Get quick answers to your questions about the article from our AI researcher chatbot
{'id': 'https://openalex.org/W2009110392', 'doi': 'https://doi.org/10.1119/1.4798583', 'title': 'On the universality of free fall, the equivalence principle, and the gravitational redshift', 'display_name': 'On the universality of free fall, the equivalence principle, and the gravitational redshift', 'publication_year': 2013, 'publication_date': '2013-07-01', 'ids': {'openalex': 'https://openalex.org/W2009110392', 'doi': 'https://doi.org/10.1119/1.4798583', 'mag': '2009110392'}, 'language': 'en', 'primary_location': {'is_oa': False, 'landing_page_url': 'https://doi.org/10.1119/1.4798583', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S38866342', 'display_name': 'American Journal of Physics', 'issn_l': '0002-9505', 'issn': ['0002-9505', '1943-2909'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310320257', 'host_organization_name': 'American Institute of Physics', 'host_organization_lineage': ['https://openalex.org/P4310320257'], 'host_organization_lineage_names': ['American Institute of Physics'], 'type': 'journal'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, 'type': 'article', 'type_crossref': 'journal-article', 'indexed_in': ['crossref'], 'open_access': {'is_oa': False, 'oa_status': 'closed', 'oa_url': None, 'any_repository_has_fulltext': False}, 'authorships': [{'author_position': 'first', 'author': {'id': 'https://openalex.org/A5088459822', 'display_name': 'A. M. Nobili', 'orcid': 'https://orcid.org/0000-0002-0363-4071'}, 'institutions': [{'id': 'https://openalex.org/I4210160382', 'display_name': 'INFN Sezione di Pisa', 'ror': 'https://ror.org/05symbg58', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I160013858', 'https://openalex.org/I27483092', 'https://openalex.org/I4210160382']}, {'id': 'https://openalex.org/I108290504', 'display_name': 'University of Pisa', 'ror': 'https://ror.org/03ad39j10', 'country_code': 'IT', 'type': 'education', 'lineage': ['https://openalex.org/I108290504']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'A. M. Nobili', 'raw_affiliation_strings': ['Department of Physics "E. Fermi," University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy and INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy'], 'affiliations': [{'raw_affiliation_string': 'Department of Physics "E. Fermi," University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy and INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy', 'institution_ids': ['https://openalex.org/I4210160382', 'https://openalex.org/I108290504']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5000312107', 'display_name': 'David Lucchesi', 'orcid': 'https://orcid.org/0000-0002-7057-4785'}, 'institutions': [{'id': 'https://openalex.org/I4210160382', 'display_name': 'INFN Sezione di Pisa', 'ror': 'https://ror.org/05symbg58', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I160013858', 'https://openalex.org/I27483092', 'https://openalex.org/I4210160382']}, {'id': 'https://openalex.org/I4210100742', 'display_name': 'Institute for Space Astrophysics and Planetology', 'ror': 'https://ror.org/0141xw169', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I4210100742', 'https://openalex.org/I875825670']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'D. M. Lucchesi', 'raw_affiliation_strings': ['INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy and INAF-IAPS-Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, 00133 Roma, Italy'], 'affiliations': [{'raw_affiliation_string': 'INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy and INAF-IAPS-Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, 00133 Roma, Italy', 'institution_ids': ['https://openalex.org/I4210160382', 'https://openalex.org/I4210100742']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5063625359', 'display_name': 'F. Crifo', 'orcid': 'https://orcid.org/0000-0003-4369-3786'}, 'institutions': [{'id': 'https://openalex.org/I4210105504', 'display_name': 'Osservatorio Astrofisico di Torino', 'ror': 'https://ror.org/00yrf4e35', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I4210105504', 