New mirror coating on the LBT

How do you make telescope mirrors so shiny bright?

Large astronomical telescopes use mirrors, rather than lenses to gather light.  The large mirrors are coated with a very thin layer of metal, say aluminum.  All the big glass does is hold this thin reflective coating in place.

For a nice diversion, watch the movie below of the recoating process for one of the mirrors at the Large Binocular Telescope.  The coatings are done in place.  First, the old coating is scrubbed off, and then a large vacuum jar is placed over the mirror.  Air is pumped out, and evaporated metal is sprayed on.


Astronomy 2895

Here’s a re-post from June.  If you haven’t taken this seminar yet, please consider it.  The seminar is especially important for students now entering the major.

I would like to bring your attention to our seminar Astronomy 2895.  This seminar is intended for first- and second-year students, but anyone can take it.  The course description reads

Prospective astronomy majors will meet weekly with different astronomy faculty to learn about current research topics, facilities, and opportunities available in the undergraduate astronomy program.

In the upcoming semester, we will have several lectures and Q/A sessions with faculty, postdocs, and senior students, who will tell us about their research into astrophysics, physics education, and many other topics. We will also have lots of discussion on study habits and survival skills for Astro majors, along with small research projects you can undertake in areas that interest you. This is a great way to see the variety of research and teaching opportunities in our department, to meet others who are excited by astrophysics, and (especially for early students) to explore ways to be successful in astronomy or any other topic.

The seminar meets Tuesday afternoons from 4:10 to 5:05 in 1005 Smith Laboratory.

Welcome reception for new Astros

This looks like fun!:

Subject: Meet us at the Astronomy Social! 

Dear Incoming Students, 

Between moving in and getting ready for classes, the beginning of the year can feel overwhelming. The astronomy community is here to support you, and we’d like to welcome you to Ohio State at our informal Astronomy Social. Come meet other astronomy majors, chat with grad students and professors, and enjoy some ice cream and popsicles! 

The social will take place on Friday, August 24th from 5:45-7 PM in Hitchcock 031. Please RSVP ( by the end of the day on Monday, August 20th.

We wish you the best of luck, and we look forward to seeing you!


The Astronomical Society 

More advice about grad school

The other day I was reading an article at the Chronicle of Higher Education.  The article discussed a guide for Ph.D. students in economics who are seeking professor jobs.  This guide, written by Dr. John Cawley (Cornell) is apparently well known in the economics profession. (The article itself is behind a paywall, but you should be able to view it if you are using an OSU computer).

The advice concerned how to select places to apply to.  It seemed to me that the advice also applied to those of you who are looking for graduate school or job opportunities.  Interestingly, the advice came in the form of a question to the author of this guide.  The reporter asked:

You make it very clear that the goal of a person’s search shouldn’t be to get a job in the highest-ranked department, but at a place where their work is understood and appreciated, and that they find enjoyable and can grow and improve. Why give that advice when it seems to be the opposite of what I’m sure some economics Ph.D.s hear from their advisers?

Dr. Cawley’s reply was:

That’s something I feel strongly about. There is often a misconception about getting a job at a “top 5” department, or at a university that will impress your parents or other people, without regard for how good a match it is for you. The problem with doing that is that your growth as a scholar depends on the quality of match, especially for that first job.

To me, this sounds spot on, and applies to people going to grad school.  Why put your sights on Caltech, if you would be happier and maybe therefore more productive at New Mexico State or Vanderbilt or Dartmouth?  Why apply to Harvard if 600 other people do, and you aren’t able to articulate why Harvard is just the place for you?

I bring this up because almost all students start their search for grad school by running down the list of “top N” places.  Instead, I would recommend having a long conversation with your adviser, or with profs that you know well, to discern what motivates you.  You also should find out what places have resources that you need, or where they do the research that interests you most.

So for those of you who will apply go grad school this autumn, please start thinking now about where you want to be, and start researching to find out which places can best help you get there.


Music inspired by astronomy












Just saw this in a NASA newsletter:

A new annotated guide (part of a series devoted to resources for enjoying or teaching astronomy) features over 250 pieces of music inspired by serious astronomy, including both classical and popular music examples. YouTube links are given for the vast majority, so you can listen to them. 

