Figure 2

Different layer sizes as a function of time in typical networks. The y axis is the cumulative number of re-postings at different layers of typical networks in Weibo and Twitter. The x axis is the time (in hours) from the time of news creation and the different colors stand for different layers. Shown examples are (A) fake news and (B) real news in Weibo, as well as (C) fake news and (D) real news on Twitter. These four typical networks are the same networks shown in Fig. 1. In Fig. 2A, the fraction of nodes located in the first layer is around 45% of all the nodes at the end of propagation. However, in Fig. 2B, the total number of nodes in the first layer occupies about 78% of all the nodes at the end of propagation. If the total number of nodes does not change much after 20 hours, we ignore the re-posting after 20 hours in order to clearly see the layers in the figure. It is seen that the layer sizes of real news and fake news are significantly different in both Weibo and Twitter. Real news networks tend to have a relatively larger first layer, while fake news networks are relatively uniformly distributed in different layers