Sagan breached securityby revealing US work ona lunar bomb projectSir — In his review of two biographies ofCarl Sagan, by William Poundstone and byKeay Davidson (Nature 401, 857; 1999),Christopher Chyba deals extensively with“Davidson’s accusation that the youngSagan wilfully and illegally revealedclassified information…” and furtherstates: “This is a serious and specific legalallegation which Davidson does notsubstantiate”.

The classified project involved, ProjectA119, entitled A Study of Lunar ResearchFlights (SECRET), was conducted atArmour Research Foundation (ARF) whileI was manager of physics research. I was alsoleader of the project, so Sagan reporteddirectly to me. I, therefore, feel obliged toextend the historical record beyond theDavidson biography by offering some addi-tional, first-hand comments.

A119 was one of a series of projects con-ducted at ARF under my direction from1949 to 1962, all concerned with the globalenvironmental effects of nuclear explosionsand related phenomena. Some time beforeMay 1958, we were asked by the US AirForce to add a small, fast-track project toinvestigate the visibility and effects of ahypothetical nuclear explosion on theMoon. I was told the Air Force was veryinterested in the possibility of a surprisedemonstration explosion, with all its obvi-ous implications for public relations andthe Cold War.

Whether the project was motivated by adesire for the United States to impress theworld (and the Soviet Union in particular),or by fear that the Soviet Union itself mighttry the stunt, I cannot say. It was empha-sized, however, that the most sensitiveaspect of the project was, as with manyother Department of Defense projects, itsvery existence. Hence it was given a separatename and work on it was classified as secret.Our task was to assess what gross visible andother phenomena might be generated bythe explosive release on the lunar surface ofa given number of kilotonnes of energy.

We were also asked to try to determinewhat legitimate scientific data might begathered from such an event: for example,about lunar chemistry. The cost to scienceof destroying the pristine lunar environ-ment did not seem of concern to our spon-sors — but it certainly was to us, as I madeclear at the time.

In staffing A119, I realised that we need-ed expertise in planetary physics and askedGerard P. Kuiper to act as our consultant.Kuiper agreed, and in time suggested that Ihire a graduate student from Yerkes/

University of Chicago called Carl Sagan,who needed a job. I gave Sagan the assign-ment of mathematically modelling theexpansion of an exploding gas/dust cloudrarifying into the space around the Moon.This was preliminary to attempts to calcu-late the visibility of such a cloud from Earth.Sagan had difficulty with the problem andconsulted Kuiper several times before Ibrought in additional help. Sagan soon sug-gested that he should try to see how anuclear explosion might be used to detectorganic molecules on the Moon. I agreed toa brief effort in that direction.

Nine monthly progress reports, all clas-sified as secret and including all of Sagan’swork, were issued by ARF to the Air ForceSpecial Weapons Center under Project A119from May 1958 to January 1959. Accordingto Armour (now the Illinois Institute ofTechnology Research Institute) archives,they were all destroyed after October 1987.

I did not know until the biographieswere published that Sagan had sent an“unclassified” (by whom?) manuscriptabout his work on A119 to any unautho-rized person — let alone to five people, asChyba remarks. Both ARF’s and Sagan’sobligations under the A119 contract, asSagan’s signed security agreement wouldhave clearly informed him, required AirForce clearance of any such revelations. Ashis boss at the time, I would have had to takeforward any such request, and Air Forcepermission would have been extremelyunlikely in those long-ago, very tense times.

In his review, Chyba argues that classi-fied documents can contain unclassifiedtitles or subsections. Perhaps so, but thatmisses the point. Fortunately for the futureof lunar science, a one- or two-horse race todetonate a nuclear explosion neveroccurred. But in my opinion Saganbreached security in March 1959 when herevealed the ARF’s classified projects on“possible lunar nuclear detonations” in hisapplication for a Miller fellowship.Leonard Reiffel Exelar Corporation, 602 Deming Place, Chicago,Illinois 60614, USA

Austria takes lab animalwelfare seriously Sir — In response to the News report“Austria taken to court for inadequate lawson animal welfare” (Nature 403, 582;2000), I would like to explain the legalsituation. Animal experiments in Austriaare regulated on the federal level by theAnimal Experiments Act. Passed in 1989,well before Austria’s accession to theEuropean Union in 1995, this law wasdrawn up to conform with the AnimalExperiment Directive (86/609/EEC), even

though at that time Austria was notobliged to do so. The act was amended lastyear. Animal welfare is regulated atprovincial level, and all nine provinceshave animal welfare legislation.

