Who are these grainy people and what do they mean to me?

I was quite touched by this image.  One of my professional specialties is the interaction of X-rays with matter, so the 20th century's advances in physics and math became matters of great practical importance to me.  I can hardly imagine putting more names from my education into one photograph.  Click for big.
In 1927, the leading lights of physics gathered in Brussels for a conference, and this photo was taken.  Wilhelm Roentgen, the discoverer of X-rays and recipient of the first Nobel Prize in physics, would have rounded it out nicely had he not passed away four years prior.  1927 was the year the Copenhagen Interpretation of quantum mechanics was being worked out.  They were chaotic times:  in 1924 de Broglie (right of center) had put forth his theory that matter could be described as either waves or particles; his doctoral committee felt that the only person on Earth capable of judging whether it had merit was Albert Einstein.  Here they are together.
  • Schroedinger - the wavefunction.
  • Pauli - the exclusion principle.
  • Heisenberg - quantum uncertainty.
  • Brillouin - propagation of electron waves in a crystal lattice.
  • Debye - the effect of temperature on X-ray diffraction patterns.
  • Bragg - the original crystallographer - discoverer of the laws of X-ray diffraction.
  • Dirac - for me, the "Dirac delta", an infinitely short and infinitely intense pulse.
  • Compton - inelastic scattering of X-rays.
  • de Broglie - wave-particle duality.
  • Born - the probability density function.
  • Bohr - the structure of atoms.
  • Langmuir - plasma probes.
  • Planck - the blackbody spectrum.
  • Curie - radiation, and probably the first death thereby, in 1934.
  • Einstein - yeah, him.
The image I've posted is a composite of a high-resolution photo, which I found at wikimedia commons, and its seating chart, which I found elsewhere at low resolution.