Abstract
On August 6, 1945, at 8:15 am, an Atomic bomb was dropped on Hiroshima city. Many people believed that no plant would grow for 75 years. However, a few months after the bombing, new shoots were sighted on the Atomic-bombed trees. Today there are many “A-bombed trees (survivor trees)” in Hiroshima city, and they are the precious living war heritage which can tell us the history of the atomic bombing. In this study we hypothesized that the effect of the atomic bombing on these trees has increased over the last 67 years, which is shown by their inclination towards Ground Zero. In order to clarify the hypothesis, we measured the direction of inclination, angle of inclination, and the direction to Ground Zero at the point of each A-bombed tree. We also checked the significance of the relative direction by using the "Rayleigh test". In this study, we focused on the “type A trees.” This type of tree has a single stem, survived the bombing, is alive at the original location and was not transplanted after the bombing. As a result, it was clarified that almost all of the “type A” A-bombed trees are inclined towards Ground Zero. The aim of this study was to clarify the abnormal formation of A-bombed trees in the positional relationship between their respective locations and Ground Zero. As a result, we found A-bombed trees possess a new significance, which is that each of them shows the direction to Ground Zero by their inclination. When you look at the city from a bird's-eye view, you will see that Ground Zero is surrounded by A-bombed trees. When you visit A-bombed trees on foot, check the direction to Ground Zero, then you will find a certain effect of the atomic bombing on the tree. A-Bombed trees offer many possibilities as “field museums” that preserve and convey the experience of atomic bombing.
