the universe. Two of them have been studied and are thought to be 3 billion years apart in age.However, their chemical makeup is quite different from each other and this may be the cause of their age difference.Then, too, one of the globular clusters is composed chiefly of blue giants and the other of red giants. Astronomers are not sure why this should be.Does it matter whether galaxies are ...
것이다.The Earth spins on its axis. If it were a perfect sphere in shape, perfectly symmetrical in its internal makeup, perfectly rigid and perfectly alone in space, it would spin eternally about an immovable axis. None of this is true, however, so Earth wobbles. Three different wobbles were known prior to this year. In July, a fourth wobble was discovered and announced.When the motions of ...
동아사이언스
디라이브러리
DS스토어
팝콘플래닛
