The Chemistry of PageRank
A chemist at Washington State University adapted the PageRank algorithm to describe molecular bonding rather than different web pages. Instead of describing the links between the millions of webpages, it describes the shapes and interactions between different molecules, or molecular structure. PageRank is described to show how a link from a more noteworthy page will increase its pagerank value by much more than a link from a less influential page. In the article, it is described as The New York Times vs. a personal blog. This theory is applied to chemistry by the chemisty at Washington State.
The specific chemistry that takes into account PageRank is the Hydrogen bond. The chemist, Aurora Clark, describes one water molecule as one webpage in a traditional PageRank scheme. Hydrogen bonds form between hydrogen atoms of one molecule and the oxygen molecule of the other molecule. These bonds allow water molecules to bond with others (albeit these are much weaker bonds than typical molecular bonds), and form a bonded group of water molecules. This can be thought of as multiple webpages linked together. Clark describes it as a water network. A PageRank for a specific molecule is dependent on the number of bonds it forms with other molecules, which determines how it will behave in a chemical reaction. Essentially, a molecule with one PageRank will react differently than a molecule with a different PageRank. This is an important application of another science (computer science in this case) to chemistry and intermolecular interactions.
This study is especially important as the accuracy of chemical reactions can be improved with a larger model, especially large in this case, as there are close to an infinite amount of molecules linked together. This study also could have even larger, practical applications, such as improving drug design. Understanding the alteration of protein shape and analyzing radioactive pollutants are both applications of likening PageRank to molecular bonds as well.
Overall, this study proves that the application of one kind of technology can be used to understand another science. This study could have extremely useful applications, and thus is a worthwhile application of PageRank.