Broadcast 2645 Dr. Mark Brodwin

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Guest:  Dr. Mark Brodwin; Topics: Galaxies, gravitational waves, and much more.  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website,   Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See  Please note that I had some difficulty adding in the second segment sponsor messages at the end of the program so I apologize in advance for the editing issues.

We welcomed Dr. Mark Brodwin to the program for a comprehensive discussion on galaxies, galaxy clusters, stars, and gravitational waves per the recent LIGO announcement.  During the first segment of our 1 hour 56 minute program, Dr. Brodwin started out by providing us with a working definition for a galaxy, galaxy clusters, and galaxy groups.  We talked about Andromeda, spiral galaxies, elliptical galaxy, the Milky Way, and the characteristics of galaxy stars and the light to mass ratio to determine the stellar mass.  Our guest said there were lots of galaxies but galaxy clusters (his area of interest) were harder to find and much rarer.  Dr. Brodwin then talked about how galaxy clusters are found, largely with x-ray telescopes and infrared telescopes such as Spitzer. 

Listeners sent in many email questions.  James wanted to know about the possibility of seeing galaxies closer to real time or extrapolating what the galaxy might be like today given we are seeing them from 7-8 billion years ago.  Ben wanted to know if telescopes would continue to improve to enable us to see even further back in time.  Dr. Brodwin had much to say about telescopes and their capabilities now and under development. 

For a change in pace, BJohn asked about galaxy rotational information, citing the Backwards Galaxy.  Tim in Montreal asked if a spiral galaxy might be better suited for life than another type of galaxy. While there was no information to support what Tim was asking, our guest did say that spiral galaxies seemed to have higher particles of dust in them and the dust helps make rocky planets so possibly a spiral galaxy might be more likely to have life on some of its planets but this was pure speculation though an interesting question.

We discussed the cluster galaxy 1426 as we did with Dr. Brodwin on the recent Hotel Mars Program from Jan. 13, 2016.  This show is archived and since it is short, I suggest you listen to it for more information on 1426 (  Additional discussion in the first segment talked about red shift, the value of studying galaxies from the public's perspective & the definition of a scientific theory.  Here, our guest explained what theory means in science compared to the use of theory in the non-science world.  This came up as a result of listener question pertaining to The Big Bang Theory. 

Tom from Seattle called in about a picture and article on Wikipedia about our place in the universe as it caused him to have several questions for our guest.  You can visit the Wikipedia page at and (scroll to the bottom of the page).  This led to a good discussion about the universe, our galaxy and more so make sure you listen to it and check out the links Tom provided us.

In the second segment, we focused on the announcement of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) last week.  The confirmation of gravitational waves confirmed after 100 years Einstein's theory (General Relativity).  There are lots of news articles about this discovery, just Google gravitational wave announcement or LIGO gravitational wave announcement for more information.  However, our guest did explain the experiment that detected the gravitational waves and he explained it in a way that we could all understand it.  He also explained its significance and why this was opening up an entirely new field allowing us to observe for the first time what happens in the high energy universe. 

Black holes were a big part of our second part discussion.  While technical at times, I urge all of you to listen carefully to what our guest had to say as he explained it in a clear and concise way for us all to understand.  Our discussion included galaxies moving toward one another and black holes at the center of each galaxy eventually merging into one super black hole.  Rather than trying to summarize this discussion in detail, let me just say its fascinating, very timely and very important. Do not miss it and when you do listen to it, stop whatever else you are doing so you can give this discussion your undivided attention.

Please post your comments/questions in the comments section of this program's archive on The Space Show website.  You can reach Dr. Brodwin through me or his university website page.







Everything you wanted to know about galaxies and more!

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14 Feb 2016 Dr. Mark Brodwin
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