There are two major principles in the world of scientific journals, or at least, two you'll need to know today:
1) Papers cite other papers.
2) The more your paper is cited, the more important it is.
These are the principles behind a set of interactive maps you'll find through this link. The idea is to map out the most important science cities in the world, or at least the top ones in physics, chemistry and psychology.
First, the mapmakers counted up the number of papers generated by each city. That number's represented by a circle laid on top of the city; the bigger the circle, the more papers you put out.
Second, the mapmakers examined the top 10% of papers cited. Each city was scored on how many papers they put out that were in that 10%, compared to how many that they should have had considering the number of papers they put out. This scores the quality of a city's papers as opposed to quantity. Cities that tend to put out important papers show up in green. Cities that put out a bunch of junk show up in red.
Big green circle = a lot of good papers.
Small green circle = not many papers, but they make them count.
Big red circle = a mountain of garbage.
Small red circle = little impact on the community.
The system isn't perfect; the direct link asks about language barriers and researchers who only cite each other, but all in all, it's more useful than useless.
A short recap:
*In the physics map, Moscow has the biggest circle in the world, but it's also one of the reddest. The Soviet bloc as a whole doesn't do very well. Some of your better performers abroad: London and Cambridge, England; Paris, France; Prague, Czech Republic; Seoul, South Korea; Hefei, China; and Munich, Karlsruhe and Garching, Germany. Within the United States, Chicago and Urbana, Illinois; Santa Fe, New Mexico; Berkeley and University, California; New York, New York; and Cambridge, Massachusetts rate highly.
*In chemistry, it's the same story with Moscow. Urbana, Berkeley and both Cambridges score big again, as well as Houston, Texas; Kyoto, Japan; Beijing, China and Singapore.
*In psychology, all the circles loaded the same size for me. But South America and the Carolinas didn't do so hot; Spain and Turkey underperformed as well.