Recently I had a light chat with one of my friends about probability. What he said forced me to think on this issues. He said that the meaning of probability implies parallel universes. For ex :- if a coin is tossed, there are 1-1 odds of getting heads/tails. This further means that in one universe there is a heads and in other there is a tails. Well, this is very complex theory. It has grave ramifications. If it is true then it would mean that there may be a Universe in which Ram is defeated by Ravan. I wouldn't want to be in that universe. There could be even more darker universes. This theory is also echoed in "The Brief History of Time". But I think that if we try to look at the book in a superficial manner we are bound to get misconcepts , like my friend.
So I decided to check for basics of Probabilty.And I was relieved.
Experts talk about probabilities only when dealing with well defined random experiments. The relative frequency of occurrence of an experiment's outcome, when repeating the experiment, is a measure of the probability of that random event. I would like to stress on the "repeating" part.
Clearly a probabilty of 1/2 when tossing a coin doesn't directly imply parallel universes. It means that if the experiment is repeated under the same conditions. Half of the turns we would get heads and in the other half tails.