The purpose of this study is to suggest the modification of activities to introduce the nature of science in earth science classrooms. A small modification can turn ordinary textbook activities into the nature of science activities. Since earth science could provide a good basis for the tentative, creative, and socially and culturally embedded nature of science, as well as appropriate understanding about scientific methods, careful modification of earth science activities could be effective for students to understand the nature of science. Considering which aspects of the nature of science are appropriate, along with the possible change in the activity, teachers will be able to modify textbook activities effectively. An example modification of H-R diagram activity was also suggested.

In this review article we introduce the 'H-R diagram' of black holes. Some fundamental concepts of black hole thermodynamics and electrodynamics are also summarized in detail.

About two hundred stars within 50 pc from the sun, whose tangential velocity larger than 100 km/sec, have been selected on the basis of their proper motions and trigonometric parallaxes. A list of them along with their photoelectric UBV data and spectral types is given. The criterion on the tangential velocity, v t > 132 km/sec, was adopted for selection of high-velocity stars. The H-R diagram of these nearby high-velocity stars resembles that of a globular cluster, with the turnoff around B − V ≈ 0.35 and M v ≈ 4.0 , and the subdwarfs among these high-velocity stars are fainter than the main-sequence stars of Hyades by the amount of 1 m .25 ± 0 m .30 in the region with B-V < 1.40 on the average.