'https://openalex.org/I875825670']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'M. T. Crosta', 'raw_affiliation_strings': ['INAF-Osservatorio Astrofisico di Torino, Pino Torinese, Torino, Italy'], 'affiliations': [{'raw_affiliation_string': 'INAF-Osservatorio Astrofisico di Torino, Pino Torinese, Torino, Italy', 'institution_ids': ['https://openalex.org/I4210105504']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5102997643', 'display_name': 'M. Shao', 'orcid': 'https://orcid.org/0009-0009-4546-7089'}, 'institutions': [{'id': 'https://openalex.org/I1334627681', 'display_name': 'Jet Propulsion Laboratory', 'ror': 'https://ror.org/027k65916', 'country_code': 'US', 'type': 'facility', 'lineage': ['https://openalex.org/I122411786', 'https://openalex.org/I1334627681', 'https://openalex.org/I4210124779']}], 'countries': ['US'], 'is_corresponding': False, 'raw_author_name': 'M. Shao', 'raw_affiliation_strings': ['Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91109'], 'affiliations': [{'raw_affiliation_string': 'Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91109', 'institution_ids': ['https://openalex.org/I1334627681']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5039807256', 'display_name': 'Slava G. Turyshev', 'orcid': 'https://orcid.org/0000-0003-4255-9497'}, 'institutions': [{'id': 'https://openalex.org/I1334627681', 'display_name': 'Jet Propulsion Laboratory', 'ror': 'https://ror.org/027k65916', 'country_code': 'US', 'type': 'facility', 'lineage': ['https://openalex.org/I122411786', 'https://openalex.org/I1334627681', 'https://openalex.org/I4210124779']}], 'countries': ['US'], 'is_corresponding': False, 'raw_author_name': 'S. G. Turyshev', 'raw_affiliation_strings': ['Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91109'], 'affiliations': [{'raw_affiliation_string': 'Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91109', 'institution_ids': ['https://openalex.org/I1334627681']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5060798890', 'display_name': 'Roberto Peron', 'orcid': 'https://orcid.org/0000-0002-1774-5725'}, 'institutions': [{'id': 'https://openalex.org/I4210100742', 'display_name': 'Institute for Space Astrophysics and Planetology', 'ror': 'https://ror.org/0141xw169', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I4210100742', 'https://openalex.org/I875825670']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'R. Peron', 'raw_affiliation_strings': ['INAF-IAPS-Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, 00133 Roma, Italy'], 'affiliations': [{'raw_affiliation_string': 'INAF-IAPS-Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, 00133 Roma, Italy', 'institution_ids': ['https://openalex.org/I4210100742']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5009598052', 'display_name': 'G. Catastini', 'orcid': None}, 'institutions': [{'id': 'https://openalex.org/I2801562428', 'display_name': 'Alenia Aermacchi', 'ror': 'https://ror.org/05mmh5r64', 'country_code': 'IT', 'type': 'company', 'lineage': ['https://openalex.org/I2801562428', 'https://openalex.org/I2802798279']}, {'id': 'https://openalex.org/I4210102386', 'display_name': 'Thales (Italy)', 'ror': 'https://ror.org/00rwwx648', 'country_code': 'IT', 'type': 'company', 'lineage': ['https://openalex.org/I4210102386', 'https://openalex.org/I4210140930']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'G. Catastini', 'raw_affiliation_strings': ['Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146 Torino, Italy'], 'affiliations': [{'raw_affiliation_string': 'Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146 Torino, Italy', 'institution_ids': ['https://openalex.org/I2801562428', 'https://openalex.org/I4210102386']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5085526556', 'display_name': 'Alberto Anselmi', 'orcid': 'https://orcid.org/0000-0001-9897-9779'}, 'institutions': [{'id': 'https://openalex.org/I2801562428', 'display_name': 'Alenia Aermacchi', 'ror': 'https://ror.org/05mmh5r64', 'country_code': 'IT', 'type': 'company', 'lineage': ['https://openalex.org/I2801562428', 'https://openalex.org/I2802798279']}, {'id': 