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A M Nobili - One of the best experts on this subject based on the ideXlab platform.
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relevance of the weak equivalence principle and experiments to test it lessons from the past and improvements expected in space
Physics Letters A, 2017Co-Authors: A M Nobili, Alberto AnselmiAbstract:Abstract Tests of the Weak Equivalence Principle (WEP) probe the foundations of physics. Ever since Galileo in the early 1600s, WEP tests have attracted some of the best experimentalists of any time. Progress has come in bursts, each stimulated by the introduction of a new technique: the torsion balance, signal modulation by Earth rotation, the rotating torsion balance. Tests for various materials in the field of the Earth and the Sun have found no violation to the level of about 1 part in 1013. A different technique, Lunar Laser Ranging (LLR), has reached comparable precision. Today, both laboratory tests and LLR have reached a point when improving by a factor of 10 is extremely hard. The promise of another quantum leap in precision rests on experiments performed in low Earth orbit. The Microscope satellite, launched in April 2016 and currently taking data, aims to test WEP in the field of Earth to 10 − 15 , a 100-fold improvement possible thanks to a driving signal in orbit almost 500 times stronger than for torsion balances on ground. The ‘Galileo Galilei’ (GG) experiment, by combining the advantages of space with those of the rotating torsion balance, aims at a WEP test 100 times more precise than Microscope, to 10 − 17 . A quantitative comparison of the key issues in the two experiments is presented, along with recent experimental measurements relevant for GG. Early results from Microscope, reported at a conference in March 2017, show measurement performance close to the expectations and confirm the key role of rotation with the advantage (unique to space) of rotating the whole spacecraft. Any non-null result from Microscope would be a major discovery and call for urgent confirmation; with 100 times better precision GG could settle the matter and provide a deeper probe of the foundations of physics.
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Galileo galilei gg space test of the weak equivalence principle to 10 17 and laboratory demonstrations
Classical and Quantum Gravity, 2012Co-Authors: A M Nobili, Slava G Turyshev, Michael Shao, R Pegna, G Zavattini, D Lucchesi, A De MicheleAbstract:The small satellite ‘Galileo Galilei’ (GG) will test the universality of free fall and hence the weak equivalence principle which is the founding pillar of general relativity to 1 part in 10 17 . It will use proof masses whose atoms differ substantially from one another in their mass energy content, so as to maximize the chance of violation. GG will improve by four orders of magnitude the current best ‘E¨ ot-Wash’ tests based on slowly rotating torsion balances, which have been able to reach their thermal noise level. In GG, the expected violation signal is a relative displacement between the proof masses of � 0.6 pm caused by a differential acceleration aGG � 8 × 10 −17 ms −2 pointing to the center of mass of the Earth as the satellite orbits around it at νGG � 1.7 × 10 −4 Hz. GG will fly an innovative acceleration sensor based on rapidly rotating macroscopic test masses weakly coupled in 2D which up-converts the signal to νspin � 1H z, a value well above the frequency of natural oscillations of the masses relative to each other νd = 1/Td � 1/(540 s). The sensor is unique in that it ensures high rotation frequency, low thermal noise and no attenuation of the signal strength (Pegna et al 2011 Phys. Rev. Lett. 107 200801). A readout based on a very
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Galileo galilei gg a small satellite to test the equivalence principle of Galileo newton and einstein
Experimental Astronomy, 2009Co-Authors: A M Nobili, Gian Luca Comandi, Suresh Doravari, D Bramanti, Rajeev Kumar, Francesco Maccarrone, E Polacco, Slava G Turyshev, Michael Shao, J A LipaAbstract:“Galileo Galilei” (GG) is a small satellite designed to fly in low Earth orbit with the goal of testing the Equivalence Principle—which is at the basis of the General Theory of Relativity—to 1 part in 1017. If successful, it would improve current laboratory results by 4 orders of magnitude. A confirmation would strongly constrain theories; proof of violation is believed to lead to a scientific revolution. The experiment design allows it to be carried out at ambient temperature inside a small 1-axis stabilized satellite (250 kg total mass). GG is under investigation at Phase A-2 level by ASI (Agenzia Spaziale Italiana) at Thales Alenia Space in Torino, while a laboratory prototype (known as GGG) is operational at INFN laboratories in Pisa, supported by INFN (Istituto Nazionale di fisica Nucleare) and ASI. A final study report will be published in 2009.
