Without usefulness, there would be no benefits from information to set against its cost.

Opportunity cost concept is very important to the view of costs of economists. It is defined as the worth or value of a forgone activity or alternative when another item is chosen. It is a relative cost of one alternative in terms of the next best alternative. It is a vital economic concept which finds application a wide range of business decisions. Decision –making is usually overlooked by opportunity cost. Opportunity costs should often subjectively estimated by decision-makers. 

Asolar eclipse occurs when the moon gets between earth and the sun, and the moon casts a shadow over earth. a solar eclipse can only take place at the phase of new moon, when the moon passes directly between the sun and earth and its shadows fall upon earth's surface.

The law of supply and demand