'https://openalex.org/I4210102386', 'display_name': 'Thales (Italy)', 'ror': 'https://ror.org/00rwwx648', 'country_code': 'IT', 'type': 'company', 'lineage': ['https://openalex.org/I4210102386', 'https://openalex.org/I4210140930']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'A. Anselmi', 'raw_affiliation_strings': ['Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146 Torino, Italy'], 'affiliations': [{'raw_affiliation_string': 'Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146 Torino, Italy', 'institution_ids': ['https://openalex.org/I2801562428', 'https://openalex.org/I4210102386']}]}, {'author_position': 'last', 'author': {'id': 'https://openalex.org/A5073670941', 'display_name': 'G. Zavattini', 'orcid': 'https://orcid.org/0000-0002-6089-7185'}, 'institutions': [{'id': 'https://openalex.org/I4210107105', 'display_name': 'INFN Sezione di Ferrara', 'ror': 'https://ror.org/00zs3y046', 'country_code': 'IT', 'type': 'facility', 'lineage': ['https://openalex.org/I160013858', 'https://openalex.org/I201324441', 'https://openalex.org/I4210107105']}, {'id': 'https://openalex.org/I201324441', 'display_name': 'University of Ferrara', 'ror': 'https://ror.org/041zkgm14', 'country_code': 'IT', 'type': 'education', 'lineage': ['https://openalex.org/I201324441']}], 'countries': ['IT'], 'is_corresponding': False, 'raw_author_name': 'G. Zavattini', 'raw_affiliation_strings': ['Department of Physics, University of Ferrara, Via Saragat 1, 44122 Ferrara, Italy and INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy'], 'affiliations': [{'raw_affiliation_string': 'Department of Physics, University of Ferrara, Via Saragat 1, 44122 Ferrara, Italy and INFN-Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy', 'institution_ids': ['https://openalex.org/I4210107105', 'https://openalex.org/I201324441']}]}], 'institution_assertions': [], 'countries_distinct_count': 2, 'institutions_distinct_count': 9, 'corresponding_author_ids': [], 'corresponding_institution_ids': [], 'apc_list': None, 'apc_paid': None, 'fwci': 2.104, 'has_fulltext': True, 'fulltext_origin': 'ngrams', 'cited_by_count': 31, 'citation_normalized_percentile': {'value': 0.925706, 'is_in_top_1_percent': False, 'is_in_top_10_percent': True}, 'cited_by_percentile_year': {'min': 93, 'max': 94}, 'biblio': {'volume': '81', 'issue': '7', 'first_page': '527', 'last_page': '536'}, 'is_retracted': False, 'is_paratext': False, 'primary_topic': {'id': 'https://openalex.org/T11960', 'display_name': 'Theory of Relativity and Unified Field Theories', 'score': 0.9994, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, 'topics': [{'id': 'https://openalex.org/T11960', 'display_name': 'Theory of Relativity and Unified Field Theories', 'score': 0.9994, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, {'id': 'https://openalex.org/T11415', 'display_name': 'Quantum Gravity and Noncommutative Field Theories', 'score': 0.9987, 'subfield': {'id': 'https://openalex.org/subfields/3109', 'display_name': 'Statistical and Nonlinear Physics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, {'id': 'https://openalex.org/T10095', 'display_name': 'Cosmological Parameters and Dark Energy', 'score': 0.9983, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}], 'keywords': [{'id': 'https://openalex.org/keywords/equivalence-principle', 'display_name': 'Equivalence principle (geometric)', 'score': 0.7078218}, {'id': 'https://openalex.org/keywords/gravity-probe-a', 'display_name': 'Gravity Probe A', 'score': 0.54175615}, {'id': 'https://openalex.org/keywords/metric-gravity', 'display_name': 'Metric Gravity', 'score': 0.499951}], 'concepts': [{'id': 'https://openalex.org/C121332964', 'wikidata': 'https://www.wikidata.org/wiki/Q413', 'display_name': 'Physics', 'level': 0, 'score': 0.8682954}, {'id': 'https://openalex.org/C147452769', 'wikidata': 'https://www.wikidata.org/wiki/Q11452', 'display_name': 'General relativity', 'level': 2, 'score': 0.7763624}, {'id': 'https://openalex.org/C180547424', 'wikidata': 'https://www.wikidata.org/wiki/Q656181', 'display_name': 'Gravitational redshift', 'level': 3, 