Sorry, the probability of coin heads up is not 50%.

This book was written by Dr. Darryl P. Robton of Durham University in England. The author tells us seven main types of probability in popular and funny language. Faced with different scenarios, people should use one or more corresponding probability types in order to make the best choice. As the British philosopher Butler said, probability is the real guide to life.

This time, our concern is: "If a coin falls on the ground, does it have 50% heads?"

Let's imagine a scene like this:

You take an ordinary coin out of your pocket.

When you throw it up and let it fall freely, what do you think is the probability of this coin being "heads"?

Is it 50%?

Do you have any different opinions?

If you think it's 50% and the coin is divided into two sides, there is no doubt that there is something wrong.

All right, let's move on.

0 1 even number.

Coins fall to the ground, it is reasonable to say that the probability of heads up is half and half. However, this assumes that the quality of both sides of a coin is uniform, but there is one factor that can upset this balance, that is, if the quality of both sides is uneven, the front side is heavy and the back side is light, then the probability of it falling is not 50%.

02 angle.

In fact, even the thinnest coin has three sides, not two. If you don't understand, take out a coin. It also has a side, which is the side of a flat cylinder. Even if its upward probability is low, it accounts for a part of the positive upward probability. At this time, if we assume that the environment is in sand, mud or stairs, the probability of coins facing up is greatly improved.

03 conditions.

In the Olympic Games and badminton, if there is no wind, it will be fair to both players. But once there is a wind factor, it will be beneficial to one party and unfavorable to the other.

In fact, some organizers have repeatedly turned on and off the air conditioner to control the air flow in order to win the national players. Similarly, if an external force, such as heavy rain, is given to the thrown coin, it is difficult for the coin to roll in the air and it is not easy to rebound when it falls on the ground full of water. So, which side is thrown up, which side is up when landing. This will also break the 50% probability standard.

04 manipulation

All the masters in the casino have one specialty, that is, manipulating coins. Of course, they throw it out of their hands, then pick it up with their hands and pat it on the back of their hands. They first observe the front of the coin before throwing it, then feel the strength of talking about the coin with their fingers, and finally choose the timing of slapping the coin with the back of their hands to control the coin.

In other words, the probability that a coin is in their hands, facing up, is not 50%, but 100% or 0%.

Having said that, what should I say?

Is to tell you that the probability of coin heads up is not 50%?

Of course not. What I want to say is that there are two kinds of probability in life, one is based on the ideal judgment of the objective world; The other is the true judgment based on multiple cognition.

In most ideal situations, just like a coin falling, the probability of heads up is 50%, which is very much. For example, trying to get rich, losing money is a blessing, taking a step back and so on. In some cases, they all make sense. However, in another scene, they are meaningless.

Many workers and peasants are hardworking, but from the perspective of wealth, they have not achieved a major financial breakthrough; Losing is a blessing, but if you meet an ungrateful person, your loss is a pure loss; "Step back and open your eyes" has also been changed by netizens to "step back and push your luck".

Ideal judgment seems reasonable, but when it is put into a complex social system, it becomes a small probability event in an ideal situation.

If you can't tell the difference between the two, your world will be full of question marks.

To sum up, probability is a tool to explain the world. After using it well, there is nothing you can't understand. The world is random, and probability is the sum of randomness, which is the embodiment of law. Look, a coin is falling.