Ascientific theory is a substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment and the science community validates each theory before it is accepted. if new evidence is discovered that the theory does not accommodate, the theory is generally modified in light of this new evidence. any scientific theory gains much credibility if it can make testable predictions that are then discovered to be valid. discuss this aspect in relation to the big bang theory.