Attributing scientific and technical progress: the case of holography

Holography, the three-dimensional imaging technology, was portrayed widely as a paradigm of progress during its decade of explosive expansion 1964–73, and during its subsequent consolidation for commercial and artistic uses up to the mid 1980s. An unusually seductive and prolific subject, holography successively spawned scientific insights, putative applications and new constituencies of practitioners and consumers. Waves of forecasts, associated with different sponsors and user communities, cast holography as a field on the verge of success—but with the dimensions of success repeatedly refashioned. This retargeting of the subject represented a degree of cynical marketeering, but was underpinned by implicit confidence in philosophical positivism and faith in technological progressivism. Each of its communities defined success in terms of expansion, and anticipated continual progressive increase. This paper discusses the contrasting definitions of progress in holography, and how they were fashioned in changing contexts. Focusing equally on reputed ‘failures’ of some aspects of the subject, it explores the varied attributes by which success and failure were linked with progress by different technical communities. This important case illuminates the peculiar post-World War II environment that melded the military, commercial and popular engagement with scientific and technological subjects, and the competing criteria by which they assessed the products of science

Overview of Perseverance’s Upper Fan Campaign

International audienceThe Mars 2020 Perseverance rover’s mission objective is to collect diverse suites of samples for return to Earth via Mars Sample Return and characterize their geologic and environmental context. Jezero crater was selected as the landing site for Perseverance partially due to the opportunity to explore the western fan deposits, which include water-lain sediments from a diverse ancient watershed that have been lithified and exposed by wind. The Upper Fan Campaign, described here, is the third campaign of the mission; it follows the crater floor campaign and the delta front campaign that explored ~40 m of sedimentary deposits at the base of two lobes of the fan. The Upper Fan Campaign includes the rover traverse from the top of the delta front campaign to the margin unit lining the inner crater rim.Prior to landing, two major geologic units were identified on the Upper Fan: the truncated curvilinear unit and the blocky unit. Our goals are to characterize the depositional context and major lithologies present in each unit and acquire samples. At time of writing, we have collected two samples and are planning 1-2 more sample acquisitions in the Upper Fan.The Melyn sample is a fine-grained sandstone from the light toned bands of the truncated curvilinear unit at Tenby, part of the Skrinkle Haven member of the Tenby formation. The sandstone lacks internal structure and decimeter-thick layers have steep (>20°) dip angles. It is interpreted to have formed in subaqueous downslope avalanches, likely on a downstream bar or delta foreset. Melyn contains detrital primary and altered silicates, minor sulfates, and Mg, Fe carbonate grains, coatings, and possible cement.The Otis_Peak sample is a cross-stratified conglomerate interpreted as part of a higher-energy delta plain braided river deposit in the Carew Castle member of the Tenby formation, overlying the Skrinkle Haven member. Proximity science and remote sensing indicate Otis_Peak contains coarse (up to 4 mm) detrital primary and altered silicates with sulfates and Fe, Mg carbonates.Perseverance is characterizing the most commonly observed boulder lithologies in the blocky unit, including boulders with dominant olivine and pyroxene spectral signatures. We plan to collect 1-2 more samples in the campaign, including a lithology representative of the latest phase of delta deposition

Overview of Perseverance’s Upper Fan Campaign

International audienceThe Mars 2020 Perseverance rover’s mission objective is to collect diverse suites of samples for return to Earth via Mars Sample Return and characterize their geologic and environmental context. Jezero crater was selected as the landing site for Perseverance partially due to the opportunity to explore the western fan deposits, which include water-lain sediments from a diverse ancient watershed that have been lithified and exposed by wind. The Upper Fan Campaign, described here, is the third campaign of the mission; it follows the crater floor campaign and the delta front campaign that explored ~40 m of sedimentary deposits at the base of two lobes of the fan. The Upper Fan Campaign includes the rover traverse from the top of the delta front campaign to the margin unit lining the inner crater rim.Prior to landing, two major geologic units were identified on the Upper Fan: the truncated curvilinear unit and the blocky unit. Our goals are to characterize the depositional context and major lithologies present in each unit and acquire samples. At time of writing, we have collected two samples and are planning 1-2 more sample acquisitions in the Upper Fan.The Melyn sample is a fine-grained sandstone from the light toned bands of the truncated curvilinear unit at Tenby, part of the Skrinkle Haven member of the Tenby formation. The sandstone lacks internal structure and decimeter-thick layers have steep (>20°) dip angles. It is interpreted to have formed in subaqueous downslope avalanches, likely on a downstream bar or delta foreset. Melyn contains detrital primary and altered silicates, minor sulfates, and Mg, Fe carbonate grains, coatings, and possible cement.The Otis_Peak sample is a cross-stratified conglomerate interpreted as part of a higher-energy delta plain braided river deposit in the Carew Castle member of the Tenby formation, overlying the Skrinkle Haven member. Proximity science and remote sensing indicate Otis_Peak contains coarse (up to 4 mm) detrital primary and altered silicates with sulfates and Fe, Mg carbonates.Perseverance is characterizing the most commonly observed boulder lithologies in the blocky unit, including boulders with dominant olivine and pyroxene spectral signatures. We plan to collect 1-2 more samples in the campaign, including a lithology representative of the latest phase of delta deposition

