Following work by Susan A. Kassin and her Galaxy Slice and Dice Group

Susan Kassin, Galaxy Slice and Dice Group, STSI, Baltimore; Associate Research Scientist, STSI;
Lead scientist, NASA Goddard Space Flight Center, Greenbelt, Maryland

ArXiv (38): A dusty starburst masquerading as an ultra-high redshift galaxy in JWST CEERS observations, August 3, 2022; Kinematic Evolution of Simulated Star-Forming Galaxies, 2014
JWST CEERS: See line 86 for Susan
Video: Astronomers Uncover a Surprising Trend in Galaxy Evolution, 2022; Star Formation Histories of Quiescent Galaxies, 2018

Second email: September 6, 2022 at 3:02 PM

Dear Dr. Susan A. Kassin:

Of course, the results coming in from JWST will be making headlines for years to come. I anticipate a time when the “proper identification” of galaxies will become exquisitely important because it will directly reflect on most basic questions about who we are, when it all began, and the proper interpretation of data. My email to you was the first within the JWST group. I wrote based on your work on galaxy identification with Hubble and its precursors. You have so proven yourself to be an arbiter for the proper count of galaxies.

Yesterday’s note to you will be part of a larger discussion so have posted it here with key references to your work. It is a first draft and will be updated often. You are also cited (#86) within this list:

Thanks again and again for everything you have done and are doing and for your Galaxy Slice and Dice Group. 

Excellent, excellent.

Most sincerely,


First email: September 5, 2022 at 10:38 PM

Dear Dr. Susan A. Kassin:

Back in 2016 I questioned Chris Conselice about his 2 trillion galaxy count. He was the expert so I listened but wasn’t profoundly convinced. Mario Livio in a recent article used the 100-200 billion figure but said in a note to me this morning that he remains open to the Conselice estimate and that JWST would eventually render a better estimate. 

Are you at all concerned that there are too many galaxies (and attendant solar systems and planets) and 13.81 billion years is just not enough time?  

I’m exploring the issue — — knowing that my views about an exponential universe are entirely idiosyncratic.

Given your work and background, your point of view would be most helpful.  Thank you.

Most sincerely,