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the Galileo galilei gg project testing the equivalence principle in space and on earth
Advances in Space Research, 2000Co-Authors: A M Nobili, D Bramanti, E Polacco, G Catastini, Alberto Anselmi, S Portigliotti, A Lenti, A SeveriAbstract:“Galileo GALILEI” (GG) is a proposal for a small, low orbit satellite devoted to testing the Equivalence Principle (EP) of Galileo, Newton and Einstein to 1 part in 1017. At the end of 1997 GG has been selected and funded by ASI (Agenzia Spaziale Italiana) for a 1-year Phase A study. The main novelty of GG is that the concentric hollow test cylinders whose relative motion (in the plane perpendicular to the spin axis) would be affected by an EP violation, spin together with the read-out capacitance sensors placed in between them. The nominal spin rate is 2 Hz, and this is the frequency at which the putative EP violation signal is modulated by the sensors. As compared to other experiments the modulation frequency is increased by more than a factor 104, thus reducing 1f (low frequency) electronic and mechanical noise. GG will have FEEP ion thrusters for drag compensation. The required amount of propellant is of a few grams only. The experiment works at room temperature. To demonstrate the feasibility of the space experiment a payload prototype for EP testing on the ground (GGG - GG on the Ground) is under development in the laboratories of Laben. The challenge in this field is to fly an experiment able to improve by many orders of magnitude the current best ground sensitivity (≅10−12). This requires spurious relative motions of the test bodies to be greatly reduced, leaving them essentially motionless. Doing that with more than one pair of bodies appears to be an unnecessary complication. This is why GG is now proposed with a single pair of test masses. Information, research papers and photographs of the ground apparatus are available on the Web (http://tycho.dm.unipi.it/nobili).
Erazo Franklin - One of the best experts on this subject based on the ideXlab platform.
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Hermenéutica acerca de la caída de los cuerpos U n modelo filosófico-pedagógico para explicar el vacío tecnológico / Debate about the falling bodies phenomena; philosophical and pedagogical model to explain the technological vacuum
2013Co-Authors: Erazo FranklinAbstract:El presente trabajo constituye una alegoría didáctica en donde los filósofos Galileo Galilei (1564-1642) y Aristóteles (384 a.C–322 a.C), en una simulada confrontación de criterios, debaten ante un tribunal científico moderno para dilucidar quién tuvo más certeza al juzgar la caída de objetos. Se plantea la pregunta: ¿si se sueltan dos objetos de distintos pesos desde un mismo nivel, cuál de ellos llegará primero al suelo? Para esto, se introduce la definición de “grave” y se realiza un estudio comparativo entre la visión clásica griega y la llamada Galileo-newtoniana, arbitrado por la ciencia moderna para lo cual se crea un modelo físico-pedagógico que explica el vacío tecnológico Desde un punto de vista puramente cualitativo, se muestra la coherencia de la física pragmática de Aristóteles frente a la física ideal de Galileo Galilei. Después de esta contraposición a nivel cualitativo, se hace una extensión cuantitativa de la visión galileana, en donde se muestra la metodología moderna de la ciencia, para concluir respondiendo la pregunta inicial y establecer en qué medida eran acertadas las posiciones de estos grandes filósofos.The present research is a didactic allegory where the philosophers Aristotle and Galilei in a simulated confrontation argue their ideas in front of a modern scientific tribunal, in order to indentify who of both was right in the case of falling bodies, and answer the question: ¿when two objects are left, which of them arrives first to the grown?. Firstly, the definition of “grave” is done with a comparative analysis between the classical philosophy and the galilean-newtonian position, under the eyes of the modern physic. to explain the vacuum, a pedagogical model is done. Judging the situation only in a qualitative way, the coherence of the Aristotle’s physics is shown in comparison with the Galilei’s ideal physics. Finally, a quantitative extension of the Galileo’s point of view is made to show the methodology of modern sciences and answer the mentioned question
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Debate about the falling bodies phenomena; philosophical and pedagogical model to explain the technological vacuum
'Salesian Polytechnic University of Ecuador', 2013Co-Authors: Erazo FranklinAbstract:El presente trabajo constituye una alegoría didáctica en donde los filósofos Galileo Galilei (1564-1642) y Aristóteles (384 a.C–322 a.C), en una simulada confrontación de criterios, debaten ante un tribunal científico moderno para dilucidar quién tuvo más certeza al juzgar la caída de objetos. Se plantea la pregunta: ¿si se sueltan dos objetos de distintos pesos desde un mismo nivel, cuál de ellos llegará primero al suelo? Para esto, se introduce la definición de “grave” y se realiza un estudio comparativo entre la visión clásica griega y la llamada Galileo-newtoniana, arbitrado por la ciencia moderna para lo cual se crea un modelo físico-pedagógico que explica el vacío tecnológico Desde un punto de vista puramente cualitativo, se muestra la coherencia de la física pragmática de Aristóteles frente a la física ideal de Galileo Galilei. Después de esta contraposición a nivel cualitativo, se hace una extensión cuantitativa de la visión galileana, en donde se muestra la metodología moderna de la ciencia, para concluir respondiendo la pregunta inicial y establecer en qué medida eran acertadas las posiciones de estos grandes filósofos. The present research is a didactic allegory where the philosophers Aristotle and Galilei in a simulated confrontation argue their ideas in front of a modern scientific tribunal, in order to indentify who of both was right in the case of falling bodies, and answer the question: ¿when two objects are left, which of them arrives first to the grown?. Firstly, the definition of “grave” is done with a comparative analysis between the classical philosophy and the galilean-newtonian position, under the eyes of the modern physic. to explain the vacuum, a pedagogical model is done. Judging the situation only in a qualitative way, the coherence of the Aristotle’s physics is shown in comparison with the Galilei’s ideal physics. Finally, a quantitative extension of the Galileo’s point of view is made to show the methodology of modern sciences and answer the mentioned question
