Node connection strength in Physics Tree.
Each node in Physics Tree can be characterized by its mean distance from every other node. Below is a histogram of mean distances for every node in the tree. The final bin includes nodes that are not connected to the main tree. Note also that only individuals whose primary affiliation is this tree are included. Nodes cross-listed from other academic trees are included on their primary tree.

Mean inter-node distance

4696-
3757-
2818-
1878-
939-

8 9 10 11 12 13 14 15 16 17 18 19 20+
Mean distance
 Number of nodes 



20 most tightly coupled nodes.
Below are the Physics Tree nodes with shortest mean distance.

Rank Mean dist Name Institution Area Date
1 7.81 Niels Bohr (Info) University of Copenhagen Theoretical nuclear physics 2005-11-09
2 8.06 Wilhelm Lenz (Info) Universität Hamburg Theoretical Chemistry 2013-05-21
3 8.19 Max Born (Info) University of Edinburgh quantum mechanics, solid-state physics, optics 2005-11-09
4 8.26 Arnold Johannes Wilhelm Sommerfeld (Info) Ludwig-Maximilians-Universität München Particle Theory 2006-04-05
5 8.29 John Archibald Wheeler (Info) University of Texas at Austin Gravitational Physics/Theoretical Astrophysics 2009-08-20
6 8.3 Isidor Isaac Rabi (Info) Columbia University magnetic resonance 2009-07-08
7 8.37 Werner Heisenberg (Info) Max-Planck-Institut für Physik in München physics (quantum mechanics) 2005-11-09
8 8.39 Wolfgang Ernst Pauli (Info) Princeton University Quantum mechanics 2010-10-24
9 8.42 J. Robert Oppenheimer (Info) University of California, Berkeley nuclear physics 2011-07-29
10 8.42 Enrico Fermi (Info) University of Chicago Particle Theory 2010-07-28
11 8.51 Ernest Rutherford (Info) University of Cambridge Atomic Structure 2008-03-27
12 8.51 Joseph John Thomson (Info) University of Cambridge Atomic Structure 2008-03-27
13 8.63 Paul Ehrenfest (Info) Leiden University statistical mechanics 2009-05-17
14 8.81 Gregory Breit (Info) Yale University physics 2009-06-03
15 8.85 George Gamow (Info) University of Colorado, Boulder nuclear theory, stellar theory, relativistic cosmogony, protein coding 2015-10-24
16 8.86 Eugene Feenberg (Info) Washington University, Saint Louis Quantum mechanics, Nuclear physics 2010-07-23
17 8.86 Subramanyan Chandrasekhar (Info) University of Chicago astrophysics 2014-05-27
18 8.89 Hendrik Antonie Kramers (Info) Leiden University quantum mechanics 2009-05-17
19 8.9 Oskar Benjamin Klein (Info) Stockholm University College 2011-04-15
20 8.9 Friedrich Hermann Hund (Info) Georg-August-Universität Göttingen Theoretical physics 2012-01-20


Distribution of individual connectivity.
Another way to look at the Physics Tree graph is to plot a histogram of researchers (nodes) based according to the number of immediate connections (edges) they have to other researchers. The final bin includes nodes with 16 or more connections. The actual distribution has a very long tail, with a maximum of 99 connections. Thanks to Adam Snyder for suggesting this analysis!

Edge vs node distribution

27809-
22247-
16685-
11124-
5562-

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16+
Number of connections
 Node count