不是新文章。但是和上星期“信息的经典物理学’讨论有相合之处。也许”动量“的比喻，还不如下面的的算法。
Searching for sudden “bursts” in the usage of particular words could be used to rapidly identify new trends and sort information more efficiently, says a US computer scientist.
Jon Kleinberg, at Cornell University in New York, has developed computer algorithms that identify bursts of word use in documents.
While other popular search techniques simply count the number of words or phrases in documents, Kleinberg’s approach also takes into account the rate at which the word usage increases.
Kleinberg suggests that the method could be applied to weblogs to track new social trends. For example, identifying word bursts in the hundreds of thousands of personal diaries now on the web could help advertisers quickly spot an emerging craze.