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LUCAS EXPERIMENT: SEARCHING FOR VEGETATION AND OTHER BIOSIGNATURES ON PLANET EARTH Danielle Briot Observatoire de Paris Meudon France danielle fr Luc Arnold Observatoire de Haute Provence France Stéphane Jacquemoud University Paris Diderot Institut de Physique du Globe de Paris France Jean Schneider Observatoire de Paris Meudon France Karim Agabi Université de Nice France Eric Aristidi Université de Nice France Jérome Berthier Observatoire de Paris Meudon France Erick Bondoux Concordia Station Dôme C Antarctica Zalpha Challita Concordia Station Dôme C Antarctica Patrick Rocher Observatoire de Paris Meudon France ABSTRACT In order to prepare the future search for biosignatures on exo Earths or exo SuperEarths we investigate the detection of life on the only planet known to shelter life to date our Earth We have to see the Earth as a dot the way future exoEarths will appear to us This is the case when we observe the Earthshine using the Moon as a huge reflector to measure the whole Earth s albedo Observations of the Earthshine made at the Haute Provence Observatory and the European Southern Observatory showed biosignatures on Earth including the Vegetation Red Edge VRE in the near infrared which is due to chlorophyll absorption spectral properties The VRE is only a few percents and higher when continents instead of oceans are facing the Moon At very high latitudes and some times of year it is possible to observe the Earthshine during most of the day which is not possible at lower latitudes Throughout these long observing windows Earth rotation brings various terrestrial landscapes in front of the Moon So we planned to make observations at the French Italian scientific Concordia Station located at the Dome C in Antarctica and for this purpose we set up the LUCAS LUmière Cendrée en Antarctique par Spectroscopie experiment A dedicated spectrograph was designed and built at the Haute Provence and Meudon Observatories The first observations began during the winterover campaign and go on icon
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LUCAS EXPERIMENT: SEARCHING FOR VEGETATION AND OTHER BIOSIGNATURES ON PLANET EARTH Danielle Briot Observatoire de Paris Meudon France danielle fr Luc Arnold Observatoire de Haute Provence France Stéphane Jacquemoud University Paris Diderot Institut de Physique du Globe de Paris France Jean Schneider Observatoire de Paris Meudon France Karim Agabi Université de Nice France Eric Aristidi Université de Nice France Jérome Berthier Observatoire de Paris Meudon France Erick Bondoux Concordia Station Dôme C Antarctica Zalpha Challita Concordia Station Dôme C Antarctica Patrick Rocher Observatoire de Paris Meudon France ABSTRACT In order to prepare the future search for biosignatures on exo Earths or exo SuperEarths we investigate the detection of life on the only planet known to shelter life to date our Earth We have to see the Earth as a dot the way future exoEarths will appear to us This is the case when we observe the Earthshine using the Moon as a huge reflector to measure the whole Earth's albedo Observations of the Earthshine made at the Haute Provence Observatory and the European Southern Observatory showed biosignatures on Earth including the Vegetation Red Edge VRE in the near infrared which is due to chlorophyll absorption spectral properties The VRE is only a few percents and higher when continents instead of oceans are facing the Moon At very high latitudes and some times of year it is possible to observe the Earthshine during most of the day which is not possible at lower latitudes Throughout these long observing windows Earth rotation brings various terrestrial landscapes in front of the Moon So we planned to make observations at the French Italian scientific Concordia Station located at the Dome C in Antarctica and for this purpose we set up the LUCAS LUmière Cendrée en Antarctique par Spectroscopie experiment A dedicated spectrograph was designed and built at the Haute Provence and Meudon Observatories The first observations began during the winterover campaign and go on

Danielle Briot

Symmetries and symmetry breakings: the fabric of physical interactions and the flow of time1 Giuseppe Longo Dépt d Informatique CNRS Ecole Normale Supérieure et CREA Polytechnique Paris http: www di ens fr users longo Summary This short note develops some ideas along the lines of the stimulating paper by Heylighen Found Sci 2010a It summarizes a theme in several writings with Francis Bailly downloadable from this author s web page The “geometrization” of time and causality is the common ground of the analysis hinted here and in Heylighen s paper Heylighen adds a logical notion consistency in order to understand a possible origin of the selective process that may have originated this organization of natural phenomena We will join our perspectives by hinting to some gnoseological complexes common to mathematics and physics which may shed light on the issues raised by Heylighen Note: Francis Bailly passed away recently: his immense experience in physics has been leading our joint work for many years Historically it is with relativist physics that there occurs a “change of perspective”: we pass from “causal laws” to the structural organization of space and time or even from causal laws to the “legality normativity of geometric structures” This understanding of causal laws by the identification of structural organizations stems essentially from the intrinsic duality existing between the characterization of the geometry of the universe and that of energy momentum within that universe By this duality and the putting into effect of the principle of invariance under the differentiable transformations of space time the “forces” are relativized to the nature of this geometry: they will even appear or disappear according to the geometric nature of the universe chosen a priori to describe physical behaviors Now it is similar for quantum physics in gauge theories Here gauge groups operate upon internal variables such as in the case of relativity where the choice of local gauges and their changes enable to define or ... icon
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Symmetries and symmetry breakings: the fabric of physical interactions and the flow of time1 Giuseppe Longo Dépt d'Informatique CNRS Ecole Normale Supérieure et CREA Polytechnique Paris http: www di ens fr users longo Summary This short note develops some ideas along the lines of the stimulating paper by Heylighen Found Sci 2010a It summarizes a theme in several writings with Francis Bailly downloadable from this author's web page The “geometrization” of time and causality is the common ground of the analysis hinted here and in Heylighen's paper Heylighen adds a logical notion consistency in order to understand a possible origin of the selective process that may have originated this organization of natural phenomena We will join our perspectives by hinting to some gnoseological complexes common to mathematics and physics which may shed light on the issues raised by Heylighen Note: Francis Bailly passed away recently: his immense experience in physics has been leading our joint work for many years Historically it is with relativist physics that there occurs a “change of perspective”: we pass from “causal laws” to the structural organization of space and time or even from causal laws to the “legality normativity of geometric structures” This understanding of causal laws by the identification of structural organizations stems essentially from the intrinsic duality existing between the characterization of the geometry of the universe and that of energy momentum within that universe By this duality and the putting into effect of the principle of invariance under the differentiable transformations of space time the “forces” are relativized to the nature of this geometry: they will even appear or disappear according to the geometric nature of the universe chosen a priori to describe physical behaviors Now it is similar for quantum physics in gauge theories Here gauge groups operate upon internal variables such as in the case of relativity where the choice of local gauges and their changes enable to define or ...

Giuseppe Longo