A successful scientific hypothesis needs to be not only valid but useful it need to tell you Something you want to know. A hypothesis is most useful when it make prediction, because those Prediction provide a way to test the hypothesis. If the predictions are reject. By an experiment, the polytheists it self must be receded. On the other hand. If the prediction are support. The more experiment testing. The hypothesis is supported. The moe experimental supported prediction a hypothesis make, the more valid the hypothesis is. For Einstein's hypothesis of relativity was at first provisionally accepted because no one cold devise an experiment that invalidated it.