現代のマイクロレベル研究と観察の理論負荷性の実際 --高アスペクト比双晶金ナノロッドの合成を例に-- (冨田恭彦教授 退職記念号)

Abstract

In ancient Greece some physiologoi thought that the world was made up of imperceptible elements, such as atoms. They tried to explain observable phenomena on the basis of some hypothetical assumption of invisible items. I denominate the basic framework of their view "double structure of observation." In the 17th century, when the ancient Greek atomism revived, the way of thinking came back. On the other hand, Norwood Russell Hanson pointed out that the observation is dependent on some theory or theories, and called it "theoryladenness of observation." These two are closely related and play an important role especially in contemporary scientific studies. In this paper I try to clarify how they work in an actual scientific research. I take up the synthesis of high-aspect-ratio twin gold nanorods as an example. In the actual experiment we synthesize high-aspect-ratio gold nanorods at first, and then confirm that the synthesized nanorods were twin. To identify the shape of the synthesized composites, we use a scanning electron microsope (SEM) and find that the products are high-aspect-ratio gold nanorods. We also use transmission electron microscope (TEM) to investigate the crystal structure of the nanorods, and find that they are twin. When we confirm that the resulting composites are high-aspect-ratio twin gold nanorods, we have recourse not only to the observational data by SEM and TEM, but also to various previous reports and the basic knowledge of those apparatus. Focusing especially on the observations with SEM and TEM, I clarify how the double structure and the theory-ladenness of observation work.