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Hermenéutica acerca de la caída de los cuerpos. Un modelo filosófico - pedagógico para explicar el vacío tecnológico
2013Co-Authors: Erazo FranklinAbstract:The present research is a didactic allegory where the philosophers Aristotle and Galilei in a simulated confrontation argue their ideas in front of a modern scientific tribunal, in order to indentify who of both was right in the case of falling bodies, and answer the question: ¿when two objects are left, which of them arrives first to the grown?. Firstly, the definition of “grave” is done with a comparative analysis between the classical philosophy and the galilean-newtonian position, under the eyes of the modern physic. to explain the vacuum, a pedagogical model is done. Judging the situation only in a qualitative way, the coherence of the Aristotle’s physics is shown in comparison with the Galilei’s ideal physics. Finally, a quantitative extension of the Galileo’s point of view is made to show the methodology of modern sciences and answer the mentioned question.El presente trabajo constituye una alegoría didáctica en donde los filósofos Galileo Galilei (1564-1642) y Aristóteles (384 a.C–322 a.C), en una simulada confrontación de criterios, debaten ante un tribunal científico moderno para dilucidar quién tuvo más certeza al juzgar la caída de objetos. Se plantea la pregunta: ¿si se sueltan dos objetos de distintos pesos desde un mismo nivel, cuál de ellos llegará primero al suelo? Para esto, se introduce la definición de “grave” y se realiza un estudio comparativo entre la visión clásica griega y la llamada Galileo-newtoniana, arbitrado por la ciencia moderna para lo cual se crea un modelo físico-pedagógico que explica el vacío tecnológico Desde un punto de vista puramente cualitativo, se muestra la coherencia de la física pragmática de Aristóteles frente a la física ideal de Galileo Galilei. Después de esta contraposición a nivel cualitativo, se hace una extensión cuantitativa de la visión galileana, en donde se muestra la metodología moderna de la ciencia, para concluir respondiendo la pregunta inicial y establecer en qué medida eran acertadas las posiciones de estos grandes filósofos.
Slava G Turyshev - One of the best experts on this subject based on the ideXlab platform.
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Galileo galilei gg space test of the weak equivalence principle to 10 17 and laboratory demonstrations
Classical and Quantum Gravity, 2012Co-Authors: A M Nobili, Slava G Turyshev, Michael Shao, R Pegna, G Zavattini, D Lucchesi, A De MicheleAbstract:The small satellite ‘Galileo Galilei’ (GG) will test the universality of free fall and hence the weak equivalence principle which is the founding pillar of general relativity to 1 part in 10 17 . It will use proof masses whose atoms differ substantially from one another in their mass energy content, so as to maximize the chance of violation. GG will improve by four orders of magnitude the current best ‘E¨ ot-Wash’ tests based on slowly rotating torsion balances, which have been able to reach their thermal noise level. In GG, the expected violation signal is a relative displacement between the proof masses of � 0.6 pm caused by a differential acceleration aGG � 8 × 10 −17 ms −2 pointing to the center of mass of the Earth as the satellite orbits around it at νGG � 1.7 × 10 −4 Hz. GG will fly an innovative acceleration sensor based on rapidly rotating macroscopic test masses weakly coupled in 2D which up-converts the signal to νspin � 1H z, a value well above the frequency of natural oscillations of the masses relative to each other νd = 1/Td � 1/(540 s). The sensor is unique in that it ensures high rotation frequency, low thermal noise and no attenuation of the signal strength (Pegna et al 2011 Phys. Rev. Lett. 107 200801). A readout based on a very
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Galileo galilei gg a small satellite to test the equivalence principle of Galileo newton and einstein
Experimental Astronomy, 2009Co-Authors: A M Nobili, Gian Luca Comandi, Suresh Doravari, D Bramanti, Rajeev Kumar, Francesco Maccarrone, E Polacco, Slava G Turyshev, Michael Shao, J A LipaAbstract:“Galileo Galilei” (GG) is a small satellite designed to fly in low Earth orbit with the goal of testing the Equivalence Principle—which is at the basis of the General Theory of Relativity—to 1 part in 1017. If successful, it would improve current laboratory results by 4 orders of magnitude. A confirmation would strongly constrain theories; proof of violation is believed to lead to a scientific revolution. The experiment design allows it to be carried out at ambient temperature inside a small 1-axis stabilized satellite (250 kg total mass). GG is under investigation at Phase A-2 level by ASI (Agenzia Spaziale Italiana) at Thales Alenia Space in Torino, while a laboratory prototype (known as GGG) is operational at INFN laboratories in Pisa, supported by INFN (Istituto Nazionale di fisica Nucleare) and ASI. A final study report will be published in 2009.
