Notícia ruim corre depressa!

Abstract

Many proverbs are created through everyday experience. Although many of them are readily understood by ordinary people, a more detailed view generates many questions and doubts related to their credibility. Motivated by one of these proverbs, in the present paper, we analyse propagation of news in a network of electronic contacts (e-mails). More specifically, we propose transmission protocols intended to reproduce properties of real systems. These protocols are simulated in a real e-mail network and in the random network proposed by P. Erdo{double acute}s and A. Rényi. The results suggest that news spreads faster in the random network. The hubs in the real network tend to attract the news, in prejudice to the less connected nodes. Copyright by the Sociedade Brasileira de Física. Printed in Brazil.