'score': 0.7112535}, {'id': 'https://openalex.org/C89748767', 'wikidata': 'https://www.wikidata.org/wiki/Q17010834', 'display_name': 'Equivalence principle (geometric)', 'level': 2, 'score': 0.7078218}, {'id': 'https://openalex.org/C14257148', 'wikidata': 'https://www.wikidata.org/wiki/Q558066', 'display_name': 'Gravitational field', 'level': 2, 'score': 0.65069115}, {'id': 'https://openalex.org/C33024259', 'wikidata': 'https://www.wikidata.org/wiki/Q76250', 'display_name': 'Redshift', 'level': 3, 'score': 0.6301852}, {'id': 'https://openalex.org/C124017977', 'wikidata': 'https://www.wikidata.org/wiki/Q11412', 'display_name': 'Gravitation', 'level': 2, 'score': 0.60194963}, {'id': 'https://openalex.org/C112918411', 'wikidata': 'https://www.wikidata.org/wiki/Q2297564', 'display_name': 'Tests of general relativity', 'level': 4, 'score': 0.57612234}, {'id': 'https://openalex.org/C179942855', 'wikidata': 'https://www.wikidata.org/wiki/Q5598059', 'display_name': 'Gravity Probe A', 'level': 4, 'score': 0.54175615}, {'id': 'https://openalex.org/C183992945', 'wikidata': 'https://www.wikidata.org/wiki/Q2495574', 'display_name': 'Universality (dynamical systems)', 'level': 2, 'score': 0.5289557}, {'id': 'https://openalex.org/C33332235', 'wikidata': 'https://www.wikidata.org/wiki/Q18362', 'display_name': 'Theoretical physics', 'level': 1, 'score': 0.5203147}, {'id': 'https://openalex.org/C146846114', 'wikidata': 'https://www.wikidata.org/wiki/Q901448', 'display_name': 'Einstein', 'level': 2, 'score': 0.42496914}, {'id': 'https://openalex.org/C74650414', 'wikidata': 'https://www.wikidata.org/wiki/Q11397', 'display_name': 'Classical mechanics', 'level': 1, 'score': 0.4132681}, {'id': 'https://openalex.org/C44870925', 'wikidata': 'https://www.wikidata.org/wiki/Q37547', 'display_name': 'Astrophysics', 'level': 1, 'score': 0.34584862}, {'id': 'https://openalex.org/C62520636', 'wikidata': 'https://www.wikidata.org/wiki/Q944', 'display_name': 'Quantum mechanics', 'level': 1, 'score': 0.32605934}, {'id': 'https://openalex.org/C98444146', 'wikidata': 'https://www.wikidata.org/wiki/Q318', 'display_name': 'Galaxy', 'level': 2, 'score': 0.29149488}], 'mesh': [], 'locations_count': 1, 'locations': [{'is_oa': False, 'landing_page_url': 'https://doi.org/10.1119/1.4798583', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S38866342', 'display_name': 'American Journal of Physics', 'issn_l': '0002-9505', 'issn': ['0002-9505', '1943-2909'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310320257', 'host_organization_name': 'American Institute of Physics', 'host_organization_lineage': ['https://openalex.org/P4310320257'], 'host_organization_lineage_names': ['American Institute of Physics'], 'type': 'journal'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}], 'best_oa_location': None, 'sustainable_development_goals': [], 'grants': [], 'datasets': [], 'versions': [], 'referenced_works_count': 51, 'referenced_works': ['https://openalex.org/W1575385377', 'https://openalex.org/W1611138248', 'https://openalex.org/W1657936683', 'https://openalex.org/W1964524512', 'https://openalex.org/W1976799607', 'https://openalex.org/W1977499976', 'https://openalex.org/W1988122755', 'https://openalex.org/W2016393861', 'https://openalex.org/W2018757625', 'https://openalex.org/W2019654967', 'https://openalex.org/W2026039348', 'https://openalex.org/W2026828586', 'https://openalex.org/W2027595139', 'https://openalex.org/W2031429407', 'https://openalex.org/W2033895718', 'https://openalex.org/W2034002159', 'https://openalex.org/W2036216744', 'https://openalex.org/W2037418735', 'https://openalex.org/W2040272773', 'https://openalex.org/W2043706066', 'https://openalex.org/W2044707870', 'https://openalex.org/W2046100476', 'https://openalex.org/W2047143543', 'https://openalex.org/W2056215018', 'https://openalex.org/W2062332993', 'https://openalex.org/W2073704760', 'https://openalex.org/W2082369899', 'https://openalex.org/W2090946289', 'https://openalex.org/W2096612807', 'https://openalex.org/W2112113099', 'https://openalex.org/W2113065370', 'https://openalex.org/W2114208852', 'https://openalex.org/W2114982331', 