The Animal Experiments Act empowersthe competent Federal Ministers to regulatetechnical matters by ministerial ordinance.Ordinances laying down specific rules (forexample, covering research centres thatbreed animals on their own premises) arecurrently under consultation. As soon asthey come into force, the last minor defi-ciencies in transposing the Directive willhave been eliminated.Wolf FrühaufFederal Ministry of Education, Science and Culture,Minoritenplatz 5, A-1014 Vienna, Austria

How metrics could havesaved UK car industry Sir — You recently featured a report, in the“100 years ago” column, (Nature 404, 27;2000) on German iron manufacturing,written by the British consul inAmsterdam in 1900. He mentioned auniform system of dimensions for articlesof universal consumption, and a system ofmetric screw threads being fixed by acommittee of engineers’ associations.Unless Britain joined the metric standard,the consul warned, “Germany and thecontinent generally will have a constantlyincreasing advantage over Britishmanufacturers”. His words were prophetic— 150 of the world’s 190 export marketsare now metric.

The engineers’ associations agreed onthe Système International (SI) of metricthreads at a special meeting, the Congressof Zurich, in October1898. This was to endthe confusion caused by different Europeancountries using different systems on theirrailways, though they didn’t enter Britishconsciousness until the Second World War,as BSI War Emergency Standard BS1095:1943. The 1898 meeting also saw thebirth of ISO metric standards for engineer-ing, which entered the British standardsenvironment in 1966 through a book pub-lished by the then Ministry of Technology.

Meanwhile, metric screw threads, stan-dard diameters, shaft/hole fits and machin-ing tolerances for the engineering industryhad been internationalized during the1920s and 1930s by a body called ISA,which was absorbed into ISO in 1946. Theold SI metric thread with its undesirablysharp fillet radius was modernized byapplication of the unified profile by ISO in1958 and standardized by all industrializednations soon afterwards. That is why allmechanical engineering assemblies madein mainland European factories since 1959

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use the same threads up to 80 mm diameter.In order to assure the free circulation of

engineering components and subassembliesin the European Common Market, the UKgovernment — led by Harold Wilson —announced in May 1965 that British indus-try would abandon the inch within tenyears and adopt ISO metric standards. Thefirst attempt to produce a British engine tometric standards was already in progress atLeyland Motors with the Leyland 500engine. However, this was marketed in con-tinental Europe only in the Leyland Nation-al bus, whose full metrication was nevercompleted: it incorporated four differentscrew-thread standards and was impossibleto manage in European workshops.

British Leyland vehicles failed to attractcontinental dealers because the inch wasalready alien in mainland Europe — it hadactually been outlawed in mechanical engineering in Germany during the 1930s.It remained only in water- and gas-pipes,and in certain items imported from theUnited States.

Inch threads had no future in Europe,but the planned conversion of British engi-neering factories did not occur. As a result,the UK’s non-metric products were reject-ed by Europe as a nuisance.

It was the abandonment of Wilson’smetrication programme, along with defi-cient marketing, that caused the stagnationof British Leyland and so many other engi-neering-based companies in the UnitedKingdom. The economic effects of Britain’sfailure to adopt the metric system on sched-ule have never been quantified. But therecent loss of the $125 million NASA MarsOrbiter probe emphasizes the vast sums ofmoney that can be lost through the unfa-miliarity of the average UK or US techno-crat with metric units. Michael T. Knowles 11 Powlett Court, Bath BA2 6QJ, UK

Instrument’s ability to dothe job is NASA’s prioritySir — In your News profile article “Sky’sthe limit as teams bid for NASA Project”(Nature 403, 587; 2000), Colin Macilwainimplies that NASA administrator DanielGoldin’s professed enthusiasm for particlephysics detector technologies would be afactor in the selection of one of twocompeting instruments for the Gamma-ray Large Area Space Telescope Mission.(High-energy gamma-ray instrumentationhas always drawn heavily from techniquesdeveloped for high-energy physicsstudies.) There is the further implicationthat contributions to the cost might alsoprovide an advantage.

