平成３０年度（２０１８年度）第9回 物理教室談話会

題目	Observations of the Cosmic Microwave Background: Early History and Future Prospects
講師 Lecturer	Martin Bucher　氏 (パリ第七大学 教授) Prof. Martin Bucher (Paris Diderot University)
日時 Date/Time	平成31年2月6日(水)　15：00～ Feb. 6th, 2019 15:00-
場所 Place	コラボレーション棟３Ｆコラボレーション室 Collaboration room, 3rd floor of the Collaboration building
	Martin Bucher教授は、パリ第七大学で宇宙論を研究しており、特に宇宙マイクロ波背景放射(CMB)に関する研究においてこれまで数々の理論的・実験的な成果を挙げてきています。日本学術振興会の外国人研究者招へい事業において、1月28日から二ヵ月間岡山大学に滞在予定です。Martin Bucher教授はアメリカのカリフォルニア工科大学(Caltech)で学位をとり、その後プリンストン大学やケンブリッジ大学で研究を続けました。ケンブリッジ大学では、ホーキング博士に従事しています。 Professor Martin Bucher is a scholar of cosmology at Paris Diderot University (Paris 7). He has presented numerous theoretical and experimental results in the field of cosmic microwave background radiation (CMB) in particular. He will be staying at Okayama University for two months from Jan. 28 as an invited fellow by the Japan Society for the Promotion of Science (JSPS) program. Prof. Bucher earned his PhD at California Institute of Technology and continued his research at Princeton University and University of Cambridge where he worked with Dr. Stephen Hawking. Abstract: Today much of our knowledge of the Early Universe derives from observations of the Cosmic Microwave Background (CMB), which was discovered in 1965 by Penzias and Wilson at Bell Labs, but in fact should have been discovered much earlier. In 1940 McKellar extracted a radiation temperature of around 2.3 K from the rotational splittings of the UV absorption spectra of cyanogen and other molecules in the interstellar medium. But at the time no one dared to fully interpret this observation. In 1950 Gerhard Herzberg (1971 Chemistry Nobel Prize) wrote in the authoritative treatise "Molecular Spectra and Molecular Structure" that the implied temperature (which was that of the CMB!) “has of course only a very restricted meaning.” The subsequent Penzias and Wilson discovery provided strong support for the then controversial Hot Big Bang model, forcing competing steady state cosmology proponents to postulate contrived explanations for the CMB and for its nearly blackbody spectrum. Because of the lack of adequate instrumentation, it took almost 30 years until the COBE team discovered the CMB anisotropy in 1992. In the meantime the WMAP and Planck satellites as well as numerous suborbital experiments have mapped out the CMB temperature anisotropies with exquisite precision. The data collected allows us to characterize the initial conditions of our universe at approximately the one per cent level. Ever better polarization measurements may culminate in the discovery of primordial gravitational waves from inflation. I will review this story emphasizing how improvements in technology have enabled the present measurements and how these measurements have transformed cosmology into a true science where theories are confronted with precision observations.
世話人	石野　宏和（内線7818）