'https://openalex.org/W2132289170', 'https://openalex.org/W2135858024', 'https://openalex.org/W2147946243', 'https://openalex.org/W2148091723', 'https://openalex.org/W2149220994', 'https://openalex.org/W2154432883', 'https://openalex.org/W2156474827', 'https://openalex.org/W2166436681', 'https://openalex.org/W2171306848', 'https://openalex.org/W2995437339', 'https://openalex.org/W3004259186', 'https://openalex.org/W3102365909', 'https://openalex.org/W3103977765', 'https://openalex.org/W4231699910', 'https://openalex.org/W4246028735', 'https://openalex.org/W4247552640', 'https://openalex.org/W4250292027', 'https://openalex.org/W4251738184'], 'related_works': ['https://openalex.org/W978698615', 'https://openalex.org/W4285059895', 'https://openalex.org/W3104997331', 'https://openalex.org/W2791365179', 'https://openalex.org/W2342367859', 'https://openalex.org/W2134014254', 'https://openalex.org/W2075750948', 'https://openalex.org/W2074060057', 'https://openalex.org/W1996203589', 'https://openalex.org/W1659561138'], 'abstract_inverted_index': {'Through': [0], 'the': [1, 10, 16, 22, 69, 74, 80, 84, 107, 125, 159, 169, 172, 176, 184, 191, 195], 'contributions': [2], 'of': [3, 12, 57, 73, 106, 112, 124, 171, 178], 'Galileo,': [4], 'Newton,': [5], 'and': [6, 21, 51, 86, 89, 133, 155, 174, 189], 'Einstein,': [7], 'we': [8, 78, 142], 'recall': [9], 'universality': [11], 'free': [13], 'fall': [14], '(UFF),': [15], 'weak': [17], 'equivalence': [18, 24], 'principle': [19, 25], '(WEP),': [20], 'strong': [23], '(SEP),': [26], 'in': [27, 42, 152, 158, 168, 205], 'order': [28], 'to': [29, 38, 53], 'stress': [30], 'that': [31, 46, 163, 175], 'general': [32], 'relativity': [33, 88], 'requires': [34, 49], 'all': [35], 'test': [36, 111, 150, 173], 'masses': [37, 148, 202], 'be': [39], 'equally': [40], 'accelerated': [41], 'a': [43, 99, 110], 'gravitational': [44, 81, 126], 'field;': [45], 'is,': [47], 'it': [48, 186, 197], 'UFF': [50], 'WEP': [52, 85], 'hold.': [54], 'The': [55], 'possibility': [56], 'testing': [58], 'this': [59], 'crucial': [60], 'fact': [61], 'with': [62, 117], 'null,': [63], 'highly': [64], 'sensitive': [65], 'experiments': [66, 145], 'makes': [67], 'these': [68], 'most': [70], 'powerful': [71], 'tests': [72], 'theory.': [75], 'Following': [76], 'Schiff,': [77], 'derive': [79], 'redshift': [82, 108, 127], 'from': [83], 'special': [87], 'show': [90], 'that,': [91], 'as': [92, 94, 149], 'long': [93], 'clocks': [95], 'are': [96], 'affected': [97], 'by': [98], 'gravitating': [100], 'body': [101], 'like': [102], 'normal': [103], 'matter,': [104], 'measurement': [105, 123], 'is': [109, 137, 165], 'UFF/WEP': [113, 144], 'but': [114], 'cannot': [115], 'compete': [116], 'direct': [118], 'null': [119], 'tests.': [120], 'A': [121], 'new': [122], 'based': [128], 'on': [129, 183, 190], 'free-falling': [130], 'cold': [131, 156], 'atoms': [132, 157], 'an': [134], 'absolute': [135], 'gravimeter': [136], 'not': [138], 'competitive': [139], 'either.': [140], 'Finally,': [141], 'compare': [143], 'using': [146], 'macroscopic': [147, 200], 'bodies': [151], 'one': [153], 'case': [154], 'other.': [160], 'We': [161], 'conclude': [162], 'there': [164], 'no': [166], 'difference': [167], 'nature': [170], 'merit': [177], 'any': [179], 'such': [180], 'experiment': [181], 'rests': [182], 'accuracy': [185], 'can': [187, 198], 'achieve': [188], 'physical': [192], 'differences': [193], 'between': [194], 'elements': [196], 'test,': [199], 'proof': [201], 'being': [203], 'superior': [204], 'both': [206], 'respects.': [207]}, 'cited_by_api_url': 'https://api.openalex.org/works?filter=cites:W2009110392', 'counts_by_year': [{'year': 2024, 'cited_by_count': 1}, {'year': 2023, 'cited_by_count': 1}, {'year': 2022, 'cited_by_count': 1}, {'year': 2021, 'cited_by_count': 3}, {'year': 2020, 'cited_by_count': 4}, {'year': 2019, 'cited_by_count': 2}, {'year': 2018, 'cited_by_count': 3}, {'year': 2017, 'cited_by_count': 3}, {'year': 2016, 'cited_by_count': 7}, {'year': 2015, 'cited_by_count': 4}, {'year': 2014, 'cited_by_count': 2}], 'updated_date': '2024-09-16T02:49:52.299755', 'created_date': '2016-06-24'}