Question

activity on hypothesis

Answer 1

Hypotheses
Can we prove that aliens visited Earth? In other words, there is a hypothesis that aliens visited our planet. The contrasting hypothesis is that aliens have not been here. The latter hypothesis is called the null hypothesis because it states that aliens have not come here. It is called the "null hypothesis" because it says that the factor (aliens) we are trying to prove had an effect did not have that effect. That is, it contains the null element that the factor does not have an effect, exerts no influence, makes no difference.

In order to prove the alternative hypothesis that aliens have been here, we set out to reject the null hypothesis that they have not. If the alternative hypothesis is reasonable, then you should feel comfortable in accepting its conclusion if you obtain enough evidence to reject the null hypothesis. Other possible null hypotheses are, "There is no trace of a visit to Earth by aliens," or "Life started spontaneously on Earth." Note two aspects of this process. First, we justify our alternative hypothesis by proving that the null hypothesis is incorrect. Second, we advance our understanding only if the alternative hypothesis is a more accurate statement of the effect of the causal factor.