For example, in astronomy it is clearly impossible, when testing the hypothesis "Stars are collapsed clouds of hydrogen", to start out with a giant cloud of hydrogen, and then perform the experiment of waiting a few billion years for it to form a star.
Minakadi, ring astronomi pastika nénten mresidayang, rikala nguji hipotesis "Bintang inggih punika awan hidrogen sané runtuh", pinaka ngawitin antuk awan hidrogen raksasa, miwah raris ngamargiang  eksperimen nyantosang makudang-kudang miliar warsa mangda prasida ngwentuk bintang.