Overview of Perseverance’s Upper Fan Campaign

International audienceThe Mars 2020 Perseverance rover’s mission objective is to collect diverse suites of samples for return to Earth via Mars Sample Return and characterize their geologic and environmental context. Jezero crater was selected as the landing site for Perseverance partially due to the opportunity to explore the western fan deposits, which include water-lain sediments from a diverse ancient watershed that have been lithified and exposed by wind. The Upper Fan Campaign, described here, is the third campaign of the mission; it follows the crater floor campaign and the delta front campaign that explored ~40 m of sedimentary deposits at the base of two lobes of the fan. The Upper Fan Campaign includes the rover traverse from the top of the delta front campaign to the margin unit lining the inner crater rim.Prior to landing, two major geologic units were identified on the Upper Fan: the truncated curvilinear unit and the blocky unit. Our goals are to characterize the depositional context and major lithologies present in each unit and acquire samples. At time of writing, we have collected two samples and are planning 1-2 more sample acquisitions in the Upper Fan.The Melyn sample is a fine-grained sandstone from the light toned bands of the truncated curvilinear unit at Tenby, part of the Skrinkle Haven member of the Tenby formation. The sandstone lacks internal structure and decimeter-thick layers have steep (>20°) dip angles. It is interpreted to have formed in subaqueous downslope avalanches, likely on a downstream bar or delta foreset. Melyn contains detrital primary and altered silicates, minor sulfates, and Mg, Fe carbonate grains, coatings, and possible cement.The Otis_Peak sample is a cross-stratified conglomerate interpreted as part of a higher-energy delta plain braided river deposit in the Carew Castle member of the Tenby formation, overlying the Skrinkle Haven member. Proximity science and remote sensing indicate Otis_Peak contains coarse (up to 4 mm) detrital primary and altered silicates with sulfates and Fe, Mg carbonates.Perseverance is characterizing the most commonly observed boulder lithologies in the blocky unit, including boulders with dominant olivine and pyroxene spectral signatures. We plan to collect 1-2 more samples in the campaign, including a lithology representative of the latest phase of delta deposition

OVERVIEW OF THE MARS 2020 MISSION PERSEVERANCE ROVER THIRD SCIENCE CAMPAIGN: EXPLORING JEZERO CRATER’S UPPER FAN

International audienceThe objective of the Mars 2020 mission is to characterize the geologic history and astrobiological potential of Jezero crater, as well as to collect and document a suite of samples for potential future return to Earth [1]. Jezero crater was selected as the landing site for the Perseverance rover in part due to the presence of the exceptionally well-preserved “western fan” (Fig. 1). This fan was interpreted from orbiter images to be a river delta, formed in the late Noachian to early Hesperian in a lake that was once present inside the crater [2-5]. The Upper Fan Campaign is the third campaign of the Mars 2020 mission. It began in February 2023 (sol 708) with the rover’s arrival at the top of the fan front and ended in September 2023 (~sol 910) when the rover crossed into the Margin unit lining the inner crater rim (Fig. 1)

A controvérsia sobre o uso de alimentação 'alternativa' no combate à subnutrição no Brasil: analysis of a controversy The policy and politics of alternative food programs in Brazil

É consensual a urgência de eliminar a subnutrição infantil no Brasil, mas como fazê-lo é motivo de debates. O Programa de Alimentação Alternativa implementado pela Pastoral da Criança da Confederação Nacional dos Bispos do Brasil (CNBB) e financiado pelo governo federal e organismos internacionais é um exemplo típico de tais controvérsias. Os críticos do programa têm apresentado "evidências científicas" de que existem problemas de ordem nutricional com os produtos utilizados (partes desprezadas de alimentos) no preparo daquele alimento alternativo ou multimistura. Os proponentes do programa, por sua vez, também se utilizam do mesmo instrumental acadêmico para "demonstrar" o valor nutricional dos produtos utilizados.Este artigo é uma reconstrução e análise do conteúdo e contexto desta controvérsia.<br>The urgency to solve infant malnutrition in Brazil is undisputed. Policies to achieve that, however, are not consensual. The Alternative Food Program, put forward by the Catholic National Confederation of Brazilian Bishops' Children Pastoral with the support of various federal organizations and international agencies, has been the focus of heated debate. Although the initiative per se has much to be praised for, program opponents argue that nutritional problems in food byproducts have been "demonstrated" by scientific research. To counteract their critics, program proponents also point to scientific results that have just as well "demonstrated" the nutritional value of the used products. The present article reconstructs and analyzes the content and context of this controversy