Are the odds really even?

Author details:
My name is Suhas(9A) and, as you must have seen above, i am a student of grade nine. I greatly enjoy playing basketball, eating exotic foods, and spending time with friends and family.

From the vast expanses of a cricket stadium to our everyday lives, flipping a coin has remained as a trusty way of deciding between two options and as the result is completely random. But are the chances truly equal?

New researches conducted by Persi Diaconis (Professor at Stanford university and former magician) concluded that this popular trick does indeed involve bias, as the face of the coin that is up before the flip is more likely to be the face that triumphs in the end. For example, if head faces up before the flip, there is a 51% chance that it will land with heads facing up.

This theory is based upon the angle that is formed between the normal on the coin and the angular momentum vector. Angular momentum is the amount of rotation of an object and is a product of moment of inertia (an object’s tendency to resist angular acceleration) and angular velocity (the change in angular position of an object in rotation).
There are two scenarios in which the side of the coin facing up always remains the side which faces up in the end (that is, a hundred percent chance):

●When the normal and the angular momentum vector coincide (it occurs when the coin is hit exactly in the center when flipping it). This will cause the coin to fly up and land without spinning around vigorously.

●If the angle is less than 45 degrees. This will cause the coin to wobble in the air but not flip over, leading to the same result.

Now you may be thinking that since flipping a coin is an option that is ruled out, spinning a coin is the next best way to get an unbiased result. Well, professor Diaconis has debunked that myth too. His experiments have depicted that spinning a coin results in an even more lopsided result, due to the fact that the heads side of a coin is heavier than the tails side. This results in a whopping 81% chance of tales landing up.

So, the next time you pull out a coin to decide between two options, think again, because the odds are not really even.