Although the winning team, from Stan-

ford, contains particle physicists sponsoredby the Department of Energy, this had nodirect bearing on the selection. It is NASA’spolicy to select instruments for its missionsthrough a peer-review process that evalu-ates first and foremost the proposed scienceand the proposed instrument’s ability toachieve that science. There are other fac-tors, but these do not include the participa-tion of other partners, either foreign ordomestic, unless they can help the teamachieve their science goals.

Incidentally, your News profile statedthat the competing instrument was fromNASA’s Marshall Space Flight Center(MSFC). Although MSFC did participate,along with several other institutions, theprincipal investigator was from the Univer-sity of Alabama in Huntsville, and the pro-posal was submitted through the university.The selected instrument also included ateam from NASA’s Goddard Space FlightCenter, as well as several other institutions,both domestic and foreign.Donald A. KniffenNASA Headquarters, Office of Space Science,Research Program Management Division,Washington DC 20546, USA

Putting marine mammalsback in the mainstreamSir— I read with interest Vaclav Smil’s Mil-lennium Essay1, in which he describes thegeneral importance to bioenergetics of MaxKleiber’s studies on the scaling relationshipof metabolic rate with body mass in ani-mals. Across 18 orders of magnitude fromunicellular organisms to whales, it seemsmetabolic rate is proportional to body massraised to the power of 0.75; the so-calledthree-quarters rule, exemplified by the well-known mouse-to-elephant curve.

Smil gives the example of marinemammals as species whose metabolic rateslie outside this relationship because,apparently, seals and whales have basalmetabolic rates (BMR) about twice as highas those of other animals their size, whichillustrates their environmental special-ization for thermoregulation in cold water.However, there is evidence that isinconsistent with this view2.

The perception that pinnipeds (seals,sea lions, fur seals and walrus) andcetaceans (whales, dolphins and porpoises)have BMRs twice as high as similar sizedanimals is an idea that has been widelyaccepted for decades. It primarily arisesfrom comparisons of marine withterrestrial mammal data.

In his studies, Kleiber was very specificabout the conditions under which BMRmeasurements should be made, in a bid toreduce variance between comparisons of

basal rates in animals of different size andfrom different taxonomic groups.(Measurements should be made on matureanimals in a post-absorptive state, non-reproductive, at thermoneutral ambienttemperatures, and without abnormalactivity2.) For these reasons, Kleiberrejected the use of the two determinationsfor marine mammal BMR available to himwhen preparing his original paper.

Nevertheless, published BMR data formarine mammals often have notconformed to these criteria, but have beenincluded in comparative analyses with datathat do. This has led to the widely heldview that marine mammals have higherBMRs and that they are therefore not‘normal’ mammals.

In the analysis by Lavigne et al.2, wheredata from studies on seals and whales wereexcluded when determinations did notfulfil Kleiber’s criteria, it appears thatmetabolic rates of marine mammals wereindistinguishable from those predicted forother mammals under similar conditions.In support of this conclusion, the bestavailable data on minke whale(Baleanoptera acutorostrata) metabolicrates, determined from field trackingstudies and heat loss determinations3 , givea value at zero swimming speed only 17 percent greater than the BMR value predictedfrom Kleiber’s general equation.

Clearly, these studies suggest thatKleiber’s relationship applies just as well tomarine mammals as to terrestrial species.David W. SimsDepartment of Zoology, University of Aberdeen,Aberdeen AB24 2TZ, UK1. Nature 403, 597 (2000).

2. Lavigne, D. M. et al. Can. J. Zool. 64, 279–284 (1986).

3. Blix, A. S. & Folkow, L. P. Acta Physiol. Scand. 153, 61–66 (1995).

Persian role in floweringof Islamic science Sir — Giovanni Bignami in hisMillennium Essay (Nature 404, 227; 2000)qualified two Persian thinkers, Avicennaand Omar Khayyàm, as belonging to theArabic world. Occidental writersfrequently take “Muslim” to mean “Arab”and consider Islamic culture to be Arabic.Yet even 1,000 years ago the Islamic worldwas composed of people of quite differentorigins. Many of the thinkers who partic-ipated in the blossoming of science at thatperiod were in fact Persians and not Arabs. Saadi KhochbinINSERM U309, Institut Albert Bonniot, 38706 La Tronche Cedex, France

Erratum The number of signatories to the letter“Distinguished scientists back Germany’s DFG…” (Nature404, 922; 2000) is 1,641 — not 1,164, as stated in thecorrespondence. Nature apologizes for this error.

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