Michael Shao - One of the best experts on this subject based on the ideXlab platform.
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Galileo galilei gg space test of the weak equivalence principle to 10 17 and laboratory demonstrations
Classical and Quantum Gravity, 2012Co-Authors: A M Nobili, Slava G Turyshev, Michael Shao, R Pegna, G Zavattini, D Lucchesi, A De MicheleAbstract:The small satellite ‘Galileo Galilei’ (GG) will test the universality of free fall and hence the weak equivalence principle which is the founding pillar of general relativity to 1 part in 10 17 . It will use proof masses whose atoms differ substantially from one another in their mass energy content, so as to maximize the chance of violation. GG will improve by four orders of magnitude the current best ‘E¨ ot-Wash’ tests based on slowly rotating torsion balances, which have been able to reach their thermal noise level. In GG, the expected violation signal is a relative displacement between the proof masses of � 0.6 pm caused by a differential acceleration aGG � 8 × 10 −17 ms −2 pointing to the center of mass of the Earth as the satellite orbits around it at νGG � 1.7 × 10 −4 Hz. GG will fly an innovative acceleration sensor based on rapidly rotating macroscopic test masses weakly coupled in 2D which up-converts the signal to νspin � 1H z, a value well above the frequency of natural oscillations of the masses relative to each other νd = 1/Td � 1/(540 s). The sensor is unique in that it ensures high rotation frequency, low thermal noise and no attenuation of the signal strength (Pegna et al 2011 Phys. Rev. Lett. 107 200801). A readout based on a very
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Galileo galilei gg a small satellite to test the equivalence principle of Galileo newton and einstein
Experimental Astronomy, 2009Co-Authors: A M Nobili, Gian Luca Comandi, Suresh Doravari, D Bramanti, Rajeev Kumar, Francesco Maccarrone, E Polacco, Slava G Turyshev, Michael Shao, J A LipaAbstract:“Galileo Galilei” (GG) is a small satellite designed to fly in low Earth orbit with the goal of testing the Equivalence Principle—which is at the basis of the General Theory of Relativity—to 1 part in 1017. If successful, it would improve current laboratory results by 4 orders of magnitude. A confirmation would strongly constrain theories; proof of violation is believed to lead to a scientific revolution. The experiment design allows it to be carried out at ambient temperature inside a small 1-axis stabilized satellite (250 kg total mass). GG is under investigation at Phase A-2 level by ASI (Agenzia Spaziale Italiana) at Thales Alenia Space in Torino, while a laboratory prototype (known as GGG) is operational at INFN laboratories in Pisa, supported by INFN (Istituto Nazionale di fisica Nucleare) and ASI. A final study report will be published in 2009.
A De Michele - One of the best experts on this subject based on the ideXlab platform.
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Galileo galilei gg space test of the weak equivalence principle to 10 17 and laboratory demonstrations
Classical and Quantum Gravity, 2012Co-Authors: A M Nobili, Slava G Turyshev, Michael Shao, R Pegna, G Zavattini, D Lucchesi, A De MicheleAbstract:The small satellite ‘Galileo Galilei’ (GG) will test the universality of free fall and hence the weak equivalence principle which is the founding pillar of general relativity to 1 part in 10 17 . It will use proof masses whose atoms differ substantially from one another in their mass energy content, so as to maximize the chance of violation. GG will improve by four orders of magnitude the current best ‘E¨ ot-Wash’ tests based on slowly rotating torsion balances, which have been able to reach their thermal noise level. In GG, the expected violation signal is a relative displacement between the proof masses of � 0.6 pm caused by a differential acceleration aGG � 8 × 10 −17 ms −2 pointing to the center of mass of the Earth as the satellite orbits around it at νGG � 1.7 × 10 −4 Hz. GG will fly an innovative acceleration sensor based on rapidly rotating macroscopic test masses weakly coupled in 2D which up-converts the signal to νspin � 1H z, a value well above the frequency of natural oscillations of the masses relative to each other νd = 1/Td � 1/(540 s). The sensor is unique in that it ensures high rotation frequency, low thermal noise and no attenuation of the signal strength (Pegna et al 2011 Phys. Rev. Lett. 107 200801). A readout based on a very
