Silk, Joseph

Joseph Silk

Gresham Professor of Astronomy, London
• Research scientist, Service d’Astrophysique, CEA, Saclay
• Research scientist, Institut d’Astrophysique, Université Pierre et Marie Curie, Paris
• Homewood Professor, Department of Physics and Astronomy, Johns Hopkins University, Baltimore
• Senior Fellow, Beecroft Institute for Particle Astrophysics & Cosmology, Department of Physics, University of Oxford

Leading expert: Theoretical cosmology, dark matter, galaxy formation, cosmic microwave background, homogeneities in the cosmic microwave background and density fluctuations in the matter of the early universe. A damping effect has become known as Silk damping.

Balzan Prize: Pioneering work on the infant universe.

References: Feedback by Massive Black Holes in Dwarf Galaxies
Challenges in Cosmology from the Big Bang to Dark Energy, Dark Matter and Galaxy Formation
Simplified galaxy formation   (

Most recent email (Update): January 9, 2019 
Originally sent:  Wednesday, June 14, 2017

Dear Prof. Dr. Joseph Silk:

Base-2 notation from the Planck units to the Age of the Universe requires just 202 notations. The first 64 notations provide a perfect little outline for a sub-grid mathematical physics whereby Langlands, Wilczek et al (with 31 dimensionless constants), Rees (Just Six Numbers), Weinberg, Witten and a rather sizable group of others might find a few helpful numbers to interpret.

Of course, I thank you for all your very brilliant work over the years.

Ours is a high school study of the Planck base units.
At the 67th notation we found unusual numbers:
2.38509×10-15 meters with a mass of 3.211962×1012kg
276.789 coulombs within a duration of 7.9563×10-24seconds

We have so much to learn; so again, I wanted to thank you for all that you do and for your most recent writings and lectures.

Most sincerely,

Bruce Camber

First email:  January 11, 2017, 10:21 PM

RE: High school geometry and physics classes
to make your 20 December 2016 paper
a target for study for the rest of this school year.

Dear Prof. Dr. Joseph Silk:

Thank you for your up-to-the-minute accounting of issues facing astrophysics and cosmology in 2017.

We are quite idiosyncratic and we need as much guidance as we can find to show us where we went wrong in December 2011. That is when we backed into a very simplistic model of the universe using base-2 notation, i.e. exponentiation from the Planck base units to the Age of the Universe in just over 200 doublings, steps, or groups.  An introduction  Just the numbers.

Might you enjoy receiving an update on our results as we work through this — — and your other ArXiv submissions?  Thank you.