单词	Hubble's constant
释义	Hubble's constant /ˈhʌb(ə)lz / noun Astronomy The ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer. The reciprocal of the constant is called Hubble time and represents the length of time for which the universe has been expanding, and hence the age of the universe.The HST key programme on the distance scale is expected to fix the value of Hubble's constant to an accuracy of about 10 per cent.... The questions in the exam paper itself were a mixture of modern cosmology, such as calculating Hubble's constant from a graph of recent data, and more traditional fare about the various forces acting on the balloon. Spectral studies requiring dedicated Hubble time would be routine with every one of SNAP's supernova observations.
随便看	paragrammatism paragraph paragrapher paragraphia paragraphic paragraphical paragraphically paragraphism paragraphist paragraphize paragraph mark paragraph symbol Para grass Paraguay Paraguayan Paraguay River Paraguay tea paragutta paraheliotropic paraheliotropism parahelium parahippocampal parahopeite parahormone parahuman

英语词典包含243303条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。