KentuckyFC writes: Memes are the cultural equivalent of genes: units that transfer ideas or practices from one human to another by means of imitation. In recent years, network scientists have become increasingly interested in how memes spread, work that has led to important insights into the nature of news cycles, into information avalanches on social networks and so on. But what exactly makes a meme and distinguishes it from other forms of information is not well understood. Now a team of researchers has developed a way to automatically distinguish scientific memes from other forms of information for the first time. Their technique exploits the way scientific papers reference older papers on related topics. They scoured the half a million papers published by Physical Review between 1893 and 2010 looking for common words or phrases. They define an interesting meme as one that is more likely to appear in a paper that cites another paper in which the same meme occurs. In other words, interesting memes are more likely to replicate. They end up with a list of words and phrases that have spread by replication and can also see how this spreading has changed over the last 100 years. The top five phrases are: loop quantum cosmology, unparticle, sonoluminescence, MgB2 and stochastic resonance; all of which are important topics in physics. The team say the technique is interesting because it provides a way to distinguish memes from other forms of information that do not spread in the same way through replication.