Irrational beliefs are beliefs that are impossible to be proven, and only can be speculated on. Some of these include myths, legends, superstitions, extra-terrestrial activity or supernatural happenings, for example, the belief that aliens make crop circles.
Some people feel that these beliefs should be disregarded, for they cannot be proven by scientific experiments or cold, hard, facts. Others find this the work of a greater being, commonly refered to as God, or possibly of creatures we have never (?) met, for example, aliens or ghosts/spirits.
I personally feel that irrational beliefs can be believed and have a possibility of being true, but this is not for certain unless further reliable evidence is found.
Science cannot prove everything because sometimes there are no solid facts or evidence to prove anything. For example, we cannot be sure that God exists. There are no solid facts that show this except for the Bible, and its origins are also in question.
But the big guy in question could still exist, and with only the Bible as 'so called' evidence! Thus, using science to prove beliefs is totally useless without reliable evidence.
There are many types of irrational beliefs, on different topics. In the past, there were many beliefs that were deemed impossible by the scientific world. But years later, due to founding of new facts or discoveries, they were found to be correct. One example is the theory of plate tectonics. When it was first suggested by Mr Alfred Wagner, it was laughed at as impossible, despite the evidence provided. He was told that the evidence was not reliable, despite the arguments he had previously put up. It was only years later, after his death, that the scientists continuing his work used Sonar to scan the ocean floor, discovering mid-ocean ridges,