For a 10 people, including the party huai also incognizant who, along with the guests began to talk to the beginning, the social relation also began to form. At first, different group is mutual space (left >. Although the group exist social link (in attachment >, but said a this group, with other people, everyone still strangers. With shao the passage of time (the right picture >, there are three people in the small group at other, “; the big crowd formed. Though not everyone to know each other, but has formed contains everyone’s single social network along now. The social links, we can find the path will be linked to any two guests.

Assumption everyone passed the information on to his new understanding of all people, so, for in the end of the if everyone can know the news of our wine? If everyone to know each other words, so everyone know to get no label good wine to drink. But, even met a person greet every 10 minutes, see 99 guests also want to 16 hours, and party rarely continue & 1 long time. Therefore, you may feel the wine’s secrets to his friends of friends also just as well “to the end of the party, there must be left.

Paul ‘the proms and Alfred riley don’t agree with this view. The proms often quoted riley’s words, “mathematicians can drink coffee from a theorem to.” “Fruit, have so a cup of coffee, zhu hit by drink a often leads the theorem is with: if everyone know at least another guest, and soon everyone know to drink good wine. According to the proms and riley’s point of view, only half a small, can form the guests of the invisible covering all social network. That is to say, a guest in a few minutes earlier heard good wine business, to take will find that the bottle is empty.

Party guest problem is founded euler branch of mathematics ^ graph theory for a while with the part of the problem. Guests can be regarded as a point, and every met a man, set up the two men set up the social connection. Such a network, or as a graphic creation, points to be edge connection into a network. Computer use PA3399U-1BAS battery telephone line networking, in our body biological molecules through chemical reaction networks, the enterprise and the consumer through the trade union nets, neurons through the axon networking, networking, these islands through the bridge is network diagram example. No argument and edge is the nature of what, in the mathematician eyes, they are the same thing: network diagram or network.

Although the delicate, but will be simplified to network it network diagram is not simple. Clubs will, the Internet and cell or brain can use network diagram to each other, but said the difference between the different are high. It is hard to imagine, the human society and the existing between the cells have much in common. In the human society, we through the opportunity and the conscious decision with people; And in the cells, the control of the reaction between the molecules is relentless chemistry and physics law set. The nature of the link between the different network, its rules must be very different. On the surface, to find the system model describing all seems to be not to.

However, the ultimate goal of scientists, is to find the most simple is very complex phenomenon ? explanation. Therefore, the proms and riley put forward the delicate mathematical solutions, in a single structure description of complex network diagram. Different system following their completely different rules to build a network, the proms and riley it deliberately ignore them a different between the sex, obtained the nature can provide the most simple answer: random connected node. He concluded that create the most simple solution is network rolls the dice: choose two nodes, if thrust out 6, in between two add a link. If throws the other number, don’t connect the two nodes, but in another choose to open a beginning. Therefore, the proms and riley think network diagram and they represent the world from root the terms are random.

The proms like to say: “there is an old debate Li mathematics, whether it is human creation, or find out. In other words, is mathematics truth is inherently exist? Or the people want to out of?” For this problem, the proms a clear answer: mathematical justice and other absolute truth is the same, is already exists, what we do is to find them. Random graph looks delicate and simple, in his view is in eternity of justice. But now we know, random network of our universe organization for the role of extremely limited. Instead, the nature of several basic use double is, these we will in the following chapter was introduced. The proms founded the number of theoretical study justice, and graph theory, the development of random provides us with cheer on in the world of NC4400 battery new perspective. He himself to create the human brain and social nature of the secret and can not know, hence take bets on god like rolls the dice. His friends in Princeton, let the inauguration of Albert Einstein was tend to the opposite of the double point: “for the universe, god does not like dice.”

Now let us go back to the party and random graph theory to practice. Beginning, we have a big quantity node. And imitate the mode of random encounter between the guest, between the nodes with machine add a link. If only add a few, then can only make contact with some node to the. Continue to link down, inevitably will put some have matched quarter point and other nodes connected with DuoGe, form nodes with string. But when you add links enough to each node, to have an average of a link, can appear magical vision: a unique huge node string is produced. Also, says most of the node is governed by a single node string, and no matter from which node set out, can link node to the line by another node. It is to this time, your good wine to suffer, because such appeared giant node string, everyone can through own channel hear the gossip. Several experts will this phenomenon is called giant structure of the birth of the so-called giant structure contains all the node is part of the network. Physicists have described it as permeability (1100 , and will be strict previous state called phase change (blunt and read and Fang such as), this and water to icy moments of similar. Social scientists will say Dell 500M battery you object of study just group into a social group. Although different subjects in different terms expression, but the now like we all agree with the idea: when we randomly choose and will link up the network nodes, will cause the special situation happened in one network add a quantitative link, will produce sharp change. Previously, only exist some contain less make node of the isolated node string, each other mutual don’t know only in the group of the exchange within node. Later, appeared giant node string, almost everyone involved.