 Among the pieces included is:

1) a Hubble Space Telescope cantata,

2) eight rock songs about black holes with reasonable science,

3) a supernova piano sonata,

4) a musical exploration of the Messier catalog of nebulae, clusters, and galaxies,

5) a moving song about Stephen Hawking,

6) Moon songs by the Grateful Dead, George Harrison, and the Police,

7) piano pieces “for children with small hands” named after the constellations,

8) operas about Galileo, Kepler, and Einstein, and many more (including planetary topics from Asteroids to Venus). 

You can access this guide directly by going to:

Any favorites of yours on list list?  Any good ones that are missing?  Tell us in the comments below.

GRE scores and graduate school

If you will be applying for grad schools in Astronomy, Physics, or any other subject, you might want to check out an article from the AstroBetter blog about which schools require scores from the Graduate Record Examination (GRE).

There has been a lot of discussion in recent years about how GRE scores should be used, and what (if anything) they predict.  The article linked above itself has many links that can give you a lot of background.  The American Astronomical Society (AAS) recently issued this statement on the GRE:

Given the research indicating that the GRE and PGRE are poor predictors of graduate student success, that their use in graduate admissions has a particularly negative impact on underrepresented groups, and that they represent a financial burden for many students in pursuing advanced degrees in the astronomical sciences, the AAS recommends that graduate programs eliminate or make optional the GRE and PGRE as metrics of evaluation for graduate applicants. If GRE or PGRE scores are used, the AAS recommends that admissions criteria account explicitly for the known systematics in scores as a function of gender, race, and socioeconomic status, and that cutoff scores not be used to eliminate candidates from admission, scholarships/fellowships, or financial support, in accordance with ETS recommendations.

Check out the article!  It’s very important.  This is one piece of information that you can use when putting together a list of places you are applying to.



Study abroad opportunity

Here’s a course announcement I received yesterday:

Subject: Course Announcement – Scientific Roots in the UK and EU; From/on Behalf of Profs. John Cogan and Caroline Breitenberger

Biology 4798, Scientific Roots in the UK and EU, will be offered again this spring if enough students enroll. This is a great opportunity to get started in study abroad, if that is in your plans. We will be visiting London, England and Paris, France again this year along with other sites that students choose.  We will be reading about and visiting important sites in the history of scientific discovery.  This year’s focus will be discoveries that changed the world and changed paradigms.  It should be interesting and useful for any future scientist. We will be holding information sessions in the fall, but if you know you are interested, please contact us now ( If you have decided to enroll, I would like to remind you that the deadline for application will be on or around Oct 31. Scholarship opportunities also exist and some have earlier deadlines.  The application is available on the website of the office of International Affairs (

I hope you can join us! It is a blast!

Dr. John G. Cogan
Auxiliary Assistant Professor
Dept. of Chemistry and Biochemistry
College of Arts and Sciences

Major fellowships for grad school

Graduating this year?  Planning on applying for grad school?

Here’s a useful resource: a list of major US fellowships for graduate students.  Many of these permit senior undergrads to apply.  These are hard to get but really worth it, since they can finance several years of grad school and often include a research stipend as well.

Watch this blog for more posts directed at graduating seniors.  I plan to hold a meeting in around 1 October where we can go over typical requirements for grad school and discuss the application process.

“Find your passion”

A common piece of advice from your teachers and mentors is to “find your passion.”  Certainly it helps to be enthusiastic about your studies, since that can motivate you to do the hard work required for success.

But this advice is not as straightforward as it might seem.  Check out this article from the Atlantic, called “‘Find Your Passion’ Doesn’t Mean What You Think It Does.”  For me, the money quote is this:

Young people routinely mistake “find your passion” to mean “pick your interest early and do not waver from it,” rather than “constantly search for the things that make your soul alive and pursue them diligently.”

I’d like to hear your reactions to this article, which contains many thoughtful reflections on the idea of passion for work or a career.  Use the comment mechanism below.