Observing with Street Lights

Observing with Street Lights
Dark sky sites not always necessary to see the Milky Way (This image was taken ouside of a B&B in Julian, CA)

Wednesday, April 13, 2016

After vacationing in Key West, met Dr Janna Levin at Science Salon, Coursera Big History Course, Physics Today article showing solar element abundances, and just for phone another Symphony of Science video with Stephan Hawking singing

Greetings from Palmia Observatory,

Well, this week has been busy getting back on my diet following the calorie and alcohol binge from vacation in party capital Key West, FL. It was a bit raining and cloudy there just like it has been here this week, although the skies here are starting to get very clear.  Nonetheless, I spent most of this week inside.

Resident Astronomer Peggy and I signed up for the Science Salon in Altadena.  These salons are a lot of fun and end with book signings and wine and hors d'oeuvres.  Wow, I never thought I would be attending salons, but they are a lot fun.  The salon was held in Harmonica Playing and Steam Punk aficionado, David's fabulous home, with great views overlooking the city below.  Thanks David.  We met up there with Math Whiz, Dave and we all heard astrophysics professor Janna Levin talk about her new book, "Black hole blues and other songs from outer space".  I had previously read her earlier book, "How the universe got its spots" and can
recommend it highly.  In fact, during the drive up to Altadena, I must of sang her praises so much, that when we arrived at the book signing, Resident Astronomer Peggy suggested I get my photo taken with Janna and she twisted my arm until  I agreed.  See attached photo.  Normally I don't get books signed or take photos, but now you can see what I like about studying astrophysics.  Yes, it's other astrophysicists!

Dr. Janna Levin graciously signs her new book for Palmai Observatory Resident Astronomer
Dr. Janna Levin graciously signs book for Palmia Observatory Resident Astronomer

The other inside activity this week was finally getting back on track with the free online Coursera course on Big History.  I'm really enjoying it, but from the lack of comments I've heard back from you, I guess I have the most enthusiasm.  Anyway,  two things from that course caught my attention and I wanted to share them.  First, in the lesson of the formation of the solar system, and in the other lessons as well, the presenters reviewed the evidence that astronomers use to back up what they say about the formation of the solar system.  This course is about science after all and the theories are all backed up by evidence, not personality or belief.  I had always wondered how the astronomers know that the material that makes up the planets and the asteroids and the sun are all made from the same materials present in the original cloud of dust and gas that collapsed to form the solar system.  Well, one way is to compare the composition and abundances of elements found in the sun, using spectroscopy, and the abundances of elements found in the earth and from fallen meteorites.  The second attached photo shows a graph, from Bernard Wood's December 2011 article in Physics Today.  Note how the abundances of the elements found in the sun and the abundances of elements found in meteorites fits a straight line.  It lines up nearly perfect.  This paper was just one of the papers referenced in the course.  See, you too could be pouring over these journal articles and having fun too.  Ok, ok, maybe it's just me.

To make up for all this technical stuff, let me share another resource video which was mentioned in the course.  This short video is one of several I've seen on the Symphony of Science. It's a really fun sounding video.    Once you listen to this maybe you can tell me what we just heard.  It's not clear to me how it seems to sound like Stephen Hawking and others singing, almost operatic like.  How did they do that?  If you know what the secret is, let me know.  

As the night skies started to clear up, I again wanted to get back to collecting astrometric data in order to calculate and predict the orbit of Jupiter or some other object in order to go over the process that astronomers several hundred years ago developed.  Remember, I discovered last week that I found I couldn't use the algorithm I had available to calculate the orbits of the moons of Jupiter.  So, I started to collect some images of our Moon in anticipation of calculating its orbit.  But guess what, the approach I was going to use might not work in that case either.  What do you say?  Do you think the Moon is in orbit around the Earth?  Well, it turns out it sort of is in orbit around the Earth, but it is also mainly in orbit around the Sun.  I used Newtonian gravitational calculations and find that the gravitational acceleration of the the Moon towards the earth is 0.003 meters per second squared and the acceleration of the moon towards the sun is 0.005 meters per second squared.  So, darn it!  The algorithm I was going to use is set up for two gravitationally bound objects, not three objects like the case of the moon which is accelerated by the sun and the earth.

I guess I will just have to use observations of Jupiter's orbit as my test case, as it can be considered as a two body gravitational system.  The problem now is that the orbital period is many years and I will need to collect three observations that are made months apart if I have any chance of getting an accurate orbit estimate. 

 Wow, just thinking about all this work and delays tires me out.  I feel like the need for a martini, but I'm trying to pace out my calorie intake.  So, how about we consider one more really beautiful night sky video instead.  Just watching this beautiful video reminds us of the beauty to be found all around us in nature if we only look.  This video of the night sky in South Dakota was forwarded to me by Looking through a Big Scope, Bob.  Check out this really beautiful night sky video.  Thank you Bob.

So that should be enough for this week.  I'm busy packing my bags for the flight to Salt Lake City to attend the APS April meeting where a couple of thousand physicists will be discussing the latest findings in cosmology, astrophysics, particle physics and gravitational wave research.  It should be fun.  I go to this meeting every year wherever it is held.  I just hope that most of these physicists are all as nice as Janna.

Until next time,
Resident Astronomer George

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