A finite universeâthat is, a universe of limited sizeâeven one with trillions and trillions of stars, just wouldn't have enough stars to light up all of space. Although the idea of a finite universe explains why Earth's sky is dark at night, other causes work to make it even darker.Not only is the universe finite in size, it is also finite in age.lthough the idea of a finite universe explains why Earth's sky is dark at night, other causes work to make it even darker. Not only is the universe finite in size, it is also finite in age.
Noun. 1. litmus-a coloring material (obtained from lichens) that turns red in acid solutions and blue in alkaline solutions; used as a very rough acid-base indicator. litmus test. acid-base indicator-an indicator that changes color on going from acidic to basic solutions.
litmus paper is widely used to distinguish between acids and bases. So widespread is the use of litmus in testing whether a solution or gas is acidic or basic, that the concept of a litmus test has spread to include any simple but definitive test. Politicians are always calling political issues a litmus test.