers should SIR-in a recent leading article (Nature be used to induce muon-catalysed fusion decide for themselves what research they 324, 509; 1986), you ask "Should editors reactions in a deuterium-tritium mixture, should undertake, but they should also now seek to protect authors from them­ an attractive solution for a low-weight strive to ensure that the knowledge they selves by banning the use of the word space nuclear reactor that could be oper­ gain is not applied to ends that are not in 'first'?". My reply is: would you care to ated in a continuous or pulsed mode. the interests of humanity, questions of join the Proceedings, which has had such a Furthermore, by collecting and cooling nationalism aside. Refusing SDI funding policy for some years? the muons (an easy task compared with is one way of expressing opposition to the I do not know exactly when the Pro­ that of cooling antiprotons) a very intense political control of science. ceedings first published priority state­ beam could be formed and sent into the We in New Zealand admire the refusnik ments. There is a 1977 memorandum in atmosphere to guide, over a range of more mentality and although there is no pro­ the files from Bernard K. Forscher, then than 10 km, a series of powerful electron spect of our being offered SDI money, managing editor, to Robert L Sinsheim­ or proton beam pulses towards a target. scientists have played an important role in er, then chairman of the editorial board, More simply, stopping the muons in a suit­ bolstering the government's policy of suggesting such a policy (which may sim­ able material would generate an extra­ refusing port visits by nuclear weapon­ ply be the earliest available written ex­ ordinarily effective X-ray lasing medium, capable vessels, of the Royal Navy and the pression of a previously unwritten policy) for the two-microsecond lifetime of the United States Navy in particular. and a letter from Sinsheimer concurring. muonic atoms. PETER WILLS Since 1983 at least, the Information for In outer space, a very low intensity Department of Physics, Contributors has stated "The Proceedings burst of antiprotons would be most suit­ University of Auckland, does not print priority statements". Thus, able for active warhead/decoy discrimina­ Private Bag, one of the duties of our editorial staff is to tion. In this and the two previous exam­ Auckland, remove such statements. Most authors ples, the amount of antiprotons needed is New Zealand accept this change with equanimity; for of the order of nanograms per engage­ those who do not, we permit the qualified ment. Conservative estimates of the tech­ statement "So far as we know, this is the nical problems involved in producing and In the greenhouse first ... ". manipulating microgram amounts of anti­ SIR-T.R. Vidyasagar (Nature 323, 390; A policy that is much more difficult to matter per day show that known technolo­ 1986) suggests a switch to a vegetarian diet implement is our proscription of state­ gy is only a couple of orders of magnitudes and reforestation of the 40 per cent of ments of novelty. I admit that this has 4 away from meeting the challenge' • present agricultural land so freed as a way been unevenly enforced, although in the We are very much concerned by the to decrease atmospheric CO,. This short­ past year we have become more strict. implications for nuclear weapons prolifer­ term measure could be supplemented by Novel fragments, novel genes, novel ation of the indisputable scientific feasibil­ fertilizing the world's forest and pasture hypothesis - the term is usually a cliche ity of several antimatter weapon concepts. soils, where applicable, with nutrients occasioned by the author's desire for an I. Gsponer, A. & Humi, J.-P. La Recherche, 17, 1440-1443 from city drains, combined with pelleted adjective, as our stated policy is to publish ( 1986); The Physics of Antimatter Induced Fusion and Ther­ spores and seeds of soil-enriching plants. reports of exceptional importance and monuclear Explosions, in Proc. 4th Inti. Con[. Emerging Only a light dressing of suitably prepared novelty. Again, would you care to join us? Nuc/. Energy Syst., Madrid, 30 June-4 July 1986 (in the press). and selected material would be required FRANCES R. ZwANZTG 2. Gsponer. A. & Hurni, J.·P. Antimatter Induced Fusion and to fortify their nutrient cycles and make (Managing Editor) Thermonuclear Explosions, report ISRI-85-05 (August 1985); prcprint ISR-80-06 Atomkernenergie!Kerntechnik. them more productive for many years. Proceedings Office, 3. Augenstein, B. W. Concepts, Problems and Opportunities Many parts of the oceans would respond National Academy of Sciences, for use of Annihilation Energy RAND Note N-2302-AF/RC (June 1985). to similar treatment by producing more 2101 Constitution A venue, 4. Walgatc. R. Nature 322.678 (1986). fish, seaweed, corals and carbonaceous Washington, DC 20418, USA .