论文部分内容阅读
生命只能出现在能发出光和热的恒星周围的行星上,但并非所有恒星都必然带有行星。星云说认为,恒星是从自转着的原始星云收缩形成的。收缩时因角动量守恒使转动加快,又因离心力的作用星云逐渐变为扁平状。当中心温度达700万度时出现由氢转变为氦的热核反应,恒星就诞生了。盘的外围部分物质在这过程中会凝聚成几个小的天体——行星。星云说可以合理解释许多观测事实,但也存在一些困难。另一方面,计算机理论模拟计算表明,如果星云物质在收缩过程中没有
Life can only occur on planets that emit light and heat, but not all stars necessarily have planets. Nebula said that the stars are formed from the contraction of the original rotating nebula. Shrinkage due to conservation of angular momentum to speed up the rotation, and because of the role of centrifugal force gradually become flat nebula. When the center reaches 7 million degrees Celsius, a thermonuclear reaction from hydrogen to helium occurs and stars are born. The outer part of the disk material in this process will be condensed into several small objects - planets. Nebula said that we can reasonably explain many observed facts, but there are also some difficulties. On the other hand, computer simulations show that if the nebula material is not shrinking